chamilo-lms2/main/inc/lib/statistics.lib.php

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

/**
 * This class provides some functions for statistics
 * @package chamilo.statistics
 */
class Statistics
{

    /**
     * Converts a number of bytes in a formatted string
     * @param int $size
     * @return string Formatted file size
     */
    static function make_size_string($size)
    {
        if ($size < pow(2, 10)) {
            return $size." bytes";
        }
        if ($size >= pow(2, 10) && $size < pow(2, 20)) {
            return round($size / pow(2, 10), 0)." KB";
        }
        if ($size >= pow(2, 20) && $size < pow(2, 30)) {
            return round($size / pow(2, 20), 1)." MB";
        }
        if ($size > pow(2, 30)) {
            return round($size / pow(2, 30), 2)." GB";
        }
    }

    /**
     * Count courses
     * @param string $category_code  Code of a course category. Default: count
     * all courses.
     * @return int Number of courses counted
     */
    static function count_courses($category_code = null)
    {
        $course_table                = Database :: get_main_table(TABLE_MAIN_COURSE);
        $access_url_rel_course_table = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
        $current_url_id              = api_get_current_access_url_id();
        if (api_is_multiple_url_enabled()) {
            $sql = "SELECT COUNT(*) AS number FROM ".$course_table." as c, ".$access_url_rel_course_table." as u
                    WHERE u.c_id = c.id AND access_url_id='".$current_url_id."'";
            if (isset ($category_code)) {
                $sql .= " AND category_code = '".Database::escape_string($category_code)."'";
            }
        } else {
            $sql = "SELECT COUNT(*) AS number FROM ".$course_table." ";
            if (isset ($category_code)) {
                $sql .= " WHERE category_code = '".Database::escape_string($category_code)."'";
            }
        }
        $res = Database::query($sql);
        $obj = Database::fetch_object($res);

        return $obj->number;
    }

    /**
     * Count courses by visibility
     * @param int Visibility (0 = closed, 1 = private, 2 = open, 3 = public)
     * all courses.
     * @return int Number of courses counted
     */
    static function count_courses_by_visibility($vis = null)
    {
        if (!isset($vis)) {
            return 0;
        }
        $course_table                = Database :: get_main_table(TABLE_MAIN_COURSE);
        $access_url_rel_course_table = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
        $current_url_id              = api_get_current_access_url_id();
        if (api_is_multiple_url_enabled()) {
            $sql = "SELECT COUNT(*) AS number
                    FROM ".$course_table." as c, ".$access_url_rel_course_table." as u
                    WHERE u.c_id = c.id AND access_url_id='".$current_url_id."'";
            if (isset ($vis)) {
                $sql .= " AND visibility = ".intval($vis);
            }
        } else {
            $sql = "SELECT COUNT(*) AS number FROM ".$course_table." ";
            if (isset ($vis)) {
                $sql .= " WHERE visibility = ".intval($vis);
            }
        }
        $res = Database::query($sql);
        $obj = Database::fetch_object($res);

        return $obj->number;
    }

    /**
     * Count users
     * @param int      optional, user status (COURSEMANAGER or STUDENT), if it's not setted it'll count all users.
     * @param string optional, code of a course category. Default: count only users without filtering category
     * @param bool count invisible courses (todo)
     * @param bool count only active users (false to only return currently active users)
     * @return int Number of users counted
     */
    static function count_users(
        $status = null,
        $category_code = null,
        $count_invisible_courses = true,
        $only_active = false
    ) {

        // Database table definitions
        $course_user_table         = Database :: get_main_table(TABLE_MAIN_COURSE_USER);
        $course_table              = Database :: get_main_table(TABLE_MAIN_COURSE);
        $user_table                = Database :: get_main_table(TABLE_MAIN_USER);
        $access_url_rel_user_table = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);
        $current_url_id            = api_get_current_access_url_id();
        $active_filter             = $only_active ? ' AND active=1' : '';
        $status_filter             = isset($status) ? ' AND status = '.intval($status) : '';

