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

use \ChamiloSession as Session;

/**
 * Class Display
 * Contains several public functions dealing with the display of
 * table data, messages, help topics, ...
 *
 * Include/require it in your code to use its public functionality.
 * There are also several display public functions in the main api library.
 *
 * All public functions static public functions inside a class called Display,
 * so you use them like this: e.g.
 * Display::display_normal_message($message)
 *
 * @package chamilo.library
 *
 */
class Display
{
    /* The main template*/
    public static $global_template;
    public static $preview_style = null;

    public function __construct()
    {
    }

    /**
     * @return array
     */
    public static function toolList()
    {
        return array(
            'group',
            'work',
            'glossary',
            'forum',
            'course_description',
            'gradebook',
            'attendance',
            'course_progress',
            'notebook'
        );
    }

     /**
     * Displays the page header
     * @param string The name of the page (will be showed in the page title)
     * @param string Optional help file name
     * @param string $page_header
     */
    public static function display_header($tool_name ='', $help = null, $page_header = null)
    {
        $origin = api_get_origin();
        $showHeader = true;
        if (isset($origin) && $origin == 'learnpath') {
            $showHeader = false;
        }
        self::$global_template = new Template($tool_name, $showHeader, $showHeader);

        // Fixing tools with any help it takes xxx part of main/xxx/index.php
        if (empty($help)) {
            $currentURL = api_get_self();
            preg_match('/main\/([^*\/]+)/', $currentURL, $matches);
            $toolList = self::toolList();
            if (!empty($matches)) {
                foreach ($matches as $match) {
                    if (in_array($match, $toolList)) {
                        $help = explode('_', $match);
                        $help = array_map('ucfirst', $help);
                        $help = implode('', $help);
                        break;
                    }
                }
            }
        }

        self::$global_template->set_help($help);

        if (!empty(self::$preview_style)) {
            self::$global_template->preview_theme = self::$preview_style;
            self::$global_template->set_css_files();
            self::$global_template->set_js_files();
        }
        if (!empty($page_header)) {
            self::$global_template->assign('header', $page_header);
        }
        echo self::$global_template->show_header_template();
    }

    /**
     * Displays the reduced page header (without banner)
     */
    public static function display_reduced_header()
    {
        global $show_learnpath, $tool_name;
        self::$global_template = new Template($tool_name, false, false, $show_learnpath);
        echo self::$global_template ->show_header_template();
    }

    public static function display_no_header()
    {
        global $tool_name, $show_learnpath;
        $disable_js_and_css_files = true;
        self::$global_template = new Template($tool_name, false, false, $show_learnpath);
        //echo self::$global_template->show_header_template();
    }

    /**
     * Displays the reduced page header (without banner)
     */
    public static function set_header() {
        global $show_learnpath;
        self::$global_template = new Template($tool_name, false, false, $show_learnpath);
    }

    /**
     * Display the page footer
     */
    public static function display_footer() {
        echo self::$global_template ->show_footer_template();
    }

    public static function page()
    {
        return new Page();
    }

    /**
     * Displays the tool introduction of a tool.
     *
     * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
     * @param string $tool These are the constants that are used for indicating the tools.
     * @param array $editor_config Optional configuration settings for the online editor.
     * return: $tool return a string array list with the "define" in main_api.lib
     * @return html code for adding an introduction
     */
    public static function display_introduction_section($tool, $editor_config = null) {
        echo self::return_introduction_section($tool, $editor_config);
    }

    /**
     * @param string $tool
     * @param array $editor_config
     * @return null
     */
    public static function return_introduction_section($tool, $editor_config = null)
    {
        $is_allowed_to_edit = api_is_allowed_to_edit();
        $moduleId = $tool;
        if (api_get_setting('enable_tool_introduction') == 'true' || $tool == TOOL_COURSE_HOMEPAGE) {
            $introduction_section = null;
            require api_get_path(INCLUDE_PATH).'introductionSection.inc.php';
            return $introduction_section;
        }
    }

    /**
     *	Displays a localised html file
     *	tries to show the file "$full_file_name"."_".$language_interface.".html"
     *	and if this does not exist, shows the file "$full_file_name".".html"
     *	warning this public function defines a global
     *	@param $full_file_name, the (path) name of the file, without .html
     *	@return return a string with the path
     */
    public static function display_localised_html_file($full_file_name) {
        global $language_interface;
        $localised_file_name = $full_file_name.'_'.$language_interface.'.html';
        $default_file_name = $full_file_name.'.html';
        if (file_exists($localised_file_name)) {
            include $localised_file_name;
        } else {
            include ($default_file_name);
        }
    }

    /**
     * Displays a table
     * @param array $header Titles for the table header
     * 						each item in this array can contain 3 values
     * 						- 1st element: the column title
     * 						- 2nd element: true or false (column sortable?)
     * 						- 3th element: additional attributes for
     *  						th-tag (eg for column-width)
     * 						- 4the element: additional attributes for the td-tags
     * @param array $content 2D-array with the tables content
     * @param array $sorting_options Keys are:
     * 					'column' = The column to use as sort-key
     * 					'direction' = SORT_ASC or SORT_DESC
     * @param array $paging_options Keys are:
     * 					'per_page_default' = items per page when switching from
     * 										 full-	list to per-page-view
     * 					'per_page' = number of items to show per page
     * 					'page_nr' = The page to display
     * @param array $query_vars Additional variables to add in the query-string
     * @param string The style that the table will show. You can set 'table' or 'grid'
     * @author bart.mollet@hogent.be
     */
    public static function display_sortable_table(
        $header,
        $content,
        $sorting_options = array(),
        $paging_options = array(),
        $query_vars = null,
        $form_actions = array(),
        $style = 'table'
    ) {
        global $origin;
        $column = isset($sorting_options['column']) ? $sorting_options['column'] : 0;
        $default_items_per_page = isset($paging_options['per_page']) ? $paging_options['per_page'] : 20;
        $table = new SortableTableFromArray($content, $column, $default_items_per_page);
        if (is_array($query_vars)) {
            $table->set_additional_parameters($query_vars);
        }
        if ($style == 'table') {
            if (is_array($header) && count($header) > 0) {
                foreach ($header as $index => $header_item) {
                    $table->set_header(
                        $index,
                        $header_item[0],
                        $header_item[1],
                        isset($header_item[2]) ? $header_item[2] : null,
                        isset($header_item[3]) ? $header_item[3] : null
                    );
                }
            }
            $table->set_form_actions($form_actions);
            $table->display();
        } else {
            $table->display_grid();
        }
    }

    public static function return_sortable_table(
        $header,
        $content,
        $sorting_options = array(),
        $paging_options = array(),
        $query_vars = null,
        $form_actions = array(),
        $style = 'table'
    ) {
        ob_start();
        self::display_sortable_table(
            $header,
            $content,
            $sorting_options,
            $paging_options,
            $query_vars,
            $form_actions,
            $style
        );
        $content = ob_get_contents();
        ob_end_clean();
        return $content;
    }

    /**
     * Shows a nice grid
     * @param string grid name (important to create css)
     * @param array header content
     * @param array array with the information to show
     * @param array $paging_options Keys are:
     * 					'per_page_default' = items per page when switching from
     * 										 full-	list to per-page-view
     * 					'per_page' = number of items to show per page
     * 					'page_nr' = The page to display
     * 					'hide_navigation' =  true to hide the navigation
     * @param array $query_vars Additional variables to add in the query-string
     * @param array $form actions Additional variables to add in the query-string
     * @param mixed An array with bool values to know which columns show. i.e: $visibility_options= array(true, false) we will only show the first column
     * 				Can be also only a bool value. TRUE: show all columns, FALSE: show nothing
     */
    public static function display_sortable_grid(
        $name,
        $header,
        $content,
        $paging_options = array(),
        $query_vars = null,
        $form_actions = array(),
        $visibility_options = true,
        $sort_data = true,
        $grid_class = array()
    ) {
        echo self::return_sortable_grid(
            $name,
            $header,
            $content,
            $paging_options,
            $query_vars,
            $form_actions,
            $visibility_options,
            $sort_data,
            $grid_class
        );
    }

    /**
     * Gets a nice grid in html string
     * @param string grid name (important to create css)
     * @param array header content
     * @param array array with the information to show
     * @param array $paging_options Keys are:
     * 					'per_page_default' = items per page when switching from
     * 										 full-	list to per-page-view
     * 					'per_page' = number of items to show per page
     * 					'page_nr' = The page to display
     * 					'hide_navigation' =  true to hide the navigation
     * @param array $query_vars Additional variables to add in the query-string
     * @param array $form actions Additional variables to add in the query-string
     * @param mixed An array with bool values to know which columns show. i.e:
     *  $visibility_options= array(true, false) we will only show the first column
     * 	Can be also only a bool value. TRUE: show all columns, FALSE: show nothing
     * @param bool  true for sorting data or false otherwise
     * @param array grid classes
     * @return 	string   html grid
     */
    public static function return_sortable_grid(
        $name,
        $header,
        $content,
        $paging_options = array(),
        $query_vars = null,
        $form_actions = array(),
        $visibility_options = true,
        $sort_data = true,
        $grid_class = array(),
        $elementCount = 0
    ) {
        $column =  0;
        $default_items_per_page = isset($paging_options['per_page']) ? $paging_options['per_page'] : 20;

