<?php
/* For licensing terms, see /license.txt */

use ChamiloSession as Session;

/**
 * Class Wiki
 * Functions library for the wiki tool.
 *
 * @author Juan Carlos Raña <herodoto@telefonica.net>
 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University, Belgium
 * @author Julio Montoya <gugli100@gmail.com> using the pdf.lib.php library
 */
class Wiki
{
    public $tbl_wiki;
    public $tbl_wiki_discuss;
    public $tbl_wiki_mailcue;
    public $tbl_wiki_conf;
    public $session_id = null;
    public $course_id = null;
    public $condition_session = null;
    public $group_id;
    public $assig_user_id;
    public $groupfilter = 'group_id=0';
    public $courseInfo;
    public $charset;
    public $page;
    public $action;
    public $wikiData = [];
    public $url;

    /**
     * Constructor.
     */
    public function __construct()
    {
        // Database table definition
        $this->tbl_wiki = Database::get_course_table(TABLE_WIKI);
        $this->tbl_wiki_discuss = Database::get_course_table(
            TABLE_WIKI_DISCUSS
        );
        $this->tbl_wiki_mailcue = Database::get_course_table(
            TABLE_WIKI_MAILCUE
        );
        $this->tbl_wiki_conf = Database::get_course_table(TABLE_WIKI_CONF);

        $this->session_id = api_get_session_id();
        $this->condition_session = api_get_session_condition($this->session_id);
        $this->course_id = api_get_course_int_id();
        $this->group_id = api_get_group_id();

        if (!empty($this->group_id)) {
            $this->groupfilter = ' group_id="'.$this->group_id.'"';
        }
        $this->courseInfo = api_get_course_info();
        $this->url = api_get_path(WEB_CODE_PATH).'wiki/index.php?'.api_get_cidreq();
    }

    /**
     * Check whether this title is already used.
     *
     * @param string $link
     *
     * @return bool False if title is already taken
     *
     * @author Patrick Cool <patrick.cool@ugent.be>, Ghent University
     */
    public function checktitle($link)
    {
        $tbl_wiki = $this->tbl_wiki;
        $condition_session = $this->condition_session;
        $course_id = $this->course_id;
        $groupfilter = $this->groupfilter;

        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE
                    c_id = '.$course_id.' AND
                    reflink="'.Database::escape_string($link).'" AND
                    '.$groupfilter.$condition_session.'';
        $result = Database::query($sql);
        $num = Database::num_rows($result);
        // the value has not been found and is this available
        if ($num == 0) {
            return true;
        } else {
            // the value has been found
            return false;
        }
    }

    /**
     * check wikilinks that has a page.
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     *
     * @param string $input
     *
     * @return string
     */
    public function links_to($input)
    {
        $input_array = preg_split(
            "/(\[\[|\]\])/",
            $input,
            -1,
            PREG_SPLIT_DELIM_CAPTURE
        );
        $all_links = [];

        foreach ($input_array as $key => $value) {
            if (isset($input_array[$key - 1]) && $input_array[$key - 1] == '[[' &&
                isset($input_array[$key + 1]) && $input_array[$key + 1] == ']]'
            ) {
                if (api_strpos($value, "|") !== false) {
                    $full_link_array = explode("|", $value);
                    $link = trim($full_link_array[0]);
                    $title = trim($full_link_array[1]);
                } else {
                    $link = trim($value);
                    $title = trim($value);
                }
                unset($input_array[$key - 1]);
                unset($input_array[$key + 1]);
                //replace blank spaces by _ within the links. But to remove links at the end add a blank space
                $all_links[] = Database::escape_string(
                    str_replace(' ', '_', $link)
                ).' ';
            }
        }
        $output = implode($all_links);

        return $output;
    }

    /**
     * detect and add style to external links.
     *
     * @author Juan Carlos Raña Trabado
     */
    public function detect_external_link($input)
    {
        $exlink = 'href=';
        $exlinkStyle = 'class="wiki_link_ext" href=';
        $output = str_replace($exlink, $exlinkStyle, $input);

        return $output;
    }

    /**
     * detect and add style to anchor links.
     *
     * @author Juan Carlos Raña Trabado
     */
    public function detect_anchor_link($input)
    {
        $anchorlink = 'href="#';
        $anchorlinkStyle = 'class="wiki_anchor_link" href="#';
        $output = str_replace($anchorlink, $anchorlinkStyle, $input);

        return $output;
    }

    /**
     * detect and add style to mail links
     * author Juan Carlos Raña Trabado.
     */
    public function detect_mail_link($input)
    {
        $maillink = 'href="mailto';
        $maillinkStyle = 'class="wiki_mail_link" href="mailto';
        $output = str_replace($maillink, $maillinkStyle, $input);

        return $output;
    }

    /**
     * detect and add style to ftp links.
     *
     * @author Juan Carlos Raña Trabado
     */
    public function detect_ftp_link($input)
    {
        $ftplink = 'href="ftp';
        $ftplinkStyle = 'class="wiki_ftp_link" href="ftp';
        $output = str_replace($ftplink, $ftplinkStyle, $input);

        return $output;
    }

    /**
     * detect and add style to news links.
     *
     * @author Juan Carlos Raña Trabado
     */
    public function detect_news_link($input)
    {
        $newslink = 'href="news';
        $newslinkStyle = 'class="wiki_news_link" href="news';
        $output = str_replace($newslink, $newslinkStyle, $input);

        return $output;
    }

    /**
     * detect and add style to irc links.
     *
     * @author Juan Carlos Raña Trabado
     */
    public function detect_irc_link($input)
    {
        $irclink = 'href="irc';
        $irclinkStyle = 'class="wiki_irc_link" href="irc';
        $output = str_replace($irclink, $irclinkStyle, $input);

        return $output;
    }

    /**
     * This function allows users to have [link to a title]-style links like in most regular wikis.
     * It is true that the adding of links is probably the most anoying part of Wiki for the people
     * who know something about the wiki syntax.
     *
     * @author Patrick Cool <patrick.cool@ugent.be>, Ghent University
     * Improvements [[]] and [[ | ]]by Juan Carlos Raña
     * Improvements internal wiki style and mark group by Juan Carlos Raña
     */
    public function make_wiki_link_clickable($input)
    {
        $groupId = api_get_group_id();
        //now doubles brackets
        $input_array = preg_split(
            "/(\[\[|\]\])/",
            $input,
            -1,
            PREG_SPLIT_DELIM_CAPTURE
        );

        foreach ($input_array as $key => $value) {
            //now doubles brackets
            if (isset($input_array[$key - 1]) &&
                $input_array[$key - 1] == '[[' && $input_array[$key + 1] == ']]'
            ) {
                // now full wikilink
                if (api_strpos($value, "|") !== false) {
                    $full_link_array = explode("|", $value);
                    $link = trim(strip_tags($full_link_array[0]));
                    $title = trim($full_link_array[1]);
                } else {
                    $link = trim(strip_tags($value));
                    $title = trim($value);
                }

                //if wikilink is homepage
                if ($link == 'index') {
                    $title = get_lang('Home');
                }
                if ($link == get_lang('Home')) {
                    $link = 'index';
                }

                // note: checkreflink checks if the link is still free. If it is not used then it returns true, if it is used, then it returns false. Now the title may be different
                if (self::checktitle(
                    strtolower(str_replace(' ', '_', $link))
                )) {
                    $link = api_html_entity_decode($link);
                    $input_array[$key] = '<a href="'.api_get_path(WEB_PATH).'main/wiki/index.php?'.api_get_cidreq().'&action=addnew&title='.Security::remove_XSS($link).'&group_id='.$groupId.'" class="new_wiki_link">'.$title.'</a>';
                } else {
                    $input_array[$key] = '<a href="'.api_get_path(WEB_PATH).'main/wiki/index.php?'.api_get_cidreq().'&action=showpage&title='.urlencode(strtolower(str_replace(' ', '_', $link))).'&group_id='.$groupId.'" class="wiki_link">'.$title.'</a>';
                }
                unset($input_array[$key - 1]);
                unset($input_array[$key + 1]);
            }
        }
        $output = implode('', $input_array);

        return $output;
    }

    /**
     * This function saves a change in a wiki page.
     *
     * @author Patrick Cool <patrick.cool@ugent.be>, Ghent University
     *
     * @param array $values
     *
     * @return language string saying that the changes are stored
     */
    public function save_wiki($values)
    {
        $tbl_wiki = $this->tbl_wiki;
        $tbl_wiki_conf = $this->tbl_wiki_conf;

        $_course = $this->courseInfo;
        $time = api_get_utc_datetime();
        $session_id = api_get_session_id();
        $groupId = api_get_group_id();
        $userId = api_get_user_id();
        $groupInfo = GroupManager::get_group_properties($groupId);
        $course_id = api_get_course_int_id();

        $_clean = [
            'task' => '',
            'feedback1' => '',
            'feedback2' => '',
            'feedback3' => '',
            'fprogress1' => '',
            'fprogress2' => '',
            'fprogress3' => '',
            'max_text' => 0,
            'max_version' => 0,
            'delayedsubmit' => '',
            'assignment' => 0,
        ];

        $pageId = intval($values['page_id']);

        // NOTE: visibility, visibility_disc and ratinglock_disc changes
        // are not made here, but through the interce buttons

        // cleaning the variables
        if (api_get_setting('htmlpurifier_wiki') == 'true') {
            //$purifier = new HTMLPurifier();
            $values['content'] = Security::remove_XSS($values['content']);
        }
        $version = intval($values['version']) + 1;
        $linkTo = self::links_to($values['content']); //and check links content

        //cleaning config variables
        if (!empty($values['task'])) {
            $_clean['task'] = $values['task'];
        }

        if (!empty($values['feedback1']) ||
            !empty($values['feedback2']) ||
            !empty($values['feedback3'])
        ) {
            $_clean['feedback1'] = $values['feedback1'];
            $_clean['feedback2'] = $values['feedback2'];
            $_clean['feedback3'] = $values['feedback3'];
            $_clean['fprogress1'] = $values['fprogress1'];
            $_clean['fprogress2'] = $values['fprogress2'];
            $_clean['fprogress3'] = $values['fprogress3'];
        }

        if (isset($values['initstartdate']) && $values['initstartdate'] == 1) {
            $_clean['startdate_assig'] = $values['startdate_assig'];
        } else {
            $_clean['startdate_assig'] = null;
        }

        if (isset($values['initenddate']) && $values['initenddate'] == 1) {
            $_clean['enddate_assig'] = $values['enddate_assig'];
        } else {
            $_clean['enddate_assig'] = null;
        }

        if (isset($values['delayedsubmit'])) {
            $_clean['delayedsubmit'] = $values['delayedsubmit'];
        }

        if (!empty($values['max_text']) || !empty($values['max_version'])) {
            $_clean['max_text'] = $values['max_text'];
            $_clean['max_version'] = $values['max_version'];
        }

        $values['assignment'] = isset($values['assignment']) ? $values['assignment'] : 0;
        $values['page_id'] = isset($values['page_id']) ? $values['page_id'] : 0;

        $params = [
            'c_id' => $course_id,
            'addlock' => 1,
            'visibility' => 1,
            'visibility_disc' => 1,
            'addlock_disc' => 1,
            'ratinglock_disc' => 1,
            'page_id' => $pageId,
            'reflink' => trim($values['reflink']),
            'title' => trim($values['title']),
            'content' => $values['content'],
            'user_id' => $userId,
            'group_id' => $groupId,
            'dtime' => $time,
            'assignment' => $values['assignment'],
            'comment' => $values['comment'],
            'progress' => $values['progress'],
            'version' => $version,
            'linksto' => $linkTo,
            'user_ip' => $_SERVER['REMOTE_ADDR'],
            'session_id' => $session_id,
            'page_id' => $values['page_id'],
            'editlock' => 0,
            'is_editing' => 0,
            'time_edit' => $time,
            'tag' => '',
        ];

        $id = Database::insert($tbl_wiki, $params);

        if ($id > 0) {
            $sql = "UPDATE $tbl_wiki SET id = iid WHERE iid = $id";
            Database::query($sql);

            // insert into item_property
            api_item_property_update(
                $_course,
                TOOL_WIKI,
                $id,
                'WikiAdded',
                $userId,
                $groupInfo
            );

            if ($values['page_id'] == 0) {
                $sql = 'UPDATE '.$tbl_wiki.' SET page_id="'.$id.'"
                        WHERE c_id = '.$course_id.' AND iid ="'.$id.'"';
                Database::query($sql);
            }
        }

        // Update wiki config
        if ($values['reflink'] == 'index' && $version == 1) {
            $params = [
                'c_id' => $course_id,
                'page_id' => $id,
                'task' => $_clean['task'],
                'feedback1' => $_clean['feedback1'],
                'feedback2' => $_clean['feedback2'],
                'feedback3' => $_clean['feedback3'],
                'fprogress1' => $_clean['fprogress1'],
                'fprogress2' => $_clean['fprogress2'],
                'fprogress3' => $_clean['fprogress3'],
                'max_text' => intval($_clean['max_text']),
                'max_version' => intval($_clean['max_version']),
                'startdate_assig' => $_clean['startdate_assig'],
                'enddate_assig' => $_clean['enddate_assig'],
                'delayedsubmit' => $_clean['delayedsubmit'],
            ];
            Database::insert($tbl_wiki_conf, $params);
        } else {
            $params = [
                'task' => $_clean['task'],
                'feedback1' => $_clean['feedback1'],
                'feedback2' => $_clean['feedback2'],
                'feedback3' => $_clean['feedback3'],
                'fprogress1' => $_clean['fprogress1'],
                'fprogress2' => $_clean['fprogress2'],
                'fprogress3' => $_clean['fprogress3'],
                'max_text' => intval($_clean['max_text']),
                'max_version' => intval($_clean['max_version']),
                'startdate_assig' => $_clean['startdate_assig'],
                'enddate_assig' => $_clean['enddate_assig'],
                'delayedsubmit' => $_clean['delayedsubmit'],
            ];
            Database::update(
                $tbl_wiki_conf,
                $params,
                ['page_id = ? AND c_id = ?' => [$pageId, $course_id]]
            );
        }

        api_item_property_update(
            $_course,
            'wiki',
            $id,
            'WikiAdded',
            $userId,
            $groupInfo
        );
        self::check_emailcue($_clean['reflink'], 'P', $time, $userId);
        $this->setWikiData($id);

        return get_lang('Saved');
    }

    /**
     * This function restore a wikipage.
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     *
     * @return string Message of success (to be printed on screen)
     */
    public function restore_wikipage(
        $r_page_id,
        $r_reflink,
        $r_title,
        $r_content,
        $r_group_id,
        $r_assignment,
        $r_progress,
        $c_version,
        $r_version,
        $r_linksto
    ) {
        $tbl_wiki = $this->tbl_wiki;
        $_course = $this->courseInfo;
        $r_user_id = api_get_user_id();
        $r_dtime = api_get_utc_datetime();
        $r_version = $r_version + 1;
        $r_comment = get_lang('Restored from version').': '.$c_version;
        $session_id = api_get_session_id();
        $course_id = api_get_course_int_id();
        $groupInfo = GroupManager::get_group_properties($r_group_id);

        $params = [
            'c_id' => $course_id,
            'page_id' => $r_page_id,
            'reflink' => $r_reflink,
            'title' => $r_title,
            'content' => $r_content,
            'user_id' => $r_user_id,
            'group_id' => $r_group_id,
            'dtime' => $r_dtime,
            'assignment' => $r_assignment,
            'comment' => $r_comment,
            'progress' => $r_progress,
            'version' => $r_version,
            'linksto' => $r_linksto,
            'user_ip' => $_SERVER['REMOTE_ADDR'],
            'session_id' => $session_id,
        ];
        $id = Database::insert($tbl_wiki, $params);

        if ($id) {
            $sql = "UPDATE $tbl_wiki SET id = iid WHERE iid = $id";
            Database::query($sql);

            api_item_property_update(
                $_course,
                'wiki',
                $id,
                'WikiAdded',
                api_get_user_id(),
                $groupInfo
            );
            self::check_emailcue($r_reflink, 'P', $r_dtime, $r_user_id);
        }

        return get_lang('The page has been restored. You can view it by clicking');
    }

    /**
     * This function delete a wiki.
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     *
     * @return string Message of success (to be printed)
     */
    public function delete_wiki()
    {
        $tbl_wiki = $this->tbl_wiki;
        $tbl_wiki_discuss = $this->tbl_wiki_discuss;
        $tbl_wiki_mailcue = $this->tbl_wiki_mailcue;
        $tbl_wiki_conf = $this->tbl_wiki_conf;
        $conditionSession = $this->condition_session;
        $groupFilter = $this->groupfilter;
        $course_id = $this->course_id;

        $sql = "SELECT page_id FROM $tbl_wiki
                WHERE c_id = $course_id AND $groupFilter $conditionSession
                ORDER BY id DESC";

        $result = Database::query($sql);
        $pageList = Database::store_result($result);
        if ($pageList) {
            foreach ($pageList as $pageData) {
                $pageId = $pageData['page_id'];
                $sql = "DELETE FROM $tbl_wiki_conf
                        WHERE c_id = $course_id AND page_id = $pageId";
                Database::query($sql);

                $sql = "DELETE FROM $tbl_wiki_discuss
                        WHERE c_id = $course_id AND publication_id = $pageId";
                Database::query($sql);
            }
        }

        $sql = "DELETE FROM $tbl_wiki_mailcue
                WHERE c_id = $course_id AND $groupFilter $conditionSession ";
        Database::query($sql);

        $sql = "DELETE FROM $tbl_wiki
                WHERE c_id = $course_id AND $groupFilter $conditionSession ";
        Database::query($sql);

        return get_lang('Your Group wiki has been deleted');
    }

    /**
     * This function saves a new wiki page.
     *
     * @author Patrick Cool <patrick.cool@ugent.be>, Ghent University
     *
     * @todo consider merging this with the function save_wiki into one single function.
     *
     * @return string Message of success
     */
    public function save_new_wiki($values)
    {
        $tbl_wiki = $this->tbl_wiki;
        $tbl_wiki_conf = $this->tbl_wiki_conf;
        $assig_user_id = $this->assig_user_id;
        $_clean = [];

        // cleaning the variables
        $_clean['assignment'] = '';
        if (isset($values['assignment'])) {
            $_clean['assignment'] = $values['assignment'];
        }

        // session_id
        $session_id = api_get_session_id();
        // Unlike ordinary pages of pages of assignments.
        // Allow create a ordinary page although there is a assignment with the same name
        if ($_clean['assignment'] == 2 || $_clean['assignment'] == 1) {
            $page = str_replace(
                ' ',
                '_',
                $values['title']."_uass".$assig_user_id
            );
        } else {
            $page = str_replace(' ', '_', $values['title']);
        }
        $_clean['reflink'] = $page;
        $_clean['title'] = trim($values['title']);
        $_clean['content'] = $values['content'];

        if (api_get_setting('htmlpurifier_wiki') === 'true') {
            $purifier = new HTMLPurifier();
            $_clean['content'] = $purifier->purify($_clean['content']);
        }

        //re-check after strip_tags if the title is empty
        if (empty($_clean['title']) || empty($_clean['reflink'])) {
            return false;
        }

        if ($_clean['assignment'] == 2) {
            //config by default for individual assignment (students)
            //Identifies the user as a creator, not the teacher who created
            $_clean['user_id'] = intval($assig_user_id);
            $_clean['visibility'] = 0;
            $_clean['visibility_disc'] = 0;
            $_clean['ratinglock_disc'] = 0;
        } else {
            $_clean['user_id'] = api_get_user_id();
            $_clean['visibility'] = 1;
            $_clean['visibility_disc'] = 1;
            $_clean['ratinglock_disc'] = 1;
        }

        $_clean['comment'] = $values['comment'];
        $_clean['progress'] = $values['progress'];
        $_clean['version'] = 1;

        $groupId = api_get_group_id();
        $groupInfo = GroupManager::get_group_properties($groupId);

        //check wikilinks
        $_clean['linksto'] = self::links_to($_clean['content']);

        // cleaning config variables
        $_clean['task'] = isset($values['task']) ? $values['task'] : '';
        $_clean['feedback1'] = isset($values['feedback1']) ? $values['feedback1'] : '';
        $_clean['feedback2'] = isset($values['feedback2']) ? $values['feedback2'] : '';
        $_clean['feedback3'] = isset($values['feedback3']) ? $values['feedback3'] : '';
        $_clean['fprogress1'] = isset($values['fprogress1']) ? $values['fprogress1'] : '';
        $_clean['fprogress2'] = isset($values['fprogress2']) ? $values['fprogress2'] : '';
        $_clean['fprogress3'] = isset($values['fprogress3']) ? $values['fprogress3'] : '';

        if (isset($values['initstartdate']) && $values['initstartdate'] == 1) {
            $_clean['startdate_assig'] = $values['startdate_assig'];
        } else {
            $_clean['startdate_assig'] = null;
        }

        if (isset($values['initenddate']) && $values['initenddate'] == 1) {
            $_clean['enddate_assig'] = $values['enddate_assig'];
        } else {
            $_clean['enddate_assig'] = null;
        }

        $_clean['delayedsubmit'] = isset($values['delayedsubmit']) ? $values['delayedsubmit'] : '';
        $_clean['max_text'] = isset($values['max_text']) ? $values['max_text'] : '';
        $_clean['max_version'] = isset($values['max_version']) ? $values['max_version'] : '';

        $course_id = api_get_course_int_id();

        // Filter no _uass
        if (api_strtoupper(trim($values['title'])) === 'INDEX') {
            Display::addFlash(
                Display::return_message(
                    get_lang('To start Group wiki go and edit Main page'),
                    'warning',
                    false
                )
            );
        } else {
            $var = $_clean['reflink'];
            $group_id = intval($_GET['group_id']);
            if (!self::checktitle($var)) {
                return get_lang('This page name already exists. To edit the page content, click here:').
                    '<a href="index.php?action=edit&title='.$var.'&group_id='.$group_id.'">'.
                    $values['title'].'</a>';
            } else {
                $dtime = api_get_utc_datetime();

                $params = [
                    'c_id' => $course_id,
                    'reflink' => $_clean['reflink'],
                    'title' => $_clean['title'],
                    'content' => $_clean['content'],
                    'user_id' => $_clean['user_id'],
                    'group_id' => $groupId,
                    'dtime' => $dtime,
                    'visibility' => $_clean['visibility'],
                    'visibility_disc' => $_clean['visibility_disc'],
                    'ratinglock_disc' => $_clean['ratinglock_disc'],
                    'assignment' => $_clean['assignment'],
                    'comment' => $_clean['comment'],
                    'progress' => $_clean['progress'],
                    'version' => $_clean['version'],
                    'linksto' => $_clean['linksto'],
                    'user_ip' => $_SERVER['REMOTE_ADDR'],
                    'session_id' => $session_id,
                    'addlock_disc' => 1,
                ];
                $id = Database::insert($tbl_wiki, $params);
                if ($id > 0) {
                    $sql = "UPDATE $tbl_wiki SET id = iid WHERE iid = $id";
                    Database::query($sql);

                    //insert into item_property
                    api_item_property_update(
                        api_get_course_info(),
                        TOOL_WIKI,
                        $id,
                        'WikiAdded',
                        api_get_user_id(),
                        $groupInfo
                    );

                    $sql = 'UPDATE '.$tbl_wiki.' SET page_id="'.$id.'"
                            WHERE c_id = '.$course_id.' AND id = "'.$id.'"';
                    Database::query($sql);

                    // insert wiki config
                    $params = [
                        'c_id' => $course_id,
                        'page_id' => $id,
                        'task' => $_clean['task'],
                        'feedback1' => $_clean['feedback1'],
                        'feedback2' => $_clean['feedback2'],
                        'feedback3' => $_clean['feedback3'],
                        'fprogress1' => $_clean['fprogress1'],
                        'fprogress2' => $_clean['fprogress2'],
                        'fprogress3' => $_clean['fprogress3'],
                        'max_text' => $_clean['max_text'],
                        'max_version' => $_clean['max_version'],
                        'startdate_assig' => $_clean['startdate_assig'],
                        'enddate_assig' => $_clean['enddate_assig'],
                        'delayedsubmit' => $_clean['delayedsubmit'],
                    ];

                    Database::insert($tbl_wiki_conf, $params);

                    $this->setWikiData($id);
                    self::check_emailcue(0, 'A');

                    return get_lang('The wiki page has been saved..');
                }
            }
        }
    }

    /**
     * @param FormValidator $form
     * @param array         $row
     */
    public function setForm($form, $row = [])
    {
        $toolBar = api_is_allowed_to_edit(null, true)
            ? [
                'ToolbarSet' => 'Wiki',
                'Width' => '100%',
                'Height' => '400',
            ]
            : [
                'ToolbarSet' => 'WikiStudent',
                'Width' => '100%',
                'Height' => '400',
                'UserStatus' => 'student',
            ];

        $form->addHtmlEditor(
            'content',
            get_lang('Content'),
            false,
            false,
            $toolBar
        );
        //$content
        $form->addElement('text', 'comment', get_lang('Comments'));
        $progress = ['', 10, 20, 30, 40, 50, 60, 70, 80, 90, 100];

        $form->addElement(
            'select',
            'progress',
            get_lang('Progress'),
            $progress
        );

        if ((api_is_allowed_to_edit(false, true) ||
            api_is_platform_admin()) &&
            isset($row['reflink']) && $row['reflink'] != 'index'
        ) {
            $form->addElement(
                'advanced_settings',
                'advanced_params',
                get_lang('Advanced settings')
            );
            $form->addElement(
                'html',
                '<div id="advanced_params_options" style="display:none">'
            );

            $form->addHtmlEditor(
                'task',
                get_lang('Description of the assignment'),
                false,
                false,
                [
                    'ToolbarSet' => 'wiki_task',
                    'Width' => '100%',
                    'Height' => '200',
                ]
            );

            $form->addElement('label', null, get_lang('Add guidance messages associated with the progress on the page'));
            $form->addElement('textarea', 'feedback1', get_lang('First message'));
            $form->addElement(
                'select',
                'fprogress1',
                get_lang('Progress'),
                $progress
            );

            $form->addElement('textarea', 'feedback2', get_lang('Second message'));
            $form->addElement(
                'select',
                'fprogress2',
                get_lang('Progress'),
                $progress
            );

            $form->addElement('textarea', 'feedback3', get_lang('Third message'));
            $form->addElement(
                'select',
                'fprogress3',
                get_lang('Progress'),
                $progress
            );

            $form->addElement(
                'checkbox',
                'initstartdate',
                null,
                get_lang('Start Date'),
                ['id' => 'start_date_toggle']
            );

            $style = "display:block";
            $row['initstartdate'] = 1;
            if (empty($row['startdate_assig'])) {
                $style = "display:none";
                $row['initstartdate'] = null;
            }

            $form->addElement(
                'html',
                '<div id="start_date" style="'.$style.'">'
            );
            $form->addDatePicker('startdate_assig', '');
            $form->addElement('html', '</div>');
            $form->addElement(
                'checkbox',
                'initenddate',
                null,
                get_lang('End Date'),
                ['id' => 'end_date_toggle']
            );

            $style = "display:block";
            $row['initenddate'] = 1;
            if (empty($row['enddate_assig'])) {
                $style = "display:none";
                $row['initenddate'] = null;
            }