        if (api_is_multiple_url_enabled()) {
            $sql = "SELECT COUNT(DISTINCT(u.user_id)) AS number
                    FROM $user_table as u, $access_url_rel_user_table as url
                    WHERE u.user_id=url.user_id AND access_url_id='".$current_url_id."' $status_filter $active_filter";
            if (isset ($category_code)) {
                $sql = "SELECT COUNT(DISTINCT(cu.user_id)) AS number
                        FROM $course_user_table cu, $course_table c, $access_url_rel_user_table as url
                        WHERE   c.id = cu.c_id AND
                                c.category_code = '".Database::escape_string($category_code)."' AND
                                cu.user_id=url.user_id AND
                                access_url_id='".$current_url_id."' $status_filter $active_filter";
            }
        } else {
            $sql = "SELECT COUNT(DISTINCT(user_id)) AS number FROM $user_table WHERE 1=1 $status_filter $active_filter";
            if (isset ($category_code)) {
                $status_filter = isset($status) ? ' AND status = '.intval($status) : '';
                $sql           = "SELECT COUNT(DISTINCT(cu.user_id)) AS number
                FROM $course_user_table cu, $course_table c
                WHERE c.id = cu.c_id AND c.category_code = '".Database::escape_string(
                        $category_code
                    )."' $status_filter $active_filter";
            }
        }

        $res = Database::query($sql);
        $obj = Database::fetch_object($res);

        return $obj->number;
    }

    /**
     * Count activities from track_e_default_table
     * @return int Number of activities counted
     */
    static function get_number_of_activities()
    {
        $track_e_default           = Database :: get_main_table(TABLE_STATISTIC_TRACK_E_DEFAULT);
        $table_user                = Database::get_main_table(TABLE_MAIN_USER);
        $access_url_rel_user_table = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);
        $current_url_id            = api_get_current_access_url_id();
        if (api_is_multiple_url_enabled()) {
            $sql = "SELECT count(default_id) AS total_number_of_items FROM $track_e_default, $table_user user, $access_url_rel_user_table url WHERE default_user_id = user.user_id AND user.user_id=url.user_id AND access_url_id='".$current_url_id."'";
        } else {
            $sql = "SELECT count(default_id) AS total_number_of_items FROM $track_e_default, $table_user user WHERE default_user_id = user.user_id ";
        }

        if (isset($_GET['keyword'])) {
            $keyword = Database::escape_string(trim($_GET['keyword']));
            $sql .= " AND (user.username LIKE '%".$keyword."%' OR default_event_type LIKE '%".$keyword."%' OR default_value_type LIKE '%".$keyword."%' OR default_value LIKE '%".$keyword."%') ";
        }

        $res = Database::query($sql);
        $obj = Database::fetch_object($res);

        return $obj->total_number_of_items;
    }

    /**
     * Get activities data to display
     */
    static function get_activities_data($from, $number_of_items, $column, $direction)
    {
        global $dateTimeFormatLong;
        $track_e_default           = Database::get_main_table(TABLE_STATISTIC_TRACK_E_DEFAULT);
        $table_user                = Database::get_main_table(TABLE_MAIN_USER);
        $access_url_rel_user_table = Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);
        $current_url_id            = api_get_current_access_url_id();

        $column          = intval($column);
        $from            = intval($from);
        $number_of_items = intval($number_of_items);

        if (!in_array($direction, array('ASC', 'DESC'))) {
            $direction = 'DESC';
        }
        if (api_is_multiple_url_enabled()) {
            $sql = "SELECT ".
                "default_event_type  as col0, ".
                "default_value_type    as col1, ".
                "default_value        as col2, ".
                "user.username         as col3, ".
                "user.user_id         as col4, ".
                "default_date         as col5 ".
                "FROM $track_e_default as track_default, $table_user as user, $access_url_rel_user_table as url ".
                "WHERE track_default.default_user_id = user.user_id AND url.user_id=user.user_id AND access_url_id='".$current_url_id."'";
        } else {
            $sql = "SELECT ".
                "default_event_type  as col0, ".
                "default_value_type    as col1, ".
                "default_value        as col2, ".
                "user.username         as col3, ".
                "user.user_id         as col4, ".
                "default_date         as col5 ".
                "FROM $track_e_default track_default, $table_user user ".
                "WHERE track_default.default_user_id = user.user_id ";
        }

        if (isset($_GET['keyword'])) {
            $keyword = Database::escape_string(trim($_GET['keyword']));
            $sql .= " AND (user.username LIKE '%".$keyword."%' OR default_event_type LIKE '%".$keyword."%' OR default_value_type LIKE '%".$keyword."%' OR default_value LIKE '%".$keyword."%') ";
        }

        if (!empty($column) && !empty($direction)) {
            $sql .= " ORDER BY col$column $direction";
        } else {
            $sql .= " ORDER BY col5 DESC ";
        }
        $sql .= " LIMIT $from, $number_of_items ";

