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

<?php
/* For licensing terms, see /license.txt*/
/**
 * This is the course library for Chamilo.
 *
 * All main course functions should be placed here.
 *
 *
 * The implementation changed, initially a course was a real course
 * if target_course_code was 0 , this was changed to NULL.
 * There are probably some places left with the wrong code.
 *
 * @package chamilo.library
 */
/**
 *    CourseManager Class
 *    @package chamilo.library
 */
class CourseManager
{
    const MAX_COURSE_LENGTH_CODE = 40;

    //This constant is used to show separate user names in the course list (userportal), footer, etc
    const USER_SEPARATOR = ' |';

    public $columns = array();

    /**
     * Creates a course
     * @param   array   with the columns in the main.course table
     * @param   mixed   false if the course was not created, array with the course info
     * @return mixed False on error, or an array with course attributes on success
     * @todo remove globals
     * @assert () === false
     */
    public static function create_course($params)
    {
        global $_configuration;

        // Check portal limits
        $access_url_id = 1;
        if (api_get_multiple_access_url()) {
            $access_url_id = api_get_current_access_url_id();
        }

        if (is_array($_configuration[$access_url_id]) && isset($_configuration[$access_url_id]['hosting_limit_courses']) && $_configuration[$access_url_id]['hosting_limit_courses'] > 0) {
            $num = self::count_courses();
            if ($num >= $_configuration[$access_url_id]['hosting_limit_courses']) {
                return api_set_failure('PortalCoursesLimitReached');
            }
        }

        if (empty($params['title'])) {
            return false;
        }

        if (empty($params['wanted_code'])) {
            $params['wanted_code'] = $params['title'];
            // Check whether the requested course code has already been occupied.
            $params['wanted_code'] = self::generate_course_code(api_substr($params['title'], 0, self::MAX_COURSE_LENGTH_CODE));
        }

        // Create the course keys
        $keys = self::define_course_keys($params['wanted_code']);

        $params['exemplary_content'] = isset($params['exemplary_content']) ? $params['exemplary_content'] : false;

        if (count($keys)) {

            $params['code']             = $keys['currentCourseCode'];
            $params['visual_code']      = $keys['currentCourseId'];
            $params['directory']        = $keys['currentCourseRepository'];

            $course_info = api_get_course_info($params['code']);

            if (empty($course_info)) {
                $course_id      = self::register_course($params);
                $course_info    = api_get_course_info_by_id($course_id);

                if (!empty($course_info)) {
                    self::prepare_course_repository($course_info['directory'], $course_info['code']);
                    self::fill_db_course($course_id, $course_info['directory'], $course_info['course_language'], $params['exemplary_content']);

                    //Create an empty gradebook
                    if (isset($params['create_gradebook_evaluation']) && $params['create_gradebook_evaluation'] == true) {
                        require_once api_get_path(SYS_CODE_PATH).'gradebook/lib/gradebook_functions.inc.php';
                        $category_id = create_default_course_gradebook($course_info['code']);
                        if ($category_id && isset($params['gradebook_params'])) {
                            $eval = new Evaluation();
                            $eval->set_name($params['gradebook_params']['name']);
                            $eval->set_user_id($params['gradebook_params']['user_id']);
                            $eval->set_course_code($course_info['code']);
                            $eval->set_category_id($category_id);
                            $eval->set_weight($params['gradebook_params']['weight']);
                            $eval->set_max($params['gradebook_params']['max']);
                            $eval->set_visible(0);
                            $eval->add();
                        }
                    }
                    if (api_get_setting('gradebook_enable_grade_model') == 'true') {
                        //Create gradebook_category for the new course and add a gradebook model for the course
                        if (isset($params['gradebook_model_id']) && !empty($params['gradebook_model_id']) && $params['gradebook_model_id'] != '-1') {
                            require_once api_get_path(SYS_CODE_PATH).'gradebook/lib/gradebook_functions.inc.php';
                            create_default_course_gradebook($course_info['code'], $params['gradebook_model_id']);
                        }
                    }

                    //Saving extra course fields
                    $field_value = new ExtraFieldValue('course');
                    $params['course_code'] = $course_info['code'];
                    $field_value->save_field_values($params);

                    return $course_info;
                }
            } else {
                //Course already exists
                if (isset($params['return_item_if_already_exists']) && $params['return_item_if_already_exists']) {
                    return $course_info;
                }
            }
        }
        return false;
    }
    /**
     * Updates a course with the given array of attributes
     * @param array Array of attributes
     * @return array Array of course attributes
     * @assert () === false
     */
    public static function update($params)
    {
        if (!is_array($params) or count($params)<1) {
            return false;
        }
        $course_user_table  = Database::get_main_table(TABLE_MAIN_COURSE_USER);
        $course_table       = Database::get_main_table(TABLE_MAIN_COURSE);

        $course_code = $params['code'];
        $courseInfo = api_get_course_info($course_code);
        $visual_code = $params['visual_code'];

        $field_value = new ExtraFieldValue('course');
        $params['course_code'] = $course_code;
        $field_value->save_field_values($params);

        /*$tutor_id = $params['tutor_name'];
        $tutor_name=$platform_teachers[$tutor_id];*/

        $teachers = $params['group']['course_teachers'];

        $title = $params['title'];
        $category_code = $params['category_code'];
        $department_name = $params['department_name'];
        $department_url = $params['department_url'];
        $course_language = $params['course_language'];

        $course['disk_quota'] = $params['disk_quota']*1024*1024;

        $disk_quota = $params['disk_quota'];
        $visibility = $params['visibility'];
        $subscribe = $params['subscribe'];
        $unsubscribe = $params['unsubscribe'];
        if (!stristr($department_url, 'http://')) {
            $department_url = 'http://'.$department_url;
        }

        //tutor_name='".Database::escape_string($tutor_name)."',
        $sql = "UPDATE $course_table SET
                    course_language='".Database::escape_string($course_language)."',
                    title='".Database::escape_string($title)."',
                    category_code='".Database::escape_string($category_code)."',
                    visual_code='".Database::escape_string($visual_code)."',
                    department_name='".Database::escape_string($department_name)."',
                    department_url='".Database::escape_string($department_url)."',
                    disk_quota='".Database::escape_string($disk_quota)."',
                    visibility = '".Database::escape_string($visibility)."',
                    subscribe = '".Database::escape_string($subscribe)."',
                    unsubscribe='".Database::escape_string($unsubscribe)."'
                WHERE code='".Database::escape_string($course_code)."'";
        Database::query($sql);

        //Delete only teacher relations that doesn't match the selected teachers
        $cond='';
        if (count($teachers)>0) {
            foreach($teachers as $key) {
                $cond.=" AND user_id<>'".$key."'";
            }
        }
        $sql = 'DELETE FROM '.$course_user_table.' WHERE c_id = "'.Database::escape_string($courseInfo['real_id']).'" AND status="1"'.$cond;
        Database::query($sql);

        if (count($teachers)>0) {
            foreach ($teachers as $key) {
                //We check if the teacher is already subscribed in this course
                $sql_select_teacher = 'SELECT 1 FROM '.$course_user_table.' WHERE user_id = "'.$key.'" AND c_id = "'.$courseInfo['real_id'].'" ';
                $result = Database::query($sql_select_teacher);

                if (Database::num_rows($result) == 1) {
                    $sql = 'UPDATE '.$course_user_table.' SET status = "1" WHERE c_id = "'.$courseInfo['real_id'].'" AND user_id = "'.$key.'"  ';
                } else {
                    $sql = "INSERT INTO ".$course_user_table . " SET
                        c_id = '".Database::escape_string($courseInfo['real_id']). "',
                        user_id = '".$key . "',
                        status = '1',
                        role = '',
                        tutor_id = '0',
                        sort = '0',
                        user_course_cat = '0'";
                }
                Database::query($sql);
            }
        }