            $form->addHtml('<div id="end_date" style="'.$style.'">');
            $form->addDatePicker('enddate_assig', '');
            $form->addHtml('</div>');
            $form->addElement(
                'checkbox',
                'delayedsubmit',
                null,
                get_lang('Allow delayed sending')
            );
            $form->addElement('text', 'max_text', get_lang('Maximum number of words'));
            $form->addElement('text', 'max_version', get_lang('Maximum number of versions'));
            $form->addElement(
                'checkbox',
                'assignment',
                null,
                get_lang('This will create a special wiki page in which the teacher can describe the task and which will be automatically linked to the wiki pages where learners perform the task. Both the teacher\'s and the learner\'s pages are created automatically. in these tasks, learners can only edit and view theirs pages, but this can be changed easily if you need to.')
            );
            $form->addElement('html', '</div>');
        }

        $form->addElement('hidden', 'page_id');
        $form->addElement('hidden', 'reflink');
        $form->addElement('hidden', 'version');
        $form->addElement('hidden', 'wpost_id', api_get_unique_id());
    }

    /**
     * This function displays the form for adding a new wiki page.
     *
     * @author Patrick Cool <patrick.cool@ugent.be>, Ghent University
     *
     * @return string html code
     */
    public function display_new_wiki_form()
    {
        $url = api_get_self().'?'.api_get_cidreq(
            ).'&action=addnew&group_id='.api_get_group_id();
        $form = new FormValidator('wiki_new', 'post', $url);
        $form->addElement('text', 'title', get_lang('Title'));
        $form->addRule('title', get_lang('Required field'), 'required');
        self::setForm($form);
        $title = isset($_GET['title']) ? Security::remove_XSS(
            $_GET['title']
        ) : '';
        $form->setDefaults(['title' => $title]);
        $form->addElement('button', 'SaveWikiNew', get_lang('Save'));
        $form->display();

        if ($form->validate()) {
            $values = $form->exportValues();
            if (isset($values['startdate_assig']) &&
                isset($values['enddate_assig']) &&
                strtotime($values['startdate_assig']) > strtotime(
                    $values['enddate_assig']
                )
            ) {
                Display::addFlash(
                    Display::return_message(
                        get_lang("End DateCannotBeBeforeTheStart Date"),
                        'error',
                        false
                    )
                );
            } elseif (!self::double_post($_POST['wpost_id'])) {
                //double post
            } else {
                if (isset($values['assignment']) && $values['assignment'] == 1) {
                    self::auto_add_page_users($values);
                }

                $return_message = self::save_new_wiki($values);

                if ($return_message == false) {
                    Display::addFlash(
                        Display::return_message(
                            get_lang('Your changes have been saved. You still have to give a name to the page'),
                            'error',
                            false
                        )
                    );
                } else {
                    Display::addFlash(
                        Display::return_message(
                            $return_message,
                            'confirmation',
                            false
                        )
                    );
                }

                $wikiData = self::getWikiData();
                $redirectUrl = $this->url.'&action=showpage&title='.$wikiData['reflink'].'&'.api_get_cidreq();
                header('Location: '.$redirectUrl);
                exit;
            }
        }
    }

    /**
     * This function displays a wiki entry.
     *
     * @author Patrick Cool <patrick.cool@ugent.be>, Ghent University
     * @author Juan Carlos Raña Trabado
     *
     * @param string $newtitle
     *
     * @return string html code
     */
    public function display_wiki_entry($newtitle)
    {
        $tbl_wiki = $this->tbl_wiki;
        $tbl_wiki_conf = $this->tbl_wiki_conf;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $page = $this->page;

        $session_id = api_get_session_id();
        $course_id = api_get_course_int_id();

        if ($newtitle) {
            $pageMIX = $newtitle; //display the page after it is created
        } else {
            $pageMIX = $page; //display current page
        }

        $filter = null;
        if (isset($_GET['view']) && $_GET['view']) {
            $_clean['view'] = Database::escape_string($_GET['view']);
            $filter = ' AND w.id="'.$_clean['view'].'"';
        }

        // First, check page visibility in the first page version
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE
                    c_id = '.$course_id.' AND
                    reflink="'.Database::escape_string($pageMIX).'" AND
                   '.$groupfilter.$condition_session.'
                ORDER BY id ASC';
        $result = Database::query($sql);
        $row = Database::fetch_array($result, 'ASSOC');

        $KeyVisibility = $row['visibility'];

        // second, show the last version
        $sql = 'SELECT * FROM '.$tbl_wiki.' w
                INNER JOIN '.$tbl_wiki_conf.' wc
                ON (wc.page_id = w.page_id AND wc.c_id = w.c_id)
                WHERE
                    w.c_id 		  = '.$course_id.' AND
                    w.reflink	  = "'.Database::escape_string($pageMIX).'" AND
                    w.session_id  = '.$session_id.' AND
                    w.'.$groupfilter.'  '.$filter.'
                ORDER BY id DESC';

        $result = Database::query($sql);
        // we do not need a while loop since we are always displaying the last version
        $row = Database::fetch_array($result, 'ASSOC');

        //log users access to wiki (page_id)
        if (!empty($row['page_id'])) {
            Event::addEvent(LOG_WIKI_ACCESS, LOG_WIKI_PAGE_ID, $row['page_id']);
        }
        //update visits
        if ($row['id']) {
            $sql = 'UPDATE '.$tbl_wiki.' SET hits=(hits+1)
                    WHERE c_id = '.$course_id.' AND id='.$row['id'].'';
            Database::query($sql);
        }

        $groupInfo = GroupManager::get_group_properties(api_get_group_id());

        // if both are empty and we are displaying the index page then we display the default text.
        if ($row['content'] == '' && $row['title'] == '' && $page == 'index') {
            if (api_is_allowed_to_edit(false, true) ||
                api_is_platform_admin() ||
                GroupManager::is_user_in_group(api_get_user_id(), $groupInfo) ||
                api_is_allowed_in_course()
            ) {
                //Table structure for better export to pdf
                $default_table_for_content_Start = '<table align="center" border="0"><tr><td align="center">';
                $default_table_for_content_End = '</td></tr></table>';
                $content = $default_table_for_content_Start.
                    sprintf(
                        get_lang(' <br/> <br/> <p align="center"> <img src="%swiki/wcollaborative.png" alt="Working as a team" title="Working as a team" /></p> <p align="center">To begin editing this page and remove this text</p>'),
                        api_get_path(WEB_IMG_PATH)
                    ).
                    $default_table_for_content_End;
                $title = get_lang('Home');
            } else {
                return Display::addFlash(
                    Display::return_message(
                        get_lang('This Group wiki is frozen so far. A trainer must start it.'),
                        'normal',
                        false
                    )
                );
            }
        } else {
            $content = Security::remove_XSS($row['content']);
            $title = Security::remove_XSS($row['title']);
        }

        //assignment mode: identify page type
        $icon_assignment = null;
        if ($row['assignment'] == 1) {
            $icon_assignment = Display::return_icon(
                'wiki_assignment.png',
                get_lang('This page is an assignment proposed by a trainer'),
                '',
                ICON_SIZE_SMALL
            );
        } elseif ($row['assignment'] == 2) {
            $icon_assignment = Display::return_icon(
                'wiki_work.png',
                get_lang('Learner paper'),
                '',
                ICON_SIZE_SMALL
            );
        }

        // task mode
        $icon_task = null;
        if (!empty($row['task'])) {
            $icon_task = Display::return_icon(
                'wiki_task.png',
                get_lang('Standard Task'),
                '',
                ICON_SIZE_SMALL
            );
        }

        // Show page. Show page to all users if isn't hide page. Mode assignments: if student is the author, can view
        if ($KeyVisibility == "1" ||
            api_is_allowed_to_edit(false, true) ||
            api_is_platform_admin() ||
            ($row['assignment'] == 2 && $KeyVisibility == "0" && (api_get_user_id() == $row['user_id'])) ||
            api_is_allowed_in_course()
        ) {
            $actionsLeft = '';
            // menu edit page
            $editLink = '<a href="index.php?'.api_get_cidreq().'&action=edit&title='.api_htmlentities(urlencode($page)).'"'.self::is_active_navigation_tab('edit').'>'.
                Display::return_icon(
                    'edit.png',
                    get_lang('Edit this page'),
                    '',
                    ICON_SIZE_MEDIUM
                ).'</a>';

            if (api_is_allowed_to_edit(false, true)) {
                $actionsLeft .= $editLink;
            } else {
                if ((api_is_allowed_in_course() ||
                    GroupManager::is_user_in_group(
                        api_get_user_id(),
                        $groupInfo
                    ))
                ) {
                    $actionsLeft .= $editLink;
                } else {
                    $actionsLeft .= '';
                }
            }

            $actionsRight = '';

            $protect_page = null;
            $lock_unlock_protect = null;
            // page action: protecting (locking) the page
            if (api_is_allowed_to_edit(false, true) ||
                api_is_platform_admin()
            ) {
                if (self::check_protect_page() == 1) {
                    $protect_page = Display::return_icon(
                        'lock.png',
                        get_lang('This page is protected. Trainers only can change it'),
                        '',
                        ICON_SIZE_MEDIUM
                    );
                    $lock_unlock_protect = 'unlock';
                } else {
                    $protect_page = Display::return_icon(
                        'unlock.png',
                        get_lang('This page is unprotected. All course users or group members can edit this page'),
                        '',
                        ICON_SIZE_MEDIUM
                    );
                    $lock_unlock_protect = 'lock';
                }
            }

            if ($row['id']) {
                $actionsRight .= '<a href="index.php?'.api_get_cidreq().'&action=showpage&actionpage='.$lock_unlock_protect.'&title='.api_htmlentities(urlencode($page)).'">'.
                $protect_page.'</a>';
            }

            $visibility_page = null;
            $lock_unlock_visibility = null;
            //page action: visibility
            if (api_is_allowed_to_edit(false, true) ||
                api_is_platform_admin()
            ) {
                if (self::check_visibility_page() == 1) {
                    $visibility_page = Display::return_icon(
                        'visible.png',
                        get_lang('Now the page is visible by all users'),
                        '',
                        ICON_SIZE_MEDIUM
                    );
                    $lock_unlock_visibility = 'invisible';
                } else {
                    $visibility_page = Display::return_icon(
                        'invisible.png',
                        get_lang('Now the page only is visible by trainer'),
                        '',
                        ICON_SIZE_MEDIUM
                    );
                    $lock_unlock_visibility = 'visible';
                }
            }

            if ($row['id']) {
                $actionsRight .= '<a href="index.php?'.api_get_cidreq().'&action=showpage&actionpage='.$lock_unlock_visibility.'&title='.api_htmlentities(urlencode($page)).'">'.
                    $visibility_page.'</a>';
            }

            //page action: notification
            if (api_is_allowed_to_session_edit()) {
                if (self::check_notify_page($page) == 1) {
                    $notify_page = Display::return_icon(
                        'messagebox_info.png',
                        get_lang('Notify me by e-mail when somebody replies'),
                        '',
                        ICON_SIZE_MEDIUM
                    );
                    $lock_unlock_notify_page = 'unlocknotify';
                } else {
                    $notify_page = Display::return_icon(
                        'mail.png',
                        get_lang('CancelNotify me by e-mail when somebody replies'),
                        '',
                        ICON_SIZE_MEDIUM
                    );
                    $lock_unlock_notify_page = 'locknotify';
                }
            }

            // Only available if row['id'] is set
            if ($row['id']) {
                if (api_is_allowed_to_session_edit(false, true) &&
                    api_is_allowed_to_edit() ||
                    GroupManager::is_user_in_group(
                        api_get_user_id(),
                        $groupInfo
                    )
                ) {
                    // menu discuss page
                    $actionsRight .= '<a href="index.php?'.api_get_cidreq().'&action=discuss&title='.api_htmlentities(
                            urlencode($page)
                        ).'" '.self::is_active_navigation_tab('discuss').'>'.
                        Display::return_icon(
                            'discuss.png',
                            get_lang('Discuss this page'),
                            '',
                            ICON_SIZE_MEDIUM
                        ).'</a>';
                }

                //menu history
                $actionsRight .= '<a href="index.php?'.api_get_cidreq().'&action=history&title='.api_htmlentities(
                        urlencode($page)
                    ).'" '.self::is_active_navigation_tab('history').'>'.
                    Display::return_icon(
                        'history.png',
                        get_lang('History'),
                        '',
                        ICON_SIZE_MEDIUM
                    ).'</a>';
                //menu linkspages
                $actionsRight .= '<a href="index.php?'.api_get_cidreq().'action=links&title='.api_htmlentities(
                        urlencode($page)
                    ).'" '.self::is_active_navigation_tab('links').'>'.
                    Display::return_icon(
                        'what_link_here.png',
                        get_lang('What links here'),
                        '',
                        ICON_SIZE_MEDIUM
                    ).'</a>';

                //menu delete wikipage
                if (api_is_allowed_to_edit(false, true) ||
                    api_is_platform_admin()
                ) {
                    $actionsRight .= '<a href="index.php?action=delete&'.api_get_cidreq().'&title='.api_htmlentities(
                            urlencode($page)
                        ).'"'.self::is_active_navigation_tab('delete').'>'.
                        Display::return_icon(
                            'delete.png',
                            get_lang('Delete this page'),
                            '',
                            ICON_SIZE_MEDIUM
                        ).'</a>';
                }

                $actionsRight .= '<a href="index.php?'.api_get_cidreq().'&action=showpage&actionpage='.$lock_unlock_notify_page.'&title='.api_htmlentities(
                        urlencode($page)
                    ).'">'.
                    $notify_page.'</a>';

                // Page action: copy last version to doc area
                if (api_is_allowed_to_edit(false, true) ||
                    api_is_platform_admin()
                ) {
                    $actionsRight .= '<a href="index.php?'.api_get_cidreq().'&action=export2doc&wiki_id='.$row['id'].'">'.
                        Display::return_icon(
                            'export_to_documents.png',
                            get_lang('Export latest version of this page to Documents'),
                            '',
                            ICON_SIZE_MEDIUM
                        ).'</a>';
                }

                $actionsRight .= '<a href="index.php?'.api_get_cidreq().'&action=export_to_pdf&wiki_id='.$row['id'].'">'.
                    Display::return_icon(
                        'pdf.png',
                        get_lang('Export to PDF'),
                        '',
                        ICON_SIZE_MEDIUM
                    ).'</a>';

                $unoconv = api_get_configuration_value('unoconv.binaries');
                if ($unoconv) {
                    $actionsRight .= '<a href="'.api_get_path(WEB_CODE_PATH).'wiki/index.php?action=export_to_doc_file&id='.$row['id'].'&'.api_get_cidreq().'">'.
                        Display::return_icon(
                            'export_doc.png',
                            get_lang('Export to .doc'),
                            [],
                            ICON_SIZE_MEDIUM
                        ).'</a>';
                }

                //export to print?>
                <script>
                    function goprint() {
                        var a = window.open('', '', 'width=800,height=600');
                        a.document.open("text/html");
                        a.document.write($('#wikicontent .panel-heading').html());
                        a.document.write($('#wikicontent .panel-body').html());
                        a.document.close();
                        a.print();
                    }
                </script>
                <?php
                $actionsRight .= Display::url(
                    Display::return_icon(
                        'printer.png',
                        get_lang('Print'),
                        '',
                        ICON_SIZE_MEDIUM
                    ),
                    '#',
                    ['onclick' => "javascript: goprint();"]
                );
            }

            echo Display::toolbarAction(
                'toolbar-wikistudent',
                [$actionsLeft, $actionsRight]
            );

            if (self::wiki_exist($title)) {
                $pageTitle = $icon_assignment.'&nbsp;'.
                    $icon_task.'&nbsp;'.api_htmlentities($title);
            } else {
                $pageTitle = api_htmlentities($title);
            }

            $pageWiki = self::make_wiki_link_clickable(
                self::detect_external_link(
                    self::detect_anchor_link(
                        self::detect_mail_link(
                            self::detect_ftp_link(
                                self::detect_irc_link(
                                    self::detect_news_link($content)
                                )
                            )
                        )
                    )
                )
            );

            $footerWiki =
                get_lang('Progress').': '.($row['progress'] * 10).'%&nbsp;&nbsp;&nbsp;'.
                get_lang('Rating').': '.$row['score'].'&nbsp;&nbsp;&nbsp;'.
                get_lang('Words').': '.self::word_count($content);
            // wikicontent require to print wiki document
            echo '<div id="wikicontent">'.Display::panel($pageWiki, $pageTitle, $footerWiki).'</div>';
        } //end filter visibility
    }

    /**
     * This function counted the words in a document. Thanks Adeel Khan.
     *
     * @param   string  Document's text
     *
     * @return int Number of words
     */
    public function word_count($document)
    {
        $search = [
            '@<script[^>]*?>.*?</script>@si',
            '@<style[^>]*?>.*?</style>@siU',
            '@<div id="player.[^>]*?>.*?</div>@',
            '@<![\s\S]*?--[ \t\n\r]*>@',
        ];

        $document = preg_replace($search, '', $document);

        // strip all html tags
        $wc = strip_tags($document);
        $wc = html_entity_decode(
            $wc,
            ENT_NOQUOTES,
            'UTF-8'
        ); // TODO:test also old html_entity_decode(utf8_encode($wc))

        // remove 'words' that don't consist of alphanumerical characters or punctuation. And fix accents and some letters
        $pattern = "#[^(\w|\d|\'|\"|\.|\!|\?|;|,|\\|\/|\-|:|\&|@|á|é|í|ó|ú|à|è|ì|ò|ù|ä|ë|ï|ö|ü|Á|É|Í|Ó|Ú|À|È|Ò|Ù|Ä|Ë|Ï|Ö|Ü|â|ê|î|ô|û|Â|Ê|Î|Ô|Û|ñ|Ñ|ç|Ç)]+#";
        $wc = trim(preg_replace($pattern, " ", $wc));

        // remove one-letter 'words' that consist only of punctuation
        $wc = trim(
            preg_replace(
                "#\s*[(\'|\"|\.|\!|\?|;|,|\\|\/|\-|:|\&|@)]\s*#",
                " ",
                $wc
            )
        );

        // remove superfluous whitespace
        $wc = preg_replace("/\s\s+/", " ", $wc);

        // split string into an array of words
        $wc = explode(" ", $wc);

        // remove empty elements
        $wc = array_filter($wc);

        // return the number of words
        return count($wc);
    }

    /**
     * This function checks if wiki title exist.
     */
    public function wiki_exist($title)
    {
        $tbl_wiki = $this->tbl_wiki;
        $groupfilter = $this->groupfilter;
        $condition_session = $this->condition_session;
        $course_id = api_get_course_int_id();

        $sql = 'SELECT id FROM '.$tbl_wiki.'
              WHERE
                c_id = '.$course_id.' AND
                title="'.Database::escape_string($title).'" AND
                '.$groupfilter.$condition_session.'
              ORDER BY id ASC';
        $result = Database::query($sql);
        $cant = Database::num_rows($result);
        if ($cant > 0) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * Checks if this navigation tab has to be set to active.
     *
     * @author Patrick Cool <patrick.cool@ugent.be>, Ghent University
     *
     * @return string html code
     */
    public function is_active_navigation_tab($paramwk)
    {
        if (isset($_GET['action']) && $_GET['action'] == $paramwk) {
            return ' class="active"';
        }
    }

    /**
     * Lock add pages.
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     * return current database status of protect page and change it if get action
     */
    public function check_addnewpagelock()
    {
        $tbl_wiki = $this->tbl_wiki;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $course_id = api_get_course_int_id();

        $sql = 'SELECT *
                FROM '.$tbl_wiki.'
                WHERE c_id = '.$course_id.' AND '.$groupfilter.$condition_session.'
                ORDER BY id ASC';

        $result = Database::query($sql);
        $row = Database::fetch_array($result);

        $status_addlock = $row['addlock'];

        // Change status
        if (api_is_allowed_to_edit(false, true) ||
            api_is_platform_admin()
        ) {
            if (isset($_GET['actionpage'])) {
                if ($_GET['actionpage'] == 'lockaddnew' && $status_addlock == 1) {
                    $status_addlock = 0;
                }
                if ($_GET['actionpage'] == 'unlockaddnew' && $status_addlock == 0) {
                    $status_addlock = 1;
                }
                $sql = 'UPDATE '.$tbl_wiki.' SET
                            addlock="'.Database::escape_string($status_addlock).'"
                        WHERE c_id = '.$course_id.' AND '.$groupfilter.$condition_session;
                Database::query($sql);
            }

            $sql = 'SELECT *
                    FROM '.$tbl_wiki.'
                    WHERE c_id = '.$course_id.' AND '.$groupfilter.$condition_session.'
                    ORDER BY id ASC';
            $result = Database::query($sql);
            $row = Database::fetch_array($result);
        }

        return $row['addlock'];
    }

    /**
     * Protect page.
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     * return current database status of protect page and change it if get action
     */
    public function check_protect_page()
    {
        $tbl_wiki = $this->tbl_wiki;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $page = $this->page;

        $course_id = api_get_course_int_id();
        $sql = 'SELECT * FROM '.$tbl_wiki.'
              WHERE
                c_id = '.$course_id.' AND
                reflink="'.Database::escape_string($page).'" AND
                '.$groupfilter.$condition_session.'
              ORDER BY id ASC';

        $result = Database::query($sql);
        $row = Database::fetch_array($result);
        $status_editlock = $row['editlock'];
        $id = $row['page_id'];

        // Change status
        if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
            if (isset($_GET['actionpage']) && $_GET['actionpage'] == 'lock' && $status_editlock == 0) {
                $status_editlock = 1;
            }
            if (isset($_GET['actionpage']) && $_GET['actionpage'] == 'unlock' && $status_editlock == 1) {
                $status_editlock = 0;
            }

            $sql = 'UPDATE '.$tbl_wiki.' SET 
                    editlock="'.Database::escape_string($status_editlock).'"
                    WHERE c_id = '.$course_id.' AND page_id="'.$id.'"';
            Database::query($sql);

            $sql = 'SELECT * FROM '.$tbl_wiki.'
                    WHERE
                        c_id = '.$course_id.' AND
                        reflink="'.Database::escape_string($page).'" AND
                    '.$groupfilter.$condition_session.'
                  ORDER BY id ASC';
            $result = Database::query($sql);
            $row = Database::fetch_array($result);
        }

        //show status
        return $row['editlock'];
    }

    /**
     * Visibility page.
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     * return current database status of visibility and change it if get action
     */
    public function check_visibility_page()
    {
        $tbl_wiki = $this->tbl_wiki;
        $page = $this->page;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $course_id = api_get_course_int_id();

        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE
                    c_id = '.$course_id.' AND
                    reflink="'.Database::escape_string($page).'" AND
                    '.$groupfilter.$condition_session.'
                ORDER BY id ASC';
        $result = Database::query($sql);
        $row = Database::fetch_array($result);
        $status_visibility = $row['visibility'];
        //change status
        if (api_is_allowed_to_edit(false, true) ||
            api_is_platform_admin()
        ) {
            if (isset($_GET['actionpage']) &&
                $_GET['actionpage'] == 'visible' &&
                $status_visibility == 0
            ) {
                $status_visibility = 1;
            }
            if (isset($_GET['actionpage']) &&
                $_GET['actionpage'] == 'invisible' &&
                $status_visibility == 1
            ) {
                $status_visibility = 0;
            }

            $sql = 'UPDATE '.$tbl_wiki.' SET 
                    visibility = "'.Database::escape_string($status_visibility).'"
                    WHERE 
                        c_id = '.$course_id.' AND 
                        reflink="'.Database::escape_string($page).'" AND 
                        '.$groupfilter.$condition_session;
            Database::query($sql);

            // Although the value now is assigned to all (not only the first),
            // these three lines remain necessary.
            // They do that by changing the page state is
            // made when you press the button and not have to wait to change his page
            $sql = 'SELECT * FROM '.$tbl_wiki.'
                    WHERE
                        c_id = '.$course_id.' AND
                        reflink="'.Database::escape_string($page).'" AND
                        '.$groupfilter.$condition_session.'
                    ORDER BY id ASC';
            $result = Database::query($sql);
            $row = Database::fetch_array($result);
        }

        if (empty($row['id'])) {
            $row['visibility'] = 1;
        }

        //show status
        return $row['visibility'];
    }

    /**
     * Visibility discussion.
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     *
     * @return int current database status of discuss visibility
     *             and change it if get action page
     */
    public function check_visibility_discuss()
    {
        $tbl_wiki = $this->tbl_wiki;
        $page = $this->page;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $course_id = api_get_course_int_id();

        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE
                    c_id = '.$course_id.' AND
                    reflink="'.Database::escape_string($page).'" AND
                    '.$groupfilter.$condition_session.'
                ORDER BY id ASC';
        $result = Database::query($sql);
        $row = Database::fetch_array($result);

        $status_visibility_disc = $row['visibility_disc'];

        //change status
        if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
            if (isset($_GET['actionpage']) &&
                $_GET['actionpage'] == 'showdisc' &&
                $status_visibility_disc == 0
            ) {
                $status_visibility_disc = 1;
            }
            if (isset($_GET['actionpage']) &&
                $_GET['actionpage'] == 'hidedisc' &&
                $status_visibility_disc == 1
            ) {
                $status_visibility_disc = 0;
            }

            $sql = 'UPDATE '.$tbl_wiki.' SET 
                    visibility_disc="'.Database::escape_string($status_visibility_disc).'"
                    WHERE
                        c_id = '.$course_id.' AND
                        reflink="'.Database::escape_string($page).'" AND
                        '.$groupfilter.$condition_session;
            Database::query($sql);

            // Although the value now is assigned to all (not only the first),
            // these three lines remain necessary.
            // They do that by changing the page state is made when you press
            // the button and not have to wait to change his page
            $sql = 'SELECT * FROM '.$tbl_wiki.'
                    WHERE
                        c_id = '.$course_id.' AND
                        reflink="'.Database::escape_string($page).'" AND
                        '.$groupfilter.$condition_session.'
                    ORDER BY id ASC';
            $result = Database::query($sql);
            $row = Database::fetch_array($result);
        }

        return $row['visibility_disc'];
    }

    /**
     * Lock add discussion.
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     *
     * @return int current database status of lock dicuss and change if get action
     */
    public function check_addlock_discuss()
    {
        $tbl_wiki = $this->tbl_wiki;
        $page = $this->page;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $course_id = api_get_course_int_id();

        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE
                    c_id = '.$course_id.' AND
                    reflink="'.Database::escape_string($page).'" AND
                    '.$groupfilter.$condition_session.'
                ORDER BY id ASC';
        $result = Database::query($sql);
        $row = Database::fetch_array($result);

        $status_addlock_disc = $row['addlock_disc'];

        //change status
        if (api_is_allowed_to_edit() || api_is_platform_admin()) {
            if (isset($_GET['actionpage']) &&
                $_GET['actionpage'] == 'lockdisc' &&
                $status_addlock_disc == 0
            ) {
                $status_addlock_disc = 1;
            }
            if (isset($_GET['actionpage']) &&
                $_GET['actionpage'] == 'unlockdisc' &&
                $status_addlock_disc == 1
            ) {
                $status_addlock_disc = 0;
            }

            $sql = 'UPDATE '.$tbl_wiki.' SET
                    addlock_disc="'.Database::escape_string($status_addlock_disc).'"
                    WHERE
                        c_id = '.$course_id.' AND
                        reflink = "'.Database::escape_string($page).'" AND
                         '.$groupfilter.$condition_session;
            Database::query($sql);