        $res        = Database::query($sql);
        $activities = array();
        while ($row = Database::fetch_row($res)) {
            if (strpos($row[1], '_object') === false) {
                $row[2] = $row[2];
            } else {
                if (!empty($row[2])) {
                    $row[2] = unserialize($row[2]);
                    if (is_array($row[2]) && !empty($row[2])) {
                        $row[2] = Text::implode_with_key(', ', $row[2]);
                    }
                }
            }
            if (!empty($row['default_date']) && $row['default_date'] != '0000-00-00 00:00:00') {
                $row['default_date'] = api_get_local_time($row['default_date']);
            } else {
                $row['default_date'] = '-';
            }
            if (!empty($row[4])) { //user ID
                $row[3] = Display::url(
                    $row[3],
                    api_get_path(WEB_CODE_PATH).'admin/user_information?user_id='.$row[5],
                    array('title' => get_lang('UserInfo'))
                );

                $row[4] = TrackingUserLog::get_ip_from_user_event($row[4], $row[5], true);
                if (empty($row[4])) {
                    $row[4] = get_lang('Unknown');
                }
            }
            $activities[] = $row;
        }

        return $activities;
    }

    /**
     * Get all course categories
     * @return array All course categories (code => name)
     */
    static function get_course_categories()
    {
        $category_table = Database :: get_main_table(TABLE_MAIN_CATEGORY);
        $sql            = "SELECT code, name FROM $category_table ORDER BY tree_pos";
        $res            = Database::query($sql);
        $categories     = array();
        while ($category = Database::fetch_object($res)) {
            $categories[$category->code] = $category->name;
        }

        return $categories;
    }

    /**
     * Rescale data
     * @param array $data The data that should be rescaled
     * @param int $max The maximum value in the rescaled data (default = 500);
     * @return array The rescaled data, same key as $data
     */
    static function rescale($data, $max = 500)
    {
        $data_max = 1;
        foreach ($data as $index => $value) {
            $data_max = ($data_max < $value ? $value : $data_max);
        }
        reset($data);
        $result = array();
        $delta  = $max / $data_max;
        foreach ($data as $index => $value) {
            $result[$index] = (int)round($value * $delta);
        }

        return $result;
    }

    /**
     * Show statistics
     * @param string $title The title
     * @param array $stats
     * @param bool $show_total
     * @param bool $is_file_size
     */
    static function print_stats($title, $stats, $show_total = true, $is_file_size = false)
    {
        $total = 0;
        $data  = Statistics::rescale($stats);

        echo '<table class="data_table" cellspacing="0" cellpadding="3">
                <tr><th colspan="'.($show_total ? '4' : '3').'">'.$title.'</th></tr>';
        $i = 0;
        foreach ($stats as $subtitle => $number) {
            $total += $number;
        }

        foreach ($stats as $subtitle => $number) {
            if (!$is_file_size) {
                $number_label = number_format($number, 0, ',', '.');
            } else {
                $number_label = Statistics::make_size_string($number);
            }
            $percentage = ($total > 0 ? number_format(100 * $number / $total, 1, ',', '.') : '0');

            echo '<tr class="row_'.($i % 2 == 0 ? 'odd' : 'even').'">
                    <td width="150">'.$subtitle.'</td>
                    <td width="550">'.Display::bar_progress($percentage, false).'</td>
                    <td align="right">'.$number_label.'</td>';
            if ($show_total) {
                echo '<td align="right"> '.$percentage.'%</td>';
            }
            echo '</tr>';
            $i++;
        }
        if ($show_total) {
            if (!$is_file_size) {
                $total_label = number_format($total, 0, ',', '.');
            } else {
                $total_label = Statistics::make_size_string($total);
            }
            echo '<tr><th  colspan="4" align="right">'.get_lang('Total').': '.$total_label.'</td></tr>';
        }
        echo '</table>';
    }