        $table = new SortableTableFromArray($content, $column, $default_items_per_page, $name);
        $table->total_number_of_items = intval($elementCount);
        if (is_array($query_vars)) {
            $table->set_additional_parameters($query_vars);
        }

        return $table->display_simple_grid(
            $visibility_options,
            $paging_options['hide_navigation'],
            $default_items_per_page,
            $sort_data,
            $grid_class
        );
    }

    /**
     * Displays a table with a special configuration
     * @param array $header Titles for the table header
     * 						each item in this array can contain 3 values
     * 						- 1st element: the column title
     * 						- 2nd element: true or false (column sortable?)
     * 						- 3th element: additional attributes for
     *  						th-tag (eg for column-width)
     * 						- 4the element: additional attributes for the td-tags
     * @param array $content 2D-array with the tables content
     * @param array $sorting_options Keys are:
     * 					'column' = The column to use as sort-key
     * 					'direction' = SORT_ASC or SORT_DESC
     * @param array $paging_options Keys are:
     * 					'per_page_default' = items per page when switching from
     * 										 full-	list to per-page-view
     * 					'per_page' = number of items to show per page
     * 					'page_nr' = The page to display
     * @param array $query_vars Additional variables to add in the query-string
     * @param array $column_show Array of binaries 1= show columns 0. hide a column
     * @param array $column_order An array of integers that let us decide how the columns are going to be sort.
     * 						      i.e:  $column_order=array('1''4','3','4'); The 2nd column will be order like the 4th column
     * @param array $form_actions Set optional forms actions
     *
     * @author Julio Montoya
     */
    public static function display_sortable_config_table(
        $table_name,
        $header,
        $content,
        $sorting_options = array(),
        $paging_options = array(),
        $query_vars = null,
        $column_show = array(),
        $column_order = array(),
        $form_actions = array()
    ) {
        global $origin;
        $column = isset($sorting_options['column']) ? $sorting_options['column'] : 0;
        $default_items_per_page = isset($paging_options['per_page']) ? $paging_options['per_page'] : 20;

        $table = new SortableTableFromArrayConfig($content, $column, $default_items_per_page, $table_name, $column_show, $column_order);

        if (is_array($query_vars)) {
            $table->set_additional_parameters($query_vars);
        }
        // Show or hide the columns header
        if (is_array($column_show)) {
            for ($i = 0; $i < count($column_show); $i++) {
                if (!empty($column_show[$i])) {
                    $val0 = isset($header[$i][0]) ? $header[$i][0] : null;
                    $val1 = isset($header[$i][1]) ? $header[$i][1] : null;
                    $val2 = isset($header[$i][2]) ? $header[$i][2] : null;
                    $val3 = isset($header[$i][3]) ? $header[$i][3] : null;
                    $table->set_header($i, $val0, $val1, $val2, $val3);
                }
            }
        }
        $table->set_form_actions($form_actions);
        $table->display();
    }

    /**
     * Displays a normal message. It is recommended to use this public function
     * to display any normal information messages.
     *
     * @param bool	Filter (true) or not (false)
     * @return void
     */
    public static function display_normal_message($message, $filter = true, $returnValue = false)
    {
    	$message = self::return_message($message, 'normal', $filter);
        if ($returnValue) {
            return $message;
        } else {
            echo $message;
        }
    }

    /**
     * Displays an warning message. Use this if you want to draw attention to something
     * This can also be used for instance with the hint in the exercises
     *
     */
    public static function display_warning_message($message, $filter = true, $returnValue = false)
    {
        $message = self::return_message($message, 'warning', $filter);
        if ($returnValue) {
            return $message;
        } else {
            echo $message;
        }
    }

    /**
     * Displays an confirmation message. Use this if something has been done successfully
     * @param bool	Filter (true) or not (false)
     * @return void
     */
    public static function display_confirmation_message ($message, $filter = true, $returnValue = false)
    {
        $message = self::return_message($message, 'confirm', $filter);
        if ($returnValue) {
            return $message;
        } else {
            echo $message;
        }
    }

    /**
     * Displays an error message. It is recommended to use this public function if an error occurs
     * @param string $message - include any additional html
     *                          tags if you need them
     * @param bool	Filter (true) or not (false)
     * @return void
     */
    public static function display_error_message ($message, $filter = true, $returnValue = false)
    {
        $message = self::return_message($message, 'error', $filter);
        if ($returnValue) {
            return $message;
        } else {
            echo $message;
        }
    }

    /**
     * @param string $message
     * @param string $type
     * @param bool $filter
     */
    public static function return_message_and_translate($message, $type='normal', $filter = true)
    {
        $message = get_lang($message);
        echo self::return_message($message, $type, $filter);
    }

    /**
     * Returns a div html string with
     * @param   string  The message
     * @param   string  The message type (confirm,normal,warning,error)
     * @param   bool    Whether to XSS-filter or not
     * @return  string  Message wrapped into an HTML div
     */
    public static function return_message($message, $type = 'normal', $filter = true)
    {
        if ($filter) {
        	$message = api_htmlentities($message, ENT_QUOTES, api_is_xml_http_request() ? 'UTF-8' : api_get_system_encoding());
            //$message = Security::remove_XSS($message);
        }

        $class = "";
        switch($type) {
            case 'warning':
               $class .= 'warning-message';
               break;
            case 'error':
               $class .= 'error-message';
               break;
            case 'confirmation':
            case 'confirm':
            case 'success':
                $class .= 'confirmation-message';
               break;
            case 'normal':
            default:
                $class .= 'normal-message';
        }
        return self::div($message, array('class'=> $class));
    }

    /**
     * Returns an encrypted mailto hyperlink
     *
     * @param string  e-mail
     * @param string  clickable text
     * @param string  optional, class from stylesheet
     * @return string encrypted mailto hyperlink
     */
    public static function encrypted_mailto_link ($email, $clickable_text = null, $style_class = '')
    {
        if (is_null($clickable_text)) {
            $clickable_text = $email;
        }
        // "mailto:" already present?
        if (substr($email, 0, 7) != 'mailto:') {
            $email = 'mailto:'.$email;
        }
        // Class (stylesheet) defined?
        if ($style_class != '') {
            $style_class = ' class="'.$style_class.'"';
        }
        // Encrypt email
        $hmail = '';
        for ($i = 0; $i < strlen($email); $i ++) {
            $hmail .= '&#'.ord($email {
            $i }).';';
        }
        $hclickable_text = null;
        // Encrypt clickable text if @ is present
        if (strpos($clickable_text, '@')) {
            for ($i = 0; $i < strlen($clickable_text); $i ++) {
                $hclickable_text .= '&#'.ord($clickable_text {
                $i }).';';
            }
        } else {
            $hclickable_text = @htmlspecialchars($clickable_text, ENT_QUOTES, api_get_system_encoding());
        }
        // Return encrypted mailto hyperlink
        return '<a href="'.$hmail.'"'.$style_class.' class="clickable_email_link">'.$hclickable_text.'</a>';
    }

    /**
     * Returns an mailto icon hyperlink
     *
     * @param string  e-mail
     * @param string  icon source file from the icon lib
     * @param integer  icon size from icon lib
     * @param string  optional, class from stylesheet
     * @return string encrypted mailto hyperlink
     */
    public static function icon_mailto_link($email, $icon_file = "mail.png", $icon_size = 22, $style_class = '')
    {
        // "mailto:" already present?
        if (substr($email, 0, 7) != 'mailto:') {
            $email = 'mailto:'.$email;
        }
        // Class (stylesheet) defined?
        if ($style_class != '') {
            $style_class = ' class="'.$style_class.'"';
        }
        // Encrypt email
        $hmail = '';
        for ($i = 0; $i < strlen($email); $i ++) {
            $hmail .= '&#'.ord($email {
            $i }).';';
        }
        // icon html code
        $icon_html_source = self::return_icon($icon_file, $hmail, '', $icon_size);
        // Return encrypted mailto hyperlink
        return '<a href="'.$hmail.'"'.$style_class.' class="clickable_email_link">'.$icon_html_source.'</a>';
    }

    /**
     *	Creates a hyperlink to the platform homepage.
     *	@param string $name, the visible name of the hyperlink, default is sitename
     *	@return string with html code for hyperlink
     */
    public static function get_platform_home_link_html($name = '')
    {
        if ($name == '') {
            $name = api_get_setting('siteName');
        }
        return '<a href="'.api_get_path(WEB_PATH).'index.php">'.$name.'</a>';
    }