            // Although the value now is assigned to all (not only the first),
            // these three lines remain necessary.
            // They do that by changing the page state is made when you press
            // the button and not have to wait to change his page
            $sql = 'SELECT * FROM '.$tbl_wiki.'
                    WHERE
                        c_id = '.$course_id.' AND
                        reflink="'.Database::escape_string($page).'" AND
                        '.$groupfilter.$condition_session.'
                    ORDER BY id ASC';
            $result = Database::query($sql);
            $row = Database::fetch_array($result);
        }

        return $row['addlock_disc'];
    }

    /**
     * Lock rating discussion.
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     *
     * @return int current database status of rating discuss and change it if get action
     */
    public function check_ratinglock_discuss()
    {
        $tbl_wiki = $this->tbl_wiki;
        $page = $this->page;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $course_id = api_get_course_int_id();

        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE
                    c_id = '.$course_id.' AND
                    reflink="'.Database::escape_string($page).'" AND
                    '.$groupfilter.$condition_session.'
                ORDER BY id ASC';
        $result = Database::query($sql);
        $row = Database::fetch_array($result);
        $status_ratinglock_disc = $row['ratinglock_disc'];

        //change status
        if (api_is_allowed_to_edit(false, true) ||
            api_is_platform_admin()
        ) {
            if (isset($_GET['actionpage']) &&
                $_GET['actionpage'] == 'lockrating' &&
                $status_ratinglock_disc == 0
            ) {
                $status_ratinglock_disc = 1;
            }
            if (isset($_GET['actionpage']) &&
                $_GET['actionpage'] == 'unlockrating' &&
                $status_ratinglock_disc == 1
            ) {
                $status_ratinglock_disc = 0;
            }

            $sql = 'UPDATE '.$tbl_wiki.'
                    SET ratinglock_disc="'.Database::escape_string($status_ratinglock_disc).'"
                    WHERE
                        c_id = '.$course_id.' AND
                        reflink="'.Database::escape_string($page).'" AND
                        '.$groupfilter.$condition_session;
            // Visibility. Value to all,not only for the first
            Database::query($sql);

            // Although the value now is assigned to all (not only the first),
            // these three lines remain necessary. They do that by changing the
            // page state is made when you press the button and not have to wait
            // to change his page
            $sql = 'SELECT * FROM '.$tbl_wiki.'
                    WHERE
                        c_id = '.$course_id.' AND
                        reflink="'.Database::escape_string($page).'" AND
                    '.$groupfilter.$condition_session.'
                  ORDER BY id ASC';
            $result = Database::query($sql);
            $row = Database::fetch_array($result);
        }

        return $row['ratinglock_disc'];
    }

    /**
     * Notify page changes.
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     *
     * @return int the current notification status
     */
    public function check_notify_page($reflink)
    {
        $tbl_wiki = $this->tbl_wiki;
        $tbl_wiki_mailcue = $this->tbl_wiki_mailcue;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $groupId = api_get_group_id();
        $session_id = api_get_session_id();
        $course_id = api_get_course_int_id();
        $userId = api_get_user_id();

        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE 
                    c_id = '.$course_id.' AND 
                    reflink="'.$reflink.'" AND 
                    '.$groupfilter.$condition_session.'
                ORDER BY id ASC';
        $result = Database::query($sql);
        $row = Database::fetch_array($result);
        $id = $row['id'];
        $sql = 'SELECT * FROM '.$tbl_wiki_mailcue.'
                WHERE
                    c_id = '.$course_id.' AND 
                    id="'.$id.'" AND 
                    user_id="'.api_get_user_id().'" AND 
                    type="P"';
        $result = Database::query($sql);
        $row = Database::fetch_array($result);
        $idm = $row['id'];
        if (empty($idm)) {
            $status_notify = 0;
        } else {
            $status_notify = 1;
        }

        // Change status
        if (isset($_GET['actionpage']) &&
            $_GET['actionpage'] == 'locknotify' &&
            $status_notify == 0
        ) {
            $sql = "SELECT id FROM $tbl_wiki_mailcue
                    WHERE c_id = $course_id AND id = $id AND user_id = $userId";
            $result = Database::query($sql);
            $exist = false;
            if (Database::num_rows($result)) {
                $exist = true;
            }
            if ($exist == false) {
                $sql = "INSERT INTO ".$tbl_wiki_mailcue." (c_id, id, user_id, type, group_id, session_id) VALUES
                ($course_id, '".$id."','".api_get_user_id()."','P','".$groupId."','".$session_id."')";
                Database::query($sql);
            }
            $status_notify = 1;
        }

        if (isset($_GET['actionpage']) &&
            $_GET['actionpage'] == 'unlocknotify' &&
            $status_notify == 1
        ) {
            $sql = 'DELETE FROM '.$tbl_wiki_mailcue.'
                    WHERE 
                        id="'.$id.'" AND 
                        user_id="'.api_get_user_id().'" AND 
                        type="P" AND 
                        c_id = '.$course_id;
            Database::query($sql);
            $status_notify = 0;
        }

        return $status_notify;
    }

    /**
     * Notify discussion changes.
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     *
     * @param string $reflink
     *
     * @return int current database status of rating discuss and change it if get action
     */
    public function check_notify_discuss($reflink)
    {
        $tbl_wiki_mailcue = $this->tbl_wiki_mailcue;
        $tbl_wiki = $this->tbl_wiki;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;

        $course_id = api_get_course_int_id();
        $groupId = api_get_group_id();
        $session_id = api_get_session_id();

        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE 
                    c_id = '.$course_id.' AND 
                    reflink="'.$reflink.'" AND 
                    '.$groupfilter.$condition_session.'
                ORDER BY id ASC';
        $result = Database::query($sql);
        $row = Database::fetch_array($result);
        $id = $row['id'];
        $sql = 'SELECT * FROM '.$tbl_wiki_mailcue.'
                WHERE 
                    c_id = '.$course_id.' AND id="'.$id.'" AND user_id="'.api_get_user_id().'" AND type="D"';
        $result = Database::query($sql);
        $row = Database::fetch_array($result);
        $idm = $row['id'];

        if (empty($idm)) {
            $status_notify_disc = 0;
        } else {
            $status_notify_disc = 1;
        }

        // change status
        if (isset($_GET['actionpage']) &&
            $_GET['actionpage'] == 'locknotifydisc' &&
            $status_notify_disc == 0
        ) {
            $sql = "INSERT INTO ".$tbl_wiki_mailcue." (c_id, id, user_id, type, group_id, session_id) VALUES
            ($course_id, '".$id."','".api_get_user_id()."','D','".$groupId."','".$session_id."')";
            Database::query($sql);
            $status_notify_disc = 1;
        }
        if (isset($_GET['actionpage']) &&
            $_GET['actionpage'] == 'unlocknotifydisc' &&
            $status_notify_disc == 1
        ) {
            $sql = 'DELETE FROM '.$tbl_wiki_mailcue.'
                    WHERE 
                        c_id = '.$course_id.' AND 
                        id="'.$id.'" AND 
                        user_id="'.api_get_user_id().'" AND 
                        type="D" AND 
                        c_id = '.$course_id;
            Database::query($sql);
            $status_notify_disc = 0;
        }

        return $status_notify_disc;
    }

    /**
     * Notify all changes.
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     */
    public function check_notify_all()
    {
        $tbl_wiki_mailcue = $this->tbl_wiki_mailcue;
        $course_id = api_get_course_int_id();
        $groupId = api_get_group_id();
        $session_id = api_get_session_id();

        $sql = 'SELECT * FROM '.$tbl_wiki_mailcue.'
                WHERE
                    c_id = '.$course_id.' AND
                    user_id="'.api_get_user_id().'" AND
                    type="F" AND
                    group_id="'.$groupId.'" AND
                    session_id="'.$session_id.'"';
        $result = Database::query($sql);
        $row = Database::fetch_array($result);

        $idm = $row['user_id'];

        if (empty($idm)) {
            $status_notify_all = 0;
        } else {
            $status_notify_all = 1;
        }

        //change status
        if (isset($_GET['actionpage']) &&
            $_GET['actionpage'] == 'locknotifyall' &&
            $status_notify_all == 0
        ) {
            $sql = "INSERT INTO ".$tbl_wiki_mailcue." (c_id, user_id, type, group_id, session_id) VALUES
            ($course_id, '".api_get_user_id()."','F','".$groupId."','".$session_id."')";
            Database::query($sql);
            $status_notify_all = 1;
        }

        if (isset($_GET['actionpage']) &&
            isset($_GET['actionpage']) &&
            $_GET['actionpage'] == 'unlocknotifyall' &&
            $status_notify_all == 1
        ) {
            $sql = 'DELETE FROM '.$tbl_wiki_mailcue.'
                   WHERE
                    c_id = '.$course_id.' AND
                    user_id="'.api_get_user_id().'" AND
                    type="F" AND
                    group_id="'.$groupId.'" AND
                    session_id="'.$session_id.'" AND
                    c_id = '.$course_id;
            Database::query($sql);
            $status_notify_all = 0;
        }

        //show status
        return $status_notify_all;
    }

    /**
     * Sends pending e-mails.
     */
    public function check_emailcue(
        $id_or_ref,
        $type,
        $lastime = '',
        $lastuser = ''
    ) {
        $tbl_wiki_mailcue = $this->tbl_wiki_mailcue;
        $tbl_wiki = $this->tbl_wiki;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $_course = $this->courseInfo;
        $groupId = api_get_group_id();
        $session_id = api_get_session_id();
        $course_id = api_get_course_int_id();
        $group_properties = GroupManager::get_group_properties($groupId);
        $group_name = $group_properties['name'];
        $allow_send_mail = false; //define the variable to below
        $email_assignment = null;
        if ($type == 'P') {
            //if modifying a wiki page
            //first, current author and time
            //Who is the author?
            $userinfo = api_get_user_info($lastuser);
            $email_user_author = get_lang('edited by').': '.$userinfo['complete_name'];

            //When ?
            $year = substr($lastime, 0, 4);
            $month = substr($lastime, 5, 2);
            $day = substr($lastime, 8, 2);
            $hours = substr($lastime, 11, 2);
            $minutes = substr($lastime, 14, 2);
            $seconds = substr($lastime, 17, 2);
            $email_date_changes = $day.' '.$month.' '.$year.' '.$hours.":".$minutes.":".$seconds;

            //second, extract data from first reg
            $sql = 'SELECT * FROM '.$tbl_wiki.'
                    WHERE 
                        c_id = '.$course_id.' AND 
                        reflink="'.$id_or_ref.'" AND 
                        '.$groupfilter.$condition_session.'
                    ORDER BY id ASC';
            $result = Database::query($sql);
            $row = Database::fetch_array($result);
            $id = $row['id'];
            $email_page_name = $row['title'];
            if ($row['visibility'] == 1) {
                $allow_send_mail = true; //if visibility off - notify off
                $sql = 'SELECT * FROM '.$tbl_wiki_mailcue.'
                        WHERE
                            c_id = '.$course_id.' AND
                            id="'.$id.'" AND
                            type="'.$type.'" OR
                            type="F" AND
                            group_id="'.$groupId.'" AND
                            session_id="'.$session_id.'"';
                //type: P=page, D=discuss, F=full.
                $result = Database::query($sql);
                $emailtext = get_lang('It has modified the page').
                    '<strong>'.$email_page_name.'</strong> '.
                    get_lang('Group wiki');
            }
        } elseif ($type == 'D') {
            //if added a post to discuss
            //first, current author and time
            //Who is the author of last message?
            $userinfo = api_get_user_info($lastuser);
            $email_user_author = get_lang('added by').': '.$userinfo['complete_name'];

            //When ?
            $year = substr($lastime, 0, 4);
            $month = substr($lastime, 5, 2);
            $day = substr($lastime, 8, 2);
            $hours = substr($lastime, 11, 2);
            $minutes = substr($lastime, 14, 2);
            $seconds = substr($lastime, 17, 2);
            $email_date_changes = $day.' '.$month.' '.$year.' '.$hours.":".$minutes.":".$seconds;
            //second, extract data from first reg
            $id = $id_or_ref; //$id_or_ref is id from tblwiki
            $sql = 'SELECT * FROM '.$tbl_wiki.'
                    WHERE c_id = '.$course_id.' AND id="'.$id.'"
                    ORDER BY id ASC';

            $result = Database::query($sql);
            $row = Database::fetch_array($result);

            $email_page_name = $row['title'];
            if ($row['visibility_disc'] == 1) {
                $allow_send_mail = true; //if visibility off - notify off
                $sql = 'SELECT * FROM '.$tbl_wiki_mailcue.'
                        WHERE
                            c_id = '.$course_id.' AND
                            id="'.$id.'" AND
                            type="'.$type.'" OR
                            type="F" AND
                            group_id="'.$groupId.'" AND
                            session_id="'.$session_id.'"';
                //type: P=page, D=discuss, F=full
                $result = Database::query($sql);
                $emailtext = get_lang(
                        'EmailGroup wikiPageDiscAdded'
                    ).' <strong>'.$email_page_name.'</strong> '.get_lang(
                        'Group wiki'
                    );
            }
        } elseif ($type == 'A') {
            //for added pages
            $id = 0; //for tbl_wiki_mailcue
            $sql = 'SELECT * FROM '.$tbl_wiki.'
                    WHERE c_id = '.$course_id.'
                    ORDER BY id DESC'; //the added is always the last

            $result = Database::query($sql);
            $row = Database::fetch_array($result);
            $email_page_name = $row['title'];

            //Who is the author?
            $userinfo = api_get_user_info($row['user_id']);
            $email_user_author = get_lang('added by').': '.$userinfo['complete_name'];

            //When ?
            $year = substr($row['dtime'], 0, 4);
            $month = substr($row['dtime'], 5, 2);
            $day = substr($row['dtime'], 8, 2);
            $hours = substr($row['dtime'], 11, 2);
            $minutes = substr($row['dtime'], 14, 2);
            $seconds = substr($row['dtime'], 17, 2);
            $email_date_changes = $day.' '.$month.' '.$year.' '.$hours.":".$minutes.":".$seconds;

            if ($row['assignment'] == 0) {
                $allow_send_mail = true;
            } elseif ($row['assignment'] == 1) {
                $email_assignment = get_lang('This page is an assignment proposed by a trainer').' ('.get_lang('individual assignment mode').')';
                $allow_send_mail = true;
            } elseif ($row['assignment'] == 2) {
                $allow_send_mail = false; //Mode tasks: avoids notifications to all users about all users
            }

            $sql = 'SELECT * FROM '.$tbl_wiki_mailcue.'
                    WHERE
                        c_id = '.$course_id.' AND  
                        id="'.$id.'" AND 
                        type="F" AND 
                        group_id="'.$groupId.'" AND 
                        session_id="'.$session_id.'"';

            //type: P=page, D=discuss, F=full
            $result = Database::query($sql);
            $emailtext = get_lang('EmailGroup wikiPageAdded').' <strong>'.
                $email_page_name.'</strong> '.get_lang('in').' '.get_lang('Group wiki');
        } elseif ($type == 'E') {
            $id = 0;
            $allow_send_mail = true;
            // Who is the author?
            $userinfo = api_get_user_info(api_get_user_id()); //current user
            $email_user_author = get_lang('deleted by').': '.$userinfo['complete_name'];
            //When ?
            $today = date('r'); //current time
            $email_date_changes = $today;
            $sql = 'SELECT * FROM '.$tbl_wiki_mailcue.'
                    WHERE
                        c_id = '.$course_id.' AND
                        id="'.$id.'" AND type="F" AND
                        group_id="'.$groupId.'" AND
                        session_id="'.$session_id.'"'; //type: P=page, D=discuss, F=wiki
            $result = Database::query($sql);
            $emailtext = get_lang('EmailGroup wikipageDedeleted');
        }
        ///make and send email
        if ($allow_send_mail) {
            while ($row = Database::fetch_array($result)) {
                $userinfo = api_get_user_info(
                    $row['user_id']
                ); //$row['user_id'] obtained from tbl_wiki_mailcue
                $name_to = $userinfo['complete_name'];
                $email_to = $userinfo['email'];
                $sender_name = api_get_setting('emailAdministrator');
                $sender_email = api_get_setting('emailAdministrator');
                $email_subject = get_lang(
                        'EmailGroup wikiChanges'
                    ).' - '.$_course['official_code'];
                $email_body = get_lang('Dear user').' '.api_get_person_name(
                        $userinfo['firstname'],
                        $userinfo['lastname']
                    ).',<br /><br />';
                if ($session_id == 0) {
                    $email_body .= $emailtext.' <strong>'.$_course['name'].' - '.$group_name.'</strong><br /><br /><br />';
                } else {
                    $email_body .= $emailtext.' <strong>'.$_course['name'].' ('.api_get_session_name(
                            api_get_session_id()
                        ).') - '.$group_name.'</strong><br /><br /><br />';
                }
                $email_body .= $email_user_author.' ('.$email_date_changes.')<br /><br /><br />';
                $email_body .= $email_assignment.'<br /><br /><br />';
                $email_body .= '<font size="-2">'.get_lang(
                        'EmailGroup wikiChangesExt_1'
                    ).': <strong>'.get_lang('Notify me of changes').'</strong><br />';
                $email_body .= get_lang(
                        'EmailGroup wikiChangesExt_2'
                    ).': <strong>'.get_lang(
                        'NotNotify me of changes'
                    ).'</strong></font><br />';
                @api_mail_html(
                    $name_to,
                    $email_to,
                    $email_subject,
                    $email_body,
                    $sender_name,
                    $sender_email
                );
            }
        }
    }

    /**
     * Function export last wiki page version to document area.
     *
     * @param int $doc_id wiki page id
     *
     * @return mixed
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     */
    public function export2doc($doc_id)
    {
        $_course = $this->courseInfo;
        $groupId = api_get_group_id();
        $groupInfo = GroupManager::get_group_properties($groupId);
        $data = self::getWikiDataFromDb($doc_id);

        if (empty($data)) {
            return false;
        }

        $wikiTitle = $data['title'];
        $wikiContents = $data['content'];

        $template =
            '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
            <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="{LANGUAGE}" lang="{LANGUAGE}">
            <head>
            <title>{TITLE}</title>
            <meta http-equiv="Content-Type" content="text/html; charset={ENCODING}" />
            <style type="text/css" media="screen, projection">
            /*<![CDATA[*/
            {CSS}
            /*]]>*/
            </style>
            {ASCIIMATHML_SCRIPT}</head>
            <body dir="{TEXT_DIRECTION}">
            {CONTENT}
            </body>
            </html>';

        $css_file = api_get_path(SYS_CSS_PATH).'themes/'.api_get_setting('stylesheets').'/default.css';
        if (file_exists($css_file)) {
            $css = @file_get_contents($css_file);
        } else {
            $css = '';
        }
        // Fixing some bugs in css files.
        $root_rel = api_get_path(REL_PATH);
        $css_path = 'main/css/';
        $theme = api_get_setting('stylesheets').'/';
        $css = str_replace(
            'behavior:url("/main/css/csshover3.htc");',
            '',
            $css
        );
        $css = str_replace('main/', $root_rel.'main/', $css);
        $css = str_replace(
            'images/',
            $root_rel.$css_path.$theme.'images/',
            $css
        );
        $css = str_replace('../../img/', $root_rel.'main/img/', $css);
        $asciimathmal_script = (api_contains_asciimathml(
                $wikiContents
            ) || api_contains_asciisvg($wikiContents))
            ? '<script src="'.api_get_path(
                WEB_CODE_PATH
            ).'inc/lib/javascript/asciimath/ASCIIMathML.js" type="text/javascript"></script>'."\n" : '';

        $template = str_replace(
            [
                '{LANGUAGE}',
                '{ENCODING}',
                '{TEXT_DIRECTION}',
                '{TITLE}',
                '{CSS}',
                '{ASCIIMATHML_SCRIPT}',
            ],
            [
                api_get_language_isocode(),
                api_get_system_encoding(),
                api_get_text_direction(),
                $wikiTitle,
                $css,
                $asciimathmal_script,
            ],
            $template
        );

        if (0 != $groupId) {
            $groupPart = '_group'.$groupId; // and add groupId to put the same document title in different groups
            $group_properties = GroupManager::get_group_properties($groupId);
            $groupPath = $group_properties['directory'];
        } else {
            $groupPart = '';
            $groupPath = '';
        }

        $exportDir = api_get_path(SYS_COURSE_PATH).api_get_course_path(
            ).'/document'.$groupPath;
        $exportFile = api_replace_dangerous_char($wikiTitle).$groupPart;
        $wikiContents = trim(
            preg_replace(
                "/\[[\[]?([^\]|]*)[|]?([^|\]]*)\][\]]?/",
                "$1",
                $wikiContents
            )
        );
        //TODO: put link instead of title
        $wikiContents = str_replace('{CONTENT}', $wikiContents, $template);
        // replace relative path by absolute path for courses, so you can see
        // items into this page wiki (images, mp3, etc..) exported in documents
        if (api_strpos(
                $wikiContents,
                '../..'.api_get_path(REL_COURSE_PATH)
            ) !== false) {
            $web_course_path = api_get_path(WEB_COURSE_PATH);
            $wikiContents = str_replace(
                '../..'.api_get_path(REL_COURSE_PATH),
                $web_course_path,
                $wikiContents
            );
        }

        $i = 1;
        //only export last version, but in new export new version in document area
        while (file_exists($exportDir.'/'.$exportFile.'_'.$i.'.html')) {
            $i++;
        }

        $wikiFileName = $exportFile.'_'.$i.'.html';
        $exportPath = $exportDir.'/'.$wikiFileName;

        file_put_contents($exportPath, $wikiContents);
        $document = DocumentManager::addDocument(
            $_course,
            $groupPath.'/'.$wikiFileName,
            'file',
            filesize($exportPath),
            $wikiTitle
        );

        $id = $document->getId();

        return $id;
    }

    /**
     * Exports the wiki page to PDF.
     */
    public function export_to_pdf($id, $course_code)
    {
        if (!api_is_platform_admin()) {
            if (api_get_setting('students_export2pdf') !== 'true') {
                Display::addFlash(
                    Display::return_message(
                        get_lang('PDF download is not allowed for students'),
                        'error',
                        false
                    )
                );

                return false;
            }
        }

        $data = self::getWikiDataFromDb($id);
        $content_pdf = api_html_entity_decode(
            $data['content'],
            ENT_QUOTES,
            api_get_system_encoding()
        );

        //clean wiki links
        $content_pdf = trim(
            preg_replace(
                "/\[[\[]?([^\]|]*)[|]?([^|\]]*)\][\]]?/",
                "$1",
                $content_pdf
            )
        );
        //TODO: It should be better to display the link insted of the tile but it is hard for [[title]] links

        $title_pdf = api_html_entity_decode(
            $data['title'],
            ENT_QUOTES,
            api_get_system_encoding()
        );
        $title_pdf = api_utf8_encode($title_pdf, api_get_system_encoding());
        $content_pdf = api_utf8_encode($content_pdf, api_get_system_encoding());

        $html = '
        <!-- defines the headers/footers - this must occur before the headers/footers are set -->

        <!--mpdf
        <pageheader name="odds" content-left="'.$title_pdf.'"  header-style-left="color: #880000; font-style: italic;"  line="1" />
        <pagefooter name="odds" content-right="{PAGENO}/{nb}" line="1" />

        <!-- set the headers/footers - they will occur from here on in the document -->
        <!--mpdf
        <setpageheader name="odds" page="odd" value="on" show-this-page="1" />
        <setpagefooter name="odds" page="O" value="on" />

        mpdf-->'.$content_pdf;

        $css_file = api_get_path(SYS_CSS_PATH).'themes/'.api_get_setting('stylesheets').'/print.css';
        if (file_exists($css_file)) {
            $css = @file_get_contents($css_file);
        } else {
            $css = '';
        }

        $pdf = new PDF();
        $pdf->content_to_pdf($html, $css, $title_pdf, $course_code);
        exit;
    }

    /**
     * Function prevent double post (reload or F5).
     */
    public function double_post($wpost_id)
    {
        $postId = Session::read('wpost_id');
        if (!empty($postId)) {
            if ($wpost_id == $postId) {
                return false;
            } else {
                Session::write('wpost_id', $wpost_id);

                return true;
            }
        } else {
            Session::write('wpost_id', $wpost_id);

            return true;
        }
    }

    /**
     * Function wizard individual assignment.
     *
     * @author Juan Carlos Raña <herodoto@telefonica.net>
     */
    public function auto_add_page_users($values)
    {
        $assignment_type = $values['assignment'];
        $session_id = $this->session_id;
        $groupId = api_get_group_id();
        $groupInfo = GroupManager::get_group_properties($groupId);
        if ($groupId == 0) {
            //extract course members
            if (!empty($session_id)) {
                $a_users_to_add = CourseManager::get_user_list_from_course_code(
                    api_get_course_id(),
                    $session_id
                );
            } else {
                $a_users_to_add = CourseManager::get_user_list_from_course_code(
                    api_get_course_id(),
                    0
                );
            }
        } else {
            //extract group members
            $subscribed_users = GroupManager::get_subscribed_users($groupInfo);
            $subscribed_tutors = GroupManager::get_subscribed_tutors(
                $groupInfo
            );
            $a_users_to_add_with_duplicates = array_merge(
                $subscribed_users,
                $subscribed_tutors
            );
            //remove duplicates
            $a_users_to_add = $a_users_to_add_with_duplicates;
            $a_users_to_add = array_unique($a_users_to_add);
        }

        $all_students_pages = [];
        // Data about teacher
        $userId = api_get_user_id();
        $userinfo = api_get_user_info($userId);
        $username = api_htmlentities(
            sprintf(get_lang('Login: %s'), $userinfo['username'], ENT_QUOTES)
        );
        $name = $userinfo['complete_name']." - ".$username;
        $photo = '<img src="'.$userinfo['avatar'].'" alt="'.$name.'"  width="40" height="50" align="top" title="'.$name.'"  />';

        // teacher assignment title
        $title_orig = $values['title'];

        // teacher assignment reflink
        $link2teacher = $values['title'] = $title_orig."_uass".$userId;

        // first: teacher name, photo, and assignment description (original content)
        $content_orig_A = '<div align="center" style="background-color: #F5F8FB; border:solid; border-color: #E6E6E6">
        <table border="0">
            <tr><td style="font-size:24px">'.get_lang('Assignment proposed by the trainer').'</td></tr>
            <tr><td>'.$photo.'<br />'.Display::tag(
                'span',
                api_get_person_name(
                    $userinfo['firstname'],
                    $userinfo['lastname']
                ),
                ['title' => $username]
            ).'</td></tr>
        </table></div>';

        $content_orig_B = '<br/><div align="center" style="font-size:24px">'.
            get_lang('Assignment proposed by the trainerription').': '.
            $title_orig.'</div><br/>'.Security::remove_XSS($_POST['content']);

        //Second: student list (names, photo and links to their works).
        //Third: Create Learners work pages.
        foreach ($a_users_to_add as $o_user_to_add) {
            if ($o_user_to_add['user_id'] != $userId) {
                // except that puts the task
                $assig_user_id = $o_user_to_add['user_id'];
                // identifies each page as created by the student, not by teacher

                $userPicture = UserManager::getUserPicture($assig_user_id);
                $username = api_htmlentities(
                    sprintf(
                        get_lang('Login: %s'),
                        $o_user_to_add['username'],
                        ENT_QUOTES
                    )
                );
                $name = api_get_person_name(
                        $o_user_to_add['firstname'],
                        $o_user_to_add['lastname']
                    )." . ".$username;
                $photo = '<img src="'.$userPicture.'" alt="'.$name.'"  width="40" height="50" align="bottom" title="'.$name.'"  />';