    /**
     * Show some stats about the number of logins
     * @param string $type month, hour or day
     */
    static function print_login_stats($type)
    {
        $table                     = Database::get_main_table(TABLE_STATISTIC_TRACK_E_LOGIN);
        $access_url_rel_user_table = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);
        $current_url_id            = api_get_current_access_url_id();
        if (api_is_multiple_url_enabled()) {
            $table_url      = ", $access_url_rel_user_table";
            $where_url      = " WHERE login_user_id=user_id AND access_url_id='".$current_url_id."'";
            $where_url_last = ' AND login_date > DATE_SUB(NOW(),INTERVAL 1 %s)';
        } else {
            $table_url      = '';
            $where_url      = '';
            $where_url_last = ' WHERE login_date > DATE_SUB(NOW(),INTERVAL 1 %s)';
        }
        switch ($type) {
            case 'month':
                $months     = api_get_months_long();
                $period     = get_lang('PeriodMonth');
                $sql        = "SELECT DATE_FORMAT( login_date, '%Y-%m' ) AS stat_date , count( login_id ) AS number_of_logins FROM ".$table.$table_url.$where_url." GROUP BY stat_date ORDER BY login_date ";
                $sql_last_x = "SELECT DATE_FORMAT( login_date, '%Y-%m' ) AS stat_date , count( login_id ) AS number_of_logins FROM ".$table.$table_url.$where_url.sprintf(
                        $where_url_last,
                        'YEAR'
                    )." GROUP BY stat_date ORDER BY login_date ";
                break;
            case 'hour':
                $period     = get_lang('PeriodHour');
                $sql        = "SELECT DATE_FORMAT( login_date, '%H' ) AS stat_date , count( login_id ) AS number_of_logins FROM ".$table.$table_url.$where_url." GROUP BY stat_date ORDER BY stat_date ";
                $sql_last_x = "SELECT DATE_FORMAT( login_date, '%H' ) AS stat_date , count( login_id ) AS number_of_logins FROM ".$table.$table_url.$where_url.sprintf(
                        $where_url_last,
                        'DAY'
                    )." GROUP BY stat_date ORDER BY stat_date ";
                break;
            case 'day':
                $week_days  = api_get_week_days_long();
                $period     = get_lang('PeriodDay');
                $sql        = "SELECT DATE_FORMAT( login_date, '%w' ) AS stat_date , count( login_id ) AS number_of_logins FROM ".$table.$table_url.$where_url." GROUP BY stat_date ORDER BY DATE_FORMAT( login_date, '%w' ) ";
                $sql_last_x = "SELECT DATE_FORMAT( login_date, '%w' ) AS stat_date , count( login_id ) AS number_of_logins FROM ".$table.$table_url.$where_url.sprintf(
                        $where_url_last,
                        'WEEK'
                    )." GROUP BY stat_date ORDER BY DATE_FORMAT( login_date, '%w' ) ";
                break;
        }
        $res_last_x    = Database::query($sql_last_x);
        $result_last_x = array();
        while ($obj = Database::fetch_object($res_last_x)) {
            $stat_date = $obj->stat_date;
            switch ($type) {
                case 'month':
                    $stat_date    = explode('-', $stat_date);
                    $stat_date[1] = $months[$stat_date[1] - 1];
                    $stat_date    = implode(' ', $stat_date);
                    break;
                case 'day':
                    $stat_date = $week_days[$stat_date];
                    break;
            }
            $result_last_x[$stat_date] = $obj->number_of_logins;
        }
        Statistics::print_stats(get_lang('LastLogins').' ('.$period.')', $result_last_x, true);
        flush(); //flush web request at this point to see something already while the full data set is loading
        echo '<br />';
        $res    = Database::query($sql);
        $result = array();
        while ($obj = Database::fetch_object($res)) {
            $stat_date = $obj->stat_date;
            switch ($type) {
                case 'month':
                    $stat_date    = explode('-', $stat_date);
                    $stat_date[1] = $months[$stat_date[1] - 1];
                    $stat_date    = implode(' ', $stat_date);
                    break;
                case 'day':
                    $stat_date = $week_days[$stat_date];
                    break;
            }
            $result[$stat_date] = $obj->number_of_logins;
        }
        Statistics::print_stats(get_lang('AllLogins').' ('.$period.')', $result, true);
    }