    /**
     * Prints an <option>-list with all letters (A-Z).
     * @param char $selected_letter The letter that should be selected
     * @todo This is English language specific implementation.
     * It should be adapted for the other languages.
     */
    public static function get_alphabet_options($selected_letter = '')
    {
        $result = '';
        for ($i = 65; $i <= 90; $i ++) {
            $letter = chr($i);
            $result .= '<option value="'.$letter.'"';
            if ($selected_letter == $letter) {
                $result .= ' selected="selected"';
            }
            $result .= '>'.$letter.'</option>';
        }
        return $result;
    }

    /**
     * Get the options withing a select box within the given values
     * @param int   Min value
     * @param int   Max value
     * @param int   Default value
     * @return string HTML select options
     */
    public static function get_numeric_options($min, $max, $selected_num = 0)
    {
        $result = '';
        for ($i = $min; $i <= $max; $i ++) {
            $result .= '<option value="'.$i.'"';
            if (is_int($selected_num))
                if ($selected_num == $i) {
                    $result .= ' selected="selected"';
                }
            $result .= '>'.$i.'</option>';
        }
        return $result;
    }

    /**
     * Shows the so-called "left" menu for navigating
     */
    public static function show_course_navigation_menu($isHidden = false)
    {
        global $output_string_menu;
        global $_setting;

        // Check if the $_SERVER['REQUEST_URI'] contains already url parameters (thus a questionmark)
        if (strpos($_SERVER['REQUEST_URI'], '?') === false) {
            $sourceurl = api_get_self().'?';
        } else {
            $sourceurl = $_SERVER['REQUEST_URI'];
        }
        $output_string_menu = '';
        if ($isHidden == 'true' and $_SESSION['hideMenu']) {

            $_SESSION['hideMenu'] = 'hidden';

            $sourceurl = str_replace('&isHidden=true', '', $sourceurl);
            $sourceurl = str_replace('&isHidden=false', '', $sourceurl);

            $output_string_menu .= ' <a href="'.$sourceurl.'&isHidden=false"><img src="../../main/img/expand.gif" alt="'.'Show menu1'.'" padding:"2px"/></a>';
        } elseif ($isHidden == 'false' && $_SESSION['hideMenu']) {
            $sourceurl = str_replace('&isHidden=true', '', $sourceurl);
            $sourceurl = str_replace('&isHidden=false', '', $sourceurl);

            $_SESSION['hideMenu'] = 'shown';
            $output_string_menu .= '<div id="leftimg"><a href="'.$sourceurl.'&isHidden=true"><img src="../../main/img/collapse.gif" alt="'.'Hide menu2'.'" padding:"2px"/></a></div>';
        } elseif ($_SESSION['hideMenu']) {
            if ($_SESSION['hideMenu'] == 'shown') {
                $output_string_menu .= '<div id="leftimg"><a href="'.$sourceurl.'&isHidden=true"><img src="../../main/img/collapse.gif" alt="'.'Hide menu3'.' padding:"2px"/></a></div>';
            }
            if ($_SESSION['hideMenu'] == 'hidden') {
                $sourceurl = str_replace('&isHidden=true', '', $sourceurl);
                $output_string_menu .= '<a href="'.$sourceurl.'&isHidden=false"><img src="../../main/img/expand.gif" alt="'.'Hide menu4'.' padding:"2px"/></a>';
            }
        } elseif (!$_SESSION['hideMenu']) {
            $_SESSION['hideMenu'] = 'shown';
            if (isset($_cid)) {
                $output_string_menu .= '<div id="leftimg"><a href="'.$sourceurl.'&isHidden=true"><img src="main/img/collapse.gif" alt="'.'Hide menu5'.' padding:"2px"/></a></div>';
            }
        }
    }

    /**
     * This public function displays an icon
     * @param string   The filename of the file (in the main/img/ folder
     * @param string   The alt text (probably a language variable)
     * @param array    additional attributes (for instance height, width, onclick, ...)
     * @param integer  The wanted width of the icon (to be looked for in the corresponding img/icons/ folder)
     * @return void
    */
    public static function display_icon(
        $image,
        $alt_text = '',
        $additional_attributes = array(),
        $size = null
    ) {
        echo self::return_icon($image, $alt_text, $additional_attributes, $size);
    }

    /**
     * This public function returns the htmlcode for an icon
     *
     * @param string   The filename of the file (in the main/img/ folder
     * @param string   The alt text (probably a language variable)
     * @param array    Additional attributes (for instance height, width, onclick, ...)
     * @param integer  The wanted width of the icon (to be looked for in the corresponding img/icons/ folder)
     * @return string  An HTML string of the right <img> tag
     *
     * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University 2006
     * @author Julio Montoya 2010 Function improved, adding image constants
     * @author Yannick Warnier 2011 Added size handler
     * @version Feb 2011
    */
    public static function return_icon(
        $image,
        $alt_text = '',
        $additional_attributes = array(),
        $size = ICON_SIZE_SMALL,
        $show_text = true,
        $return_only_path = false
    ) {

        $code_path   = api_get_path(SYS_CODE_PATH);
        $w_code_path = api_get_path(WEB_CODE_PATH);

        $image = trim($image);
        $theme = 'css/'.api_get_visual_theme().'/icons/';
        $icon = '';
        $size_extra = '';

        if (isset($size)) {
            $size = intval($size);
            $size_extra = $size.'/';
        } else {
            $size = ICON_SIZE_SMALL;
        }

        //Checking the theme icons folder example: main/css/chamilo/icons/XXX
        if (is_file($code_path.$theme.$size_extra.$image)) {
            $icon = $w_code_path.$theme.$size_extra.$image;
        } elseif (is_file($code_path.'img/icons/'.$size_extra.$image)) {
            //Checking the main/img/icons/XXX/ folder
            $icon = $w_code_path.'img/icons/'.$size_extra.$image;
        } else {
            //Checking the img/ folder
            $icon = $w_code_path.'img/'.$image;
        }
        $icon = api_get_cdn_path($icon);
        if ($return_only_path) {
            return $icon;
        }

        $img = self::img($icon, $alt_text, $additional_attributes);
        if (SHOW_TEXT_NEAR_ICONS == true and !empty($alt_text)) {
            if ($show_text) {
                $img = "$img $alt_text";
            }
        }
        return $img;
    }

    /**
     * Returns the htmlcode for an image
     *
     * @param string $image the filename of the file (in the main/img/ folder
     * @param string $alt_text the alt text (probably a language variable)
     * @param array additional attributes (for instance height, width, onclick, ...)
     * @author Julio Montoya 2010
     */
    public static function img($image_path, $alt_text = '', $additional_attributes = array())
    {
        // Sanitizing the parameter $image_path
        $image_path = Security::filter_img_path($image_path);

        // alt text = the image name if there is none provided (for XHTML compliance)
        if ($alt_text == '') {
            $alt_text = basename($image_path);
        }

        $additional_attributes['src'] = $image_path;

        if (empty($additional_attributes['alt'])) {
            $additional_attributes['alt'] = $alt_text;
        }
        if (empty($additional_attributes['title'])) {
            $additional_attributes['title'] = $alt_text;
        }
        //return '<img src="'.$image_path.'" alt="'.$alt_text.'"  title="'.$alt_text.'" '.$attribute_list.' />';
        return self::tag('img', '', $additional_attributes);
    }

    /**
     * Returns the htmlcode for a tag (h3, h1, div, a, button), etc
     *
     * @param string $tag the tag name
     * @param string $content the tag's content
     * @param array $additional_attributes (for instance height, width, onclick, ...)
     * @author Julio Montoya 2010
     */
    public static function tag($tag, $content, $additional_attributes = array())
    {
        $attribute_list = '';
        // Managing the additional attributes
        if (!empty($additional_attributes) && is_array($additional_attributes)) {
            $attribute_list = '';
            foreach ($additional_attributes as $key => & $value) {
                $attribute_list .= $key.'="'.$value.'" ';
            }
        }
        //some tags don't have this </XXX>
        if (in_array($tag, array('img','input','br'))) {
            $return_value = '<'.$tag.' '.$attribute_list.' />';
        } else {
            $return_value = '<'.$tag.' '.$attribute_list.' > '.$content.'</'.$tag.'>';
        }
        return $return_value;
    }

    /**
     * Creates a URL anchor
     */
    public static function url($name, $url, $extra_attributes = array())
    {
        if (!empty($url)) {
            $url = preg_replace('#&amp;#', '&', $url);
            $url = htmlspecialchars($url, ENT_QUOTES, 'UTF-8');
            $extra_attributes['href'] = $url;
        }
        return self::tag('a', $name, $extra_attributes);
    }

    /**
     * Creates a div tag
     *
     * @param $content
     * @param array $extra_attributes
     * @return string
     */
    public static function div($content, $extra_attributes = array())
    {
        return self::tag('div', $content, $extra_attributes);
    }

    /**
     * Creates a span tag
     */
    public static function span($content, $extra_attributes = array())
    {
        return self::tag('span', $content, $extra_attributes);
    }