                $is_tutor_of_group = GroupManager::is_tutor_of_group(
                    $assig_user_id,
                    $groupInfo
                ); //student is tutor
                $is_tutor_and_member = GroupManager::is_tutor_of_group(
                        $assig_user_id,
                        $groupInfo
                    ) &&
                    GroupManager::is_subscribed($assig_user_id, $groupInfo);
                // student is tutor and member
                if ($is_tutor_and_member) {
                    $status_in_group = get_lang('Coach and group member');
                } else {
                    if ($is_tutor_of_group) {
                        $status_in_group = get_lang('Group tutor');
                    } else {
                        $status_in_group = " "; //get_lang('GroupStandardMember')
                    }
                }

                if ($assignment_type == 1) {
                    $values['title'] = $title_orig;
                    $values['content'] = '<div align="center" style="background-color: #F5F8FB; border:solid; border-color: #E6E6E6">
                    <table border="0">
                    <tr><td style="font-size:24px">'.get_lang('Learner paper').'</td></tr>
                    <tr><td>'.$photo.'<br />'.$name.'</td></tr></table>
                    </div>[['.$link2teacher.' | '.get_lang(
                            'AssignmentLinktoTrainerPage'
                        ).']] ';
                    //If $content_orig_B is added here, the task written by
                    // the professor was copied to the page of each student.
                    // TODO: config options
                    // AssignmentLinktoTeacherPage
                    $all_students_pages[] = '<li>'.
                        Display::tag(
                            'span',
                            strtoupper(
                                $o_user_to_add['lastname']
                            ).', '.$o_user_to_add['firstname'],
                            ['title' => $username]
                        ).
                        ' [['.Security::remove_XSS(
                            $_POST['title']
                        )."_uass".$assig_user_id.' | '.$photo.']] '.$status_in_group.'</li>';
                    // don't change this line without guaranteeing
                    // that users will be ordered by last names in the
                    // following format (surname, name)
                    $values['assignment'] = 2;
                }
                $this->assig_user_id = $assig_user_id;
                self::save_new_wiki($values);
            }
        }

        foreach ($a_users_to_add as $o_user_to_add) {
            if ($o_user_to_add['user_id'] == $userId) {
                $assig_user_id = $o_user_to_add['user_id'];
                if ($assignment_type == 1) {
                    $values['title'] = $title_orig;
                    $values['comment'] = get_lang('Assignment proposed by the trainer');
                    sort($all_students_pages);
                    $values['content'] = $content_orig_A.$content_orig_B.'<br/>
                    <div align="center" style="font-size:18px; background-color: #F5F8FB; border:solid; border-color:#E6E6E6">
                    '.get_lang('Access to the papers written by learners').'
                    </div><br/>
                    <div style="background-color: #F5F8FB; border:solid; border-color:#E6E6E6">
                    <ol>'.implode($all_students_pages).'</ol>
                    </div>
                    <br/>';
                    $values['assignment'] = 1;
                }
                $this->assig_user_id = $assig_user_id;
                self::save_new_wiki($values);
            }
        }
    }

    /**
     * Displays the results of a wiki search.
     *
     * @param   string  Search term
     * @param   int     Whether to search the contents (1) or just the titles (0)
     * @param int
     */
    public function display_wiki_search_results(
        $search_term,
        $search_content = 0,
        $all_vers = 0
    ) {
        $tbl_wiki = $this->tbl_wiki;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $_course = $this->courseInfo;
        $course_id = api_get_course_int_id();
        echo '<legend>'.get_lang('Group wikiSearchResults').': '.Security::remove_XSS(
                $search_term
            );
        echo '</legend>';

        //only by professors when page is hidden
        if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
            if ($all_vers == '1') {
                if ($search_content == '1') {
                    $sql = "SELECT * FROM ".$tbl_wiki."
                            WHERE
                                c_id = $course_id AND
                                title LIKE '%".Database::escape_string($search_term)."%' OR
                                content LIKE '%".Database::escape_string(
                            $search_term
                        )."%' AND ".$groupfilter.$condition_session;
                } else {
                    $sql = "SELECT * FROM ".$tbl_wiki."
                            WHERE
                                c_id = $course_id AND
                                title LIKE '%".Database::escape_string(
                            $search_term
                        )."%' AND ".$groupfilter.$condition_session;
                }
            } else {
                if ($search_content == '1') {
                    // warning don't use group by reflink because don't return the last version
                    $sql = "SELECT * FROM ".$tbl_wiki." s1
                            WHERE
                                s1.c_id = $course_id AND
                                title LIKE '%".Database::escape_string($search_term)."%' OR
                                content LIKE '%".Database::escape_string($search_term)."%' AND
                                id=(
                                    SELECT MAX(s2.id)
                                    FROM ".$tbl_wiki." s2
                                    WHERE
                                        s2.c_id = $course_id AND
                                        s1.reflink = s2.reflink AND
                                        ".$groupfilter.$condition_session.")";
                } else {
                    // warning don't use group by reflink because don't return the last version
                    $sql = "SELECT * FROM ".$tbl_wiki." s1
                            WHERE
                                s1.c_id = $course_id AND
                                title LIKE '%".Database::escape_string(
                            $search_term
                        )."%' AND
                                id = (
                                    SELECT MAX(s2.id)
                                    FROM ".$tbl_wiki." s2
                                    WHERE
                                        s2.c_id = $course_id AND
                                        s1.reflink = s2.reflink AND
                                        ".$groupfilter.$condition_session.")";
                }
            }
        } else {
            if ($all_vers == '1') {
                if ($search_content == '1') {
                    //search all pages and all versions
                    $sql = "SELECT * FROM ".$tbl_wiki."
                            WHERE
                                c_id = $course_id AND
                                visibility=1 AND
                                title LIKE '%".Database::escape_string($search_term)."%' OR
                                content LIKE '%".Database::escape_string($search_term)."%' AND
                                ".$groupfilter.$condition_session;
                } else {
                    $sql = "SELECT * FROM ".$tbl_wiki."
                            WHERE
                                c_id = $course_id AND
                                visibility=1 AND
                                title LIKE '%".Database::escape_string($search_term)."%' AND
                                ".$groupfilter.$condition_session;
                }
            } else {
                if ($search_content == '1') {
                    $sql = "SELECT * FROM ".$tbl_wiki." s1
                            WHERE
                                s1.c_id = $course_id AND
                                visibility=1 AND
                                title LIKE '%".Database::escape_string($search_term)."%' OR
                                content LIKE '%".Database::escape_string($search_term)."%' AND
                                id=(
                                    SELECT MAX(s2.id)
                                    FROM ".$tbl_wiki." s2
                                    WHERE s2.c_id = $course_id AND
                                    s1.reflink = s2.reflink AND
                                    ".$groupfilter.$condition_session.")";
                } else {
                    // warning don't use group by reflink because don't return the last version
                    $sql = "SELECT * FROM ".$tbl_wiki." s1
                            WHERE
                                s1.c_id = $course_id AND
                                visibility=1 AND
                                title LIKE '%".Database::escape_string($search_term)."%' AND
                            id = (
                                SELECT MAX(s2.id) FROM ".$tbl_wiki." s2
                                WHERE s2.c_id = $course_id AND
                                s1.reflink = s2.reflink AND
                                ".$groupfilter.$condition_session.")";
                }
            }
        }

        $result = Database::query($sql);

        //show table
        $rows = [];
        if (Database::num_rows($result) > 0) {
            while ($obj = Database::fetch_object($result)) {
                // get author
                $userinfo = api_get_user_info($obj->user_id);
                // get time
                $year = substr($obj->dtime, 0, 4);
                $month = substr($obj->dtime, 5, 2);
                $day = substr($obj->dtime, 8, 2);
                $hours = substr($obj->dtime, 11, 2);
                $minutes = substr($obj->dtime, 14, 2);
                $seconds = substr($obj->dtime, 17, 2);

                //get type assignment icon
                if ($obj->assignment == 1) {
                    $ShowAssignment = Display::return_icon(
                        'wiki_assignment.png',
                        get_lang('Assignment proposed by the trainer'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($obj->assignment == 2) {
                    $ShowAssignment = Display::return_icon(
                        'wiki_work.png',
                        get_lang('Learner paper'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($obj->assignment == 0) {
                    $ShowAssignment = Display::return_icon(
                        'px_transparent.gif'
                    );
                }
                $row = [];
                $row[] = $ShowAssignment;

                if ($all_vers == '1') {
                    $row[] = '<a href="'.api_get_self().'?'.api_get_cidreq(
                        ).'&action=showpage&title='.api_htmlentities(
                            urlencode($obj->reflink)
                        ).'&view='.$obj->id.'&session_id='.api_htmlentities(
                            urlencode($_GET['$session_id'])
                        ).'&group_id='.api_htmlentities(
                            urlencode($_GET['group_id'])
                        ).'">'.
                        api_htmlentities($obj->title).'</a>';
                } else {
                    $row[] = '<a href="'.api_get_self().'?'.api_get_cidreq(
                        ).'&action=showpage&title='.api_htmlentities(
                            urlencode($obj->reflink)
                        ).'&session_id='.api_htmlentities(
                            $_GET['session_id']
                        ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                        $obj->title.'</a>';
                }

                $row[] = ($obj->user_id != 0 && $userinfo !== false) ? UserManager::getUserProfileLink(
                    $userinfo
                ) : get_lang('Anonymous').' ('.$obj->user_ip.')';
                $row[] = $year.'-'.$month.'-'.$day.' '.$hours.":".$minutes.":".$seconds;

                if ($all_vers == '1') {
                    $row[] = $obj->version;
                } else {
                    $showdelete = '';
                    if (api_is_allowed_to_edit(
                            false,
                            true
                        ) || api_is_platform_admin()) {
                        $showdelete = ' <a href="'.api_get_self(
                            ).'?'.api_get_cidreq(
                            ).'&action=delete&title='.api_htmlentities(
                                urlencode($obj->reflink)
                            ).'&group_id='.api_htmlentities(
                                $_GET['group_id']
                            ).'">'.
                            Display::return_icon(
                                'delete.png',
                                get_lang('Delete'),
                                '',
                                ICON_SIZE_SMALL
                            );
                    }
                    $row[] = '<a href="'.api_get_self().'?'.api_get_cidreq(
                        ).'&action=edit&title='.api_htmlentities(
                            urlencode($obj->reflink)
                        ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                        Display::return_icon(
                            'edit.png',
                            get_lang('Edit'),
                            '',
                            ICON_SIZE_SMALL
                        ).'</a>
                        <a href="'.api_get_self(
                        ).'?cidReq='.$_course['code'].'&action=discuss&title='.api_htmlentities(
                            urlencode($obj->reflink)
                        ).'&session_id='.api_htmlentities(
                            $_GET['session_id']
                        ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                        Display::return_icon(
                            'discuss.png',
                            get_lang('Discuss'),
                            '',
                            ICON_SIZE_SMALL
                        ).'</a>
                        <a href="'.api_get_self(
                        ).'?cidReq='.$_course['code'].'&action=history&title='.api_htmlentities(
                            urlencode($obj->reflink)
                        ).'&session_id='.api_htmlentities(
                            $_GET['session_id']
                        ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                        Display::return_icon(
                            'history.png',
                            get_lang('History'),
                            '',
                            ICON_SIZE_SMALL
                        ).'</a> <a href="'.api_get_self(
                        ).'?cidReq='.$_course['code'].'&action=links&title='.api_htmlentities(
                            urlencode($obj->reflink)
                        ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                        Display::return_icon(
                            'what_link_here.png',
                            get_lang('What links here'),
                            '',
                            ICON_SIZE_SMALL
                        ).'</a>'.$showdelete;
                }
                $rows[] = $row;
            }

            $table = new SortableTableFromArrayConfig(
                $rows,
                1,
                10,
                'SearchPages_table',
                '',
                '',
                'ASC'
            );
            $table->set_additional_parameters(
                [
                    'cidReq' => $_GET['cidReq'],
                    'action' => $_GET['action'],
                    'group_id' => intval($_GET['group_id']),
                    'mode_table' => 'yes2',
                    'search_term' => $search_term,
                    'search_content' => $search_content,
                    'all_vers' => $all_vers,
                ]
            );
            $table->set_header(
                0,
                get_lang('Type'),
                true,
                ['style' => 'width:30px;']
            );
            $table->set_header(1, get_lang('Title'), true);
            if ($all_vers == '1') {
                $table->set_header(2, get_lang('Author'), true);
                $table->set_header(3, get_lang('Date'), true);
                $table->set_header(4, get_lang('Version'), true);
            } else {
                $table->set_header(
                    2,
                    get_lang('Author').' ('.get_lang('Latest version').')',
                    true
                );
                $table->set_header(
                    3,
                    get_lang('Date').' ('.get_lang('Latest version').')',
                    true
                );
                $table->set_header(
                    4,
                    get_lang('Detail'),
                    false,
                    ['style' => 'width:130px;']
                );
            }
            $table->display();
        } else {
            echo get_lang('No search results');
        }
    }

    /**
     * Get wiki information.
     *
     * @param   int|bool wiki id
     *
     * @return array wiki data
     */
    public function getWikiDataFromDb($id)
    {
        $tbl_wiki = $this->tbl_wiki;
        $course_id = api_get_course_int_id();
        if ($id === false) {
            return [];
        }
        $id = intval($id);
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE c_id = '.$course_id.' AND id = '.$id.' ';
        $result = Database::query($sql);
        $data = [];
        while ($row = Database::fetch_array($result, 'ASSOC')) {
            $data = $row;
        }

        return $data;
    }

    /**
     * @param string $refLink
     *
     * @return array
     */
    public function getLastWikiData($refLink)
    {
        $tbl_wiki = $this->tbl_wiki;
        $groupfilter = $this->groupfilter;
        $condition_session = $this->condition_session;
        $course_id = api_get_course_int_id();

        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE
                    c_id = '.$course_id.' AND
                    reflink="'.Database::escape_string($refLink).'" AND
                    '.$groupfilter.$condition_session.'
                ORDER BY id DESC';

        $result = Database::query($sql);

        return Database::fetch_array($result);
    }

    /**
     * Get wiki information.
     *
     * @param   string     wiki id
     * @param int $courseId
     *
     * @return array wiki data
     */
    public function getPageByTitle($title, $courseId = null)
    {
        $tbl_wiki = $this->tbl_wiki;
        if (empty($courseId)) {
            $courseId = api_get_course_int_id();
        } else {
            $courseId = intval($courseId);
        }

        if (empty($title) || empty($courseId)) {
            return [];
        }

        $title = Database::escape_string($title);
        $sql = "SELECT * FROM $tbl_wiki
                WHERE c_id = $courseId AND reflink = '$title'";
        $result = Database::query($sql);
        $data = [];
        if (Database::num_rows($result)) {
            $data = Database::fetch_array($result, 'ASSOC');
        }

        return $data;
    }

    /**
     * @param string $title
     * @param int    $courseId
     * @param string
     * @param string
     *
     * @return bool
     */
    public function deletePage(
        $title,
        $courseId,
        $groupfilter = null,
        $condition_session = null
    ) {
        $tbl_wiki = $this->tbl_wiki;
        $tbl_wiki_discuss = $this->tbl_wiki_discuss;
        $tbl_wiki_mailcue = $this->tbl_wiki_mailcue;
        $tbl_wiki_conf = $this->tbl_wiki_conf;

        $pageInfo = self::getPageByTitle($title, $courseId);
        if (!empty($pageInfo)) {
            $pageId = $pageInfo['id'];
            $sql = "DELETE FROM $tbl_wiki_conf
                    WHERE c_id = $courseId AND page_id = $pageId";
            Database::query($sql);

            $sql = 'DELETE FROM '.$tbl_wiki_discuss.'
                    WHERE c_id = '.$courseId.' AND publication_id = '.$pageId;
            Database::query($sql);

            $sql = 'DELETE FROM  '.$tbl_wiki_mailcue.'
                    WHERE c_id = '.$courseId.' AND id = '.$pageId.' AND '.$groupfilter.$condition_session.'';
            Database::query($sql);

            $sql = 'DELETE FROM '.$tbl_wiki.'
                    WHERE c_id = '.$courseId.' AND id = '.$pageId.' AND '.$groupfilter.$condition_session.'';
            Database::query($sql);
            self::check_emailcue(0, 'E');

            return true;
        }

        return false;
    }

    /**
     * @return array
     */
    public function getAllWiki()
    {
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $condition_session = $this->condition_session;

        $sql = "SELECT * FROM $tbl_wiki
                WHERE
                    c_id = $course_id AND
                    is_editing != '0' ".$condition_session;
        $result = Database::query($sql);

        return Database::store_result($result, 'ASSOC');
    }

    /**
     * @param int $isEditing
     */
    public function updateWikiIsEditing($isEditing)
    {
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $condition_session = $this->condition_session;
        $isEditing = Database::escape_string($isEditing);

        $sql = 'UPDATE '.$tbl_wiki.' SET
                is_editing = "0",
                time_edit = NULL
                WHERE
                    c_id = '.$course_id.' AND
                    is_editing="'.$isEditing.'" '.
            $condition_session;
        Database::query($sql);
    }

    /**
     * Release of blocked pages to prevent concurrent editions.
     *
     * @param int    $userId
     * @param string $action
     */
    public function blockConcurrentEditions($userId, $action = null)
    {
        $result = self::getAllWiki();
        if (!empty($result)) {
            foreach ($result as $is_editing_block) {
                $max_edit_time = 1200; // 20 minutes
                $timestamp_edit = strtotime($is_editing_block['time_edit']);
                $time_editing = time() - $timestamp_edit;

                // First prevent concurrent users and double version
                if ($is_editing_block['is_editing'] == $userId) {
                    Session::write('_version', $is_editing_block['version']);
                } else {
                    Session::erase('_version');
                }
                // Second checks if has exceeded the time that a page may
                // be available or if a page was edited and saved by its author
                if ($time_editing > $max_edit_time ||
                    ($is_editing_block['is_editing'] == $userId &&
                        $action != 'edit')
                ) {
                    self::updateWikiIsEditing($is_editing_block['is_editing']);
                }
            }
        }
    }

    /**
     * Showing wiki stats.
     */
    public function getStats()
    {
        if (!api_is_allowed_to_edit(false, true)) {
            return false;
        }

        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $session_id = $this->session_id;
        $tbl_wiki_conf = $this->tbl_wiki_conf;

        echo '<div class="actions">'.get_lang('Statistics').'</div>';

        // Check all versions of all pages
        $total_words = 0;
        $total_links = 0;
        $total_links_anchors = 0;
        $total_links_mail = 0;
        $total_links_ftp = 0;
        $total_links_irc = 0;
        $total_links_news = 0;
        $total_wlinks = 0;
        $total_images = 0;
        $clean_total_flash = 0;
        $total_flash = 0;
        $total_mp3 = 0;
        $total_flv_p = 0;
        $total_flv = 0;
        $total_youtube = 0;
        $total_multimedia = 0;
        $total_tables = 0;

        $sql = "SELECT *, COUNT(*) AS TOTAL_VERS, SUM(hits) AS TOTAL_VISITS
                FROM ".$tbl_wiki."
                WHERE c_id = $course_id AND ".$groupfilter.$condition_session."";

        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_versions = $row['TOTAL_VERS'];
            $total_visits = intval($row['TOTAL_VISITS']);
        }

        $sql = "SELECT * FROM ".$tbl_wiki."
                WHERE c_id = $course_id AND ".$groupfilter.$condition_session."";
        $allpages = Database::query($sql);

        while ($row = Database::fetch_array($allpages)) {
            $total_words = $total_words + self::word_count($row['content']);
            $total_links = $total_links + substr_count(
                $row['content'],
                "href="
            );
            $total_links_anchors = $total_links_anchors + substr_count(
                $row['content'],
                'href="#'
            );
            $total_links_mail = $total_links_mail + substr_count(
                $row['content'],
                'href="mailto'
            );
            $total_links_ftp = $total_links_ftp + substr_count(
                $row['content'],
                'href="ftp'
            );
            $total_links_irc = $total_links_irc + substr_count(
                $row['content'],
                'href="irc'
            );
            $total_links_news = $total_links_news + substr_count(
                $row['content'],
                'href="news'
            );
            $total_wlinks = $total_wlinks + substr_count($row['content'], "[[");
            $total_images = $total_images + substr_count(
                $row['content'],
                "<img"
            );
            $clean_total_flash = preg_replace(
                '/player.swf/',
                ' ',
                $row['content']
            );
            $total_flash = $total_flash + substr_count(
                $clean_total_flash,
                '.swf"'
            );
            //.swf" end quotes prevent insert swf through flvplayer (is not counted)
            $total_mp3 = $total_mp3 + substr_count($row['content'], ".mp3");
            $total_flv_p = $total_flv_p + substr_count($row['content'], ".flv");
            $total_flv = $total_flv_p / 5;
            $total_youtube = $total_youtube + substr_count(
                $row['content'],
                "http://www.youtube.com"
            );
            $total_multimedia = $total_multimedia + substr_count(
                $row['content'],
                "video/x-msvideo"
            );
            $total_tables = $total_tables + substr_count(
                $row['content'],
                "<table"
            );
        }

        // Check only last version of all pages (current page)
        $sql = ' SELECT *, COUNT(*) AS TOTAL_PAGES, SUM(hits) AS TOTAL_VISITS_LV
                FROM  '.$tbl_wiki.' s1
                WHERE s1.c_id = '.$course_id.' AND id=(
                    SELECT MAX(s2.id)
                    FROM '.$tbl_wiki.' s2
                    WHERE
                        s2.c_id = '.$course_id.' AND
                        s1.reflink = s2.reflink AND
                        '.$groupfilter.' AND
                        session_id='.$session_id.')';
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_pages = $row['TOTAL_PAGES'];
            $total_visits_lv = intval($row['TOTAL_VISITS_LV']);
        }

        $total_words_lv = 0;
        $total_links_lv = 0;
        $total_links_anchors_lv = 0;
        $total_links_mail_lv = 0;
        $total_links_ftp_lv = 0;
        $total_links_irc_lv = 0;
        $total_links_news_lv = 0;
        $total_wlinks_lv = 0;
        $total_images_lv = 0;
        $clean_total_flash_lv = 0;
        $total_flash_lv = 0;
        $total_mp3_lv = 0;
        $total_flv_p_lv = 0;
        $total_flv_lv = 0;
        $total_youtube_lv = 0;
        $total_multimedia_lv = 0;
        $total_tables_lv = 0;

        $sql = 'SELECT * FROM  '.$tbl_wiki.' s1
                WHERE s1.c_id = '.$course_id.' AND id=(
                    SELECT MAX(s2.id) FROM '.$tbl_wiki.' s2
                    WHERE
                        s2.c_id = '.$course_id.' AND
                        s1.reflink = s2.reflink AND
                        '.$groupfilter.' AND
                        session_id='.$session_id.'
                )';
        $allpages = Database::query($sql);

        while ($row = Database::fetch_array($allpages)) {
            $total_words_lv = $total_words_lv + self::word_count(
                $row['content']
            );
            $total_links_lv = $total_links_lv + substr_count(
                $row['content'],
                "href="
            );
            $total_links_anchors_lv = $total_links_anchors_lv + substr_count(
                $row['content'],
                'href="#'
            );
            $total_links_mail_lv = $total_links_mail_lv + substr_count(
                $row['content'],
                'href="mailto'
            );
            $total_links_ftp_lv = $total_links_ftp_lv + substr_count(
                $row['content'],
                'href="ftp'
            );
            $total_links_irc_lv = $total_links_irc_lv + substr_count(
                $row['content'],
                'href="irc'
            );
            $total_links_news_lv = $total_links_news_lv + substr_count(
                $row['content'],
                'href="news'
            );
            $total_wlinks_lv = $total_wlinks_lv + substr_count(
                $row['content'],
                "[["
            );
            $total_images_lv = $total_images_lv + substr_count(
                $row['content'],
                "<img"
            );
            $clean_total_flash_lv = preg_replace(
                '/player.swf/',
                ' ',
                $row['content']
            );
            $total_flash_lv = $total_flash_lv + substr_count(
                $clean_total_flash_lv,
                '.swf"'
            );
            //.swf" end quotes prevent insert swf through flvplayer (is not counted)
            $total_mp3_lv = $total_mp3_lv + substr_count(
                $row['content'],
                ".mp3"
            );
            $total_flv_p_lv = $total_flv_p_lv + substr_count(
                $row['content'],
                ".flv"
            );
            $total_flv_lv = $total_flv_p_lv / 5;
            $total_youtube_lv = $total_youtube_lv + substr_count(
                $row['content'],
                "http://www.youtube.com"
            );
            $total_multimedia_lv = $total_multimedia_lv + substr_count(
                $row['content'],
                "video/x-msvideo"
            );
            $total_tables_lv = $total_tables_lv + substr_count(
                $row['content'],
                "<table"
            );
        }

        //Total pages edited at this time
        $total_editing_now = 0;
        $sql = 'SELECT *, COUNT(*) AS TOTAL_EDITING_NOW
                FROM  '.$tbl_wiki.' s1
                WHERE is_editing!=0 AND s1.c_id = '.$course_id.' AND
                id=(
                    SELECT MAX(s2.id)
                    FROM '.$tbl_wiki.' s2
                    WHERE
                        s2.c_id = '.$course_id.' AND
                        s1.reflink = s2.reflink AND
                        '.$groupfilter.' AND
                        session_id='.$session_id.'
        )';

        // Can not use group by because the mark is set in the latest version
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_editing_now = $row['TOTAL_EDITING_NOW'];
        }

        // Total hidden pages
        $total_hidden = 0;
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE  
                    c_id = '.$course_id.' AND 
                    visibility = 0 AND 
                    '.$groupfilter.$condition_session.'
                GROUP BY reflink';
        // or group by page_id. As the mark of hidden places it in all
        // versions of the page, I can use group by to see the first
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_hidden = $total_hidden + 1;
        }

        //Total protect pages
        $total_protected = 0;
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE  
                    c_id = '.$course_id.' AND 
                    editlock = 1 AND
                     '.$groupfilter.$condition_session.'
                GROUP BY reflink';
        // or group by page_id. As the mark of protected page is the
        // first version of the page, I can use group by
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_protected = $total_protected + 1;
        }

        // Total empty versions.
        $total_empty_content = 0;
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE
                    c_id = '.$course_id.' AND
                    content="" AND
                    '.$groupfilter.$condition_session.'';
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_empty_content = $total_empty_content + 1;
        }

        //Total empty pages (last version)

        $total_empty_content_lv = 0;
        $sql = 'SELECT  * FROM  '.$tbl_wiki.' s1
                WHERE s1.c_id = '.$course_id.' AND content="" AND id=(
                    SELECT MAX(s2.id) FROM '.$tbl_wiki.' s2
                    WHERE 
                        s1.c_id = '.$course_id.' AND 
                        s1.reflink = s2.reflink AND 
                        '.$groupfilter.' AND 
                        session_id='.$session_id.'
                )';
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_empty_content_lv = $total_empty_content_lv + 1;
        }

        // Total locked discuss pages
        $total_lock_disc = 0;
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE c_id = '.$course_id.' AND addlock_disc=0 AND '.$groupfilter.$condition_session.'
                GROUP BY reflink'; //group by because mark lock in all vers, then always is ok
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_lock_disc = $total_lock_disc + 1;
        }

        // Total hidden discuss pages.
        $total_hidden_disc = 0;
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE c_id = '.$course_id.' AND visibility_disc=0 AND '.$groupfilter.$condition_session.'
                GROUP BY reflink';
        //group by because mark lock in all vers, then always is ok
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_hidden_disc = $total_hidden_disc + 1;
        }

        // Total versions with any short comment by user or system
        $total_comment_version = 0;
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE c_id = '.$course_id.' AND comment!="" AND '.$groupfilter.$condition_session.'';
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_comment_version = $total_comment_version + 1;
        }

        // Total pages that can only be scored by teachers.
        $total_only_teachers_rating = 0;
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE c_id = '.$course_id.' AND
                ratinglock_disc = 0 AND
                '.$groupfilter.$condition_session.'
                GROUP BY reflink'; //group by because mark lock in all vers, then always is ok
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_only_teachers_rating = $total_only_teachers_rating + 1;
        }

        // Total pages scored by peers
        // put always this line alfter check num all pages and num pages rated by teachers
        $total_rating_by_peers = $total_pages - $total_only_teachers_rating;

        //Total pages identified as standard task
        $total_task = 0;
        $sql = 'SELECT * FROM '.$tbl_wiki.', '.$tbl_wiki_conf.'
              WHERE '.$tbl_wiki_conf.'.c_id = '.$course_id.' AND
               '.$tbl_wiki_conf.'.task!="" AND
               '.$tbl_wiki_conf.'.page_id='.$tbl_wiki.'.page_id AND
                '.$tbl_wiki.'.'.$groupfilter.$condition_session;
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_task = $total_task + 1;
        }

        //Total pages identified as teacher page (wiki portfolio mode - individual assignment)
        $total_teacher_assignment = 0;
        $sql = 'SELECT  * FROM  '.$tbl_wiki.' s1
                WHERE s1.c_id = '.$course_id.' AND assignment=1 AND id=(
                    SELECT MAX(s2.id)
                    FROM '.$tbl_wiki.' s2
                    WHERE 
                        s2.c_id = '.$course_id.' AND
                        s1.reflink = s2.reflink AND 
                        '.$groupfilter.' AND
                         session_id='.$session_id.'
                )';
        //mark all versions, but do not use group by reflink because y want the pages not versions
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_teacher_assignment = $total_teacher_assignment + 1;
        }

        //Total pages identifies as student page (wiki portfolio mode - individual assignment)
        $total_student_assignment = 0;
        $sql = 'SELECT  * FROM  '.$tbl_wiki.' s1
                WHERE s1.c_id = '.$course_id.' AND assignment=2 AND
                id = (SELECT MAX(s2.id) FROM '.$tbl_wiki.' s2
                WHERE 
                    s2.c_id = '.$course_id.' AND 
                    s1.reflink = s2.reflink AND 
                    '.$groupfilter.' AND 
                    session_id='.$session_id.'
                )';
        //mark all versions, but do not use group by reflink because y want the pages not versions
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_student_assignment = $total_student_assignment + 1;
        }

        //Current Wiki status add new pages
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE c_id = '.$course_id.' AND '.$groupfilter.$condition_session.'
                GROUP BY addlock'; //group by because mark 0 in all vers, then always is ok
        $allpages = Database::query($sql);
        $wiki_add_lock = null;
        while ($row = Database::fetch_array($allpages)) {
            $wiki_add_lock = $row['addlock'];
        }

        if ($wiki_add_lock == 1) {
            $status_add_new_pag = get_lang('Yes');
        } else {
            $status_add_new_pag = get_lang('No');
        }

        // Creation date of the oldest wiki page and version
        $first_wiki_date = null;
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE c_id = '.$course_id.' AND '.$groupfilter.$condition_session.'
                ORDER BY dtime ASC 
                LIMIT 1';
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $first_wiki_date = api_get_local_time($row['dtime']);
        }

        // Date of publication of the latest wiki version.