        //user_id = '".$tutor_id . "',
        $sql = "INSERT IGNORE INTO ".$course_user_table . " SET
                    course_code = '".Database::escape_string($course_code). "',
                    status = '1',
                    role = '',
                    tutor_id='0',
                    sort='0',
                    user_course_cat='0'";
        Database::query($sql);

        $course_info = api_get_course_info($course_code);

        return $course_info;
    }

    /**
     * Returns all the information of a given coursecode from the course table
     * @param string $course_code, the course code
     * @return an array with all the fields of the course table
     * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
     * @assert (array(1,2,3)) === false
     */
    public static function get_course_information($course_code)
    {
        return Database::fetch_array(Database::query(
            "SELECT *, id as real_id FROM ".Database::get_main_table(TABLE_MAIN_COURSE)."
            WHERE code='".Database::escape_string($course_code)."'"),'ASSOC'
        );
    }

    /**
     * Returns all the information of a given coursecode from the course
     * table by it integer ID
     * @param   int     the course id
     * @return an array with all the fields of the course table
     * @assert (-1) === false
     */
    public static function get_course_information_by_id($course_id)
    {
        return Database::select('*, id as real_id', Database::get_main_table(TABLE_MAIN_COURSE), array('where'=>array('id = ?' =>intval($course_id))),'first');
    }

    /**
     * Returns a list of courses. Should work with quickform syntax
     * @param    integer    Offset (from the 7th = '6'). Optional.
     * @param    integer    Number of results we want. Optional.
     * @param    string    The column we want to order it by. Optional, defaults to first column.
     * @param    string    The direction of the order (ASC or DESC). Optional, defaults to ASC.
     * @param    string    The visibility of the course, or all by default.
     * @param    string    If defined, only return results for which the course *title* begins with this string
     * @return mixed Array of courses details, or false on error
     * @assert (array(1,2,3)) === false
     */
    public static function get_courses_list($from = 0, $howmany = 0, $orderby = 1, $orderdirection = 'ASC', $visibility = -1, $startwith = '')
    {

        $sql = "SELECT * FROM ".Database::get_main_table(TABLE_MAIN_COURSE)." ";
        if (!empty($startwith)) {
            $sql .= "WHERE title LIKE '".Database::escape_string($startwith)."%' ";
            if ($visibility !== -1 && $visibility == strval(intval($visibility))) {
                $sql .= " AND visibility = $visibility ";
            }
        } else {
            $sql .= "WHERE 1 ";
            if ($visibility !== -1 && $visibility == strval(intval($visibility))) {
                $sql .= " AND visibility = $visibility ";
            }
        }
        if (!empty($orderby)) {
            $sql .= " ORDER BY ".Database::escape_string($orderby)." ";
        } else {
            $sql .= " ORDER BY 1 ";
        }

        if (!in_array($orderdirection, array('ASC', 'DESC'))) {
            $sql .= 'ASC';
        } else {
            $sql .= Database::escape_string($orderdirection);
        }

        if (!empty($howmany) && is_int($howmany) and $howmany > 0) {
            $sql .= ' LIMIT '.Database::escape_string($howmany);
        } else {
            $sql .= ' LIMIT 1000000'; //virtually no limit
        }
        if (!empty($from)) {
            $from = intval($from);
            $sql .= ' OFFSET '.Database::escape_string($from);
        } else {
            $sql .= ' OFFSET 0';
        }

        return Database::store_result(Database::query($sql));
    }

    /**
     * Returns the access settings of the course:
     * which visibility;
     * wether subscribing is allowed;
     * wether unsubscribing is allowed.
     *
     * @param string $course_code, the course code
     * @todo for more consistency: use course_info call from database API
     * @return an array with int fields "visibility", "subscribe", "unsubscribe"
     * @assert () === false
     */
    public static function get_access_settings($course_code)
    {
        return Database::fetch_array(Database::query(
            "SELECT visibility, subscribe, unsubscribe from ".Database::get_main_table(TABLE_MAIN_COURSE)."
            WHERE code = '".Database::escape_string($course_code)."'")
        );
    }

    /**
     * Returns the status of a user in a course, which is COURSEMANAGER
     * or STUDENT.
     * @param   int      User ID
     * @param   string   Course code
     * @return int the status of the user in that course
     * @assert () === false
     */
    public static function get_user_in_course_status($user_id, $courseId)
    {
        $result = Database::fetch_array(Database::query(
            "SELECT status FROM ".Database::get_main_table(TABLE_MAIN_COURSE_USER)."
            WHERE c_id = '".Database::escape_string($courseId)."' AND user_id = ".Database::escape_string($user_id))
        );
        return $result['status'];
    }
    /**
     * Gets the ID of a course tutor for a user, given the user and the course
     * @param int User ID
     * @param string Course code
     * @return mixed The tutor ID
     * @assert () === false
     */
    public static function get_tutor_in_course_status($user_id, $courseId)
    {
        $result = Database::fetch_array(Database::query(
                "SELECT tutor_id FROM ".Database::get_main_table(TABLE_MAIN_COURSE_USER)."
                WHERE c_id = '".Database::escape_string($courseId)."' AND user_id = ".Database::escape_string($user_id))
        );
        return $result['tutor_id'];
    }

    /**
     * Unsubscribe one or more users from a course
     * @param   mixed   user_id or an array with user ids
     * @param   int     session id
     * @param   int   course id
     * @return  mixed   False on user ID not found, void otherwise
     * @assert () === false
     */
    public static function unsubscribe_user($user_id, $courseId, $session_id = 0)
    {
        if (!isset($user_id)) {
            return false;
        }
        if (!is_array($user_id)) {
            $user_id = array($user_id);
        }

        if (count($user_id) == 0) {
            return false;
        }
        $table_user = Database :: get_main_table(TABLE_MAIN_USER);

        if (!empty($session_id)) {
            $session_id = intval($session_id);
        } else {
            $session_id = api_get_session_id();
        }

        $user_list = array();

        //Cleaning the $user_id variable
        if (is_array($user_id)) {
            $new_user_id_list = array();
            foreach ($user_id as $my_user_id) {
                $new_user_id_list[]= intval($my_user_id);
            }
            $new_user_id_list = array_filter($new_user_id_list);
            $user_list = $new_user_id_list;
            $user_ids = implode(',', $new_user_id_list);
        } else {
            $user_ids = intval($user_id);
            $user_list[] = $user_id;
        }

        $courseId = intval($courseId);
        $courseInfo = api_get_course_info_by_id($courseId);
        $courseCode = $courseInfo['code'];

        // Unsubscribe user from all groups in the course.
        Database::query("DELETE FROM ".Database::get_course_table(TABLE_GROUP_USER)."  WHERE c_id = $courseId AND user_id IN (".$user_ids.")");
        Database::query("DELETE FROM ".Database::get_course_table(TABLE_GROUP_TUTOR)." WHERE c_id = $courseId AND user_id IN (".$user_ids.")");

        // Erase user student publications (works) in the course - by André Boivin
        //@todo field student_publication.author should be the user id