    /**
     * Displays an HTML input tag
     *
     */
    public static function input($type, $name, $value, $extra_attributes = array())
    {
         if (isset($type)) {
            $extra_attributes['type']= $type;
         }
         if (isset($name)) {
            $extra_attributes['name']= $name;
         }
         if (isset($value)) {
            $extra_attributes['value']= $value;
        }
        return self::tag('input', '', $extra_attributes);
    }

    /**
     * @param $name
     * @param $value
     * @param array $extra_attributes
     * @return string
     */
    public static function button($name, $value, $extra_attributes = array())
    {
    	if (!empty($name)) {
    		$extra_attributes['name']= $name;
    	}
    	return self::tag('button', $value, $extra_attributes);
    }

    /**
     * Displays an HTML select tag
     *
     */
    public static function select(
        $name,
        $values,
        $default = -1,
        $extra_attributes = array(),
        $show_blank_item = true,
        $blank_item_text = null
    ) {
        $html = '';
        $extra = '';
        $default_id =  'id="'.$name.'" ';
        foreach($extra_attributes as $key=>$parameter) {
            if ($key == 'id') {
                $default_id = '';
            }
            $extra .= $key.'="'.$parameter.'"';
        }
        $html .= '<select name="'.$name.'" '.$default_id.' '.$extra.'>';

        if ($show_blank_item) {
            if (empty($blank_item_text)) {
                $blank_item_text = get_lang('Select');
            } else {
                $blank_item_text = Security::remove_XSS($blank_item_text);
            }
            $html .= self::tag('option', '-- '.$blank_item_text.' --', array('value'=>'-1'));
        }
        if ($values) {
            foreach ($values as $key => $value) {
                if(is_array($value) && isset($value['name'])) {
                    $value = $value['name'];
                }
                $html .= '<option value="'.$key.'"';

                if (is_array($default)) {
                    foreach($default as $item) {
                        if ($item == $key) {
                            $html .= 'selected="selected"';
                            break;
                        }
                    }
                } else {
                    if ($default == $key) {
                        $html .= 'selected="selected"';
                    }
                }

                $html .= '>'.$value.'</option>';
            }
        }
        $html .= '</select>';
        return $html;
    }

    /**
     * Creates a tab menu
     * Requirements: declare the jquery, jquery-ui libraries + the jquery-ui.css
     * in the $htmlHeadXtra variable before the display_header
     * Add this script
     * @example
             * <script>
                    $(function() {
                        $( "#tabs" ).tabs();
                    });
                </script>
     * @param   array   list of the tab titles
     * @param   array   content that will be showed
     * @param   string  the id of the container of the tab in the example "tabs"
     * @param   array   attributes for the ul
     *
     */
    public static function tabs($header_list, $content_list, $id = 'tabs', $attributes = array(), $ul_attributes = array())
    {
        if (empty($header_list) || count($header_list) == 0 ) {
            return '';
        }

        $lis = '';
        $i = 1;
        foreach ($header_list as $item) {
            $item =self::tag('a', $item, array('href'=>'#'.$id.'-'.$i));
            $lis .=self::tag('li', $item, $ul_attributes);
            $i++;
        }
        $ul = self::tag('ul',$lis);

        $i = 1;
        $divs = '';
        foreach ($content_list as $content) {
            $content = self::tag('p',$content);
            $divs .=self::tag('div', $content, array('id'=>$id.'-'.$i));
            $i++;
        }
        $attributes['id'] = $id;
        $main_div = self::tag('div',$ul.$divs, $attributes);
        return $main_div ;
    }

    public static function tabs_only_link($header_list, $selected = null)
    {
         $id = uniqid();
         $i = 1;
         $lis = null;
         foreach ($header_list as $item) {
            $class = null;
            if ($i == $selected) {
                $class = 'active';
            }
            $item =self::tag('a', $item['content'], array('id'=>$id.'-'.$i, 'href' => $item['url']));
            $lis .=self::tag('li', $item, array('class' => $class));
            $i++;
        }
        return self::tag('ul',$lis, array('class' => 'nav nav-tabs'));
    }

    /**
     * In order to display a grid using jqgrid you have to:
     * @example
     * After your Display::display_header function you have to add the nex javascript code:     *
     * <script>
     *      echo Display::grid_js('my_grid_name',  $url,$columns, $column_model, $extra_params,array()); // for more information of this function check the grid_js() function
     * </script>
     * //Then you have to call the grid_html
     * echo Display::grid_html('my_grid_name');
     * As you can see both function use the same "my_grid_name" this is very important otherwise nothing will work
     *
     * @param   string  the div id, this value must be the same with the first parameter of Display::grid_js()
     * @return  string  html
     *
     */
    public static function grid_html($div_id)
    {
        $table  = self::tag('table','', array('id' => $div_id));
        $table .= self::tag('div','', array('id' => $div_id.'_pager'));
        return $table;
    }

    /**
     * @param string $label
     * @param string $form_item
     * @return string
     */
    public static function form_row($label, $form_item)
    {
        $label = self::span($label, array('class' =>'control-label'));
        $form_item = self::div($form_item, array('class' =>'controls'));
        return self::div($label.$form_item, array('class'=>'control-group'));
    }

    /**
     * This is a wrapper to use the jqgrid in Chamilo.
     * For the other jqgrid options visit http://www.trirand.com/jqgridwiki/doku.php?id=wiki:options
     * This function need to be in the ready jquery function
     * example --> $(function() { <?php echo Display::grid_js('grid' ...); ?> }
     * In order to work this function needs the Display::grid_html function with the same div id
     *
     * @param   string  $div_id div id
     * @param   string  $url url where the jqgrid will ask for data (if datatype = json)
     * @param   array   $column_names Visible columns (you should use get_lang). An array in which we place the names of the columns.
     * 					This is the text that appears in the head of the grid (Header layer).
     * 					Example: colname   {name:'date',     index:'date',   width:120, align:'right'},
     * @param   array   $column_model the column model :  Array which describes the parameters of the columns.This is the most important part of the grid.
     * 					For a full description of all valid values see colModel API. See the url above.
     * @param   array   $extra_params extra parameters
     * @param   array   $data data that will be loaded
     * @param	string	$formatter A string that will be appended to the JSON returned
     * @param	bool	$fixed_width not implemented yet
     * @return  string  the js code
     *
     */
    public static function grid_js(
        $div_id,
        $url,
        $column_names,
        $column_model,
        $extra_params,
        $data = array(),
        $formatter = '',
        $fixed_width = false
    ) {
        $obj = new stdClass();
        $obj->first = 'first';

        if (!empty($url)) {
            $obj->url = $url;
        }

        //This line should only be used/modified in case of having characters
        // encoding problems - see #6159
        //$column_names = array_map("utf8_encode", $column_names);

        $obj->colNames      = $column_names;
        $obj->colModel      = $column_model;
        $obj->pager         = '#'.$div_id.'_pager';
        $obj->datatype  = 'json';
        $obj->viewrecords = 'true';

        $all_value = 10000000;

        // Default row quantity
        if (!isset($extra_params['rowList'])) {
            $extra_params['rowList'] = array(20, 50, 100, 500, 1000, $all_value);
        }

        $json = '';
        if (!empty($extra_params['datatype'])) {
            $obj->datatype  = $extra_params['datatype'];
        }

        // Row even odd style.
        $obj->altRows = true;
        if (!empty($extra_params['altRows'])) {
            $obj->altRows = $extra_params['altRows'];
        }

        if (!empty($extra_params['sortname'])) {
            $obj->sortname      = $extra_params['sortname'];
        }

        if (!empty($extra_params['sortorder'])) {
            $obj->sortorder     = $extra_params['sortorder'];
        }

        if (!empty($extra_params['rowList'])) {
            $obj->rowList     = $extra_params['rowList'];
        }
        //Sets how many records we want to view in the grid
        $obj->rowNum = 20;
        if (!empty($extra_params['rowNum'])) {
            $obj->rowNum     = $extra_params['rowNum'];
        }

        if (!empty($extra_params['viewrecords'])) {
            $obj->viewrecords   = $extra_params['viewrecords'];
        }

        $beforeSelectRow = null;
        if (isset($extra_params['beforeSelectRow'])) {
            $beforeSelectRow = "beforeSelectRow: ".$extra_params['beforeSelectRow'].", ";
            unset($extra_params['beforeSelectRow']);
        }

        // Adding extra params
        if (!empty($extra_params)) {
            foreach ($extra_params as $key => $element) {
                // the groupHeaders key gets a special treatment
                if ($key != 'groupHeaders') {
                    $obj->$key = $element;
                }
            }
        }

        // Adding static data.
        if (!empty($data)) {
            $data_var = $div_id.'_data';
            $json.=' var '.$data_var.' = '.json_encode($data).';';
            $obj->data = $data_var;
            $obj->datatype = 'local';
            $json.="\n";
        }

        $obj->end = 'end';

        $json_encode = json_encode($obj);

        if (!empty($data)) {
            //Converts the "data":"js_variable" to "data":js_variable,
            // otherwise it will not work
            $json_encode = str_replace('"data":"'.$data_var.'"', '"data":'.$data_var.'', $json_encode);
        }