        $last_wiki_date = null;
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE c_id = '.$course_id.' AND '.$groupfilter.$condition_session.'
                ORDER BY dtime DESC 
                LIMIT 1';
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $last_wiki_date = api_get_local_time($row['dtime']);
        }

        // Average score of all wiki pages. (If a page has not scored zero rated)
        $media_score = 0;
        $sql = "SELECT *, SUM(score) AS TOTAL_SCORE FROM ".$tbl_wiki."
                WHERE c_id = $course_id AND ".$groupfilter.$condition_session."
                GROUP BY reflink ";
        //group by because mark in all versions, then always is ok.
        // Do not use "count" because using "group by", would give a wrong value
        $allpages = Database::query($sql);
        $total_score = 0;
        while ($row = Database::fetch_array($allpages)) {
            $total_score = $total_score + $row['TOTAL_SCORE'];
        }

        if (!empty($total_pages)) {
            $media_score = $total_score / $total_pages;
            //put always this line alfter check num all pages
        }

        // Average user progress in his pages.
        $media_progress = 0;
        $sql = 'SELECT  *, SUM(progress) AS TOTAL_PROGRESS
                FROM  '.$tbl_wiki.' s1
                WHERE s1.c_id = '.$course_id.' AND id=
                (
                    SELECT MAX(s2.id) FROM '.$tbl_wiki.' s2
                    WHERE
                        s2.c_id = '.$course_id.' AND
                        s1.reflink = s2.reflink AND
                        '.$groupfilter.' AND
                        session_id='.$session_id.'
                )';
        // As the value is only the latest version I can not use group by
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_progress = $row['TOTAL_PROGRESS'];
        }

        if (!empty($total_pages)) {
            $media_progress = $total_progress / $total_pages;
            //put always this line alfter check num all pages
        }

        // Total users that have participated in the Group wiki
        $total_users = 0;
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE  c_id = '.$course_id.' AND '.$groupfilter.$condition_session.'
                GROUP BY user_id';
        //as the mark of user it in all versions of the page, I can use group by to see the first
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_users = $total_users + 1;
        }

        // Total of different IP addresses that have participated in the wiki
        $total_ip = 0;
        $sql = 'SELECT * FROM '.$tbl_wiki.'
              WHERE c_id = '.$course_id.' AND '.$groupfilter.$condition_session.'
              GROUP BY user_ip';
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $total_ip = $total_ip + 1;
        }

        echo '<table class="data_table">';
        echo '<thead>';
        echo '<tr>';
        echo '<th colspan="2">'.get_lang('General').'</th>';
        echo '</tr>';
        echo '</thead>';
        echo '<tr>';
        echo '<td>'.get_lang('Learners can add new pages to the Wiki').'</td>';
        echo '<td>'.$status_add_new_pag.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('DateCreateOldestGroup wikiPage').'</td>';
        echo '<td>'.$first_wiki_date.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('DateEditLatestGroup wikiVersion').'</td>';
        echo '<td>'.$last_wiki_date.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Average rating of all pages').'</td>';
        echo '<td>'.$media_score.' %</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Mean estimated progress by users on their pages').'</td>';
        echo '<td>'.$media_progress.' %</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('TotalGroup wikiUsers').'</td>';
        echo '<td>'.$total_users.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Total different IP addresses that have contributed to Wiki').'</td>';
        echo '<td>'.$total_ip.'</td>';
        echo '</tr>';
        echo '</table>';
        echo '<br/>';

        echo '<table class="data_table">';
        echo '<thead>';
        echo '<tr>';
        echo '<th colspan="2">'.get_lang('Pages').' '.get_lang(
                'And'
            ).' '.get_lang('Versions').'</th>';
        echo '</tr>';
        echo '</thead>';
        echo '<tr>';
        echo '<td>'.get_lang('Pages').' - '.get_lang(
                'Numcontributions'
            ).'</td>';
        echo '<td>'.$total_pages.' ('.get_lang(
                'Versions'
            ).': '.$total_versions.')</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Total of empty pages').'</td>';
        echo '<td>'.$total_empty_content_lv.' ('.get_lang(
                'Versions'
            ).': '.$total_empty_content.')</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of visits').'</td>';
        echo '<td>'.$total_visits_lv.' ('.get_lang(
                'Versions'
            ).': '.$total_visits.')</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Total pages edited at this time').'</td>';
        echo '<td>'.$total_editing_now.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Total hidden pages').'</td>';
        echo '<td>'.$total_hidden.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of protected pages').'</td>';
        echo '<td>'.$total_protected.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of discussion pages blocked').'</td>';
        echo '<td>'.$total_lock_disc.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of discussion pages hidden').'</td>';
        echo '<td>'.$total_hidden_disc.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Total comments on various versions of the pages').'</td>';
        echo '<td>'.$total_comment_version.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Total pages can only be scored by a teacher').'</td>';
        echo '<td>'.$total_only_teachers_rating.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Total pages that can be scored by other learners').'</td>';
        echo '<td>'.$total_rating_by_peers.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of assignments pages proposed by a teacher').' - '.get_lang(
                'PortfolioMode'
            ).'</td>';
        echo '<td>'.$total_teacher_assignment.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of individual assignments learner pages').' - '.get_lang(
                'PortfolioMode'
            ).'</td>';
        echo '<td>'.$total_student_assignment.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of tasks').' - '.get_lang(
                'StandardMode'
            ).'</td>';
        echo '<td>'.$total_task.'</td>';
        echo '</tr>';
        echo '</table>';
        echo '<br/>';

        echo '<table class="data_table">';
        echo '<thead>';
        echo '<tr>';
        echo '<th colspan="3">'.get_lang('ContentPagesinfo').'</th>';
        echo '</tr>';
        echo '<tr>';
        echo '<td></td>';
        echo '<td>'.get_lang('inTheLatest version').'</td>';
        echo '<td>'.get_lang('inAllVersions').'</td>';
        echo '</tr>';
        echo '</thead>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of words').'</td>';
        echo '<td>'.$total_words_lv.'</td>';
        echo '<td>'.$total_words.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of external html links inserted (text, images, ...).').'</td>';
        echo '<td>'.$total_links_lv.' ('.get_lang(
                'Anchors'
            ).':'.$total_links_anchors_lv.', Mail:'.$total_links_mail_lv.', FTP:'.$total_links_ftp_lv.' IRC:'.$total_links_irc_lv.', News:'.$total_links_news_lv.', ... ) </td>';
        echo '<td>'.$total_links.' ('.get_lang(
                'Anchors'
            ).':'.$total_links_anchors.', Mail:'.$total_links_mail.', FTP:'.$total_links_ftp.', IRC:'.$total_links_irc.', News:'.$total_links_news.', ... ) </td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('NumGroup wikilinks').'</td>';
        echo '<td>'.$total_wlinks_lv.'</td>';
        echo '<td>'.$total_wlinks.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of inserted images').'</td>';
        echo '<td>'.$total_images_lv.'</td>';
        echo '<td>'.$total_images.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of inserted flash files').'</td>';
        echo '<td>'.$total_flash_lv.'</td>';
        echo '<td>'.$total_flash.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of mp3 audio files inserted').'</td>';
        echo '<td>'.$total_mp3_lv.'</td>';
        echo '<td>'.$total_mp3.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of FLV video files inserted').'</td>';
        echo '<td>'.$total_flv_lv.'</td>';
        echo '<td>'.$total_flv.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of Youtube video embedded').'</td>';
        echo '<td>'.$total_youtube_lv.'</td>';
        echo '<td>'.$total_youtube.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of audio and video files inserted (except mp3 and flv)').'</td>';
        echo '<td>'.$total_multimedia_lv.'</td>';
        echo '<td>'.$total_multimedia.'</td>';
        echo '</tr>';
        echo '<tr>';
        echo '<td>'.get_lang('Number of tables inserted').'</td>';
        echo '<td>'.$total_tables_lv.'</td>';
        echo '<td>'.$total_tables.'</td>';
        echo '</tr>';
        echo '</table>';
    }

    /**
     * @param string $action
     */
    public function getActiveUsers($action)
    {
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $_course = $this->courseInfo;

        echo '<div class="actions">'.get_lang('Most active users').'</div>';
        $sql = 'SELECT *, COUNT(*) AS NUM_EDIT FROM '.$tbl_wiki.'
                WHERE  c_id = '.$course_id.' AND '.$groupfilter.$condition_session.'
                GROUP BY user_id';
        $allpages = Database::query($sql);

        //show table
        if (Database::num_rows($allpages) > 0) {
            while ($obj = Database::fetch_object($allpages)) {
                $userinfo = api_get_user_info($obj->user_id);
                $row = [];
                if ($obj->user_id != 0 && $userinfo !== false) {
                    $row[] = UserManager::getUserProfileLink($userinfo).'
                            <a href="'.api_get_self(
                        ).'?cidReq='.$_course['code'].'&action=usercontrib&user_id='.urlencode(
                            $obj->user_id
                        ).
                        '&session_id='.api_htmlentities(
                            $_GET['session_id']
                        ).'&group_id='.api_htmlentities(
                            $_GET['group_id']
                        ).'"></a>';
                } else {
                    $row[] = get_lang('Anonymous').' ('.$obj->user_ip.')';
                }
                $row[] = '<a href="'.api_get_self(
                    ).'?cidReq='.$_course['code'].'&action=usercontrib&user_id='.urlencode(
                        $obj->user_id
                    ).'&session_id='.api_htmlentities(
                        $_GET['session_id']
                    ).'&group_id='.api_htmlentities(
                        $_GET['group_id']
                    ).'">'.$obj->NUM_EDIT.'</a>';
                $rows[] = $row;
            }

            $table = new SortableTableFromArrayConfig(
                $rows,
                1,
                10,
                'MostActiveUsersA_table',
                '',
                '',
                'DESC'
            );
            $table->set_additional_parameters(
                [
                    'cidReq' => Security::remove_XSS($_GET['cidReq']),
                    'action' => Security::remove_XSS($action),
                    'session_id' => Security::remove_XSS($_GET['session_id']),
                    'group_id' => Security::remove_XSS($_GET['group_id']),
                ]
            );
            $table->set_header(0, get_lang('Author'), true);
            $table->set_header(
                1,
                get_lang('contributions'),
                true,
                ['style' => 'width:30px;']
            );
            $table->display();
        }
    }

    /**
     * @param string $page
     */
    public function getDiscuss($page)
    {
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $tbl_wiki_discuss = $this->tbl_wiki_discuss;

        if (api_get_session_id() != 0 &&
            api_is_allowed_to_session_edit(false, true) == false
        ) {
            api_not_allowed();
        }

        if (!$_GET['title']) {
            Display::addFlash(
                Display::return_message(
                    get_lang("You must select a page first"),
                    'error',
                    false
                )
            );

            return;
        }

        // First extract the date of last version
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE
                    c_id = '.$course_id.' AND
                    reflink = "'.Database::escape_string($page).'" AND
                    '.$groupfilter.$condition_session.'
                ORDER BY id DESC';
        $result = Database::query($sql);
        $row = Database::fetch_array($result);
        $lastversiondate = api_get_local_time($row['dtime']);
        $lastuserinfo = api_get_user_info($row['user_id']);

        // Select page to discuss
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE
                    c_id = '.$course_id.' AND
                    reflink="'.Database::escape_string($page).'" AND
                    '.$groupfilter.$condition_session.'
                ORDER BY id ASC';
        $result = Database::query($sql);
        $row = Database::fetch_array($result);
        $id = $row['id'];
        $firstuserid = $row['user_id'];

        if (isset($_POST['Submit']) && self::double_post($_POST['wpost_id'])) {
            $dtime = api_get_utc_datetime();
            $message_author = api_get_user_id();

            $params = [
                'c_id' => $course_id,
                'publication_id' => $id,
                'userc_id' => $message_author,
                'comment' => $_POST['comment'],
                'p_score' => $_POST['rating'],
                'dtime' => $dtime,
            ];
            $discussId = Database::insert($tbl_wiki_discuss, $params);
            if ($discussId) {
                $sql = "UPDATE $tbl_wiki_discuss SET id = iid WHERE iid = $discussId";
                Database::query($sql);
            }

            self::check_emailcue($id, 'D', $dtime, $message_author);

            header(
                'Location: index.php?action=discuss&title='.api_htmlentities(urlencode($page)).'&'.api_get_cidreq()
            );
            exit;
        }

        // mode assignment: previous to show  page type
        $icon_assignment = null;
        if ($row['assignment'] == 1) {
            $icon_assignment = Display::return_icon(
                'wiki_assignment.png',
                get_lang('This page is an assignment proposed by a trainer'),
                '',
                ICON_SIZE_SMALL
            );
        } elseif ($row['assignment'] == 2) {
            $icon_assignment = Display::return_icon(
                'wiki_work.png',
                get_lang('Learner paperExtra'),
                '',
                ICON_SIZE_SMALL
            );
        }

        $countWPost = null;
        $avg_WPost_score = null;

        // Show title and form to discuss if page exist
        if ($id != '') {
            // Show discussion to students if isn't hidden.
            // Show page to all teachers if is hidden.
            // Mode assignments: If is hidden, show pages to student only if student is the author
            if ($row['visibility_disc'] == 1 ||
                api_is_allowed_to_edit(false, true) ||
                api_is_platform_admin() ||
                ($row['assignment'] == 2 && $row['visibility_disc'] == 0 && (api_get_user_id() == $row['user_id']))
            ) {
                echo '<div id="wikititle">';
                // discussion action: protecting (locking) the discussion
                $addlock_disc = null;
                $lock_unlock_disc = null;
                if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
                    if (self::check_addlock_discuss() == 1) {
                        $addlock_disc = Display::return_icon(
                            'unlock.png',
                            get_lang('Now all members can add comments to this discussion'),
                            '',
                            ICON_SIZE_SMALL
                        );
                        $lock_unlock_disc = 'unlockdisc';
                    } else {
                        $addlock_disc = Display::return_icon(
                            'lock.png',
                            get_lang('Now only trainers can add comments to this discussion'),
                            '',
                            ICON_SIZE_SMALL
                        );
                        $lock_unlock_disc = 'lockdisc';
                    }
                }
                echo '<span style="float:right">';
                echo '<a href="index.php?'.api_get_cidreq().'&action=discuss&actionpage='.$lock_unlock_disc.'&title='.api_htmlentities(
                        urlencode($page)
                    ).'">'.$addlock_disc.'</a>';
                echo '</span>';

                // discussion action: visibility.  Show discussion to students if isn't hidden. Show page to all teachers if is hidden.
                $visibility_disc = null;
                $hide_show_disc = null;
                if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
                    if (self::check_visibility_discuss() == 1) {
                        /// TODO: 	Fix Mode assignments: If is hidden, show discussion to student only if student is the author
                        $visibility_disc = Display::return_icon(
                            'visible.png',
                            get_lang('Now discussion is visible by all users'),
                            '',
                            ICON_SIZE_SMALL
                        );
                        $hide_show_disc = 'hidedisc';
                    } else {
                        $visibility_disc = Display::return_icon(
                            'invisible.png',
                            get_lang('Now discussion is visible by trainers only'),
                            '',
                            ICON_SIZE_SMALL
                        );
                        $hide_show_disc = 'showdisc';
                    }
                }
                echo '<span style="float:right">';
                echo '<a href="index.php?'.api_get_cidreq().'&action=discuss&actionpage='.$hide_show_disc.'&title='.api_htmlentities(
                        urlencode($page)
                    ).'">'.$visibility_disc.'</a>';
                echo '</span>';

                // discussion action: check add rating lock. Show/Hide list to rating for all student
                $lock_unlock_rating_disc = null;
                $ratinglock_disc = null;
                if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
                    if (self::check_ratinglock_discuss() == 1) {
                        $ratinglock_disc = Display::return_icon(
                            'star.png',
                            get_lang('Now all members can rate this page'),
                            '',
                            ICON_SIZE_SMALL
                        );
                        $lock_unlock_rating_disc = 'unlockrating';
                    } else {
                        $ratinglock_disc = Display::return_icon(
                            'star_na.png',
                            get_lang('Now only trainers can rate this page'),
                            '',
                            ICON_SIZE_SMALL
                        );
                        $lock_unlock_rating_disc = 'lockrating';
                    }
                }

                echo '<span style="float:right">';
                echo '<a href="index.php?'.api_get_cidreq().'&action=discuss&actionpage='.$lock_unlock_rating_disc.'&title='.api_htmlentities(
                        urlencode($page)
                    ).'">'.$ratinglock_disc.'</a>';
                echo '</span>';

                // discussion action: email notification
                if (self::check_notify_discuss($page) == 1) {
                    $notify_disc = Display::return_icon(
                        'messagebox_info.png',
                        get_lang('Notify by e-mail of new comments about this page is allowed'),
                        '',
                        ICON_SIZE_SMALL
                    );
                    $lock_unlock_notify_disc = 'unlocknotifydisc';
                } else {
                    $notify_disc = Display::return_icon(
                        'mail.png',
                        get_lang('CancelNotify by e-mail of new comments about this page is allowed'),
                        '',
                        ICON_SIZE_SMALL
                    );
                    $lock_unlock_notify_disc = 'locknotifydisc';
                }
                echo '<span style="float:right">';
                echo '<a href="index.php?'.api_get_cidreq().'&action=discuss&actionpage='.$lock_unlock_notify_disc.'&title='.api_htmlentities(
                        urlencode($page)
                    ).'">'.$notify_disc.'</a>';
                echo '</span>';
                echo $icon_assignment.'&nbsp;&nbsp;&nbsp;'.api_htmlentities(
                        $row['title']
                    );
                if ($lastuserinfo !== false) {
                    echo ' ('.get_lang('The latest version was edited by').' '.
                        UserManager::getUserProfileLink($lastuserinfo).' '.$lastversiondate.$countWPost.')'.$avg_WPost_score.' '; //TODO: read average score
                }

                echo '</div>';
                if ($row['addlock_disc'] == 1 || api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
                    //show comments but students can't add theirs
                    ?>
                    <div class="panel panel-default">
                        <div class="panel-body">
                            <form name="form1" method="post" action=""
                                  class="form-horizontal">
                                <div class="form-group">
                                    <label
                                        class="col-sm-2 control-label">
                                        <?php echo get_lang('Comments'); ?>:</label>
                                    <div class="col-sm-10">
                                        <?php echo '<input type="hidden" name="wpost_id" value="'.md5(uniqid(rand(), true)).'">'; //prevent double post?>
                                        <textarea class="form-control"
                                                  name="comment" cols="80"
                                                  rows="5"
                                                  id="comment">
                                        </textarea>
                                    </div>
                                </div>
                                <div class="form-group">
                                    <?php
                                    //check if rating is allowed
                                    if ($row['ratinglock_disc'] == 1 || api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
                                        ?>
                                        <label
                                            class="col-sm-2 control-label"><?php echo get_lang('Rating'); ?>:</label>
                                        <div class="col-sm-10">
                                            <select name="rating" id="rating" class="selectpicker">
                                                <option value="-" selected>-</option>
                                                <option value="0">0</option>
                                                <option value="1">1</option>
                                                <option value="2">2</option>
                                                <option value="3">3</option>
                                                <option value="4">4</option>
                                                <option value="5">5</option>
                                                <option value="6">6</option>
                                                <option value="7">7</option>
                                                <option value="8">8</option>
                                                <option value="9">9</option>
                                                <option value="10">10</option>
                                            </select>
                                        </div>
                                        <?php
                                    } else {
                                        echo '<input type=hidden name="rating" value="-">';
                                        // must pass a default value to avoid rate automatically
                                    } ?>

                                </div>
                                <div class="form-group">
                                    <div class="col-sm-offset-2 col-sm-10">
                                        <?php echo '<button class="btn btn-default" type="submit" name="Submit"> '.
                                            get_lang('Send message').'</button>'; ?>
                                    </div>
                                </div>
                        </div>
                    </div>
                    </form>
                    <?php
                }
                // end discuss lock

                echo '<hr noshade size="1">';
                $user_table = Database::get_main_table(TABLE_MAIN_USER);

                $sql = "SELECT *
                        FROM $tbl_wiki_discuss reviews, $user_table user
                        WHERE
                            reviews.c_id = $course_id AND
                            reviews.publication_id='".$id."' AND
                            user.user_id='".$firstuserid."'
                        ORDER BY reviews.id DESC";
                $result = Database::query($sql);

                $countWPost = Database::num_rows($result);
                echo get_lang('Comments on this page').": ".$countWPost; //comment's numbers

                $sql = "SELECT SUM(p_score) as sumWPost
                        FROM $tbl_wiki_discuss
                        WHERE c_id = $course_id AND publication_id = '".$id."' AND NOT p_score='-'
                        ORDER BY id DESC";
                $result2 = Database::query($sql);
                $row2 = Database::fetch_array($result2);

                $sql = "SELECT * FROM $tbl_wiki_discuss
                        WHERE c_id = $course_id AND publication_id='".$id."' AND NOT p_score='-'";
                $result3 = Database::query($sql);
                $countWPost_score = Database::num_rows($result3);

                echo ' - '.get_lang('Comments on this pageScore').': '.$countWPost_score;

                if ($countWPost_score != 0) {
                    $avg_WPost_score = round($row2['sumWPost'] / $countWPost_score, 2).' / 10';
                } else {
                    $avg_WPost_score = $countWPost_score;
                }

                echo ' - '.get_lang('The average rating for the page is').': '.$avg_WPost_score; // average rating

                $sql = 'UPDATE '.$tbl_wiki.' SET
                        score = "'.Database::escape_string($avg_WPost_score).'"
                        WHERE
                            c_id = '.$course_id.' AND
                            reflink="'.Database::escape_string($page).'" AND
                            '.$groupfilter.$condition_session;
                // check if work ok. TODO:
                Database::query($sql);

                echo '<hr noshade size="1">';
                while ($row = Database::fetch_array($result)) {
                    $userinfo = api_get_user_info($row['userc_id']);
                    if (($userinfo['status']) == "5") {
                        $author_status = get_lang('Learner');
                    } else {
                        $author_status = get_lang('Trainer');
                    }

                    $name = $userinfo['complete_name'];
                    $author_photo = '<img src="'.$userinfo['avatar'].'" alt="'.api_htmlentities($name).'"  width="40" height="50" align="top"  title="'.api_htmlentities($name).'"  />';

                    // stars
                    $p_score = $row['p_score'];
                    switch ($p_score) {
                        case  0:
                            $imagerating = Display::return_icon(
                                'rating/stars_0.gif'
                            );
                            break;
                        case  1:
                            $imagerating = Display::return_icon(
                                'rating/stars_5.gif'
                            );
                            break;
                        case  2:
                            $imagerating = Display::return_icon(
                                'rating/stars_10.gif'
                            );
                            break;
                        case  3:
                            $imagerating = Display::return_icon(
                                'rating/stars_15.gif'
                            );
                            break;
                        case  4:
                            $imagerating = Display::return_icon(
                                'rating/stars_20.gif'
                            );
                            break;
                        case  5:
                            $imagerating = Display::return_icon(
                                'rating/stars_25.gif'
                            );
                            break;
                        case  6:
                            $imagerating = Display::return_icon(
                                'rating/stars_30.gif'
                            );
                            break;
                        case  7:
                            $imagerating = Display::return_icon(
                                'rating/stars_35.gif'
                            );
                            break;
                        case  8:
                            $imagerating = Display::return_icon(
                                'rating/stars_40.gif'
                            );
                            break;
                        case  9:
                            $imagerating = Display::return_icon(
                                'rating/stars_45.gif'
                            );
                            break;
                        case  10:
                            $imagerating = Display::return_icon(
                                'rating/stars_50.gif'
                            );
                            break;
                    }
                    echo '<p><table>';
                    echo '<tr>';
                    echo '<td rowspan="2">'.$author_photo.'</td>';
                    $userProfile = '';
                    if ($userinfo !== false) {
                        $userProfile = UserManager::getUserProfileLink(
                            $userinfo
                        );
                    }
                    echo '<td style=" color:#999999">'.$userProfile.' ('.$author_status.') '.
                        api_get_local_time(
                            $row['dtime']
                        ).
                        ' - '.get_lang(
                            'Rating'
                        ).': '.$row['p_score'].' '.$imagerating.' </td>';
                    echo '</tr>';
                    echo '<tr>';
                    echo '<td>'.api_htmlentities($row['comment']).'</td>';
                    echo '</tr>';
                    echo "</table>";
                }
            } else {
                Display::addFlash(
                    Display::return_message(
                        get_lang('LockByTrainer'),
                        'warning',
                        false
                    )
                );
            }
        } else {
            Display::addFlash(
                Display::return_message(
                    get_lang('Discuss not available'),
                    'normal',
                    false
                )
            );
        }
    }