        $sqlu = "SELECT * FROM $table_user WHERE user_id IN (".$user_ids.")";
        $resu = Database::query($sqlu);
        $username = Database::fetch_array($resu,'ASSOC');
        $userfirstname = $username['firstname'];
        $userlastname = $username['lastname'];
        $publication_name = $userfirstname.' '.$userlastname ;

        $table_course_user_publication     = Database :: get_course_table(TABLE_STUDENT_PUBLICATION);
        $sql = "DELETE FROM $table_course_user_publication WHERE c_id = $courseId AND author = '".Database::escape_string($publication_name)."'";
        Database::query($sql);

        // Unsubscribe user from all blogs in the course.
        Database::query("DELETE FROM ".Database::get_course_table(TABLE_BLOGS_REL_USER)." WHERE c_id = $courseId AND  user_id IN (".$user_ids.")");
        Database::query("DELETE FROM ".Database::get_course_table(TABLE_BLOGS_TASKS_REL_USER)." WHERE c_id = $courseId AND  user_id IN (".$user_ids.")");

        //Deleting users in forum_notification and mailqueue course tables
        $sql_delete_forum_notification = "DELETE FROM  ".Database::get_course_table(TABLE_FORUM_NOTIFICATION)." WHERE c_id = $courseId AND user_id IN (".$user_ids.")";
        Database::query($sql_delete_forum_notification);

        $sql_delete_mail_queue = "DELETE FROM ".Database::get_course_table(TABLE_FORUM_MAIL_QUEUE)." WHERE c_id = $courseId AND user_id IN (".$user_ids.")";
        Database::query($sql_delete_mail_queue);

        $item_property_lp_subscription = "DELETE FROM  ".Database::get_course_table(TABLE_ITEM_PROPERTY)."
                                          WHERE lastedit_type = 'LearnpathSubscription' AND tool = 'learnpath' AND c_id = $courseId AND to_user_id IN (".$user_ids.")";
        Database::query($item_property_lp_subscription);

        // Unsubscribe user from the course.
        if (!empty($session_id)) {
            // Delete in table session_rel_course_rel_user
            Database::query("DELETE FROM ".Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER)."
                             WHERE id_session ='".$session_id."' AND c_id = '".$courseId."' AND id_user IN ($user_ids)");

            foreach ($user_id as $uid) {
                // check if a user is register in the session with other course
                $sql = "SELECT id_user FROM ".Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER)." WHERE id_session='$session_id' AND id_user='$uid'";
                $rs = Database::query($sql);
                if (Database::num_rows($rs) == 0) {
                    // Delete in table session_rel_user
                    Database::query("DELETE FROM ".Database::get_main_table(TABLE_MAIN_SESSION_USER)."
                                     WHERE id_session ='".$session_id."' AND id_user='$uid' AND relation_type<>".SESSION_RELATION_TYPE_RRHH."");
                }
            }

            // Update the table session
            $row = Database::fetch_array(Database::query("SELECT COUNT(*) FROM ".Database::get_main_table(TABLE_MAIN_SESSION_USER)."
                    WHERE id_session = '".$session_id."' AND relation_type<>".SESSION_RELATION_TYPE_RRHH."  "));
            $count = $row[0]; // number of users by session
            $result = Database::query("UPDATE ".Database::get_main_table(TABLE_MAIN_SESSION)." SET nbr_users = '$count'
                    WHERE id = '".$session_id."'");

            // Update the table session_rel_course
            $row = Database::fetch_array(@Database::query("SELECT COUNT(*) FROM ".Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER)."
                   WHERE id_session = '$session_id' AND c_id = '$courseId' AND status<>2" ));
            $count = $row[0]; // number of users by session and course
            $result = @Database::query("UPDATE ".Database::get_main_table(TABLE_MAIN_SESSION_COURSE)." SET nbr_users = '$count' WHERE id_session = '$session_id' AND c_id = '$courseId' ");

        } else {
            Database::query("DELETE FROM ".Database::get_main_table(TABLE_MAIN_COURSE_USER)."
                    WHERE user_id IN (".$user_ids.") AND relation_type<>".COURSE_RELATION_TYPE_RRHH." AND c_id = '".$courseId."'");

            // add event to system log
            $user_id = api_get_user_id();
            event_system(LOG_UNSUBSCRIBE_USER_FROM_COURSE, LOG_COURSE_CODE, $courseCode, api_get_utc_datetime(), $user_id);

            foreach ($user_list as $user_id_to_delete) {
                $user_info = api_get_user_info($user_id_to_delete);
                event_system(LOG_UNSUBSCRIBE_USER_FROM_COURSE, LOG_USER_OBJECT, $user_info, api_get_utc_datetime(), $user_id);
            }
        }
    }

    /**
     * Subscribe a user to a course. No checks are performed here to see if
     * course subscription is allowed.
     * @param   int     User ID
     * @param   string  Course code
     * @param   int     Status (STUDENT, COURSEMANAGER, COURSE_ADMIN, NORMAL_COURSE_MEMBER)
     * @return  bool    True on success, false on failure
     * @see add_user_to_course
     */
    public static function subscribe_user($user_id, $course_code, $status = STUDENT, $session_id = 0)
    {

        if ($user_id != strval(intval($user_id))) {
            return false; //detected possible SQL injection
        }
        $course_code = Database::escape_string($course_code);
        $courseInfo = api_get_course_info($course_code);
        $courseId = $courseInfo['real_id'];

        if (empty($user_id) || empty ($course_code)) {
            return false;
        }

        if (!empty($session_id)) {
            $session_id = intval($session_id);
        } else {
            $session_id = api_get_session_id();
        }

        $status = ($status == STUDENT || $status == COURSEMANAGER) ? $status : STUDENT;
        //$role_id = ($status == COURSEMANAGER) ? COURSE_ADMIN : NORMAL_COURSE_MEMBER;

        // A preliminary check whether the user has bben already registered on the platform.
        if (Database::num_rows(@Database::query("SELECT status FROM ".Database::get_main_table(TABLE_MAIN_USER)."
                WHERE user_id = '$user_id' ")) == 0) {
            return false; // The user has not been registered to the platform.
        }

        // Check whether the user has not been already subscribed to the course.
        if (empty($session_id)) {
            if (Database::num_rows(@Database::query("SELECT * FROM ".Database::get_main_table(TABLE_MAIN_COURSE_USER)."
                    WHERE user_id = '$user_id' AND relation_type<>".COURSE_RELATION_TYPE_RRHH." AND c_id = ".$courseId)) > 0) {
                return false; // The user has been already subscribed to the course.
            }
        }

        if (!empty($session_id)) {

            // Check whether the user has not already been stored in the session_rel_course_user table
            if (Database::num_rows(@Database::query("SELECT * FROM ".Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER)."
                    WHERE c_id = '".$courseId."'
                    AND id_session ='".$session_id."'
                    AND id_user = '".$user_id."'")) > 0) {
                return false;
            }

            // check if the user is registered in the session with other course
            $sql = "SELECT id_user FROM ".Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER)." WHERE id_session='".$session_id."' AND id_user='$user_id'";
            $rs = Database::query($sql);
            if (Database::num_rows($rs) == 0) {
                // Check whether the user has not already been stored in the session_rel_user table
                if (Database::num_rows(@Database::query("SELECT * FROM ".Database::get_main_table(TABLE_MAIN_SESSION_USER)."
                        WHERE id_session ='".$session_id."' AND id_user = '".$user_id."' AND relation_type<>".SESSION_RELATION_TYPE_RRHH." ")) > 0) {
                    return false;
                }
            }