        // Fixing true/false js values that doesn't need the ""
        $json_encode = str_replace(':"true"',':true',$json_encode);
        // wrap_cell is not a valid jqgrid attributes is a hack to wrap a text
        $json_encode = str_replace('"wrap_cell":true', 'cellattr : function(rowId, value, rowObject, colModel, arrData) { return \'class = "jqgrid_whitespace"\'; }', $json_encode);
        $json_encode = str_replace(':"false"',':false',$json_encode);
        $json_encode = str_replace('"formatter":"action_formatter"', 'formatter:action_formatter', $json_encode);
        $json_encode = str_replace(array('{"first":"first",','"end":"end"}'), '', $json_encode);

        // Creating the jqgrid element.
        $json .= '$("#'.$div_id.'").jqGrid({';
        //$json .= $beforeSelectRow;

        $json .= $json_encode;

        $json .= '});';

        // Grouping headers option
        if (isset($extra_params['groupHeaders'])) {
            $groups = '';
            foreach ($extra_params['groupHeaders'] as $group) {
                //{ "startColumnName" : "courses", "numberOfColumns" : 1, "titleText" : "Order Info" },
                $groups .= '{ "startColumnName" : "' . $group['startColumnName'] . '", "numberOfColumns" : ' . $group['numberOfColumns'] . ', "titleText" : "' . $group['titleText']  . '" },';

            }
            $json .= '$("#'.$div_id.'").jqGrid("setGroupHeaders", {
                "useColSpanStyle" : false,
                "groupHeaders"    : [
                    ' . $groups . '
                ]
            });';
        }

        $all_text = addslashes(get_lang('All'));
        $json .= '$("'.$obj->pager.' option[value='.$all_value.']").text("'.$all_text.'");';
        $json.= "\n";
        // Adding edit/delete icons.
        $json.= $formatter;

        return $json;
    }

    /**
     * @param array $headers
     * @param array $rows
     * @param array $attributes
     * @return string
     */
    public static function table($headers, $rows, $attributes = array())
    {
    	if (empty($attributes)) {
    		$attributes['class'] = 'data_table';
        }
        $table = new HTML_Table($attributes);
        $row = 0;
        $column = 0;

        //Course headers
        if (!empty($headers)) {
	        foreach ($headers as $item) {
	            $table->setHeaderContents($row, $column, $item);
	            $column++;
	        }
	        $row = 1;
	        $column = 0;
        }

        if (!empty($rows)) {
	        foreach($rows as $content) {
	            $table->setCellContents($row, $column, $content);
                $row++;
                    //$column++;
                }
        }
        return $table->toHtml();
    }

    /**
     * Returns the "what's new" icon notifications
     *
     * The general logic of this function is to track the last time the user
     * entered the course and compare to what has changed inside this course
     * since then, based on the item_property table inside this course. Note that,
     * if the user never entered the course before, he will not see notification
     * icons. This function takes session ID into account (if any) and only shows
     * the corresponding notifications.
     * @param array     Course information array, containing at least elements 'db' and 'k'
     * @return string   The HTML link to be shown next to the course
     */
    public static function show_notification($course_info)
    {
        $t_track_e_access 	= Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_LASTACCESS);
        $course_tool_table	= Database::get_course_table(TABLE_TOOL_LIST);
        $tool_edit_table 	= Database::get_course_table(TABLE_ITEM_PROPERTY);
        $course_code        = Database::escape_string($course_info['code']);

        $user_id = api_get_user_id();
        $course_id = $course_info['real_id'];
        $course_info['id_session'] = intval($course_info['id_session']);

        // Get the user's last access dates to all tools of this course
        $sql = "SELECT *
                FROM $t_track_e_access USE INDEX (access_cours_code, access_user_id)
                WHERE
                    access_cours_code = '".$course_code."' AND
                    access_user_id = '$user_id' AND
                    access_session_id ='".$course_info['id_session']."'";
        $resLastTrackInCourse = Database::query($sql);

        $oldestTrackDate = $oldestTrackDateOrig = '3000-01-01 00:00:00';
        while ($lastTrackInCourse = Database::fetch_array($resLastTrackInCourse)) {
            $lastTrackInCourseDate[$lastTrackInCourse['access_tool']] = $lastTrackInCourse['access_date'];
            if ($oldestTrackDate > $lastTrackInCourse['access_date']) {
                $oldestTrackDate = $lastTrackInCourse['access_date'];
            }
        }

        if ($oldestTrackDate == $oldestTrackDateOrig) {
            //if there was no connexion to the course ever, then take the
            // course creation date as a reference
            $course_table = Database::get_main_table(TABLE_MAIN_COURSE);
            $sql = "SELECT course.creation_date ".
                 "FROM $course_table course ".
                 "WHERE course.code = '".$course_code."'";
            $res = Database::query($sql);
            if ($res && Database::num_rows($res)>0) {
                $row = Database::fetch_array($res);
            }
            $oldestTrackDate = $row['creation_date'];
        }

        // Get the last edits of all tools of this course.
        $sql = "SELECT
                    tet.*,
                    tet.lastedit_date last_date,
                    tet.tool tool,
                    tet.ref ref,
                    tet.lastedit_type type,
                    tet.to_group_id group_id,
                    ctt.image image,
                    ctt.link link
                FROM $tool_edit_table tet, $course_tool_table ctt
                WHERE
                    tet.c_id = $course_id AND
                    ctt.c_id = $course_id AND
                    tet.lastedit_date > '$oldestTrackDate' ".
                    // Special hack for work tool, which is called student_publication in c_tool and work in c_item_property :-/ BT#7104
                    " AND (ctt.name = tet.tool OR (ctt.name = 'student_publication' AND tet.tool = 'work')) ".
                    " AND ctt.visibility = '1' ".
                    " AND tet.lastedit_user_id != $user_id AND tet.id_session = '".$course_info['id_session']."'
                 ORDER BY tet.lastedit_date";

        $res = Database::query($sql);
        // Get the group_id's with user membership.
        $group_ids = GroupManager :: get_group_ids($course_info['real_id'], $user_id);
        $group_ids[] = 0; //add group 'everyone'
        $notifications = array();
        // Filter all last edits of all tools of the course
        while ($res && ($item_property = Database::fetch_array($res))) {

            // First thing to check is if the user never entered the tool
            // or if his last visit was earlier than the last modification.
            if ((!isset($lastTrackInCourseDate[$item_property['tool']])
                 || $lastTrackInCourseDate[$item_property['tool']] < $item_property['lastedit_date'])
                // Drop the tool elements that are part of a group that the
                // user is not part of.
                && ((in_array($item_property['to_group_id'], $group_ids)
                // Drop the dropbox, notebook and chat tools (we don't care)
                && ($item_property['tool'] != TOOL_DROPBOX
                      && $item_property['tool'] != TOOL_NOTEBOOK
                      && $item_property['tool'] != TOOL_CHAT)
                   )
                )
                // Take only what's visible or "invisible but where the user is a teacher" or where the visibility is unset.
                && ($item_property['visibility'] == '1'
                    || ($course_info['status'] == '1' && $item_property['visibility'] == '0')
                    || !isset($item_property['visibility']))
            ) {
                if ($course_info['real_id'] == 1) {
                  //  var_dump($item_property);
                }
                // Also drop announcements and events that are not for the user or his group.
                if ((
                        $item_property['tool'] == TOOL_ANNOUNCEMENT ||
                        $item_property['tool'] == TOOL_CALENDAR_EVENT
                    ) &&
                    (
                        ($item_property['to_user_id'] != $user_id) &&
                        (!isset($item_property['to_group_id']) || !in_array($item_property['to_group_id'], $group_ids)))
                ) {
                   continue;
                }
                // If it's a survey, make sure the user's invited. Otherwise drop it.
                if ($item_property['tool'] == TOOL_SURVEY) {
                    $survey_info = survey_manager::get_survey($item_property['ref'], 0, $course_code);
                    if (!empty($survey_info)) {
                        $invited_users = SurveyUtil::get_invited_users(
                            $survey_info['code'],
                            $course_code
                        );
                        if (!in_array($user_id, $invited_users['course_users'])) {
                            continue;
                        }
                    }
                }
                // If it's a learning path, ensure it is currently visible to the user
                if ($item_property['tool'] == TOOL_LEARNPATH) {
                    require_once api_get_path(SYS_CODE_PATH).'newscorm/learnpath.class.php';
                    if (!learnpath::is_lp_visible_for_student($item_property['ref'], $user_id, $course_code)) {
                        continue;
                    }
                }
                if ($item_property['tool'] == 'work' && $item_property['type'] == 'DirectoryCreated') {
                    $item_property['lastedit_type'] = 'WorkAdded';
                }
                $notifications[$item_property['tool']] = $item_property;
            }
        }