    /**
     * Show all pages.
     */
    public function allPages($action)
    {
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $session_id = $this->session_id;
        $groupfilter = $this->groupfilter;
        $_course = $this->courseInfo;

        echo '<div class="actions">'.get_lang('All pages');

        // menu delete all wiki
        if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
            echo ' <a href="index.php?action=deletewiki&'.api_get_cidreq().'">'.
                Display::return_icon(
                    'delete.png',
                    get_lang('DeleteGroup wiki'),
                    '',
                    ICON_SIZE_MEDIUM
                ).'</a>';
        }
        echo '</div>';

        if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
            // only by professors if page is hidden
            // warning don't use group by reflink because does not return the last version
            $sql = 'SELECT  *
                    FROM  '.$tbl_wiki.' s1
        		    WHERE s1.c_id = '.$course_id.' AND id=(
                    SELECT MAX(s2.id) FROM '.$tbl_wiki.' s2
                    WHERE
                        s2.c_id = '.$course_id.' AND 
                        s1.reflink = s2.reflink AND 
                        '.$groupfilter.' AND 
                        session_id='.$session_id.')';
        } else {
            // warning don't use group by reflink because does not return the last version
            $sql = 'SELECT  *  FROM '.$tbl_wiki.' s1
				    WHERE visibility=1 AND s1.c_id = '.$course_id.' AND id=(
                        SELECT MAX(s2.id) FROM '.$tbl_wiki.' s2
                        WHERE 
                            s2.c_id = '.$course_id.' AND 
                            s1.reflink = s2.reflink AND
                             '.$groupfilter.' AND 
                             session_id='.$session_id.')';
        }

        $allpages = Database::query($sql);

        //show table
        if (Database::num_rows($allpages) > 0) {
            while ($obj = Database::fetch_object($allpages)) {
                //get author
                $userinfo = api_get_user_info($obj->user_id);
                $username = api_htmlentities(
                    sprintf(get_lang('Login: %s'), $userinfo['username']),
                    ENT_QUOTES
                );

                //get type assignment icon
                if ($obj->assignment == 1) {
                    $ShowAssignment = Display::return_icon(
                        'wiki_assignment.png',
                        get_lang('Assignment proposed by the trainer'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($obj->assignment == 2) {
                    $ShowAssignment = Display::return_icon(
                        'wiki_work.png',
                        get_lang('Learner paper'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($obj->assignment == 0) {
                    $ShowAssignment = Display::return_icon(
                        'px_transparent.gif'
                    );
                }

                //get icon task
                if (!empty($obj->task)) {
                    $icon_task = Display::return_icon(
                        'wiki_task.png',
                        get_lang('Standard Task'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } else {
                    $icon_task = Display::return_icon('px_transparent.gif');
                }

                $row = [];
                $row[] = $ShowAssignment.$icon_task;
                $row[] = '<a href="'.api_get_self(
                    ).'?cidReq='.$_course['code'].'&action=showpage&title='.api_htmlentities(
                        urlencode($obj->reflink)
                    ).'&session_id='.api_htmlentities(
                        $_GET['session_id']
                    ).'&group_id='.api_htmlentities($_GET['group_id']).'">
                '.api_htmlentities($obj->title).'</a>';
                if ($userinfo !== false) {
                    $row[] = UserManager::getUserProfileLink($userinfo);
                } else {
                    $row[] = get_lang('Anonymous').' ('.api_htmlentities(
                            $obj->user_ip
                        ).')';
                }
                $row[] = api_get_local_time(
                    $obj->dtime
                );
                $showdelete = '';
                if (api_is_allowed_to_edit(
                        false,
                        true
                    ) || api_is_platform_admin()) {
                    $showdelete = ' <a href="'.api_get_self(
                        ).'?cidReq='.$_course['code'].'&action=delete&title='.api_htmlentities(
                            urlencode($obj->reflink)
                        ).'&session_id='.api_htmlentities(
                            $_GET['session_id']
                        ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                        Display::return_icon(
                            'delete.png',
                            get_lang('Delete'),
                            '',
                            ICON_SIZE_SMALL
                        );
                }
                if (api_is_allowed_to_session_edit(false, true)) {
                    $row[] = '<a href="'.api_get_self(
                        ).'?cidReq='.$_course['code'].'&action=edit&title='.api_htmlentities(
                            urlencode($obj->reflink)
                        ).'&session_id='.api_htmlentities(
                            $_GET['session_id']
                        ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                        Display::return_icon(
                            'edit.png',
                            get_lang('Edit'),
                            '',
                            ICON_SIZE_SMALL
                        ).'</a> <a href="'.api_get_self(
                        ).'?cidReq='.$_course['code'].'&action=discuss&title='.api_htmlentities(
                            urlencode($obj->reflink)
                        ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                        Display::return_icon(
                            'discuss.png',
                            get_lang('Discuss'),
                            '',
                            ICON_SIZE_SMALL
                        ).'</a> <a href="'.api_get_self(
                        ).'?cidReq='.$_course['code'].'&action=history&title='.api_htmlentities(
                            urlencode($obj->reflink)
                        ).'&session_id='.api_htmlentities(
                            $_GET['session_id']
                        ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                        Display::return_icon(
                            'history.png',
                            get_lang('History'),
                            '',
                            ICON_SIZE_SMALL
                        ).'</a>
                        <a href="'.api_get_self(
                        ).'?cidReq='.$_course['code'].'&action=links&title='.api_htmlentities(
                            urlencode($obj->reflink)
                        ).'&session_id='.api_htmlentities(
                            $_GET['session_id']
                        ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                        Display::return_icon(
                            'what_link_here.png',
                            get_lang('What links here'),
                            '',
                            ICON_SIZE_SMALL
                        ).'</a>'.$showdelete;
                }
                $rows[] = $row;
            }

            $table = new SortableTableFromArrayConfig(
                $rows,
                1,
                10,
                'AllPages_table',
                '',
                '',
                'ASC'
            );
            $table->set_additional_parameters(
                [
                    'cidReq' => Security::remove_XSS($_GET['cidReq']),
                    'action' => Security::remove_XSS($action),
                    'group_id' => Security::remove_XSS($_GET['group_id']),
                ]
            );
            $table->set_header(
                0,
                get_lang('Type'),
                true,
                ['style' => 'width:30px;']
            );
            $table->set_header(1, get_lang('Title'), true);
            $table->set_header(
                2,
                get_lang('Author').' ('.get_lang('Latest version').')',
                true
            );
            $table->set_header(
                3,
                get_lang('Date').' ('.get_lang('Latest version').')',
                true
            );
            if (api_is_allowed_to_session_edit(false, true)) {
                $table->set_header(
                    4,
                    get_lang('Detail'),
                    true,
                    ['style' => 'width:130px;']
                );
            }
            $table->display();
        }
    }

    /**
     * Get recent changes.
     *
     * @param string $page
     * @param string $action
     */
    public function recentChanges($page, $action)
    {
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $tbl_wiki_conf = $this->tbl_wiki_conf;

        if (api_is_allowed_to_session_edit(false, true)) {
            if (self::check_notify_all() == 1) {
                $notify_all = Display::return_icon(
                        'messagebox_info.png',
                        get_lang('Notify me by e-mail when somebody replies'),
                        '',
                        ICON_SIZE_SMALL
                    ).' '.get_lang('NotNotify me of changes');
                $lock_unlock_notify_all = 'unlocknotifyall';
            } else {
                $notify_all = Display::return_icon(
                        'mail.png',
                        get_lang('CancelNotify me by e-mail when somebody replies'),
                        '',
                        ICON_SIZE_SMALL
                    ).' '.get_lang('Notify me of changes');
                $lock_unlock_notify_all = 'locknotifyall';
            }
        }

        echo '<div class="actions"><span style="float: right;">';
        echo '<a href="index.php?action=recentchanges&actionpage='.$lock_unlock_notify_all.'&'.api_get_cidreq().'&title='.api_htmlentities(
                urlencode($page)
            ).'">'.$notify_all.'</a>';
        echo '</span>'.get_lang('Latest changes').'</div>';

        if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
            //only by professors if page is hidden
            $sql = 'SELECT * FROM '.$tbl_wiki.', '.$tbl_wiki_conf.'
        		WHERE 	'.$tbl_wiki_conf.'.c_id= '.$course_id.' AND
        				'.$tbl_wiki.'.c_id= '.$course_id.' AND
        				'.$tbl_wiki_conf.'.page_id='.$tbl_wiki.'.page_id AND
        				'.$tbl_wiki.'.'.$groupfilter.$condition_session.'
        		ORDER BY dtime DESC'; // new version
        } else {
            $sql = 'SELECT *
                FROM '.$tbl_wiki.'
                WHERE
                    c_id = '.$course_id.' AND
                    '.$groupfilter.$condition_session.' AND
                    visibility=1
                ORDER BY dtime DESC';
            // old version TODO: Replace by the bottom line
        }

        $allpages = Database::query($sql);

        //show table
        if (Database::num_rows($allpages) > 0) {
            $rows = [];
            while ($obj = Database::fetch_object($allpages)) {
                //get author
                $userinfo = api_get_user_info($obj->user_id);

                //get type assignment icon
                if ($obj->assignment == 1) {
                    $ShowAssignment = Display::return_icon(
                        'wiki_assignment.png',
                        get_lang('Assignment proposed by the trainer'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($obj->assignment == 2) {
                    $ShowAssignment = Display::return_icon(
                        'wiki_work.png',
                        get_lang('Learner paper'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($obj->assignment == 0) {
                    $ShowAssignment = Display::return_icon(
                        'px_transparent.gif'
                    );
                }

                // Get icon task
                if (!empty($obj->task)) {
                    $icon_task = Display::return_icon(
                        'wiki_task.png',
                        get_lang('Standard Task'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } else {
                    $icon_task = Display::return_icon('px_transparent.gif');
                }

                $row = [];
                $row[] = api_get_local_time(
                    $obj->dtime
                );
                $row[] = $ShowAssignment.$icon_task;
                $row[] = '<a href="'.api_get_self().'?'.api_get_cidreq(
                    ).'&action=showpage&title='.api_htmlentities(
                        urlencode($obj->reflink)
                    ).'&view='.$obj->id.'&session_id='.api_get_session_id(
                    ).'&group_id='.api_get_group_id().'">'.
                    api_htmlentities($obj->title).'</a>';
                $row[] = $obj->version > 1 ? get_lang('edited by') : get_lang(
                    'added by'
                );
                if ($userinfo !== false) {
                    $row[] = UserManager::getUserProfileLink($userinfo);
                } else {
                    $row[] = get_lang('Anonymous').' ('.api_htmlentities(
                            $obj->user_ip
                        ).')';
                }
                $rows[] = $row;
            }

            $table = new SortableTableFromArrayConfig(
                $rows,
                0,
                10,
                'RecentPages_table',
                '',
                '',
                'DESC'
            );
            $table->set_additional_parameters(
                [
                    'cidReq' => api_get_course_id(),
                    'action' => Security::remove_XSS($action),
                    'session_id' => api_get_session_id(),
                    'group_id' => api_get_group_id(),
                ]
            );
            $table->set_header(
                0,
                get_lang('Date'),
                true,
                ['style' => 'width:200px;']
            );
            $table->set_header(
                1,
                get_lang('Type'),
                true,
                ['style' => 'width:30px;']
            );
            $table->set_header(2, get_lang('Title'), true);
            $table->set_header(
                3,
                get_lang('Detail'),
                true,
                ['style' => 'width:80px;']
            );
            $table->set_header(4, get_lang('Author'), true);
            $table->display();
        }
    }

    /**
     * What links here. Show pages that have linked this page.
     *
     * @param string $page
     */
    public function getLinks($page)
    {
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $_course = $this->courseInfo;
        $action = $this->action;

        if (!$_GET['title']) {
            Display::addFlash(
                Display::return_message(
                    get_lang("You must select a page first"),
                    'error',
                    false
                )
            );
        } else {
            $sql = 'SELECT * FROM '.$tbl_wiki.'
                    WHERE
                        c_id = '.$course_id.' AND
                        reflink="'.Database::escape_string($page).'" AND
                        '.$groupfilter.$condition_session;
            $result = Database::query($sql);
            $row = Database::fetch_array($result);

            //get type assignment icon
            $ShowAssignment = '';
            if ($row['assignment'] == 1) {
                $ShowAssignment = Display::return_icon(
                    'wiki_assignment.png',
                    get_lang('Assignment proposed by the trainer'),
                    '',
                    ICON_SIZE_SMALL
                );
            } elseif ($row['assignment'] == 2) {
                $ShowAssignment = Display::return_icon(
                    'wiki_work.png',
                    get_lang('Learner paper'),
                    '',
                    ICON_SIZE_SMALL
                );
            } elseif ($row['assignment'] == 0) {
                $ShowAssignment = Display::return_icon('px_transparent.gif');
            }

            //fix Title to reflink (link Main Page)
            if ($page == get_lang('Home')) {
                $page = 'index';
            }

            echo '<div id="wikititle">';
            echo get_lang(
                    'What links hereFrom'
                ).': '.$ShowAssignment.' <a href="'.api_get_self(
                ).'?cidReq='.$_course['code'].'&action=showpage&title='.api_htmlentities(
                    urlencode($page)
                ).'&session_id='.api_htmlentities(
                    $_GET['session_id']
                ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                api_htmlentities($row['title']).'</a>';
            echo '</div>';

            //fix index to title Main page into linksto

            if ($page == 'index') {
                $page = str_replace(' ', '_', get_lang('Home'));
            }

            if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
                // only by professors if page is hidden
                $sql = "SELECT * FROM ".$tbl_wiki." s1
                        WHERE s1.c_id = $course_id AND linksto LIKE '%".Database::escape_string(
                        $page
                    )."%' AND id=(
                        SELECT MAX(s2.id) FROM ".$tbl_wiki." s2
                        WHERE s2.c_id = $course_id AND s1.reflink = s2.reflink AND ".$groupfilter.$condition_session.")";
            } else {
                //add blank space after like '%" " %' to identify each word
                $sql = "SELECT * FROM ".$tbl_wiki." s1
                        WHERE s1.c_id = $course_id AND visibility=1 AND linksto LIKE '%".Database::escape_string(
                        $page
                    )."%' AND id=(
                        SELECT MAX(s2.id) FROM ".$tbl_wiki." s2
                        WHERE s2.c_id = $course_id AND s1.reflink = s2.reflink AND ".$groupfilter.$condition_session.")";
            }

            $allpages = Database::query($sql);

            //show table
            if (Database::num_rows($allpages) > 0) {
                $rows = [];
                while ($obj = Database::fetch_object($allpages)) {
                    //get author
                    $userinfo = api_get_user_info($obj->user_id);

                    //get time
                    $year = substr($obj->dtime, 0, 4);
                    $month = substr($obj->dtime, 5, 2);
                    $day = substr($obj->dtime, 8, 2);
                    $hours = substr($obj->dtime, 11, 2);
                    $minutes = substr($obj->dtime, 14, 2);
                    $seconds = substr($obj->dtime, 17, 2);

                    //get type assignment icon
                    if ($obj->assignment == 1) {
                        $ShowAssignment = Display::return_icon(
                            'wiki_assignment.png',
                            get_lang('Assignment proposed by the trainer'),
                            '',
                            ICON_SIZE_SMALL
                        );
                    } elseif ($obj->assignment == 2) {
                        $ShowAssignment = Display::return_icon(
                            'wiki_work.png',
                            get_lang('Learner paper'),
                            '',
                            ICON_SIZE_SMALL
                        );
                    } elseif ($obj->assignment == 0) {
                        $ShowAssignment = Display::return_icon(
                            'px_transparent.gif'
                        );
                    }

                    $row = [];
                    $row[] = $ShowAssignment;
                    $row[] = '<a href="'.api_get_self(
                        ).'?cidReq='.$_course['code'].'&action=showpage&title='.api_htmlentities(
                            urlencode($obj->reflink)
                        ).'&session_id='.api_htmlentities(
                            $_GET['session_id']
                        ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                        api_htmlentities($obj->title).'</a>';
                    if ($userinfo !== false) {
                        $row[] = UserManager::getUserProfileLink($userinfo);
                    } else {
                        $row[] = get_lang('Anonymous').' ('.$obj->user_ip.')';
                    }
                    $row[] = $year.'-'.$month.'-'.$day.' '.$hours.":".$minutes.":".$seconds;
                    $rows[] = $row;
                }

                $table = new SortableTableFromArrayConfig(
                    $rows,
                    1,
                    10,
                    'AllPages_table',
                    '',
                    '',
                    'ASC'
                );
                $table->set_additional_parameters(
                    [
                        'cidReq' => Security::remove_XSS($_GET['cidReq']),
                        'action' => Security::remove_XSS($action),
                        'group_id' => intval($_GET['group_id']),
                    ]
                );
                $table->set_header(
                    0,
                    get_lang('Type'),
                    true,
                    ['style' => 'width:30px;']
                );
                $table->set_header(1, get_lang('Title'), true);
                $table->set_header(2, get_lang('Author'), true);
                $table->set_header(3, get_lang('Date'), true);
                $table->display();
            }
        }
    }

    /**
     * @param string $action
     */
    public function getSearchPages($action)
    {
        echo '<div class="actions">'.get_lang('Search').'</div>';
        if (isset($_GET['mode_table'])) {
            if (!isset($_GET['SearchPages_table_page_nr'])) {
                $_GET['search_term'] = isset($_POST['search_term']) ? $_POST['search_term'] : '';
                $_GET['search_content'] = isset($_POST['search_content']) ? $_POST['search_content'] : '';
                $_GET['all_vers'] = isset($_POST['all_vers']) ? $_POST['all_vers'] : '';
            }
            self::display_wiki_search_results(
                $_GET['search_term'],
                $_GET['search_content'],
                $_GET['all_vers']
            );
        } else {
            // initiate the object
            $form = new FormValidator(
                'wiki_search',
                'post',
                api_get_self().'?cidReq='.api_get_course_id(
                ).'&action='.api_htmlentities(
                    $action
                ).'&session_id='.api_get_session_id(
                ).'&group_id='.api_get_group_id().'&mode_table=yes1'
            );

            // Setting the form elements

            $form->addText(
                'search_term',
                get_lang('Search term'),
                true,
                ['autofocus' => 'autofocus']
            );
            $form->addElement(
                'checkbox',
                'search_content',
                null,
                get_lang('Search also in content')
            );
            $form->addElement(
                'checkbox',
                'all_vers',
                null,
                get_lang('includeAllVersions')
            );
            $form->addButtonSearch(get_lang('Search'), 'SubmitGroup wikiSearch');

            // setting the rules
            $form->addRule(
                'search_term',
                get_lang('Too short'),
                'minlength',
                3
            ); //TODO: before fixing the pagination rules worked, not now

            if ($form->validate()) {
                $form->display();
                $values = $form->exportValues();
                self::display_wiki_search_results(
                    $values['search_term'],
                    $values['search_content'],
                    $values['all_vers']
                );
            } else {
                $form->display();
            }
        }
    }

    /**
     * @param int    $userId
     * @param string $action
     */
    public function getUserContributions($userId, $action)
    {
        $_course = $this->courseInfo;
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $userId = intval($userId);
        $userinfo = api_get_user_info($userId);
        if ($userinfo !== false) {
            echo '<div class="actions">'.
                get_lang('Usercontributions').': '.UserManager::getUserProfileLink($userinfo).
                '<a href="'.api_get_self().'?cidReq='.$_course['code'].'&action=usercontrib&user_id='.$userId.
                '&session_id='.$this->session_id.'&group_id='.$this->group_id.'">'.
                '</a></div>';
        }

        if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
            //only by professors if page is hidden
            $sql = 'SELECT * FROM '.$tbl_wiki.'
                    WHERE
                        c_id = '.$course_id.' AND
                        '.$groupfilter.$condition_session.' AND
                        user_id="'.$userId.'"';
        } else {
            $sql = 'SELECT * FROM '.$tbl_wiki.'
                    WHERE
                        c_id = '.$course_id.' AND
                        '.$groupfilter.$condition_session.' AND
                        user_id="'.$userId.'" AND
                        visibility=1';
        }

        $allpages = Database::query($sql);

        //show table
        if (Database::num_rows($allpages) > 0) {
            $rows = [];
            while ($obj = Database::fetch_object($allpages)) {
                //get type assignment icon
                $ShowAssignment = '';
                if ($obj->assignment == 1) {
                    $ShowAssignment = Display::return_icon(
                        'wiki_assignment.png',
                        get_lang('This page is an assignment proposed by a trainer'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($obj->assignment == 2) {
                    $ShowAssignment = Display::return_icon(
                        'wiki_work.png',
                        get_lang('Learner paper'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($obj->assignment == 0) {
                    $ShowAssignment = Display::return_icon(
                        'px_transparent.gif'
                    );
                }

                $row = [];
                $row[] = api_get_local_time($obj->dtime);
                $row[] = $ShowAssignment;
                $row[] = '<a href="'.api_get_self(
                    ).'?cidReq='.$_course['code'].'&action=showpage&title='.api_htmlentities(
                        urlencode($obj->reflink)
                    ).'&view='.$obj->id.'&session_id='.api_get_session_id(
                    ).'&group_id='.api_get_group_id().'">'.
                    api_htmlentities($obj->title).'</a>';
                $row[] = Security::remove_XSS($obj->version);
                $row[] = Security::remove_XSS($obj->comment);
                $row[] = Security::remove_XSS($obj->progress).' %';
                $row[] = Security::remove_XSS($obj->score);
                $rows[] = $row;
            }

            $table = new SortableTableFromArrayConfig(
                $rows,
                2,
                10,
                'UsersContributions_table',
                '',
                '',
                'ASC'
            );
            $table->set_additional_parameters(
                [
                    'cidReq' => Security::remove_XSS($_GET['cidReq']),
                    'action' => Security::remove_XSS($action),
                    'user_id' => intval($userId),
                    'session_id' => intval($_GET['session_id']),
                    'group_id' => intval($_GET['group_id']),
                ]
            );
            $table->set_header(
                0,
                get_lang('Date'),
                true,
                ['style' => 'width:200px;']
            );
            $table->set_header(
                1,
                get_lang('Type'),
                true,
                ['style' => 'width:30px;']
            );
            $table->set_header(
                2,
                get_lang('Title'),
                true,
                ['style' => 'width:200px;']
            );
            $table->set_header(
                3,
                get_lang('Version'),
                true,
                ['style' => 'width:30px;']
            );
            $table->set_header(
                4,
                get_lang('Comment'),
                true,
                ['style' => 'width:200px;']
            );
            $table->set_header(
                5,
                get_lang('Progress'),
                true,
                ['style' => 'width:30px;']
            );
            $table->set_header(
                6,
                get_lang('Rating'),
                true,
                ['style' => 'width:30px;']
            );
            $table->display();
        }
    }

    /**
     * @param string $action
     */
    public function getMostChangedPages($action)
    {
        $_course = $this->courseInfo;
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;

        echo '<div class="actions">'.get_lang('Most changed pages').'</div>';

        if (api_is_allowed_to_edit(false, true) ||
            api_is_platform_admin()
        ) { //only by professors if page is hidden
            $sql = 'SELECT *, MAX(version) AS MAX FROM '.$tbl_wiki.'
                    WHERE c_id = '.$course_id.' AND '.$groupfilter.$condition_session.'
                    GROUP BY reflink'; //TODO:check MAX and group by return last version
        } else {
            $sql = 'SELECT *, MAX(version) AS MAX FROM '.$tbl_wiki.'
                    WHERE c_id = '.$course_id.' AND '.$groupfilter.$condition_session.' AND visibility=1
                    GROUP BY reflink'; //TODO:check MAX and group by return last version
        }

        $allpages = Database::query($sql);

        //show table
        if (Database::num_rows($allpages) > 0) {
            $rows = [];
            while ($obj = Database::fetch_object($allpages)) {
                //get type assignment icon
                $ShowAssignment = '';
                if ($obj->assignment == 1) {
                    $ShowAssignment = Display::return_icon(
                        'wiki_assignment.png',
                        get_lang('Assignment proposed by the trainer'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($obj->assignment == 2) {
                    $ShowAssignment = Display::return_icon(
                        'wiki_work.png',
                        get_lang('Learner paper'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($obj->assignment == 0) {
                    $ShowAssignment = Display::return_icon(
                        'px_transparent.gif'
                    );
                }

                $row = [];
                $row[] = $ShowAssignment;
                $row[] = '<a href="'.api_get_self(
                    ).'?cidReq='.$_course['code'].'&action=showpage&title='.api_htmlentities(
                        urlencode($obj->reflink)
                    ).'&session_id='.api_htmlentities(
                        $_GET['session_id']
                    ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                    api_htmlentities($obj->title).'</a>';
                $row[] = $obj->MAX;
                $rows[] = $row;
            }

            $table = new SortableTableFromArrayConfig(
                $rows,
                2,
                10,
                'MostChangedPages_table',
                '',
                '',
                'DESC'
            );
            $table->set_additional_parameters(
                [
                    'cidReq' => Security::remove_XSS($_GET['cidReq']),
                    'action' => Security::remove_XSS($action),
                    'session_id' => intval($_GET['session_id']),
                    'group_id' => intval($_GET['group_id']),
                ]
            );
            $table->set_header(
                0,
                get_lang('Type'),
                true,
                ['style' => 'width:30px;']
            );
            $table->set_header(1, get_lang('Title'), true);
            $table->set_header(2, get_lang('Changes'), true);
            $table->display();
        }
    }

    /**
     * Restore page.
     *
     * @return bool
     */
    public function restorePage()
    {
        $userId = api_get_user_id();
        $_course = $this->courseInfo;
        $current_row = $this->getWikiData();
        $last_row = $this->getLastWikiData($this->page);

        if (empty($last_row)) {
            return false;
        }

        $PassEdit = false;

        /* Only teachers and platform admin can edit the index page.
        Only teachers and platform admin can edit an assignment teacher*/
        if (($current_row['reflink'] == 'index' ||
                $current_row['reflink'] == '' ||
                $current_row['assignment'] == 1) &&
            (!api_is_allowed_to_edit(false, true) &&
                $this->group_id == 0)
        ) {
            Display::addFlash(
                Display::return_message(
                    get_lang('OnlyEditsCourseManager'),
                    'normal',
                    false
                )
            );
        } else {
            // check if is a wiki group
            if ($current_row['group_id'] != 0) {
                $groupInfo = GroupManager::get_group_properties(
                    $this->group_id
                );
                //Only teacher, platform admin and group members can edit a wiki group
                if (api_is_allowed_to_edit(false, true) ||
                    api_is_platform_admin() ||
                    GroupManager::is_user_in_group($userId, $groupInfo) ||
                    api_is_allowed_in_course()
                ) {
                    $PassEdit = true;
                } else {
                    Display::addFlash(
                        Display::return_message(
                            get_lang('OnlyEditsGroupMembers'),
                            'normal',
                            false
                        )
                    );
                }
            } else {
                $PassEdit = true;
            }