    /**
     * Print the number of recent logins
     */
    static function print_recent_login_stats()
    {
        $total_logins              = array();
        $table                     = Database::get_main_table(TABLE_STATISTIC_TRACK_E_LOGIN);
        $access_url_rel_user_table = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);
        $current_url_id            = api_get_current_access_url_id();
        if (api_is_multiple_url_enabled()) {
            $table_url = ", $access_url_rel_user_table";
            $where_url = " AND login_user_id=user_id AND access_url_id='".$current_url_id."'";
        } else {
            $table_url = '';
            $where_url = '';
        }
        $sql[get_lang(
            'Thisday'
        )] = "SELECT count(login_user_id) AS number FROM $table $table_url WHERE DATE_ADD(login_date, INTERVAL 1 DAY) >= NOW() $where_url";
        $sql[get_lang(
            'Last7days'
        )] = "SELECT count(login_user_id) AS number  FROM $table $table_url WHERE DATE_ADD(login_date, INTERVAL 7 DAY) >= NOW() $where_url";
        $sql[get_lang(
            'Last31days'
        )] = "SELECT count(login_user_id) AS number  FROM $table $table_url WHERE DATE_ADD(login_date, INTERVAL 31 DAY) >= NOW() $where_url";
        $sql[get_lang(
            'Total'
        )] = "SELECT count(login_user_id) AS number  FROM $table $table_url WHERE 1=1 $where_url";
        foreach ($sql as $index => $query) {
            $res                  = Database::query($query);
            $obj                  = Database::fetch_object($res);
            $total_logins[$index] = $obj->number;
        }
        Statistics::print_stats(get_lang('Logins'), $total_logins, false);
    }

    /**
     * Show some stats about the accesses to the different course tools
     */
    static function print_tool_stats()
    {
        $tableCourse                 = Database::get_main_table(TABLE_MAIN_COURSE);
        $table                       = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ACCESS);
        $access_url_rel_course_table = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
        $current_url_id              = api_get_current_access_url_id();

        $tools      = array(
            'announcement',
            'assignment',
            'calendar_event',
            'chat',
            'conference',
            'course_description',
            'document',
            'dropbox',
            'group',
            'learnpath',
            'link',
            'quiz',
            'student_publication',
            'user',
            'forum'
        );
        $tool_names = array();
        foreach ($tools as $tool) {
            $tool_names[$tool] = get_lang(ucfirst($tool), '');
        }
        if (api_is_multiple_url_enabled()) {
            $sql = "SELECT access_tool, count( access_id ) AS number_of_logins
                    FROM $table, $access_url_rel_course_table u, $tableCourse c
                    WHERE access_tool IN ('".implode(
                    "','",
                    $tools
                )."') AND c.id = u.c_id AND c.id = c_id AND access_url_id='".$current_url_id."' ".
                "GROUP BY access_tool ";
        } else {
            $sql = "SELECT access_tool, count( access_id ) AS number_of_logins FROM $table ".
                "WHERE access_tool IN ('".implode("','", $tools)."') ".
                "GROUP BY access_tool ";
        }
        $res    = Database::query($sql);
        $result = array();
        while ($obj = Database::fetch_object($res)) {
            $result[$tool_names[$obj->access_tool]] = $obj->number_of_logins;
        }
        Statistics::print_stats(get_lang('PlatformToolAccess'), $result, true);
    }

    /**
     * Show some stats about the number of courses per language
     */
    static function print_course_by_language_stats()
    {
        $table                       = Database :: get_main_table(TABLE_MAIN_COURSE);
        $access_url_rel_course_table = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
        $current_url_id              = api_get_current_access_url_id();

        if (api_is_multiple_url_enabled()) {
            $sql = "SELECT course_language, count( c.code ) AS number_of_courses ".
                "FROM $table as c, $access_url_rel_course_table as u
            		WHERE u.c_id = c.id AND access_url_id='".$current_url_id."'
            		GROUP BY course_language ORDER BY number_of_courses DESC";
        } else {
            $sql = "SELECT course_language, count(code) AS number_of_courses ".
                "FROM $table GROUP BY course_language ORDER BY number_of_courses DESC";
        }
        $res    = Database::query($sql);
        $result = array();
        while ($obj = Database::fetch_object($res)) {
            $result[$obj->course_language] = $obj->number_of_courses;
        }
        Statistics::print_stats(get_lang('CountCourseByLanguage'), $result, true);
    }