        // Show all tool icons where there is something new.
        $retvalue = '&nbsp;';
        while (list($key, $notification) = each($notifications)) {
            $lastDate = date('d/m/Y H:i', convert_sql_date($notification['lastedit_date']));
            $type = $notification['lastedit_type'];
            if (empty($course_info['id_session'])) {
                $my_course['id_session'] = 0;
            } else {
                $my_course['id_session'] = $course_info['id_session'];
            }
            $label = get_lang('TitleNotification').": ".get_lang($type)." ($lastDate)";
            $retvalue .= '<a href="'.api_get_path(WEB_CODE_PATH).$notification['link'].'?cidReq='.$course_code.'&amp;ref='.$notification['ref'].'&amp;gidReq='.$notification['to_group_id'].'&amp;id_session='.$my_course['id_session'].'">'.
                            Display::return_icon($notification['image'], $label).'</a>&nbsp;';
        }

        return $retvalue;
    }

    /**
     * Displays a digest e.g. short summary of new agenda and announcements items.
     * This used to be displayed in the right hand menu, but is now
     * disabled by default (see config settings in this file) because most people like
     * the what's new icons better.
     *
     * @version 1.0
     */
    public static function display_digest($toolsList, $digest, $orderKey, $courses)
    {
        $html = '';
        if (is_array($digest) && (CONFVAL_showExtractInfo == SCRIPTVAL_UnderCourseList || CONFVAL_showExtractInfo == SCRIPTVAL_Both)) {
            // // // LEVEL 1 // // //
            reset($digest);
            $html .= "<br /><br />\n";
            while (list($key1) = each($digest)) {
                if (is_array($digest[$key1])) {
                    // // // Title of LEVEL 1 // // //
                    $html .= "<strong>\n";
                    if ($orderKey[0] == 'keyTools') {
                        $tools = $key1;
                        $html .= $toolsList[$key1]['name'];
                    } elseif ($orderKey[0] == 'keyCourse') {
                        $courseSysCode = $key1;
                        $html .= "<a href=\"".api_get_path(WEB_COURSE_PATH). $courses[$key1]['coursePath']. "\">".$courses[$key1]['courseCode']. "</a>\n";
                    } elseif ($orderKey[0] == 'keyTime') {
                        $html .= api_convert_and_format_date($digest[$key1], DATE_FORMAT_LONG, date_default_timezone_get());
                    }
                    $html .= "</strong>\n";
                    // // // End Of Title of LEVEL 1 // // //
                    // // // LEVEL 2 // // //
                    reset($digest[$key1]);
                    while (list ($key2) = each($digest[$key1])) {
                        // // // Title of LEVEL 2 // // //
                        $html .= "<p>\n". "\n";
                        if ($orderKey[1] == 'keyTools') {
                            $tools = $key2;
                            $html .= $toolsList[$key2][name];
                        } elseif ($orderKey[1] == 'keyCourse') {
                            $courseSysCode = $key2;
                            $html .= "<a href=\"". api_get_path(WEB_COURSE_PATH). $courses[$key2]['coursePath']. "\">". $courses[$key2]['courseCode']. "</a>\n";
                        } elseif ($orderKey[1] == 'keyTime') {
                            $html .= api_convert_and_format_date($key2, DATE_FORMAT_LONG, date_default_timezone_get());
                        }
                        $html .= "\n";
                        $html .= "</p>";
                        // // // End Of Title of LEVEL 2 // // //
                        // // // LEVEL 3 // // //
                        reset($digest[$key1][$key2]);
                        while (list ($key3, $dataFromCourse) = each($digest[$key1][$key2])) {
                            // // // Title of LEVEL 3 // // //
                            if ($orderKey[2] == 'keyTools') {
                                $level3title = "<a href=\"".$toolsList[$key3]["path"].$courseSysCode."\">".$toolsList[$key3]['name']."</a>";
                            } elseif ($orderKey[2] == 'keyCourse') {
                                $level3title = "&#8226; <a href=\"".$toolsList[$tools]["path"].$key3."\">".$courses[$key3]['courseCode']."</a>\n";
                            } elseif ($orderKey[2] == 'keyTime') {
                                $level3title = "&#8226; <a href=\"".$toolsList[$tools]["path"].$courseSysCode."\">".api_convert_and_format_date($key3, DATE_FORMAT_LONG, date_default_timezone_get())."</a>";
                            }
                            // // // End Of Title of LEVEL 3 // // //
                            // // // LEVEL 4 (data) // // //
                            reset($digest[$key1][$key2][$key3]);
                            while (list ($key4, $dataFromCourse) = each($digest[$key1][$key2][$key3])) {
                                $html .= $level3title. ' &ndash; '. api_substr(strip_tags($dataFromCourse), 0, CONFVAL_NB_CHAR_FROM_CONTENT);
                                //adding ... (three dots) if the texts are too large and they are shortened
                                if (api_strlen($dataFromCourse) >= CONFVAL_NB_CHAR_FROM_CONTENT) {
                                    $html .= '...';
                                }
                            }
                            $html .= "<br />\n";
                        }
                    }
                }
            }
            return $html;
        }
    } // End function display_digest

    /**
     * Get the session box details as an array
     * @param int       Session ID
     * @return array    Empty array or session array ['title'=>'...','category'=>'','dates'=>'...','coach'=>'...','active'=>true/false,'session_category_id'=>int]
     */
    public static function get_session_title_box($session_id)
    {
        global $nosession;

        if (!$nosession) {
            global $now, $date_start, $date_end;
        }

        $output = array();
        if (!$nosession) {
            $main_user_table        = Database :: get_main_table(TABLE_MAIN_USER);
            $tbl_session            = Database :: get_main_table(TABLE_MAIN_SESSION);
            $active = false;
            // Request for the name of the general coach
            $sql ='SELECT tu.lastname, tu.firstname, ts.*
                    FROM '.$tbl_session.' ts  LEFT JOIN '.$main_user_table .' tu ON ts.id_coach = tu.user_id
                    WHERE ts.id = '.intval($session_id);
            $rs = Database::query($sql);
            $session_info = Database::store_result($rs, 'ASSOC');
            $session_info = $session_info[0];

            $session = array();
            $session['title'] = $session_info['name'];
            $session['coach'] = '';
            $session['dates'] =  '';

            if ($session_info['date_end'] == '0000-00-00' && $session_info['date_start'] == '0000-00-00') {
                if (api_get_setting('show_session_coach') === 'true') {
                    $session['coach'] = get_lang('GeneralCoach').': '.api_get_person_name($session_info['firstname'], $session_info['lastname']);
                }
                if (isset($session_info['duration']) && !empty($session_info['duration'])) {
                    $userDurationData = SessionManager::getUserSession(
                            api_get_user_id(),
                            $session_id
                    );
                    $userDuration = 0;
                    if (isset($userDurationData['duration'])) {
                        $userDuration = intval($userDurationData['duration']);
                    }
                    $totalDuration = $session_info['duration'] + $userDuration;

                    $daysLeft = SessionManager::getDayLeftInSession(
                        $session_id,
                        api_get_user_id(),
                        $totalDuration
                    );
                    $session['duration'] = sprintf(get_lang('SessionDurationXDaysLeft'), $daysLeft);
                }
                $active = true;
            } else {
                $start = $stop = false;
                $start_buffer = $stop_buffer = '';
                if ($session_info['date_start'] == '0000-00-00') {
                    $session_info['date_start'] = '';
                } else {
                    $start = true;
                    $start_buffer = $session_info['date_start'];
                    $session_info['date_start'] = get_lang('From').' '.$session_info['date_start'];
                }
                if ($session_info['date_end'] == '0000-00-00') {
                    $session_info['date_end'] = '';
                } else {
                    $stop = true;
                    $stop_buffer = $session_info['date_end'];
                    $session_info['date_end'] = get_lang('Until').' '.$session_info['date_end'];
                }
                if ($start && $stop) {
                    $session['dates'] = Display::tag('i', sprintf(get_lang('FromDateXToDateY'), $start_buffer, $stop_buffer));
                } else {
                    $session['dates'] = Display::tag('i', $session_info['date_start'].' '.$session_info['date_end']);
                }

                if ( api_get_setting('show_session_coach') === 'true' ) {
                    $session['coach'] = get_lang('GeneralCoach').': '.api_get_person_name($session_info['firstname'], $session_info['lastname']);
                }
                $active = ($date_start <= $now && $date_end >= $now);
            }
            $session['active'] = $active;
            $session['session_category_id'] = $session_info['session_category_id'];

            if (array_key_exists('show_description', $session_info)) {
                if (!empty($session_info['show_description'])) {
                    $session['description'] = $session_info['description'];
                }
            }

            $output = $session;
        }
        return $output;
    }

    /**
     * Return the five star HTML
     *
     * @param  string  id of the rating ul element
     * @param  string  url that will be added (for jquery see hot_courses.tpl)
	 * @param	string	point info array see function CourseManager::get_course_ranking()
	 * @param	bool	add a div wrapper
	 * @todo	use     templates
     **/
    public static function return_rating_system($id, $url, $point_info = array(), $add_div_wrapper = true)
    {
		$number_of_users_who_voted =  isset($point_info['users_who_voted']) ? $point_info['users_who_voted'] : null;