            // check if is an assignment
            //$icon_assignment = null;
            if ($current_row['assignment'] == 1) {
                Display::addFlash(
                    Display::return_message(
                        get_lang('You can edit this page, but the pages of learners will not be modified'),
                        'normal',
                        false
                    )
                );
            } elseif ($current_row['assignment'] == 2) {
                if (($userId == $current_row['user_id']) == false) {
                    if (api_is_allowed_to_edit(
                            false,
                            true
                        ) || api_is_platform_admin()) {
                        $PassEdit = true;
                    } else {
                        Display::addFlash(
                            Display::return_message(
                                get_lang('LockByTrainer'),
                                'normal',
                                false
                            )
                        );
                        $PassEdit = false;
                    }
                } else {
                    $PassEdit = true;
                }
            }

            //show editor if edit is allowed
            if ($PassEdit) {
                if ($current_row['editlock'] == 1 &&
                    (api_is_allowed_to_edit(false, true) == false ||
                        api_is_platform_admin() == false)
                ) {
                    Display::addFlash(
                        Display::return_message(
                            get_lang('This page is protected. Trainers only can change it'),
                            'normal',
                            false
                        )
                    );
                } else {
                    if ($last_row['is_editing'] != 0 && $last_row['is_editing'] != $userId) {
                        // Checking for concurrent users
                        $timestamp_edit = strtotime($last_row['time_edit']);
                        $time_editing = time() - $timestamp_edit;
                        $max_edit_time = 1200; // 20 minutes
                        $rest_time = $max_edit_time - $time_editing;
                        $userinfo = api_get_user_info($last_row['is_editing']);
                        $is_being_edited = get_lang(
                                'ThisPageisBeginedited by'
                            ).' <a href='.$userinfo['profile_url'].'>'.
                            Display::tag(
                                'span',
                                $userinfo['complete_name_with_username']
                            ).
                            get_lang('Please try again later. If the user who is currently editing the page does not save it, this page will be available to you around').' '.date(
                                "i",
                                $rest_time
                            ).' '.get_lang('minutes');
                        Display::addFlash(
                            Display::return_message(
                                $is_being_edited,
                                'normal',
                                false
                            )
                        );
                    } else {
                        Display::addFlash(
                            Display::return_message(
                                self::restore_wikipage(
                                    $current_row['page_id'],
                                    $current_row['reflink'],
                                    $current_row['title'],
                                    $current_row['content'],
                                    $current_row['group_id'],
                                    $current_row['assignment'],
                                    $current_row['progress'],
                                    $current_row['version'],
                                    $last_row['version'],
                                    $current_row['linksto']
                                ).': <a href="index.php?cidReq='.$_course['code'].'&action=showpage&title='.api_htmlentities(
                                    urlencode($last_row['reflink'])
                                ).'&session_id='.$last_row['session_id'].'&group_id='.$last_row['group_id'].'">'.
                                api_htmlentities($last_row['title']).'</a>',
                                'confirmation',
                                false
                            )
                        );
                    }
                }
            }
        }
    }

    /**
     * @param int|bool $wikiId
     */
    public function setWikiData($wikiId)
    {
        $this->wikiData = self::getWikiDataFromDb($wikiId);
    }

    /**
     * @return array
     */
    public function getWikiData()
    {
        return $this->wikiData;
    }

    /**
     * Check last version.
     *
     * @param int $view
     *
     * @return bool
     */
    public function checkLastVersion($view)
    {
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $page = $this->page;
        $_course = $this->courseInfo;

        if (empty($view)) {
            return false;
        }

        $current_row = $this->getWikiData();
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE
                    c_id = '.$course_id.' AND
                    reflink = "'.Database::escape_string($page).'" AND
                    '.$groupfilter.$condition_session.'
                ORDER BY id DESC'; //last version
        $result = Database::query($sql);
        $last_row = Database::fetch_array($result);

        if ($view < $last_row['id']) {
            $message = '<center>'.get_lang('NoAreSeeingTheLatest version').'<br />
            '.get_lang("Version").' (
            <a href="index.php?cidReq='.$_course['code'].'&action=showpage&title='.api_htmlentities(
                    urlencode($current_row['reflink'])
                ).'&group_id='.$current_row['group_id'].'&session_id='.$current_row['session_id'].'&view='.api_htmlentities(
                    $_GET['view']
                ).'" title="'.get_lang('Current version').'">
            '.$current_row['version'].'
            </a> /
            <a href="index.php?cidReq='.$_course['code'].'&action=showpage&title='.api_htmlentities(
                    urlencode($last_row['reflink'])
                ).'&group_id='.$last_row['group_id'].'&session_id='.$last_row['session_id'].'" title="'.get_lang(
                    'Latest version'
                ).'">
            '.$last_row['version'].'
            </a>) <br />'.get_lang("ConvertToLatest version").':
            <a href="index.php?cidReq='.$_course['id'].'&action=restorepage&title='.api_htmlentities(
                    urlencode($last_row['reflink'])
                ).'&group_id='.$last_row['group_id'].'&session_id='.$last_row['session_id'].'&view='.api_htmlentities(
                    $_GET['view']
                ).'">'.
                get_lang("Restore").'</a></center>';
            Display::addFlash(
                Display::return_message($message, 'warning', false)
            );
        }
    }

    /**
     *  Get most linked pages.
     */
    public function getMostLinked()
    {
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $groupfilter = $this->groupfilter;
        $condition_session = $this->condition_session;
        $_course = $this->courseInfo;

        echo '<div class="actions">'.get_lang('Pages most linked').'</div>';
        $pages = [];
        $linked = [];

        // Get name pages
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE  c_id = '.$course_id.' AND '.$groupfilter.$condition_session.'
                GROUP BY reflink
                ORDER BY reflink ASC';
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            if ($row['reflink'] == 'index') {
                $row['reflink'] = str_replace(
                    ' ',
                    '_',
                    get_lang('Home')
                );
            }
            $pages[] = $row['reflink'];
        }

        // Get name refs in last pages
        $sql = 'SELECT *
                FROM '.$tbl_wiki.' s1
                WHERE s1.c_id = '.$course_id.' AND id=(
                    SELECT MAX(s2.id) FROM '.$tbl_wiki.' s2
                    WHERE
                        s2.c_id = '.$course_id.' AND
                        s1.reflink = s2.reflink AND
                        '.$groupfilter.$condition_session.'
                )';

        $allpages = Database::query($sql);

        while ($row = Database::fetch_array($allpages)) {
            //remove self reference
            $row['linksto'] = str_replace(
                $row["reflink"],
                " ",
                trim($row["linksto"])
            );
            $refs = explode(" ", trim($row["linksto"]));

            // Find linksto into reflink. If found ->page is linked
            foreach ($refs as $v) {
                if (in_array($v, $pages)) {
                    if (trim($v) != "") {
                        $linked[] = $v;
                    }
                }
            }
        }

        $linked = array_unique($linked);
        //make a unique list. TODO:delete this line and count how many for each page
        //show table
        $rows = [];
        foreach ($linked as $linked_show) {
            $row = [];
            $row[] = '<a href="'.api_get_self(
                ).'?cidReq='.$_course['code'].'&action=showpage&title='.api_htmlentities(
                    urlencode(str_replace('_', ' ', $linked_show))
                ).'&session_id='.api_htmlentities(
                    $_GET['session_id']
                ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                str_replace('_', ' ', $linked_show).'</a>';
            $rows[] = $row;
        }

        $table = new SortableTableFromArrayConfig(
            $rows,
            0,
            10,
            'LinkedPages_table',
            '',
            '',
            'DESC'
        );
        $table->set_additional_parameters(
            [
                'cidReq' => Security::remove_XSS($_GET['cidReq']),
                'action' => Security::remove_XSS($this->action),
                'session_id' => intval($_GET['session_id']),
                'group_id' => intval($_GET['group_id']),
            ]
        );
        $table->set_header(0, get_lang('Title'), true);
        $table->display();
    }

    /**
     * Get orphan pages.
     */
    public function getOrphaned()
    {
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $groupfilter = $this->groupfilter;
        $condition_session = $this->condition_session;
        $_course = $this->courseInfo;

        echo '<div class="actions">'.get_lang('Orphaned pages').'</div>';

        $pages = [];
        $orphaned = [];

        //get name pages
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE c_id = '.$course_id.' AND '.$groupfilter.$condition_session.'
                GROUP BY reflink
                ORDER BY reflink ASC';
        $allpages = Database::query($sql);
        while ($row = Database::fetch_array($allpages)) {
            $pages[] = $row['reflink'];
        }

        //get name refs in last pages and make a unique list
        $sql = 'SELECT  *  FROM   '.$tbl_wiki.' s1
                WHERE s1.c_id = '.$course_id.' AND id=(
                SELECT MAX(s2.id) FROM '.$tbl_wiki.' s2
                WHERE
                    s2.c_id = '.$course_id.' AND
                    s1.reflink = s2.reflink AND
                    '.$groupfilter.$condition_session.'
                )';
        $allpages = Database::query($sql);
        $array_refs_linked = [];
        while ($row = Database::fetch_array($allpages)) {
            $row['linksto'] = str_replace(
                $row["reflink"],
                " ",
                trim($row["linksto"])
            ); //remove self reference
            $refs = explode(" ", trim($row["linksto"]));
            foreach ($refs as $ref_linked) {
                if ($ref_linked == str_replace(
                        ' ',
                        '_',
                        get_lang('Home')
                    )) {
                    $ref_linked = 'index';
                }
                $array_refs_linked[] = $ref_linked;
            }
        }

        $array_refs_linked = array_unique($array_refs_linked);

        //search each name of list linksto into list reflink
        foreach ($pages as $v) {
            if (!in_array($v, $array_refs_linked)) {
                $orphaned[] = $v;
            }
        }
        $rows = [];
        foreach ($orphaned as $orphaned_show) {
            // get visibility status and title
            $sql = 'SELECT *
                    FROM  '.$tbl_wiki.'
		            WHERE
		                c_id = '.$course_id.' AND
		                '.$groupfilter.$condition_session.' AND
		                reflink="'.Database::escape_string($orphaned_show).'"
                    GROUP BY reflink';
            $allpages = Database::query($sql);
            while ($row = Database::fetch_array($allpages)) {
                $orphaned_title = $row['title'];
                $orphaned_visibility = $row['visibility'];
                if ($row['assignment'] == 1) {
                    $ShowAssignment = Display::return_icon(
                        'wiki_assignment.png',
                        '',
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($row['assignment'] == 2) {
                    $ShowAssignment = Display::return_icon(
                        'wiki_work.png',
                        '',
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($row['assignment'] == 0) {
                    $ShowAssignment = Display::return_icon(
                        'px_transparent.gif'
                    );
                }
            }

            if (!api_is_allowed_to_edit(false, true) || !api_is_platform_admin(
                ) && $orphaned_visibility == 0) {
                continue;
            }

            //show table
            $row = [];
            $row[] = $ShowAssignment;
            $row[] = '<a href="'.api_get_self(
                ).'?cidReq='.$_course['code'].'&action=showpage&title='.api_htmlentities(
                    urlencode($orphaned_show)
                ).'&session_id='.api_htmlentities(
                    $_GET['session_id']
                ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                api_htmlentities($orphaned_title).'</a>';
            $rows[] = $row;
        }

        $table = new SortableTableFromArrayConfig(
            $rows,
            1,
            10,
            'OrphanedPages_table',
            '',
            '',
            'DESC'
        );
        $table->set_additional_parameters(
            [
                'cidReq' => Security::remove_XSS($_GET['cidReq']),
                'action' => Security::remove_XSS($this->action),
                'session_id' => intval($_GET['session_id']),
                'group_id' => intval($_GET['group_id']),
            ]
        );
        $table->set_header(
            0,
            get_lang('Type'),
            true,
            ['style' => 'width:30px;']
        );
        $table->set_header(1, get_lang('Title'), true);
        $table->display();
    }

    /**
     * Get wanted pages.
     */
    public function getWantedPages()
    {
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $groupfilter = $this->groupfilter;
        $condition_session = $this->condition_session;

        echo '<div class="actions">'.get_lang('Wanted pages').'</div>';
        $pages = [];
        $wanted = [];
        //get name pages
        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE  c_id = '.$course_id.' AND '.$groupfilter.$condition_session.'
                GROUP BY reflink
                ORDER BY reflink ASC';
        $allpages = Database::query($sql);

        while ($row = Database::fetch_array($allpages)) {
            if ($row['reflink'] == 'index') {
                $row['reflink'] = str_replace(
                    ' ',
                    '_',
                    get_lang('Home')
                );
            }
            $pages[] = $row['reflink'];
        }

        //get name refs in last pages
        $sql = 'SELECT * FROM   '.$tbl_wiki.' s1
                WHERE s1.c_id = '.$course_id.' AND id=(
                    SELECT MAX(s2.id) FROM '.$tbl_wiki.' s2
                    WHERE s2.c_id = '.$course_id.' AND s1.reflink = s2.reflink AND '.$groupfilter.$condition_session.'
                )';

        $allpages = Database::query($sql);

        while ($row = Database::fetch_array($allpages)) {
            $refs = explode(" ", trim($row["linksto"]));
            // Find linksto into reflink. If not found ->page is wanted
            foreach ($refs as $v) {
                if (!in_array($v, $pages)) {
                    if (trim($v) != "") {
                        $wanted[] = $v;
                    }
                }
            }
        }

        $wanted = array_unique($wanted); //make a unique list

        //show table
        $rows = [];
        foreach ($wanted as $wanted_show) {
            $row = [];
            $wanted_show = Security::remove_XSS($wanted_show);
            $row[] = '<a href="'.api_get_path(
                    WEB_PATH
                ).'main/wiki/index.php?cidReq=&action=addnew&title='.str_replace(
                    '_',
                    ' ',
                    $wanted_show
                ).'&session_id='.api_htmlentities(
                    $_GET['session_id']
                ).'&group_id='.api_htmlentities(
                    $_GET['group_id']
                ).'" class="new_wiki_link">'.str_replace(
                    '_',
                    ' ',
                    $wanted_show
                ).'</a>'; //meter un remove xss en lugar de htmlentities
            $rows[] = $row;
        }

        $table = new SortableTableFromArrayConfig(
            $rows,
            0,
            10,
            'WantedPages_table',
            '',
            '',
            'DESC'
        );
        $table->set_additional_parameters(
            [
                'cidReq' => Security::remove_XSS($_GET['cidReq']),
                'action' => Security::remove_XSS($this->action),
                'session_id' => intval($_GET['session_id']),
                'group_id' => intval($_GET['group_id']),
            ]
        );
        $table->set_header(0, get_lang('Title'), true);
        $table->display();
    }

    /**
     * Most visited.
     */
    public function getMostVisited()
    {
        $tbl_wiki = $this->tbl_wiki;
        $course_id = $this->course_id;
        $groupfilter = $this->groupfilter;
        $condition_session = $this->condition_session;
        $_course = $this->courseInfo;

        echo '<div class="actions">'.get_lang('Most visited pages').'</div>';

        if (api_is_allowed_to_edit(false, true) || api_is_platform_admin(
            )) { //only by professors if page is hidden
            $sql = 'SELECT *, SUM(hits) AS tsum FROM '.$tbl_wiki.'
                    WHERE c_id = '.$course_id.' AND '.$groupfilter.$condition_session.'
                    GROUP BY reflink';
        } else {
            $sql = 'SELECT *, SUM(hits) AS tsum FROM '.$tbl_wiki.'
                    WHERE
                        c_id = '.$course_id.' AND
                        '.$groupfilter.$condition_session.' AND
                        visibility=1
                    GROUP BY reflink';
        }

        $allpages = Database::query($sql);

        //show table
        if (Database::num_rows($allpages) > 0) {
            $rows = [];
            while ($obj = Database::fetch_object($allpages)) {
                //get type assignment icon
                $ShowAssignment = '';
                if ($obj->assignment == 1) {
                    $ShowAssignment = Display::return_icon(
                        'wiki_assignment.png',
                        get_lang('Assignment proposed by the trainer'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($obj->assignment == 2) {
                    $ShowAssignment = $ShowAssignment = Display::return_icon(
                        'wiki_work.png',
                        get_lang('Learner paper'),
                        '',
                        ICON_SIZE_SMALL
                    );
                } elseif ($obj->assignment == 0) {
                    $ShowAssignment = Display::return_icon(
                        'px_transparent.gif'
                    );
                }

                $row = [];
                $row[] = $ShowAssignment;
                $row[] = '<a href="'.api_get_self(
                    ).'?cidReq='.$_course['code'].'&action=showpage&title='.api_htmlentities(
                        urlencode($obj->reflink)
                    ).'&session_id='.api_htmlentities(
                        $_GET['session_id']
                    ).'&group_id='.api_htmlentities($_GET['group_id']).'">'.
                    api_htmlentities($obj->title).'</a>';
                $row[] = $obj->tsum;
                $rows[] = $row;
            }

            $table = new SortableTableFromArrayConfig(
                $rows,
                2,
                10,
                'MostVisitedPages_table',
                '',
                '',
                'DESC'
            );
            $table->set_additional_parameters(
                [
                    'cidReq' => Security::remove_XSS($_GET['cidReq']),
                    'action' => Security::remove_XSS($this->action),
                    'session_id' => intval($_GET['session_id']),
                    'group_id' => intval($_GET['group_id']),
                ]
            );
            $table->set_header(
                0,
                get_lang('Type'),
                true,
                ['style' => 'width:30px;']
            );
            $table->set_header(1, get_lang('Title'), true);
            $table->set_header(2, get_lang('Visits'), true);
            $table->display();
        }
    }

    /**
     * Get actions bar.
     *
     * @return string
     */
    public function showActionBar()
    {
        $_course = $this->courseInfo;
        $session_id = $this->session_id;
        $groupId = $this->group_id;
        $page = $this->page;
        $actionsLeft = '';
        $actionsLeft .= '<a href="index.php?action=showpage&title=index&cidReq='.$_course['id'].'&session_id='.$session_id.'&group_id='.$groupId.'">'.
            Display::return_icon(
                'home.png',
                get_lang('Home'),
                '',
                ICON_SIZE_MEDIUM
            ).'</a>';

        if (api_is_allowed_to_session_edit(
                false,
                true
            ) && api_is_allowed_to_edit()) {
            // menu add page
            $actionsLeft .= '<a href="index.php?cidReq='.$_course['id'].'&action=addnew&session_id='.$session_id.'&group_id='.$groupId.'"'.self::is_active_navigation_tab(
                    'addnew'
                ).'>'
                .Display::return_icon(
                    'new_document.png',
                    get_lang('Add new page'),
                    '',
                    ICON_SIZE_MEDIUM
                ).'</a>';
        }

        $lock_unlock_addnew = null;
        $protect_addnewpage = null;

        if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
            // page action: enable or disable the adding of new pages
            if (self::check_addnewpagelock() == 0) {
                $protect_addnewpage = Display::return_icon(
                    'off.png',
                    get_lang('The Add option has been protected. Trainers only can add pages to this Wiki. But learners and group members can still edit them')
                );
                $lock_unlock_addnew = 'unlockaddnew';
            } else {
                $protect_addnewpage = Display::return_icon(
                    'on.png',
                    get_lang('The add option has been enabled for all course users and group members')
                );
                $lock_unlock_addnew = 'lockaddnew';
            }
        }

        // menu find
        $actionsLeft .= '<a href="index.php?cidReq='.$_course['id'].'&action=searchpages&session_id='.$session_id.'&group_id='.$groupId.'"'.self::is_active_navigation_tab(
                'searchpages'
            ).'>'.
            Display::return_icon(
                'search.png',
                get_lang('Search'),
                '',
                ICON_SIZE_MEDIUM
            ).'</a>';
        ///menu more
        $actionsLeft .= '<a href="index.php?cidReq='.$_course['id'].'&action=searchpages&session_id='.$session_id.'&group_id='.$groupId.'&action=more&title='.api_htmlentities(
                urlencode($page)
            ).'"'.self::is_active_navigation_tab('more').'>'.
            Display::return_icon(
                'statistics.png',
                get_lang('Statistics'),
                '',
                ICON_SIZE_MEDIUM
            ).'</a>';

        // menu all pages
        $actionsLeft .= '<a href="index.php?cidReq='.$_course['id'].'&action=allpages&session_id='.$session_id.'&group_id='.$groupId.'"'.self::is_active_navigation_tab(
                'allpages'
            ).'>'.
            Display::return_icon(
                'list_badges.png',
                get_lang('All pages'),
                '',
                ICON_SIZE_MEDIUM
            ).'</a>';
        // menu recent changes
        $actionsLeft .= '<a href="index.php?cidReq='.$_course['id'].'&action=recentchanges&session_id='.$session_id.'&group_id='.$groupId.'"'.self::is_active_navigation_tab(
                'recentchanges'
            ).'>'.
            Display::return_icon(
                'history.png',
                get_lang('Latest changes'),
                '',
                ICON_SIZE_MEDIUM
            ).'</a>';
        echo Display::toolbarAction('toolbar-wiki', [$actionsLeft]);
    }

    /**
     * Showing warning.
     */
    public function deletePageWarning()
    {
        $page = $this->page;
        $course_id = $this->course_id;
        $groupfilter = $this->groupfilter;
        $condition_session = $this->condition_session;

        if (!$_GET['title']) {
            Display::addFlash(
                Display::return_message(
                    get_lang('You must select a page first'),
                    'error',
                    false
                )
            );

            return;
        }

        if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
            Display::addFlash(
                '<div id="wikititle">'.get_lang('Delete this page and all its versions').'</div>'
            );
            if ($page == "index") {
                Display::addFlash(
                    Display::return_message(
                        get_lang('Deleting the homepage of the Wiki is not recommended because it is the main access to the wiki.<br />If, however, you need to do so, do not forget to re-create this Homepage. Until then, other users will not be able to add new pages.'),
                        'warning',
                        false
                    )
                );
            }
            $message = get_lang('Are you sure you want to delete this page and its history?')."
                <a href=\"index.php?".api_get_cidreq()."\">".get_lang("No")."</a>
                <a href=\"".api_get_self()."?".api_get_cidreq(
                )."&action=delete&title=".api_htmlentities(
                    urlencode($page)
                )."&delete=yes\">".
                get_lang("Yes")."</a>";

            if (!isset($_GET['delete'])) {
                Display::addFlash(
                    Display::return_message($message, 'warning', false)
                );
            }

            if (isset($_GET['delete']) && $_GET['delete'] == 'yes') {
                $result = self::deletePage(
                    $page,
                    $course_id,
                    $groupfilter,
                    $condition_session
                );
                if ($result) {
                    Display::addFlash(
                        Display::return_message(
                            get_lang('Group wikiPageDeleted'),
                            'confirmation',
                            false
                        )
                    );
                }
            }
        } else {
            Display::addFlash(
                Display::return_message(
                    get_lang('OnlyAdminDeletePageGroup wiki'),
                    'normal',
                    false
                )
            );
        }
    }

    /**
     * Edit page.
     */
    public function editPage()
    {
        $tbl_wiki = $this->tbl_wiki;
        $tbl_wiki_conf = $this->tbl_wiki_conf;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $page = $this->page;
        $course_id = $this->course_id;
        $groupId = $this->group_id;
        $userId = api_get_user_id();

        if (api_get_session_id() != 0 &&
            api_is_allowed_to_session_edit(false, true) == false
        ) {
            api_not_allowed();
        }

        $sql = 'SELECT *
                FROM '.$tbl_wiki.' w INNER JOIN '.$tbl_wiki_conf.' c
                ON  (w.c_id = c.c_id AND w.page_id = c.page_id)
                WHERE
    		        w.c_id = '.$course_id.' AND
                    w.reflink= "'.Database::escape_string($page).'" AND
                    w.'.$groupfilter.$condition_session.'
                ORDER BY id DESC';
        $result = Database::query($sql);
        $row = Database::fetch_array($result);

        // we do not need a while loop since we are always displaying the last version
        if ($row['content'] == '' && $row['title'] == '' && $page == '') {
            Display::addFlash(
                Display::return_message(
                    get_lang('You must select a page first'),
                    'error',
                    false
                )
            );

            return;
        } elseif ($row['content'] == '' && $row['title'] == '' && $page == 'index') {
            // Table structure for better export to pdf
            $default_table_for_content_Start = '<table align="center" border="0"><tr><td align="center">';
            $default_table_for_content_End = '</td></tr></table>';
            $content = $default_table_for_content_Start.sprintf(
                    get_lang(' <br/> <br/> <p align="center"> <img src="%swiki/wcollaborative.png" alt="Working as a team" title="Working as a team" /></p> <p align="center">To begin editing this page and remove this text</p>'),
                    api_get_path(WEB_IMG_PATH)
                ).$default_table_for_content_End;
            $title = get_lang('Home');
            $page_id = 0;
        } else {
            $content = api_html_entity_decode($row['content']);
            $title = api_html_entity_decode($row['title']);
            $page_id = $row['page_id'];
        }

        // Only teachers and platform admin can edit the index page.
        // Only teachers and platform admin can edit an assignment teacher.
        // And users in groups

        if (($row['reflink'] == 'index' || $row['reflink'] == '' || $row['assignment'] == 1) &&
            (!api_is_allowed_to_edit(
                    false,
                    true
                ) && $groupId == 0) && !api_is_allowed_in_course()
        ) {
            Display::addFlash(
                Display::return_message(
                    get_lang('OnlyEditsCourseManager'),
                    'error'
                )
            );
        } else {
            $PassEdit = false;
            // Check if is a wiki group
            if (!empty($groupId)) {
                $groupInfo = GroupManager::get_group_properties($groupId);
                //Only teacher, platform admin and group members can edit a wiki group
                if (api_is_allowed_to_edit(false, true) ||
                    api_is_platform_admin() ||
                    GroupManager::is_user_in_group($userId, $groupInfo)
                ) {
                    $PassEdit = true;
                } else {
                    Display::addFlash(
                        Display::return_message(
                            get_lang('OnlyEditsGroupMembers')
                        )
                    );
                }
            } else {
                $PassEdit = true;
            }

            $icon_assignment = null;
            // check if is a assignment
            if ($row['assignment'] == 1) {
                Display::addFlash(
                    Display::return_message(get_lang('You can edit this page, but the pages of learners will not be modified'))
                );

                $icon_assignment = Display::return_icon(
                    'wiki_assignment.png',
                    get_lang('This page is an assignment proposed by a trainer'),
                    '',
                    ICON_SIZE_SMALL
                );
            } elseif ($row['assignment'] == 2) {
                $icon_assignment = Display::return_icon(
                    'wiki_work.png',
                    get_lang('Learner paperExtra'),
                    '',
                    ICON_SIZE_SMALL
                );
                if (($userId == $row['user_id']) == false) {
                    if (api_is_allowed_to_edit(
                            false,
                            true
                        ) || api_is_platform_admin()) {
                        $PassEdit = true;
                    } else {
                        Display::addFlash(
                            Display::return_message(
                                get_lang('LockByTrainer'),
                                'warning'
                            )
                        );
                        $PassEdit = false;
                    }
                } else {
                    $PassEdit = true;
                }
            }

            if ($PassEdit) {
                //show editor if edit is allowed <<<<<
                if ($row['editlock'] == 1 &&
                    (api_is_allowed_to_edit(false, true) == false ||
                        api_is_platform_admin() == false)
                ) {
                    Display::addFlash(
                        Display::return_message(
                            get_lang('This page is protected. Trainers only can change it')
                        )
                    );
                } else {
                    // Check tasks
                    if (!empty($row['startdate_assig']) && time() <
                        api_strtotime($row['startdate_assig'])
                    ) {
                        $message = get_lang(
                                'TheTaskDoesNotBeginUntil'
                            ).': '.api_get_local_time($row['startdate_assig']);

                        Display::addFlash(
                            Display::return_message(
                                $message,
                                'warning'
                            )
                        );