            // Add him/her in the table session_rel_course_rel_user
            @Database::query("INSERT INTO ".Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER)."
                    SET id_session ='".$session_id."',
                    c_id = '".$courseId."',
                    id_user = '".$user_id."'");

            // Add him/her in the table session_rel_user
            @Database::query("INSERT INTO ".Database::get_main_table(TABLE_MAIN_SESSION_USER)."SET id_session ='".$session_id."', id_user = '".$user_id."'");

            // Update the table session
            $row = Database::fetch_array(@Database::query("SELECT COUNT(*) FROM ".Database::get_main_table(TABLE_MAIN_SESSION_USER)."
                            WHERE id_session = '".$session_id."' AND relation_type<>".SESSION_RELATION_TYPE_RRHH.""));
            $count = $row[0]; // number of users by session
            $result = @Database::query("UPDATE ".Database::get_main_table(TABLE_MAIN_SESSION)." SET nbr_users = '$count' WHERE id = '".$session_id."'");

            // Update the table session_rel_course
            $row = Database::fetch_array(@Database::query("SELECT COUNT(*) FROM ".Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER)."
                   WHERE id_session = '".$session_id."' AND c_id = ".$courseId." AND status <> 2" ));
            $count = $row[0]; // number of users by session
            $result = @Database::query("UPDATE ".Database::get_main_table(TABLE_MAIN_SESSION_COURSE)." SET nbr_users = '$count'
                      WHERE id_session = '".$session_id."' AND c_id = '$courseId' ");

        } else {
            $course_sort = self::userCourseSort($user_id, $courseId);
            $result = @Database::query("INSERT INTO ".Database::get_main_table(TABLE_MAIN_COURSE_USER)."
                    SET
                        c_id = ".$courseId.",
                        user_id     = '$user_id',
                        status      = '".$status."',
                        sort        = '". ($course_sort)."'");

            // Add event to the system log
            event_system(LOG_SUBSCRIBE_USER_TO_COURSE, LOG_COURSE_CODE, $course_code, api_get_utc_datetime(), api_get_user_id());

            $user_info = api_get_user_info($user_id);
            event_system(LOG_SUBSCRIBE_USER_TO_COURSE, LOG_USER_OBJECT, $user_info, api_get_utc_datetime(), api_get_user_id());
        }
        return (bool)$result;
    }

    /**
     * Get the course id based on the original id and field name in the extra fields. Returns 0 if course was not found
     *
     * @param string Original course id
     * @param string Original field name
     * @return int Course id
     * @assert ('', '') === false
     */
    public static function get_course_code_from_original_id($original_course_id_value, $original_course_id_name) {
        $t_cfv = Database::get_main_table(TABLE_MAIN_COURSE_FIELD_VALUES);
        $table_field = Database::get_main_table(TABLE_MAIN_COURSE_FIELD);
        $sql_course = "SELECT course_code FROM $table_field cf INNER JOIN $t_cfv cfv ON cfv.field_id=cf.id
                       WHERE field_variable='$original_course_id_name' AND field_value='$original_course_id_value'";
        $res = Database::query($sql_course);
        $row = Database::fetch_object($res);
        if ($row) {
            return $row->course_code;
        } else {
            return 0;
        }
    }

    /**
     * Gets the course code from the course id. Returns null if course id was not found
     *
     * @param int Course id
     * @return string Course code
     * @assert ('') === false
     */
    public static function get_course_code_from_course_id($id) {
        $table = Database::get_main_table(TABLE_MAIN_COURSE);
        $id = intval($id);
        $sql = "SELECT code FROM $table WHERE id = '$id' ";
        $res = Database::query($sql);
        $row = Database::fetch_object($res);
        if ($row) {
            return $row->code;
        } else {
            return null;
        }
    }

    /**
     * Subscribe a user $user_id to a course $course_code.
     * @author Hugues Peeters
     * @author Roan Embrechts
     *
     * @param  int $user_id the id of the user
     * @param  int  $courseId the course code
     * @param string $status (optional) The user's status in the course
     *
     * @return boolean true if subscription succeeds, boolean false otherwise.
     * @assert ('', '') === false
     */
    public static function add_user_to_course($user_id, $courseId, $status = STUDENT) {
        $debug = false;
        $user_table         = Database::get_main_table(TABLE_MAIN_USER);
        $course_table       = Database::get_main_table(TABLE_MAIN_COURSE);
        $course_user_table  = Database::get_main_table(TABLE_MAIN_COURSE_USER);

        $status = ($status == STUDENT || $status == COURSEMANAGER) ? $status : STUDENT;
        if (empty($user_id) || empty($courseId) || ($user_id != strval(intval($user_id)))) {
            return false;
        }
        $courseId = Database::escape_string($courseId);

        // Check in advance whether the user has already been registered on the platform.
        if (Database::num_rows(Database::query("SELECT status FROM ".$user_table." WHERE user_id = '$user_id' ")) == 0) {
            if ($debug) error_log('The user has not been registered to the platform');
            return false; // The user has not been registered to the platform.
        }

        // Check whether the user has already been subscribed to this course.
        if (Database::num_rows(Database::query("SELECT * FROM ".$course_user_table." WHERE user_id = '$user_id' AND relation_type<>".COURSE_RELATION_TYPE_RRHH." AND c_id = '$courseId'")) > 0) {
            if ($debug) error_log('The user has been already subscribed to the course');
            return false; // The user has been subscribed to the course.
        }

        // Check in advance whether subscription is allowed or not for this course.
        if (Database::num_rows(Database::query("SELECT code, visibility FROM ".$course_table." WHERE id = '$courseId' AND subscribe = '".SUBSCRIBE_NOT_ALLOWED."'")) > 0) {
            if ($debug) error_log('Subscription is not allowed for this course');
            return false; // Subscription is not allowed for this course.
        }

        // Ok, subscribe the user.
        $max_sort = api_max_sort_value('0', $user_id);
        return (bool)Database::query("INSERT INTO ".$course_user_table."
                SET c_id = '$courseId',
                user_id = '$user_id',
                status = '".$status."',
                sort = '". ($max_sort + 1)."'");
    }

    /**
     *    @return true if there already are one or more courses
     *    with the same code OR visual_code (visualcode), false otherwise
     */
    public static function course_code_exists($wanted_course_code) {
        $wanted_course_code = Database::escape_string($wanted_course_code);
        $result = Database::fetch_array(Database::query("SELECT COUNT(*) as number FROM ".Database::get_main_table(TABLE_MAIN_COURSE)."
                  WHERE code = '$wanted_course_code' OR visual_code = '$wanted_course_code'"));
        return $result['number'] > 0;
    }

    /**
     *  @return an array with the course info of all real courses on the platform
     */
    public static function get_real_course_list() {
        $sql_result = Database::query("SELECT * FROM ".Database::get_main_table(TABLE_MAIN_COURSE)." WHERE target_course_code IS NULL");
        $real_course_list = array();
        while ($result = Database::fetch_array($sql_result)) {
            $real_course_list[$result['code']] = $result;
        }
        return $real_course_list;
    }


    /**
     * Get course list as coach
     *
     * @param     int        user id
     * @return    array    course list
     *
     *  */
    public static function get_course_list_as_coach($user_id, $include_courses_in_sessions = false) {