		$percentage =  isset($point_info['point_average']) ? $point_info['point_average'] : 0;

		if (!empty($percentage)) {
            $percentage = $percentage*125/100;
        }
		$accesses =  isset($point_info['accesses']) ? $point_info['accesses'] : 0;

		$star_label = sprintf(get_lang('XStarsOutOf5'), $point_info['point_average_star']);

        $html = '<ul id="'.$id.'" class="star-rating">
					<li class="current-rating" style="width:'.$percentage.'px;"></li>
					<li><a href="javascript:void(0);" data-link="'.$url.'&amp;star=1" title="'.$star_label.'" class="one-star">1</a></li>
					<li><a href="javascript:void(0);" data-link="'.$url.'&amp;star=2" title="'.$star_label.'" class="two-stars">2</a></li>
					<li><a href="javascript:void(0);" data-link="'.$url.'&amp;star=3" title="'.$star_label.'" class="three-stars">3</a></li>
					<li><a href="javascript:void(0);" data-link="'.$url.'&amp;star=4" title="'.$star_label.'" class="four-stars">4</a></li>
					<li><a href="javascript:void(0);" data-link="'.$url.'&amp;star=5" title="'.$star_label.'" class="five-stars">5</a></li>
				</ul>';

		$labels = array();

		$labels[]= $number_of_users_who_voted == 1 ? $number_of_users_who_voted.' '.get_lang('Vote') : $number_of_users_who_voted.' '.get_lang('Votes');
		$labels[]= $accesses == 1 ? $accesses.' '.get_lang('Visit') : $accesses.' '.get_lang('Visits');
		if (!empty($number_of_users_who_voted)) {
			$labels[]= get_lang('Average').' '.$point_info['point_average_star'].'/5';
		}

		$labels[]= $point_info['user_vote']  ? get_lang('YourVote').' ['.$point_info['user_vote'].']' : get_lang('YourVote'). ' [?] ';

		if (!$add_div_wrapper && api_is_anonymous()) {
			$labels[]= Display::tag('span', get_lang('LoginToVote'), array('class' => 'error'));
		}

        $html .= Display::span(implode(' | ', $labels) , array('id' =>  'vote_label_'.$id, 'class' => 'vote_label_info'));
        $html .= ' '.Display::span(' ', array('id' =>  'vote_label2_'.$id));

        if ($add_div_wrapper) {
			$html = Display::div($html, array('id' => 'rating_wrapper_'.$id));
		}
        return $html;
    }

    public static function return_default_table_class()
    {
        return 'data_table';
    }

    /**
     * @param string $title
     * @param string $second_title
     * @param string $size
     * @param bool $filter
     * @return string
     */
    public static function page_header($title, $second_title = null, $size = 'h2', $filter = true)
    {
        if ($filter) {
            $title = Security::remove_XSS($title);
        }

        if (!empty($second_title)) {
            if ($filter) {
                $second_title = Security::remove_XSS($second_title);
            }
            $title .= "<small> $second_title<small>";
        }
        return '<div class="page-header"><'.$size.'>'.$title.'</'.$size.'></div>';
    }

    public static function page_header_and_translate($title, $second_title = null)
    {
        $title = get_lang($title);
        return self::page_header($title, $second_title);
    }

     public static function page_subheader_and_translate($title, $second_title = null)
     {
        $title = get_lang($title);
        return self::page_subheader($title, $second_title);
    }

    public static function page_subheader($title, $second_title = null)
    {
        if (!empty($second_title)) {
            $second_title = Security::remove_XSS($second_title);
            $title .= "<small> $second_title<small>";
        }
        return '<h3>'.Security::remove_XSS($title).'</h3>';
    }

    public static function page_subheader2($title, $second_title = null)
    {
        return self::page_header($title, $second_title, 'h3');
    }

    public static function page_subheader3($title, $second_title = null)
    {
        return self::page_header($title, $second_title, 'h4');
    }

    public static function description($list)
    {
        $html = null;
        if (!empty($list)) {
            $html = '<dl class="dl-horizontal">';
            foreach ($list as $item) {
                $html .= '<dt>'.$item['title'].'</dd>';
                $html .= '<dd>'.$item['content'].'</dt>';
            }
            $html .= '</dl>';
        }
        return $html;
    }

    public static function bar_progress($percentage, $show_percentage = true, $extra_info = null)
    {
        $percentage = intval($percentage);
        $div = '<div class="progress progress-striped">
                    <div class="bar" style="width: '.$percentage.'%;"></div>
                </div>';
        if ($show_percentage) {
            $div .= '<div class="progresstext">'.$percentage.'%</div>';
        } else {
            if (!empty($extra_info)) {
                $div .= '<div class="progresstext">'.$extra_info.'</div>';
            }
        }
        return $div;
    }

    public static function badge($count, $type ="warning") {
        $class = '';

        switch ($type) {
            case 'success':
                $class = 'badge-success';
                break;
            case 'warning':
                $class = 'badge-warning';
                break;
            case 'important':
                $class = 'badge-important';
                break;
            case 'info':
                $class = 'badge-info';
                break;
            case 'inverse':
                $class = 'badge-inverse';
                break;
        }

        if (!empty($count)) {
            return ' <span class="badge '.$class.'">'.$count.'</span>';
        }
        return null;
    }

    /**
     * @param array $badge_list
     * @return string
     */
    public static function badge_group($badge_list)
    {
        $html = '<div class="badge-group">';
        foreach ($badge_list as $badge) {
            $html .= $badge;
        }
        $html .= '</div>';
        return $html;
    }

    /**
     * @param string $content
     * @param string $type
     * @return string
     */
    public static function label($content, $type = null)
    {
        $class = '';
        switch ($type) {
            case 'success':
                $class = 'label-success';
                break;
            case 'warning':
                $class = 'label-warning';
                break;
            case 'important':
                $class = 'label-important';
                break;
            case 'info':
                $class = 'label-info';
                break;
            case 'inverse':
                $class = 'label-inverse';
                break;
        }

        $html = '';
        if (!empty($content)) {
            $html = '<span class="label '.$class.'">';
            $html .= $content;
            $html .='</span>';
        }
        return $html;
    }

    /**
     * @param array $items
     * @return null|string
     */
    public static function actions($items, $class = 'new_actions')
    {
        $html = null;
        if (!empty($items)) {
            $html = '<div class="'.$class.'"><ul class="nav nav-pills">';
            foreach ($items as $value) {
                $class = null;
                if (isset($value['active']) && $value['active']) {
                    $class = 'class ="active"';
                }

                if (basename($_SERVER['REQUEST_URI']) == basename($value['url']) ) {
                    $class = 'class ="active"';
                }
                $html .= "<li $class >";
                $html .= self::url($value['content'], $value['url']);
                $html .= '</li>';
            }
            $html .= '</ul></div>';
        }
        return $html;
    }

    /**
     * Prints a tooltip
     */
    public static function tip($text, $tip)
    {
        if (empty($tip)) {
            return $text;
        }
        return self::span($text, array('class' => 'boot-tooltip', 'title' => strip_tags($tip)));
    }

    public static function generate_accordion($items, $type = 'jquery', $id = null)
    {
        $html = null;
        if (!empty($items)) {
            if (empty($id)) {
                $id = api_get_unique_id();
            }
            if ($type == 'jquery') {
                $html = '<div class="accordion_jquery" id="'.$id.'">'; //using jquery
            } else {
                $html = '<div class="accordion" id="'.$id.'">'; //using bootstrap
            }

            $count = 1;
            foreach ($items as $item) {
                $html .= '<div class="accordion-my-group">';
                $html .= '<div class="accordion-heading">
                                <a class="accordion-toggle" data-toggle="collapse" data-parent="#'.$id.'" href="#collapse'.$count.'">
                                '.$item['title'].'
                                </a>
                          </div>';

                $html .= '<div id="collapse'.$count.'" class="accordion-body">';
                $html .= '<div class="accordion-my-inner">
                            '.$item['content'].'
                            </div>
                          </div>';
            }
            $html .= '</div>';
        }
        return $html;
    }

    /**
     * @todo use twig
     */
    public static function group_button($title, $elements)
    {
        $html = '<div class="btn-toolbar">
            <div class="btn-group">
            <button class="btn dropdown-toggle" data-toggle="dropdown">'.$title.' <span class="caret"></span></button>
            <ul class="dropdown-menu">';
        foreach ($elements as $item) {
            $html .= Display::tag('li', Display::url($item['title'], $item['href']));
        }
        $html .= '</ul>
            </div> </div>';
        return $html;
    }