                        if (!api_is_allowed_to_edit(false, true)) {
                            $this->redirectHome();
                        }
                    }

                    if (!empty($row['enddate_assig']) &&
                        time() > strtotime($row['enddate_assig']) &&
                        $row['delayedsubmit'] == 0
                    ) {
                        $message = get_lang(
                                'TheDeadlineHasBeenCompleted'
                            ).': '.api_get_local_time($row['enddate_assig']);
                        Display::addFlash(
                            Display::return_message(
                                $message,
                                'warning'
                            )
                        );
                        if (!api_is_allowed_to_edit(false, true)) {
                            $this->redirectHome();
                        }
                    }

                    if (!empty($row['max_version']) && $row['version'] >= $row['max_version']) {
                        $message = get_lang('You have exceeded the number of versions allowed');
                        Display::addFlash(
                            Display::return_message(
                                $message,
                                'warning'
                            )
                        );
                        if (!api_is_allowed_to_edit(false, true)) {
                            $this->redirectHome();
                        }
                    }

                    if (!empty($row['max_text']) && $row['max_text'] <= self::word_count(
                            $row['content']
                        )) {
                        $message = get_lang('HasReachedMaxNumber of words');
                        Display::addFlash(
                            Display::return_message(
                                $message,
                                'warning'
                            )
                        );
                        if (!api_is_allowed_to_edit(false, true)) {
                            $this->redirectHome();
                        }
                    }

                    if (!empty($row['task'])) {
                        //previous change 0 by text
                        if (!empty($row['startdate_assig'])) {
                            $message_task_startdate = get_lang('No');
                        } else {
                            $message_task_startdate = api_get_local_time(
                                $row['startdate_assig']
                            );
                        }

                        if (!empty($row['enddate_assig'])) {
                            $message_task_enddate = get_lang('No');
                        } else {
                            $message_task_enddate = api_get_local_time(
                                $row['enddate_assig']
                            );
                        }

                        if ($row['delayedsubmit'] == 0) {
                            $message_task_delayedsubmit = get_lang('No');
                        } else {
                            $message_task_delayedsubmit = get_lang('Yes');
                        }

                        if ($row['max_version'] == 0) {
                            $message_task_max_version = get_lang('No');
                        } else {
                            $message_task_max_version = $row['max_version'];
                        }

                        if ($row['max_text'] == 0) {
                            $message_task_max_text = get_lang('No');
                        } else {
                            $message_task_max_text = $row['max_text'];
                        }

                        // Comp message
                        $message_task = '<b>'.get_lang(
                                'Description of the assignment'
                            ).'</b><p>'.$row['task'].'</p><hr>';
                        $message_task .= '<p>'.get_lang(
                                'Start Date'
                            ).': '.$message_task_startdate.'</p>';
                        $message_task .= '<p>'.get_lang(
                                'End Date'
                            ).': '.$message_task_enddate;
                        $message_task .= ' ('.get_lang(
                                'Allow delayed sending'
                            ).') '.$message_task_delayedsubmit.'</p>';
                        $message_task .= '<p>'.get_lang(
                                'OtherSettings'
                            ).': '.get_lang(
                                'Maximum number of versions'
                            ).': '.$message_task_max_version;
                        $message_task .= ' '.get_lang(
                                'Maximum number of words'
                            ).': '.$message_task_max_text;
                        // Display message
                        Display::addFlash(
                            Display::return_message(
                                $message_task
                            )
                        );
                    }

                    $feedback_message = '';
                    if ($row['progress'] == $row['fprogress1'] && !empty($row['fprogress1'])) {
                        $feedback_message = '<b>'.get_lang(
                                'Feedback'
                            ).'</b><p>'.api_htmlentities(
                                $row['feedback1']
                            ).'</p>';
                    } elseif ($row['progress'] == $row['fprogress2'] && !empty($row['fprogress2'])) {
                        $feedback_message = '<b>'.get_lang(
                                'Feedback'
                            ).'</b><p>'.api_htmlentities(
                                $row['feedback2']
                            ).'</p>';
                    } elseif ($row['progress'] == $row['fprogress3'] && !empty($row['fprogress3'])) {
                        $feedback_message = '<b>'.get_lang(
                                'Feedback'
                            ).'</b><p>'.api_htmlentities(
                                $row['feedback3']
                            ).'</p>';
                    }

                    if (!empty($feedback_message)) {
                        Display::addFlash(
                            Display::return_message(
                                $feedback_message
                            )
                        );
                    }

                    // Previous checking for concurrent editions
                    if ($row['is_editing'] == 0) {
                        Display::addFlash(
                            Display::return_message(
                                get_lang('You have 20 minutes to edit this page. After this time, if you have not saved the page, another user will be able to edit it, and you might lose your changes')
                            )
                        );
                        $time_edit = api_get_utc_datetime();
                        $sql = 'UPDATE '.$tbl_wiki.' SET
                                is_editing = "'.$userId.'",
                                time_edit = "'.$time_edit.'"
                                WHERE c_id = '.$course_id.' AND id="'.$row['id'].'"';
                        Database::query($sql);
                    } elseif ($row['is_editing'] != $userId) {
                        $timestamp_edit = strtotime($row['time_edit']);
                        $time_editing = time() - $timestamp_edit;
                        $max_edit_time = 1200; // 20 minutes
                        $rest_time = $max_edit_time - $time_editing;

                        $userinfo = api_get_user_info($row['is_editing']);
                        if ($userinfo !== false) {
                            $is_being_edited = get_lang(
                                    'ThisPageisBeginedited by'
                                ).' '.UserManager::getUserProfileLink(
                                    $userinfo
                                ).'
                            '.get_lang(
                                    'Please try again later. If the user who is currently editing the page does not save it, this page will be available to you around'
                                ).' '.date("i", $rest_time).' '.get_lang(
                                    'minutes'
                                ).'';
                        }

                        Display::addFlash(
                            Display::return_message(
                                $is_being_edited,
                                'normal',
                                false
                            )
                        );

                        $this->redirectHome();
                    }

                    // Form.
                    $url = api_get_self().'?action=edit&title='.urlencode(
                            $page
                        ).'&session_id='.api_get_session_id(
                        ).'&group_id='.api_get_group_id().'&'.api_get_cidreq();
                    $form = new FormValidator('wiki', 'post', $url);
                    $form->addElement(
                        'header',
                        $icon_assignment.str_repeat(
                            '&nbsp;',
                            3
                        ).api_htmlentities($title)
                    );
                    self::setForm($form, $row);
                    $form->addElement('hidden', 'title');
                    $form->addButtonSave(get_lang('Save'), 'SaveWikiChange');
                    $row['title'] = $title;
                    $row['page_id'] = $page_id;
                    $row['reflink'] = $page;
                    $row['content'] = $content;

                    $form->setDefaults($row);
                    $form->display();

                    // Saving a change
                    if ($form->validate()) {
                        $versionFromSession = Session::read('_version');
                        if (empty($_POST['title'])) {
                            Display::addFlash(
                                Display::return_message(
                                    get_lang("Your changes have been saved. You still have to give a name to the page"),
                                    'error'
                                )
                            );
                        } elseif (!self::double_post($_POST['wpost_id'])) {
                            //double post
                        } elseif ($_POST['version'] != '' && $versionFromSession != 0 && $_POST['version'] != $versionFromSession) {
                            //prevent concurrent users and double version
                            Display::addFlash(
                                Display::return_message(
                                    get_lang("edited byAnotherUser"),
                                    'error'
                                )
                            );
                        } else {
                            $returnMessage = self::save_wiki(
                                $form->exportValues()
                            );
                            Display::addFlash(
                                Display::return_message(
                                    $returnMessage,
                                    'confirmation'
                                )
                            );
                        }
                        $wikiData = self::getWikiData();
                        $redirectUrl = $this->url.'&action=showpage&title='.$wikiData['reflink'].'&'.api_get_cidreq(
                            );
                        header('Location: '.$redirectUrl);
                        exit;
                    }
                }
            }
        }
    }

    /**
     * Get history.
     */
    public function getHistory()
    {
        $tbl_wiki = $this->tbl_wiki;
        $condition_session = $this->condition_session;
        $groupfilter = $this->groupfilter;
        $page = $this->page;
        $course_id = $this->course_id;
        $session_id = $this->session_id;
        $userId = api_get_user_id();

        if (!$_GET['title']) {
            Display::addFlash(
                Display::return_message(
                    get_lang("You must select a page first"),
                    'error',
                    false
                )
            );

            return;
        }

        /* First, see the property visibility that is at the last register and
        therefore we should select descending order.
        But to give ownership to each record,
        this is no longer necessary except for the title. TODO: check this*/

        $sql = 'SELECT * FROM '.$tbl_wiki.'
                WHERE
                    c_id = '.$course_id.' AND
                    reflink="'.Database::escape_string($page).'" AND
                    '.$groupfilter.$condition_session.'
                ORDER BY id DESC';
        $result = Database::query($sql);

        $KeyVisibility = null;
        $KeyAssignment = null;
        $KeyTitle = null;
        $KeyUserId = null;
        while ($row = Database::fetch_array($result)) {
            $KeyVisibility = $row['visibility'];
            $KeyAssignment = $row['assignment'];
            $KeyTitle = $row['title'];
            $KeyUserId = $row['user_id'];
        }
        $icon_assignment = null;
        if ($KeyAssignment == 1) {
            $icon_assignment = Display::return_icon(
                'wiki_assignment.png',
                get_lang('This page is an assignment proposed by a trainer'),
                '',
                ICON_SIZE_SMALL
            );
        } elseif ($KeyAssignment == 2) {
            $icon_assignment = Display::return_icon(
                'wiki_work.png',
                get_lang('Learner paperExtra'),
                '',
                ICON_SIZE_SMALL
            );
        }

        // Second, show
        //if the page is hidden and is a job only sees its author and professor
        if ($KeyVisibility == 1 ||
            api_is_allowed_to_edit(false, true) ||
            api_is_platform_admin() ||
            (
                $KeyAssignment == 2 && $KeyVisibility == 0 &&
                ($userId == $KeyUserId)
            )
        ) {
            // We show the complete history
            if (!isset($_POST['HistoryDifferences']) &&
                !isset($_POST['HistoryDifferences2'])
            ) {
                $sql = 'SELECT * FROM '.$tbl_wiki.'
                        WHERE
                            c_id = '.$course_id.' AND
                            reflink="'.Database::escape_string($page).'" AND
                            '.$groupfilter.$condition_session.'
                        ORDER BY id DESC';
                $result = Database::query($sql);
                $title = $_GET['title'];
                $group_id = api_get_group_id();

                echo '<div id="wikititle">';
                echo $icon_assignment.'&nbsp;&nbsp;&nbsp;'.api_htmlentities(
                        $KeyTitle
                    );
                echo '</div>';

                echo '<form id="differences" method="POST" action="index.php?'.api_get_cidreq(
                    ).'&action=history&title='.api_htmlentities(
                        urlencode($title)
                    ).'&session_id='.api_htmlentities(
                        $session_id
                    ).'&group_id='.api_htmlentities($group_id).'">';

                echo '<ul style="list-style-type: none;">';
                echo '<br/>';
                echo '<button class="search" type="submit" name="HistoryDifferences" value="HistoryDifferences">'.
                    get_lang('Compare selected versions').' '.get_lang(
                        'line by line'
                    ).'</button>';
                echo '<button class="search" type="submit" name="HistoryDifferences2" value="HistoryDifferences2">'.
                    get_lang('Compare selected versions').' '.get_lang(
                        'word by word'
                    ).'</button>';
                echo '<br/><br/>';

                $counter = 0;
                $total_versions = Database::num_rows($result);

                while ($row = Database::fetch_array($result)) {
                    $userinfo = api_get_user_info($row['user_id']);
                    $username = api_htmlentities(
                        sprintf(get_lang('Login: %s'), $userinfo['username']),
                        ENT_QUOTES
                    );

                    echo '<li style="margin-bottom: 5px;">';
                    ($counter == 0) ? $oldstyle = 'style="visibility: hidden;"' : $oldstyle = '';
                    ($counter == 0) ? $newchecked = ' checked' : $newchecked = '';
                    ($counter == $total_versions - 1) ? $newstyle = 'style="visibility: hidden;"' : $newstyle = '';
                    ($counter == 1) ? $oldchecked = ' checked' : $oldchecked = '';
                    echo '<input name="old" value="'.$row['id'].'" type="radio" '.$oldstyle.' '.$oldchecked.'/> ';
                    echo '<input name="new" value="'.$row['id'].'" type="radio" '.$newstyle.' '.$newchecked.'/> ';
                    echo '<a href="'.api_get_self(
                        ).'?action=showpage&title='.api_htmlentities(
                            urlencode($page)
                        ).'&view='.$row['id'].'">';
                    echo '<a href="'.api_get_self().'?'.api_get_cidreq(
                        ).'&action=showpage&title='.api_htmlentities(
                            urlencode($page)
                        ).'&view='.$row['id'].'">';
                    echo api_get_local_time(
                        $row['dtime']
                    );
                    echo '</a>';
                    echo ' ('.get_lang('Version').' '.$row['version'].')';
                    echo ' '.get_lang('By').' ';
                    if ($userinfo !== false) {
                        echo UserManager::getUserProfileLink($userinfo);
                    } else {
                        echo get_lang('Anonymous').' ('.api_htmlentities(
                                $row['user_ip']
                            ).')';
                    }
                    echo ' ( '.get_lang('Progress').': '.api_htmlentities(
                            $row['progress']
                        ).'%, ';
                    $comment = $row['comment'];
                    if (!empty($comment)) {
                        $comment = api_substr($comment, 0, 100);
                        if ($comment !== false) {
                            $comment = api_htmlentities($comment);
                            echo get_lang('Comments').': '.$comment;
                            if (api_strlen($row['comment']) > 100) {
                                echo '... ';
                            }
                        }
                    } else {
                        echo get_lang('Comments').':  ---';
                    }
                    echo ' ) </li>';
                    $counter++;
                } //end while

                echo '<br/>';
                echo '<button class="search" type="submit" name="HistoryDifferences" value="HistoryDifferences">'.get_lang(
                        'Compare selected versions'
                    ).' '.get_lang('line by line').'</button>';
                echo '<button class="search" type="submit" name="HistoryDifferences2" value="HistoryDifferences2">'.get_lang(
                        'Compare selected versions'
                    ).' '.get_lang('word by word').'</button>';
                echo '</ul></form>';
            } else { // We show the differences between two versions
                $version_old = [];
                if (isset($_POST['old'])) {
                    $sql_old = "SELECT * FROM $tbl_wiki
                                WHERE c_id = $course_id AND id='".Database::escape_string(
                            $_POST['old']
                        )."'";
                    $result_old = Database::query($sql_old);
                    $version_old = Database::fetch_array($result_old);
                }

                $sql_new = "SELECT * FROM $tbl_wiki
                            WHERE 
                              c_id = $course_id AND 
                              id = '".Database::escape_string($_POST['new'])."'";
                $result_new = Database::query($sql_new);
                $version_new = Database::fetch_array($result_new);
                $oldTime = isset($version_old['dtime']) ? api_get_local_time($version_old['dtime']) : null;
                $oldContent = isset($version_old['content']) ? $version_old['content'] : null;

                if (isset($_POST['HistoryDifferences'])) {
                    include 'diff.inc.php';
                    //title
                    echo '<div id="wikititle">'.api_htmlentities(
                            $version_new['title']
                        ).'
                            <font size="-2"><i>('.get_lang('Changes in version').'</i>
                            <font style="background-color:#aaaaaa">'.api_get_local_time($version_new['dtime']).'</font>
                            <i>'.get_lang('old version of').'</i>
                            <font style="background-color:#aaaaaa">'.$oldTime.'</font>
                ) '.get_lang('Legend').':  <span class="diffAdded" >'.get_lang(
                            'Group wikiDiffAddedLine'
                        ).'</span>
                <span class="diffDeleted" >'.get_lang(
                            'Group wikiDiffDeletedLine'
                        ).'</span> <span class="diffMoved">'.get_lang(
                            'Group wikiDiffMovedLine'
                        ).'</span></font>
                </div>';
                }
                if (isset($_POST['HistoryDifferences2'])) {
                    //title
                    echo '<div id="wikititle">'.api_htmlentities(
                            $version_new['title']
                        ).'
                        <font size="-2"><i>('.get_lang(
                            'Changes in version'
                        ).'</i> <font style="background-color:#aaaaaa">'.api_get_local_time($version_new['dtime']).'</font>
                        <i>'.get_lang(
                            'old version of'
                        ).'</i> <font style="background-color:#aaaaaa">'.$oldTime.'</font>)
                        '.get_lang(
                            'Legend'
                        ).':  <span class="diffAddedTex" >'.get_lang(
                            'Group wikiDiffAddedTex'
                        ).'</span>
                        <span class="diffDeletedTex" >'.get_lang(
                            'Group wikiDiffDeletedTex'
                        ).'</span></font></div>';
                }

                if (isset($_POST['HistoryDifferences'])) {
                    echo '<table>'.diff(
                            $oldContent,
                            $version_new['content'],
                            true,
                            'format_table_line'
                        ).'</table>'; // format_line mode is better for words
                    echo '<br />';
                    echo '<strong>'.get_lang(
                            'Legend'
                        ).'</strong><div class="diff">'."\n";
                    echo '<table><tr>';
                    echo '<td>';
                    echo '</td><td>';
                    echo '<span class="diffEqual" >'.get_lang(
                            'Group wikiDiffUnchangedLine'
                        ).'</span><br />';
                    echo '<span class="diffAdded" >'.get_lang(
                            'Group wikiDiffAddedLine'
                        ).'</span><br />';
                    echo '<span class="diffDeleted" >'.get_lang(
                            'Group wikiDiffDeletedLine'
                        ).'</span><br />';
                    echo '<span class="diffMoved" >'.get_lang(
                            'Group wikiDiffMovedLine'
                        ).'</span><br />';
                    echo '</td>';
                    echo '</tr></table>';
                }

                if (isset($_POST['HistoryDifferences2'])) {
                    $lines1 = [strip_tags($oldContent)]; //without <> tags
                    $lines2 = [
                        strip_tags(
                            $version_new['content']
                        ),
                    ]; //without <> tags
                    $diff = new Text_Diff($lines1, $lines2);
                    $renderer = new Text_Diff_Renderer_inline();
                    echo '<style>del{background:#fcc}ins{background:#cfc}</style>'.$renderer->render(
                            $diff
                        ); // Code inline
                    echo '<br />';
                    echo '<strong>'.get_lang(
                            'Legend'
                        ).'</strong><div class="diff">'."\n";
                    echo '<table><tr>';
                    echo '<td>';
                    echo '</td><td>';
                    echo '<span class="diffAddedTex" >'.get_lang(
                            'Group wikiDiffAddedTex'
                        ).'</span><br />';
                    echo '<span class="diffDeletedTex" >'.get_lang(
                            'Group wikiDiffDeletedTex'
                        ).'</span><br />';
                    echo '</td>';
                    echo '</tr></table>';
                }
            }
        }
    }

    /**
     * Get stat tables.
     */
    public function getStatsTable()
    {
        $_course = $this->courseInfo;
        $session_id = $this->session_id;
        $groupId = $this->group_id;

        echo '<div class="actions">'.get_lang('More').'</div>';
        echo '<table border="0">';
        echo '  <tr>';
        echo '    <td>';
        echo '      <ul>';
        //Submenu Most active users
        echo '        <li><a href="index.php?cidReq='.$_course['code'].'&action=mactiveusers&session_id='.$session_id.'&group_id='.$groupId.'">'.get_lang(
                'Most active users'
            ).'</a></li>';
        //Submenu Most visited pages
        echo '        <li><a href="index.php?cidReq='.$_course['code'].'&action=mvisited&session_id='.$session_id.'&group_id='.$groupId.'">'.get_lang(
                'Most visited pages'
            ).'</a></li>';
        //Submenu Most changed pages
        echo '        <li><a href="index.php?cidReq='.$_course['code'].'&action=mostchanged&session_id='.$session_id.'&group_id='.$groupId.'">'.get_lang(
                'Most changed pages'
            ).'</a></li>';
        echo '      </ul>';
        echo '    </td>';
        echo '    <td>';
        echo '      <ul>';
        // Submenu Orphaned pages
        echo '        <li><a href="index.php?cidReq='.$_course['code'].'&action=orphaned&session_id='.$session_id.'&group_id='.$groupId.'">'.get_lang(
                'Orphaned pages'
            ).'</a></li>';
        // Submenu Wanted pages
        echo '        <li><a href="index.php?cidReq='.$_course['code'].'&action=wanted&session_id='.$session_id.'&group_id='.$groupId.'">'.get_lang(
                'Wanted pages'
            ).'</a></li>';
        // Submenu Most linked pages
        echo '<li><a href="index.php?cidReq='.$_course['code'].'&action=mostlinked&session_id='.$session_id.'&group_id='.$groupId.'">'.get_lang(
                'Pages most linked'
            ).'</a></li>';
        echo '</ul>';
        echo '</td>';
        echo '<td style="vertical-align:top">';
        echo '<ul>';
        // Submenu Statistics
        if (api_is_allowed_to_edit(false, true) || api_is_platform_admin()) {
            echo '<li><a href="index.php?cidReq='.$_course['id'].'&action=statistics&session_id='.$session_id.'&group_id='.$groupId.'">'.get_lang(
                    'Statistics'
                ).'</a></li>';
        }
        echo '      </ul>';
        echo '    </td>';
        echo '  </tr>';
        echo '</table>';
    }

    /**
     * Kind of controller.
     *
     * @param string $action
     */
    public function handleAction($action)
    {
        $page = $this->page;
        switch ($action) {
            case 'export_to_pdf':
                if (isset($_GET['wiki_id'])) {
                    self::export_to_pdf($_GET['wiki_id'], api_get_course_id());
                    break;
                }
                break;
            case 'export2doc':
                if (isset($_GET['wiki_id'])) {
                    $export2doc = self::export2doc($_GET['wiki_id']);
                    if ($export2doc) {
                        Display::addFlash(
                            Display::return_message(
                                get_lang('The page has been exported to the document tool'),
                                'confirmation',
                                false
                            )
                        );
                    }
                }
                break;
            case 'restorepage':
                self::restorePage();
                break;
            case 'more':
                self::getStatsTable();
                break;
            case 'statistics':
                self::getStats();
                break;
            case 'mactiveusers':
                self::getActiveUsers($action);
                break;
            case 'usercontrib':
                self::getUserContributions($_GET['user_id'], $action);
                break;
            case 'mostchanged':
                $this->getMostChangedPages($action);
                break;
            case 'mvisited':
                self::getMostVisited();
                break;
            case 'wanted':
                $this->getWantedPages();
                break;
            case 'orphaned':
                self::getOrphaned();
                break;
            case 'mostlinked':
                self::getMostLinked();
                break;
            case 'delete':
                self::deletePageWarning($page);
                break;
            case 'deletewiki':
                $title = '<div class="actions">'.get_lang(
                        'DeleteGroup wiki'
                    ).'</div>';
                if (api_is_allowed_to_edit(
                        false,
                        true
                    ) || api_is_platform_admin()) {
                    $message = get_lang('ConfirmDeleteGroup wiki');
                    $message .= '<p>
                        <a href="index.php?'.api_get_cidreq().'">'.get_lang(
                            'No'
                        ).'</a>
                        &nbsp;&nbsp;|&nbsp;&nbsp;
                        <a href="'.api_get_self().'?'.api_get_cidreq(
                        ).'&action=deletewiki&delete=yes">'.
                        get_lang('Yes').'</a>
                    </p>';

                    if (!isset($_GET['delete'])) {
                        Display::addFlash(
                            $title.Display::return_message(
                                $message,
                                'warning',
                                false
                            )
                        );
                    }
                } else {
                    Display::addFlash(
                        Display::return_message(
                            get_lang("OnlyAdminDeleteGroup wiki"),
                            'normal',
                            false
                        )
                    );
                }

                if (api_is_allowed_to_edit(
                        false,
                        true
                    ) || api_is_platform_admin()) {
                    if (isset($_GET['delete']) && $_GET['delete'] == 'yes') {
                        $return_message = self::delete_wiki();
                        Display::addFlash(
                            Display::return_message(
                                $return_message,
                                'confirmation',
                                false
                            )
                        );
                        $this->redirectHome();
                    }
                }
                break;
            case 'searchpages':
                self::getSearchPages($action);
                break;
            case 'links':
                self::getLinks($page);
                break;
            case 'addnew':
                if (api_get_session_id() != 0 && api_is_allowed_to_session_edit(
                        false,
                        true
                    ) == false) {
                    api_not_allowed();
                }
                $groupInfo = GroupManager::get_group_properties(
                    api_get_group_id()
                );
                echo '<div class="actions">'.get_lang('Add new page').'</div>';
                echo '<br/>';
                //first, check if page index was created. chektitle=false
                if (self::checktitle('index')) {
                    if (api_is_allowed_to_edit(false, true) ||
                        api_is_platform_admin() ||
                        GroupManager::is_user_in_group(
                            api_get_user_id(),
                            $groupInfo
                        ) ||
                        api_is_allowed_in_course()
                    ) {
                        Display::addFlash(
                            Display::return_message(
                                get_lang('To start Group wiki go and edit Main page'),
                                'normal',
                                false
                            )
                        );
                    } else {
                        Display::addFlash(
                            Display::return_message(
                                get_lang('This Group wiki is frozen so far. A trainer must start it.'),
                                'normal',
                                false
                            )
                        );
                    }
                } elseif (self::check_addnewpagelock(
                    ) == 0 && (api_is_allowed_to_edit(
                            false,
                            true
                        ) == false || api_is_platform_admin() == false)) {
                    Display::addFlash(
                        Display::return_message(
                            get_lang('The add option has been temporarily disabled by the trainer'),
                            'error',
                            false
                        )
                    );
                } else {
                    $groupinfo = GroupManager::get_group_properties(
                        api_get_group_id()
                    );
                    if (api_is_allowed_to_edit(false, true) ||
                        api_is_platform_admin() ||
                        GroupManager::is_user_in_group(
                            api_get_user_id(),
                            $groupInfo
                        ) ||
                        $_GET['group_id'] == 0
                    ) {
                        self::display_new_wiki_form();
                    } else {
                        Display::addFlash(
                            Display::return_message(
                                get_lang('Trainers and members of this group only can add pages to the group Wiki'),
                                'normal',
                                false
                            )
                        );
                    }
                }
                break;
            case 'show':
                self::display_wiki_entry($page);
                break;
            case 'showpage':
                self::display_wiki_entry($page);
                break;
            case 'edit':
                self::editPage();
                break;
            case 'history':
                self::getHistory();
                break;
            case 'recentchanges':
                self::recentChanges($page, $action);
                break;
            case 'allpages':
                self::allPages($action);
                break;
            case 'discuss':
                self::getDiscuss($page);
                break;
            case 'export_to_doc_file':
                self::exportTo($_GET['id'], 'odt');
                exit;
                break;
        }
    }

    /**
     * Redirect to home.
     */
    public function redirectHome()
    {
        $redirectUrl = $this->url.'&action=showpage&title=index';
        header('Location: '.$redirectUrl.'&'.api_get_cidreq());
        exit;
    }

    /**
     * Export wiki content in a ODF.
     *
     * @param int $id
     * @param string int
     *
     * @return bool
     */
    public function exportTo($id, $format = 'doc')
    {
        $data = self::getWikiDataFromDb($id);

        if (isset($data['content']) && !empty($data['content'])) {
            Export::htmlToOdt($data['content'], $data['reflink'], $format);
        }

        return false;
    }
}