    /**
     * Shows the number of users having their picture uploaded in Dokeos.
     */
    static function print_user_pictures_stats()
    {
        $user_table                = Database :: get_main_table(TABLE_MAIN_USER);
        $access_url_rel_user_table = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);
        $current_url_id            = api_get_current_access_url_id();
        if (api_is_multiple_url_enabled()) {
            $url_condition  = ", $access_url_rel_user_table as url WHERE url.user_id=u.user_id AND access_url_id='".$current_url_id."'";
            $url_condition2 = " AND url.user_id=u.user_id AND access_url_id='".$current_url_id."'";
            $table          = ", $access_url_rel_user_table as url ";
        }
        $sql    = "SELECT COUNT(*) AS n FROM $user_table as u ".$url_condition;
        $res    = Database::query($sql);
        $count1 = Database::fetch_object($res);
        $sql    = "SELECT COUNT(*) AS n FROM $user_table as u $table ".
            "WHERE LENGTH(picture_uri) > 0 $url_condition2";
        $res    = Database::query($sql);
        $count2 = Database::fetch_object($res);
        // #users without picture
        $result[get_lang('No')]  = $count1->n - $count2->n;
        $result[get_lang('Yes')] = $count2->n; // #users with picture
        Statistics::print_stats(get_lang('CountUsers').' ('.get_lang('UserPicture').')', $result, true);
    }

    static function print_activities_stats()
    {
        echo '<h4>'.get_lang('ImportantActivities').'</h4>';

        // Create a search-box
        $form     = new FormValidator('search_simple', 'get', api_get_path(
                WEB_CODE_PATH
            ).'admin/statistics/index.php', '', 'width=200px', false);
        $renderer =& $form->defaultRenderer();
        $renderer->setElementTemplate('<span>{element}</span> ');
        $form->addElement('hidden', 'report', 'activities');
        $form->addElement('hidden', 'activities_direction', 'DESC');
        $form->addElement('hidden', 'activities_column', '4');
        $form->addElement('text', 'keyword', get_lang('keyword'));
        $form->addElement('style_submit_button', 'submit', get_lang('Search'), 'class="search"');
        echo '<div class="actions">';
        $form->display();
        echo '</div>';

        $table      = new SortableTable('activities', array(
            'Statistics',
            'get_number_of_activities'
        ), array(
            'Statistics',
            'get_activities_data'
        ), 5, 50, 'DESC');
        $parameters = array();

        $parameters['report'] = 'activities';
        if (isset($_GET['keyword'])) {
            $parameters['keyword'] = Security::remove_XSS($_GET['keyword']);
        }

        $table->set_additional_parameters($parameters);
        $table->set_header(0, get_lang('EventType'));
        $table->set_header(1, get_lang('DataType'));
        $table->set_header(2, get_lang('Value'));
        $table->set_header(3, get_lang('UserName'));
        $table->set_header(4, get_lang('IPAddress'));
        $table->set_header(5, get_lang('Date'));
        $table->display();
    }

    /**
     * Shows statistics about the time of last visit to each course.
     */
    static function print_course_last_visit()
    {
        $access_url_rel_course_table = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
        $current_url_id              = api_get_current_access_url_id();