    /**
     * @param string $file
     * @param array $params
     * @return null|string
     */
    public static function getMediaPlayer($file, $params = array())
    {
        $fileInfo = pathinfo($file);

        switch ($fileInfo['extension']) {
            case 'wav':
                if (isset($params['url'])) {
                    $url = DocumentManager::generateAudioTempFile(basename($file), $file);
                    return DocumentManager::readNanogongFile($url);
                }
                break;
            case 'mp3':
            case 'webm':
                $autoplay = null;
                if (isset($params['autoplay']) && $params['autoplay'] == 'true') {
                    $autoplay = 'autoplay';
                }
                $width = isset($params['width']) ? 'width="'.$params['width'].'"' : null;
                $id = isset($params['id']) ? $params['id'] : $fileInfo['basename'];
                $class = isset($params['class']) ? ' class="'.$params['class'].'"' : null;

                $html = '<audio id="'.$id.'" '.$class.' controls '.$autoplay.' '.$width.' src="'.$params['url'].'" >';
                $html .= '<object width="'.$width.'" height="50" type="application/x-shockwave-flash" data="'.api_get_path(WEB_LIBRARY_PATH).'javascript/mediaelement/flashmediaelement.swf">
                            <param name="movie" value="'.api_get_path(WEB_LIBRARY_PATH).'javascript/mediaelement/flashmediaelement.swf" />
                            <param name="flashvars" value="controls=true&file='.$params['url'].'" />
                          </object>';
                $html .= '</audio>';
                return $html;
                break;
        }

        return null;
    }


    /**
     *
     * @param int $nextValue
     * @param array $list
     * @param int $current
     * @param int $fixedValue
     * @param array $conditions
     * @param string $link
     * @param bool $isMedia
     * @param bool $addHeaders

     * @return string
     */
    public static function progressPaginationBar(
        $nextValue,
        $list,
        $current,
        $fixedValue = null,
        $conditions = array(),
        $link = null,
        $isMedia = false,
        $addHeaders = true,
        $linkAttributes = array()
    ) {
        if ($addHeaders) {
            $pagination_size = 'pagination-mini';
            $html = '<div class="exercise_pagination pagination '.$pagination_size.'"><ul>';
        } else {
            $html = null;
        }

        $affectAllItems = false;

        if ($isMedia && isset($fixedValue) && ($nextValue + 1 == $current)) {
            $affectAllItems = true;
        }

        $localCounter = 0;
        foreach ($list as $itemId) {
            $isCurrent = false;
            if ($affectAllItems) {
                $isCurrent = true;
            } else {
                if (!$isMedia) {
                    $isCurrent = $current == ($localCounter + $nextValue + 1) ? true : false;
                }
            }

            $html .= self::parsePaginationItem(
                $itemId,
                $isCurrent,
                $conditions,
                $link,
                $nextValue,
                $isMedia,
                $localCounter,
                $fixedValue,
                $linkAttributes
            );

            $localCounter++;
        }

        if ($addHeaders) {
            $html .= '</ul></div>';
        }
        return $html;
    }

    /**
     *
     * @param int $itemId
     * @param bool $isCurrent
     * @param array $conditions
     * @param string $link
     * @param int $nextValue
     * @param bool $isMedia
     * @param int $localCounter
     * @param int $fixedValue
     * @return string
     */
    static function parsePaginationItem(
        $itemId,
        $isCurrent,
        $conditions,
        $link,
        $nextValue = 0,
        $isMedia = false,
        $localCounter = null,
        $fixedValue = null,
        $linkAttributes = array())
    {
        $defaultClass = "before";
        $class = $defaultClass;

        foreach ($conditions as $condition) {
            $array = isset($condition['items']) ? $condition['items'] : array();
            $class_to_applied = $condition['class'];
            $type = isset($condition['type']) ? $condition['type'] : 'positive';
            $mode = isset($condition['mode']) ? $condition['mode'] : 'add';
            switch ($type) {
                case 'positive':
                    if (in_array($itemId, $array)) {
                        if ($mode == 'overwrite') {
                            $class = " $defaultClass $class_to_applied";
                        } else {
                            $class .= " $class_to_applied";
                        }
                    }
                    break;
                case 'negative':
                    if (!in_array($itemId, $array)) {
                        if ($mode == 'overwrite') {
                            $class = " $defaultClass $class_to_applied";
                        } else {
                            $class .= " $class_to_applied";
                        }
                    }
                    break;
            }
        }

        if ($isCurrent) {
            $class = "before current";
        }

        if ($isMedia && $isCurrent) {
            $class = "before current";
        }

        if (empty($link)) {
            $link_to_show = "#";
        } else {
            $link_to_show = $link.($nextValue + $localCounter);
        }

        $label = $nextValue + $localCounter + 1;

        if ($isMedia) {
            $label = ($fixedValue + 1) .' '.chr(97 + $localCounter);
            $link_to_show = $link.$fixedValue.'#questionanchor'.$itemId;
        }

        $link = Display::url($label.' ', $link_to_show, $linkAttributes);

        return  '<li class = "'.$class.'">'.$link.'</li>';
    }

    /**
     * @param int $current
     * @param int $total
     * @return string
     */
    public static function paginationIndicator($current, $total)
    {
        $html = null;
        if (!empty($current) && !empty($total)) {
            $label = sprintf(get_lang('PaginationXofY'), $current, $total);
            $html = self::url($label, '#', array('class' => 'btn disabled'));
        }
        return $html;
    }

    /**
     * Adds a message in the queue
     * @param string $message
     */
    public static function addFlash($message)
    {
        $messages = Session::read('flash_messages');
        if (empty($messages)) {
            $messages[] = $message;
        } else {
            array_push($messages, $message);
        }
        Session::write('flash_messages', $messages);
    }

    /**
     * @return string
     */
    public static function getFlashToString()
    {
        $messages = Session::read('flash_messages');
        $messageToString = '';
        if (!empty($messages)) {
            foreach ($messages as $message) {
                $messageToString .= $message;
            }
        }
        return $messageToString;
    }

    /**
     * Shows the message from the session
     */
    public static function showFlash()
    {
        echo self::getFlashToString();
    }

    /**
     * Destroys the message session
     */
    public static function cleanFlashMessages()
    {
        Session::erase('flash_messages');
    }

    /**
     * @param string $content
     * @param string $title
     * @param string $footer
     * @param string $style primary|success|info|warning|danger
     * @param string $extra
     *
     * @return string
     */
    public static function panel($content, $title = '', $footer = '', $style = '', $extra = '')
    {
        $title = !empty($title) ? '<div class="panel-heading"><h3 class="panel-title">'.$title.'</h3>'.$extra.'</div>' : '';
        $footer = !empty($footer) ? '<div class="panel-footer ">'.$footer.'</div>' : '';
        $styles = ['primary','success','info','warning','danger'];
        $style = !in_array($style, $styles) ? 'default' : $style;

        return '
            <div class="panel panel-'.$style.'">
                '.$title.'
                '.self::contentPanel($content).'
                '.$footer.'
            </div>'
            ;
    }

    /**
     * @param string $content
     * @return string
     */
    public static function contentPanel($content)
    {
        return '<div class="panel-body">
                '.$content.'
                </div>';
    }

    /**
     * Get the button HTML with an Awesome Font icon
     * @param string $text The button content
     * @param string $url The url to button
     * @param string $icon The Awesome Font class for icon
     * @param string $type Optional. The button Bootstrap class. Default 'default' class
     * @param array $attributes The additional attributes
     * @return string The button HTML
     */
    public static function toolbarButton(
        $text,
        $url,
        $icon = 'check',
        $type = 'default',
        array $attributes = [],
        $includeText = true
    ) {
        $buttonClass = "btn btn-$type";
        $icon = self::tag('i', null, ['class' => "fa fa-$icon fa-fw", 'aria-hidden' => 'true']);
        $attributes['class'] = isset($attributes['class']) ? "$buttonClass {$attributes['class']}" : $buttonClass;

        if (!$includeText) {
            $text = '<span class="sr-only">' . $text . '</span>';
        }

        return self::url("$icon $text", $url, $attributes);
    }

    /**
     * @param int $id
     * @param array $content
     * @param int $col
     * @param bool|true $right
     * @return string
     */
    public static function toolbarAction($id, $content = array(), $col = 2, $right = true)
    {
        $columns = 12/$col;
        $html = '';
        $html .= '<div id="' . $id . '" class="actions">';
        $html .= '<div class="row-fluid">';
        if ($col > 4) {
            $html = '<div class="alert alert-warning" role="alert">Action toolbar design does not work when exceeding four columns - check Display::toolbarAction()</div>';
        } else {
            for ( $i = 0; $i < $col; $i++ ) {
                $html .= '<div class="span' . $columns . '">';
                if ( $col == 2 && $i == 1 ) {
                    if ($right === true) {
                        $html .= '<div class="pull-right">';
                        $html .= (isset($content[$i]) ? $content[$i] : '');
                        $html .= '</div>';
                    } else {
                        $html .= $content[$i];
                    }
                } else {
                    $html .= $content[$i];
                }
                $html .= '</div>';
            }
        }
        $html .= '</div>';
        $html .= '</div>';

        return $html;
    }
}