        //1. Getting courses as teacher (No session)
        $courses_temp           = CourseManager::get_course_list_of_user_as_course_admin($user_id);
        $courses_as_admin         = array();

        if (!empty($courses_temp)) {
            foreach($courses_temp as $course_item) {
                $courses_as_admin[0][$course_item['real_id']] = $course_item['real_id'];
            }
        }

        //2. Include courses in sessions
        if ($include_courses_in_sessions) {
            $sessions      = SessionManager::get_sessions_coached_by_user($user_id);

            if (!empty($sessions)) {
                foreach($sessions as $session_item) {
                    $courses  = Tracking :: get_courses_followed_by_coach($user_id, $session_item['id']);
                    if (is_array($courses)) {
                        foreach($courses as $course_item) {
                            $courses_as_admin[$session_item['id']][$course_item] = $course_item;
                        }
                    }
                }
            }
        }
        return $courses_as_admin;
    }

    public static function get_user_list_from_courses_as_coach($user_id, $include_sessions = true) {
        $students_in_courses = array();

        $sessions = CourseManager::get_course_list_as_coach($user_id, true);
        if (!empty($sessions)) {
            foreach($sessions as $session_id => $courses) {
                if (!$include_sessions) {
                    if (!empty($session_id)) {
                        continue;
                    }
                }
                if (empty($session_id)) {
                    foreach($courses as $course_code) {
                        $students_in_course = CourseManager::get_user_list_from_course_code($course_code);

                        foreach($students_in_course as $user_item) {
                            //Only students
                            if ($user_item['status_rel'] == STUDENT)
                                $students_in_courses[$user_item['user_id']] = $user_item['user_id'];
                        }
                    }
                } else {
                    $students_in_course = SessionManager::get_users_by_session($session_id, '0');
                    if (is_array($students_in_course)) {
                        foreach ($students_in_course as $user_item) {
                            if ($user_item['moved_to'] == 0) {
                                $students_in_courses[$user_item['user_id']] = $user_item['user_id'];
                            }
                        }
                    }
                }
            }
        }

        $students = Tracking :: get_student_followed_by_coach($user_id);
        if (!empty($students_in_courses)) {
            if (!empty($students)) {
                $students = array_merge($students, $students_in_courses);
            } else {
                $students = $students_in_courses;
            }
        }

        if (!empty($students)) {
            $students = array_unique($students);
        }
        return $students;
    }

    /**
     *    @return an array with the course info of all the courses of whichthe current user is course admin
     */
    public static function get_course_list_of_user_as_course_admin($user_id) {
        if ($user_id != strval(intval($user_id))) {
            return array();
        }

        // Definitions database tables and variables
        $tbl_course      = Database::get_main_table(TABLE_MAIN_COURSE);
        $tbl_course_user = Database::get_main_table(TABLE_MAIN_COURSE_USER);
        $user_id = intval($user_id);
        $data = array();

        $sql_nb_cours = "SELECT course_rel_user.c_id,
                                course.title, course.id,
                                course.db_name,
                                course.id as real_id
                        FROM $tbl_course_user as course_rel_user
                        INNER JOIN $tbl_course as course
                            ON course.id = course_rel_user.c_id
                        WHERE course_rel_user.user_id='$user_id' AND course_rel_user.status='1'
                        ORDER BY course.title";

        if (api_get_multiple_access_url()) {
            $tbl_course_rel_access_url = Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
            $access_url_id = api_get_current_access_url_id();
            if ($access_url_id != -1) {
                $sql_nb_cours = "    SELECT course_rel_user.c_id, course.title, course.id, course.db_name, course.id as real_id
                    FROM $tbl_course_user as course_rel_user
                    INNER JOIN $tbl_course as course
                        ON course.id = course_rel_user.c_id
                      INNER JOIN $tbl_course_rel_access_url course_rel_url
                        ON (course_rel_url.c_id = course.id)
                      WHERE access_url_id =  $access_url_id  AND course_rel_user.user_id='$user_id' AND course_rel_user.status='1'
                      ORDER BY course.title";
            }
        }

        $result_nb_cours = Database::query($sql_nb_cours);
        if (Database::num_rows($result_nb_cours) > 0) {
            while ($row = Database::fetch_array($result_nb_cours,'ASSOC')) {
                $data[$row['c_id']] = $row;
            }
        }
        return $data;
    }

    /**
     * Check if user is subscribed inside a course
     * @param     int        User id
     * @param    string    Course code, if this parameter is null, it'll check for all courses
     * @param    bool    True for checking inside sessions too, by default is not checked
     * @return     bool     true if the user is registered in the course, false otherwise
     */
    public static function is_user_subscribed_in_course($user_id, $courseId = null, $in_a_session = false, $session_id = null) {

        $user_id = intval($user_id);

        if (empty($session_id)) {
            $session_id = api_get_session_id();
        } else {
            $session_id = intval($session_id);
        }

        $condition_course_id = null;
        if (isset($courseId)) {
            $courseId = intval($courseId);
            $condition_course_id = ' AND c_id = "'.$courseId.'" ';
        }

        $sql = "SELECT * FROM ".Database::get_main_table(TABLE_MAIN_COURSE_USER)."
                WHERE user_id = $user_id AND relation_type<>".COURSE_RELATION_TYPE_RRHH." $condition_course_id ";

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

        if (!empty($result)) {
            return true; // The user has been registered in this course.
        }

        if (!$in_a_session) {
            return false; // The user has not been registered in this course.
        }

        if (Database::num_rows(Database::query('SELECT 1 FROM '.Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER).
                ' WHERE id_user = '.$user_id.' '.$condition_course_id.' ')) > 0) {
            return true;
        }

        if (Database::num_rows(Database::query('SELECT 1 FROM '.Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER).
                ' WHERE id_user = '.$user_id.' AND status=2 '.$condition_course_id.' ')) > 0) {
            return true;
        }

        if (Database::num_rows(Database::query('SELECT 1 FROM '.Database::get_main_table(TABLE_MAIN_SESSION).
                ' WHERE id='.$session_id.' AND id_coach='.$user_id)) > 0) {
            return true;
        }
        return false;
    }

    /**
     *    Is the user a teacher in the given course?
     *
     *    @param int $user_id, the id (int) of the user
     *    @param int $course_code, the course code
     *
     *    @return true if the user is a teacher in the course, false otherwise
     */
    public static function is_course_teacher($user_id, $courseId) {
        if ($user_id != strval(intval($user_id))) {
            return false;
        }
        $sql_result = Database::query('SELECT status FROM '.Database::get_main_table(TABLE_MAIN_COURSE_USER).
                ' WHERE c_id ="'.Database::escape_string($courseId).'" and user_id="'.$user_id.'"');
        if (Database::num_rows($sql_result) > 0) {
            return Database::result($sql_result, 0, 'status') == 1;
        }
        return false;
    }

    /**
     *    Is the user subscribed in the real course or linked courses?
     *
     *    @param int the id of the user
     *    @param array info about the course (comes from course table, see database lib)
     *
     *    @return true if the user is registered in the real course or linked courses, false otherwise
     */
    public static function is_user_subscribed_in_real_or_linked_course ($user_id, $courseId, $session_id = '') {

        if ($user_id != strval(intval($user_id))) {
            return false;
        }

        $session_id = intval($session_id);

        $courseId = Database::escape_string($courseId);

        if ($session_id == '') {
            $result = Database::fetch_array(Database::query("SELECT *
                    FROM ".Database::get_main_table(TABLE_MAIN_COURSE)." course
                    LEFT JOIN ".Database::get_main_table(TABLE_MAIN_COURSE_USER)." course_user
                    ON course.id = course_user.c_id
                    WHERE   course_user.user_id = '$user_id' AND
                            course_user.relation_type<>".COURSE_RELATION_TYPE_RRHH." AND
                            course.id = '$courseId'"));
            return !empty($result);
        }

        // From here we trust session id.