        $columns[0]           = 'c_id';
        $columns[1]           = 'access_date';
        $sql_order[SORT_ASC]  = 'ASC';
        $sql_order[SORT_DESC] = 'DESC';
        $per_page             = isset($_GET['per_page']) ? intval($_GET['per_page']) : 10;
        $page_nr              = isset($_GET['page_nr']) ? intval($_GET['page_nr']) : 1;
        $column               = isset($_GET['column']) ? intval($_GET['column']) : 0;
        $date_diff            = isset($_GET['date_diff']) ? intval($_GET['date_diff']) : 60;
        if (!in_array($_GET['direction'], array(SORT_ASC, SORT_DESC))) {
            $direction = SORT_ASC;
        } else {
            $direction = isset($_GET['direction']) ? $_GET['direction'] : SORT_ASC;
        }
        $form = new FormValidator('courselastvisit', 'get');
        $form->addElement('hidden', 'report', 'courselastvisit');
        $form->add_textfield('date_diff', get_lang('Days'), true);
        $form->addRule('date_diff', 'InvalidNumber', 'numeric');
        $form->addElement('style_submit_button', 'submit', get_lang('Search'), 'class="search"');
        if (!isset($_GET['date_diff'])) {
            $defaults['date_diff'] = 60;
        } else {
            $defaults['date_diff'] = Security::remove_XSS($_GET['date_diff']);
        }
        $form->setDefaults($defaults);
        $form->display();
        $values      = $form->exportValues();
        $date_diff   = $values['date_diff'];
        $table       = Database::get_main_table(TABLE_STATISTIC_TRACK_E_LASTACCESS);
        $tableCourse = Database::get_main_table(TABLE_MAIN_COURSE);
        if (api_is_multiple_url_enabled()) {
            $sql = "SELECT access_date, c.code FROM $table s , $access_url_rel_course_table u, $tableCourse c
                    WHERE c.id = u.c_id AND c.id = s.c_id AND access_url_id='".$current_url_id."' ".
                "GROUP BY access_cours_code ".
                "HAVING s.c_id <> '' ".
                "AND DATEDIFF( '".date('Y-m-d h:i:s')."' , access_date ) <= ".$date_diff;
        } else {
            $sql = "SELECT access_date, c.code FROM $table , $tableCourse c
                    WHERE c_id = c.id
                    GROUP BY c_id
                    HAVING c_id <> ''AND
                    DATEDIFF( '".date('Y-m-d h:i:s')."' , access_date ) <= ".$date_diff;
        }
        $res               = Database::query($sql);
        $number_of_courses = Database::num_rows($res);
        $sql .= ' ORDER BY '.$columns[$column].' '.$sql_order[$direction];
        $from = ($page_nr - 1) * $per_page;
        $sql .= ' LIMIT '.$from.','.$per_page;
        echo '<p>'.get_lang('LastAccess').' &gt;= '.$date_diff.' '.get_lang('Days').'</p>';
        $res = Database::query($sql);
        if (Database::num_rows($res) > 0) {
            $courses = array();
            while ($obj = Database::fetch_object($res)) {
                $course   = array();
                $course[] = '<a href="'.api_get_path(WEB_PATH).'courses/'.$obj->code.'">'.$obj->code.' <a>';
                //Allow sort by date hiding the numerical date
                $course[]  = '<span style="display:none;">'.$obj->access_date.'</span>'.api_convert_and_format_date(
                        $obj->access_date
                    );
                $courses[] = $course;
            }
            $parameters['date_diff'] = $date_diff;
            $parameters['report']    = 'courselastvisit';
            $table_header[]          = array(get_lang("CourseCode"), true);
            $table_header[]          = array(get_lang("LastAccess"), true);
            Display :: display_sortable_table(
                $table_header,
                $courses,
                array('column' => $column, 'direction' => $direction),
                array(),
                $parameters
            );
        } else {
            echo get_lang('NoSearchResults');
        }
    }

    /**
     * Displays the statistics of the messages sent and received by each user in the social network
     * @param string    Type of message: 'sent' or 'received'
     * @return array    Message list
     */
    static function get_messages($message_type)
    {
        $message_table             = Database::get_main_table(TABLE_MAIN_MESSAGE);
        $user_table                = Database::get_main_table(TABLE_MAIN_USER);
        $access_url_rel_user_table = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);

        $current_url_id = api_get_current_access_url_id();

        switch ($message_type) {
            case 'sent':
                $field = 'user_sender_id';
                break;
            case 'received':
                $field = 'user_receiver_id';
                break;
        }
        if (api_is_multiple_url_enabled()) {

            $sql = "SELECT lastname, firstname, username, COUNT($field) AS count_message ".
                "FROM ".$access_url_rel_user_table." as url, ".$message_table." m ".
                "LEFT JOIN ".$user_table." u ON m.$field = u.user_id ".
                "WHERE  url.user_id = m.$field AND  access_url_id='".$current_url_id."' ".
                "GROUP BY m.$field ORDER BY count_message DESC ";
        } else {
            $sql = "SELECT lastname, firstname, username, COUNT($field) AS count_message ".
                "FROM ".$message_table." m ".
                "LEFT JOIN ".$user_table." u ON m.$field = u.user_id ".
                "GROUP BY m.$field ORDER BY count_message DESC ";
        }
        $res           = Database::query($sql);
        $messages_sent = array();
        while ($messages = Database::fetch_array($res)) {
            if (empty($messages['username'])) {
                $messages['username'] = get_lang('Unknown');
            }
            $users                 = api_get_person_name(
                    $messages['firstname'],
                    $messages['lastname']
                ).'<br />('.$messages['username'].')';
            $messages_sent[$users] = $messages['count_message'];
        }

        return $messages_sent;
    }

    /**
     * Count the number of friends for social network users
     */
    static function get_friends()
    {
        $user_friend_table         = Database::get_main_table(TABLE_MAIN_USER_REL_USER);
        $user_table                = Database::get_main_table(TABLE_MAIN_USER);
        $access_url_rel_user_table = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);
        $current_url_id            = api_get_current_access_url_id();

        if (api_is_multiple_url_enabled()) {
            $sql = "SELECT lastname, firstname, username, COUNT(friend_user_id) AS count_friend ".
                "FROM ".$access_url_rel_user_table." as url, ".$user_friend_table." uf ".
                "LEFT JOIN ".$user_table." u ON uf.user_id = u.user_id ".
                "WHERE uf.relation_type <> '".USER_RELATION_TYPE_RRHH."' AND uf.user_id = url.user_id AND  access_url_id='".$current_url_id."' ".
                "GROUP BY uf.user_id ORDER BY count_friend DESC ";
        } else {
            $sql = "SELECT lastname, firstname, username, COUNT(friend_user_id) AS count_friend ".
                "FROM ".$user_friend_table." uf ".
                "LEFT JOIN ".$user_table." u ON uf.user_id = u.user_id ".
                "WHERE uf.relation_type <> '".USER_RELATION_TYPE_RRHH."' ".
                "GROUP BY uf.user_id ORDER BY count_friend DESC ";
        }
        $res          = Database::query($sql);
        $list_friends = array();
        while ($friends = Database::fetch_array($res)) {
            $users                = api_get_person_name(
                    $friends['firstname'],
                    $friends['lastname']
                ).'<br />('.$friends['username'].')';
            $list_friends[$users] = $friends['count_friend'];
        }

        return $list_friends;
    }

    /**
     * Print the number of users that didn't login for a certain period of time
     */
    static function print_users_not_logged_in_stats()
    {
        $total_logins              = array();
        $table                     = Database::get_main_table(TABLE_STATISTIC_TRACK_E_LOGIN);
        $access_url_rel_user_table = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);
        $current_url_id            = api_get_current_access_url_id();
        $total                     = self::count_users();
        if (api_is_multiple_url_enabled()) {
            $table_url = ", $access_url_rel_user_table";
            $where_url = " AND login_user_id=user_id AND access_url_id='".$current_url_id."'";
        } else {
            $table_url = '';
            $where_url = '';
        }
        $sql[get_lang('Thisday')]                 =
            "SELECT count(distinct(login_user_id)) AS number ".
            " FROM $table $table_url ".
            " WHERE DATE_ADD(login_date, INTERVAL 1 DAY) >= NOW() $where_url";
        $sql[get_lang('Last7days')]               =
            "SELECT count(distinct(login_user_id)) AS number ".
            " FROM $table $table_url ".
            " WHERE DATE_ADD(login_date, INTERVAL 7 DAY) >= NOW() $where_url";
        $sql[get_lang('Last31days')]              =
            "SELECT count(distinct(login_user_id)) AS number ".
            " FROM $table $table_url ".
            " WHERE DATE_ADD(login_date, INTERVAL 31 DAY) >= NOW() $where_url";
        $sql[sprintf(get_lang('LastXMonths'), 6)] =
            "SELECT count(distinct(login_user_id)) AS number ".
            " FROM $table $table_url ".
            " WHERE DATE_ADD(login_date, INTERVAL 6 MONTH) >= NOW() $where_url";
        $sql[get_lang('NeverConnected')]          =
            "SELECT count(distinct(login_user_id)) AS number ".
            " FROM $table $table_url WHERE 1=1 $where_url";
        foreach ($sql as $index => $query) {
            $res                  = Database::query($query);
            $obj                  = Database::fetch_object($res);
            $r                    = $total - $obj->number;
            $total_logins[$index] = $r < 0 ? 0 : $r;
        }
        Statistics::print_stats(get_lang('StatsUsersDidNotLoginInLastPeriods'), $total_logins, false);
    }
}