        // Is he/she subscribed to the session's course?

        // A user?
        if (Database::num_rows(Database::query("SELECT id_user
                    FROM ".Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER)."
                    WHERE id_session='".$session_id."'
                    AND id_user='$user_id'"))) {
            return true;
        }

        // A course coach?
        if (Database::num_rows(Database::query("SELECT id_user
                    FROM ".Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER)."
                    WHERE id_session='".$session_id."'
                    AND id_user = '$user_id' AND status = 2
                    AND c_id ='$courseId'"))) {
            return true;
        }

        // A session coach?
        if (Database::num_rows(Database::query("SELECT id_coach
                    FROM ".Database::get_main_table(TABLE_MAIN_SESSION)." AS session
                    WHERE session.id='".$session_id."'
                    AND id_coach='$user_id'"))) {
            return true;
        }
        return false;
    }

    /**
     * Return user info array of all users registered in the specified course
     * This only returns the users that are registered in this actual course, not linked courses.
     *
     * @param string    $course_code the code of the course
     * @param boolean   $with_session determines if the course is used in a session or not
     * @param integer   $session_id the id of the session
     * @param string    $limit the LIMIT statement of the sql statement
     * @param string    $order_by the field to order the users by. Valid values are 'lastname', 'firstname', 'username', 'email', 'official_code' OR a part of a SQL statement that starts with ORDER BY ...
     * @param int       if using the session_id: 0 or 2 (student, coach), if using session_id = 0 STUDENT or COURSEMANAGER
     * @return array
     */
    public static function get_user_list_from_course_code($course_code = null, $session_id = 0, $limit = null, $order_by = null, $filter_by_status = null, $return_count = null, $add_reports = false, $resumed_report = false, $extra_field = null)
    {
        // variable initialisation
        $session_id     = intval($session_id);
        $course_code    = Database::escape_string($course_code);
        $where          = array();

        // if the $order_by does not contain 'ORDER BY' we have to check if it is a valid field that can be sorted on
        if (!strstr($order_by,'ORDER BY')) {
            //if (!empty($order_by) AND in_array($order_by, array('lastname', 'firstname', 'username', 'email', 'official_code'))) {
            if (!empty($order_by)) {
                $order_by = 'ORDER BY '.$order_by;
            } else {
                $order_by = '';
            }
        }

        $courseInfo = api_get_course_info($course_code);
        $courseId = null;
        if ($courseInfo) {
            $courseId = $courseInfo['real_id'];
        }

        $filter_by_status_condition = null;

        if (!empty($session_id) && !empty($courseId)) {
            $sql = 'SELECT DISTINCT user.user_id, session_course_user.status as status_session, user.*  ';
            $sql .= ' FROM '.Database::get_main_table(TABLE_MAIN_USER).' as user ';
            $sql .= ' LEFT JOIN '.Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER).' as session_course_user
                      ON user.user_id = session_course_user.id_user
                      AND session_course_user.c_id="'.$courseId.'"
                      AND session_course_user.id_session = '.$session_id;
            $where[] = ' session_course_user.c_id IS NOT NULL ';

            // 2 = coach
            // 0 = student
            if (isset($filter_by_status)) {
                $filter_by_status = intval($filter_by_status);
                $filter_by_status_condition = " session_course_user.status = $filter_by_status AND ";
            }
        } else {
            if ($return_count) {
                $sql = " SELECT COUNT(*) as count";
                if ($resumed_report) {
                    //$sql = " SELECT count(field_id) ";
                }
            } else {
                if (empty($course_code)) {
                    $sql = 'SELECT DISTINCT course.title, course.code, course_rel_user.status as status_rel, user.user_id, course_rel_user.role, course_rel_user.tutor_id, user.*  ';
                } else {
                    $sql  = 'SELECT DISTINCT course_rel_user.status as status_rel, user.user_id, course_rel_user.role, course_rel_user.tutor_id, user.*  ';
                }
            }

            $sql .= ' FROM '.Database::get_main_table(TABLE_MAIN_USER).' as user ';
            $sql .= ' LEFT JOIN '.Database::get_main_table(TABLE_MAIN_COURSE_USER).' as course_rel_user
                        ON user.user_id = course_rel_user.user_id AND
                        course_rel_user.relation_type <> '.COURSE_RELATION_TYPE_RRHH;
            if (!empty($courseInfo)) {
                $sql .= " AND course_rel_user.c_id = ".$courseId;
            } else {
                $course_table = Database::get_main_table(TABLE_MAIN_COURSE);
                $sql .= " INNER JOIN $course_table course ON course_rel_user.c_id = course.id";
            }
            $where[] = ' course_rel_user.c_id IS NOT NULL ';

            if (isset($filter_by_status) && $filter_by_status != '') {
                $filter_by_status = intval($filter_by_status);
                $filter_by_status_condition = " course_rel_user.status = $filter_by_status AND ";
            }
        }

        $multiple_access_url = api_get_multiple_access_url();
        if ($multiple_access_url) {
            $sql  .= ' LEFT JOIN '.Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER).'  au ON (au.user_id = user.user_id) ';
        }

        if ($return_count && $resumed_report) {
            $extra_field_info = UserManager::get_extra_field_information_by_name($extra_field);
            $sql .= ' LEFT JOIN '.Database::get_main_table(TABLE_MAIN_USER_FIELD_VALUES).' as ufv ON (user.user_id = ufv.user_id AND (field_id = '.$extra_field_info['id'].' OR field_id IS NULL ) )';
        }
        $sql .= ' WHERE '.$filter_by_status_condition.' '.implode(' OR ', $where);

        if ($multiple_access_url) {
            $current_access_url_id = api_get_current_access_url_id();
            $sql .= " AND (access_url_id =  $current_access_url_id ) ";
        }
        if ($return_count && $resumed_report) {
            $sql .= ' AND field_id IS NOT NULL  GROUP BY field_value ';
        }

        $sql .= ' '.$order_by.' '.$limit;

        $rs = Database::query($sql);
        $users = array();
        if ($add_reports) {
            $extra_fields = UserManager::get_extra_fields(0, 100, null, null, true, true);
        }
        $counter = 1;
        $count_rows = Database::num_rows($rs);
        if ($return_count && $resumed_report) {
            return $count_rows;
        }
        $table_user_field_value = Database::get_main_table(TABLE_MAIN_USER_FIELD_VALUES);
        if ($count_rows) {
            while ($user = Database::fetch_array($rs)) {
                $report_info = array();

                if ($return_count) {
                    return $user['count'];
                }
                $user_info = $user;
                $user_info['status'] = $user['status'];

                if (isset($user['role'])) {
                    $user_info['role'] = $user['role'];
                }

                if (isset($user['tutor_id'])) {
                    $user_info['tutor_id'] = $user['tutor_id'];
                }

                if (!empty($session_id)) {
                    $user_info['status_session'] = $user['status_session'];
                }

                $user_info['complete_name'] = api_get_person_name($user_info['firstname'], $user_info['lastname']);

                if ($add_reports) {
                    $course_code = $user['code'];
                    if ($resumed_report) {

                        foreach ($extra_fields as $extra) {
                            if ($extra['1'] == $extra_field) {
                                $user_data = UserManager::get_extra_user_data_by_field($user['user_id'], $extra['1']);
                                break;
                            }
                        }

                        if (empty($user_data[$extra['1']])) {
                            $row_key = '-1';
                            $name = '-';
                        } else {
                            $row_key = $user_data[$extra['1']];
                            $name = $user_data[$extra['1']];
                        }

                        $users[$row_key]['extra_'.$extra['1']] = $name;
                        $users[$row_key]['training_hours'] += Tracking::get_time_spent_on_the_course($user['user_id'], $courseId, 0);
                        $users[$row_key]['count_users'] += $counter;
                        $registered_users_with_extra_field = 0;

                        if (!empty($name) && $name != '-') {
                            $name = Database::escape_string($name);
                            $sql = "SELECT count(user_id) as count FROM $table_user_field_value WHERE field_value = '$name'";
                            $result_count = Database::query($sql);
                            if (Database::num_rows($result_count)) {
                                $row_count = Database::fetch_array($result_count);
                                $registered_users_with_extra_field = $row_count['count'];
                            }
                        }

                        $users[$row_key]['count_users_registered'] = $registered_users_with_extra_field;
                        $users[$row_key]['average_hours_per_user'] = $users[$row_key]['training_hours'] / $users[$row_key]['count_users'];

                        $category = Category::load (null, null, $course_code);
                        if (!isset($users[$row_key]['count_certificates'])) {
                            $users[$row_key]['count_certificates'] = 0;
                        }
                        if (isset($category[0]) && $category[0]->is_certificate_available($user['user_id'])) {
                            $users[$row_key]['count_certificates']++;
                        }
                    } else {
                    $report_info['course'] = $user['title'];
                    $report_info['user'] = api_get_person_name($user['firstname'], $user['lastname']);
                    $report_info['time'] = api_time_to_hms(Tracking::get_time_spent_on_the_course($user['user_id'], $courseId, 0));


                    $category = Category :: load (null, null, $course_code);
                    $report_info['certificate'] = Display::label(get_lang('No'));
                    if (isset($category[0]) && $category[0]->is_certificate_available($user['user_id'])) {
                        $report_info['certificate'] = Display::label(get_lang('Yes'), 'success');
                    }
                    //$report_info['score'] = Tracking::get_avg_student_score($user['user_id'], $courseId, array(), 0);

                    $progress = intval(Tracking::get_avg_student_progress($user['user_id'], $courseId, array(), 0));
                    $report_info['progress_100'] =  $progress == 100 ? Display::label(get_lang('Yes'), 'success') : Display::label(get_lang('No'));
                    $report_info['progress'] = $progress."%";

                    foreach ($extra_fields as $extra) {
                        $user_data = UserManager::get_extra_user_data_by_field($user['user_id'], $extra['1']);
                        $report_info[$extra['1']] = $user_data[$extra['1']];
                    }
                    $users[] = $report_info;
                    }
                } else {
                    $users[$user['user_id']] = $user_info;
                }
            }
            $counter++;
        }
        return $users;
    }

    static function get_count_user_list_from_course_code($resumed_report = false, $extra_field = null) {
        return self::get_user_list_from_course_code(null, 0, null, null, null, true, false, $resumed_report, $extra_field);
    }

    /**
     * Gets subscribed users in a course or in a course/session
     *
     * @param   string    $course_code
     * @param   int       $session_id
     * @return  int
     */
    public static function get_users_count_in_course($course_code, $session_id = 0) {
        // variable initialisation
        $session_id     = intval($session_id);
        $course_code    = Database::escape_string($course_code);

        $courseInfo = api_get_course_info($course_code);
        $courseId = $courseInfo['real_id'];

        $sql = 'SELECT DISTINCT count(*) as count  FROM '.Database::get_main_table(TABLE_MAIN_USER).' as user ';
        $where = array();
        if (!empty($session_id)) {
            $sql .= ' LEFT JOIN '.Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER).' as session_course_user
                      ON user.user_id = session_course_user.id_user
                      AND session_course_user.c_id = "'.$courseId.'"
                      AND session_course_user.id_session  = '.$session_id.'
                      INNER JOIN '.Database::get_main_table(TABLE_MAIN_SESSION_USER).' as su
                      ON ( su.id_session = session_course_user.id_session AND
                           user.user_id = su.id_user AND
                           su.moved_to = 0 AND
                           su.moved_status <> '.SessionManager::SESSION_CHANGE_USER_REASON_ENROLLMENT_ANNULATION.'
                         )';

            $where[] = ' session_course_user.c_id IS NOT NULL ';
        } else {
            $sql .= ' LEFT JOIN '.Database::get_main_table(TABLE_MAIN_COURSE_USER).' as course_rel_user
                        ON user.user_id = course_rel_user.user_id AND course_rel_user.relation_type<>'.COURSE_RELATION_TYPE_RRHH.'
                        AND course_rel_user.c_id ="'.$courseId.'"';
            $where[] = ' course_rel_user.c_id IS NOT NULL ';
        }

        $multiple_access_url = api_get_multiple_access_url();
        if ($multiple_access_url) {
            $sql  .= ' LEFT JOIN '.Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER).'  au ON (au.user_id = user.user_id) ';
        }

        $sql .= ' WHERE '.implode(' OR ', $where);

        if ($multiple_access_url) {
            $current_access_url_id = api_get_current_access_url_id();
            $sql .= " AND (access_url_id =  $current_access_url_id ) ";
        }
        $rs = Database::query($sql);
        $count = 0;
        if (Database::num_rows($rs)) {
            $user = Database::fetch_array($rs);
            $count = $user['count'];
        }
        return $count;
    }

    /**
     * Get a list of coaches of a course and a session
     * @param   string  Course code
     * @param   int     Session ID
     * @return  array   List of users
     */
    public static function get_coach_list_from_course_code($courseId, $session_id) {

        if ($session_id != strval(intval($session_id))) {
            return array();
        }

        $courseId = Database::escape_string($courseId);

        $users = array();

        // We get the coach for the given course in a given session.
        $rs = Database::query('SELECT id_user FROM '.Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER).
                ' WHERE id_session="'.$session_id.'" AND c_id="'.$courseId.'" AND status = 2');
        while ($user = Database::fetch_array($rs)) {
            $user_info = api_get_user_info($user['id_user']);
            $user_info['status'] = $user['status'];
            $user_info['role'] = $user['role'];
            $user_info['tutor_id'] = $user['tutor_id'];
            $user_info['email'] = $user['email'];
            $users[$user['id_user']] = $user_info;
        }

        // We get the session coach.
        $rs = Database::query('SELECT id_coach FROM '.Database::get_main_table(TABLE_MAIN_SESSION).' WHERE id="'.$session_id.'"');
        $session_id_coach = Database::result($rs, 0, 'id_coach');
        $user_info = api_get_user_info($session_id_coach);
        $user_info['status'] = $user['status'];
        $user_info['role'] = $user['role']; //Role field exists?
        $user_info['tutor_id'] = $user['tutor_id'];
        $user_info['email'] = $user['email'];
        $users[$session_id_coach] = $user_info;
        return $users;
    }

    /**
     *    Return user info array of all users registered in the specified real or virtual course
     *    This only returns the users that are registered in this actual course, not linked courses.
     *
     *    @param string $course_code
     *    @param boolean $full list to true if we want sessions students too
     *    @return array with user id
     */
    public static function get_student_list_from_course_code($courseId, $with_session = false, $session_id = 0, $group_id = 0) {
        $session_id = intval($session_id);
        $courseId = Database::escape_string($courseId);

        $students = array();

        if ($session_id == 0) {
            if (empty($group_id)) {
                // students directly subscribed to the course
                $sql = "SELECT * FROM ".Database::get_main_table(TABLE_MAIN_COURSE_USER)."
                       WHERE c_id = ".$courseId." AND status = ".STUDENT;
                $rs = Database::query($sql);
                while ($student = Database::fetch_array($rs)) {
                    $students[$student['user_id']] = $student;
                }
            } else {
                $students = GroupManager::get_users($group_id, false, $courseId);
                $students = array_flip($students);
            }
        }

        // students subscribed to the course through a session

        if ($with_session) {
            $sql_query = "SELECT * FROM ".Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER)."
                          WHERE c_id = '$courseId' AND status <> 2";
            if ($session_id != 0) {
                $sql_query .= ' AND id_session = '.$session_id;
            }
            $rs = Database::query($sql_query);
            while($student = Database::fetch_array($rs)) {
                $students[$student['id_user']] = $student;
            }
        }
        return $students;
    }

    /**
     *    Return user info array of all teacher-users registered in the specified real or virtual course
     *    This only returns the users that are registered in this actual course, not linked courses.
     *
     *    @param int $courseId
     *    @return array with user id
     */
    public static function get_teacher_list_from_course_code($courseId)
    {
        $courseId = Database::escape_string($courseId);
        $teachers = array();
        $sql = "SELECT DISTINCT u.user_id, u.lastname, u.firstname, u.email, u.username, u.status
                FROM ".Database::get_main_table(TABLE_MAIN_COURSE_USER)." cu INNER JOIN ".Database::get_main_table(TABLE_MAIN_USER)." u
                ON (cu.user_id = u.user_id)
                WHERE   cu.c_id = '$courseId' AND
                        cu.status = 1 ";
        $rs = Database::query($sql);
        while ($teacher = Database::fetch_array($rs)) {
            $teachers[$teacher['user_id']] = $teacher;
        }
        return $teachers;
    }

    /**
     * @param $courseId
     * @param string $separator
     * @param bool $add_link_to_profile
     * @return string
     */
    public static function get_teacher_list_from_course_code_to_string($courseId, $separator = null, $add_link_to_profile = false)
    {
        $teacher_list = self::get_teacher_list_from_course_code($courseId);

        return self::formatUserListToString($teacher_list, $separator, $add_link_to_profile);
    }

    public static function formatUserListToString($userList, $separator = null, $add_link_to_profile = false)
    {
        if (empty($separator)) {
            $separator = self::USER_SEPARATOR;
        }
        $teacher_string = '';
        $list = array();
        if (!empty($userList)) {
            foreach($userList as $teacher) {
                $teacher_name = api_get_person_name($teacher['firstname'], $teacher['lastname']);
                if ($add_link_to_profile) {
                    $url = api_get_path(WEB_AJAX_PATH).'user_manager.ajax.php?a=get_user_popup&resizable=0&height=300&user_id='.$teacher['user_id'];
                    $teacher_name = Display::url($teacher_name, $url, array('class' => 'ajax'));
                }
                 $list[]= $teacher_name;
            }
            if (!empty($list)) {
                $teacher_string = ArrayClass::array_to_string($list, $separator);
            }
        }
        return $teacher_string;
    }

    /**
    * This function returns information about coachs from a course in session
    * @param int       - optional, session id
    * @param string    - optional, course code
    * @return array    - array containing user_id, lastname, firstname, username
    *
    */
    public static function get_coachs_from_course($session_id = 0, $courseId = null) {

        if (!empty($session_id)) {
            $session_id = intval($session_id);
        } else {
            $session_id = api_get_session_id();
        }

        if (!empty($courseId)) {
            $courseId = Database::escape_string($courseId);
        } else {
            $courseId = api_get_course_int_id();
        }

        $tbl_user                   = Database :: get_main_table(TABLE_MAIN_USER);
        $tbl_session_course_user    = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
        $coaches = array();

        $sql = "SELECT DISTINCT u.user_id, u.lastname, u.firstname, u.username
                FROM $tbl_user u, $tbl_session_course_user scu
                WHERE u.user_id = scu.id_user AND scu.id_session = '$session_id' AND scu.c_id = $courseId AND scu.status = 2";
        $rs = Database::query($sql);

        if (Database::num_rows($rs) > 0) {
            while ($row = Database::fetch_array($rs)) {
                $coaches[] = $row;
            }
            return $coaches;
        } else {
            return false;
        }
    }

    public static function get_coachs_from_course_to_string($session_id = 0, $courseId = null, $separator = self::USER_SEPARATOR, $add_link_to_profile = false) {
        $coachs_course = self::get_coachs_from_course($session_id, $courseId);
        $course_coachs = array();

        if (is_array($coachs_course)) {
            foreach ($coachs_course as $coach_course) {
                $coach_name = api_get_person_name($coach_course['firstname'], $coach_course['lastname']);
                if ($add_link_to_profile) {
                    $url = api_get_path(WEB_AJAX_PATH).'user_manager.ajax.php?a=get_user_popup&resizable=0&height=300&user_id='.$coach_course['user_id'];
                    $coach_name = Display::url($coach_name, $url, array('class' => 'ajax'));
                }
                $course_coachs[] = $coach_name;
            }
        }
        $coaches_to_string = null;
        if (is_array($course_coachs) && count($course_coachs)> 0 ) {
            $coaches_to_string = ArrayClass::array_to_string($course_coachs, $separator);
        }
        return $coaches_to_string;
    }

    public static function get_coach_list_from_course_code_to_string($courseId, $session_id) {
        $tutor_data = '';
        if ($session_id != 0) {
            $coaches = self::get_email_of_tutor_to_session($session_id, $courseId);
            $coach_list = array();
            foreach ($coaches as $coach) {
                $coach_list[] = $coach['complete_name'];
            }
            if (!empty($coach_list)) {
                $tutor_data = implode(self::USER_SEPARATOR, $coach_list);
            }
        }
        return $tutor_data;
    }


    /**
     *    Return user info array of all users registered in the specified course
     *    this includes the users of the course itsel and the users of all linked courses.
     *
     *    @param array $course_info
     *    @return array with user info
     */
    public static function get_real_and_linked_user_list($course_code, $with_sessions = true, $session_id = 0, $order_by = null) {
        $complete_user_list = array();

        //get users from real course
        $user_list = self::get_user_list_from_course_code($course_code, $session_id, null, $order_by);
        foreach ($user_list as $this_user) {
            $complete_user_list[] = $this_user;
        }
        return $complete_user_list;
    }

    /*
        GROUP FUNCTIONS
    */

    /**
     * Get the list of groups from the course
     * @param   string  Course code
     * @param   int     Session ID (optional)
     * @param   boolean get empty groups (optional)
     * @return  array   List of groups info
     */
    public static function get_group_list_of_course($course_code, $session_id = 0, $in_get_empty_group = 0) {
        $course_info = api_get_course_info($course_code);
        $course_id = $course_info['real_id'];
        $group_list = array();
        $session_id != 0 ? $session_condition = ' WHERE g.session_id IN(1,'.intval($session_id).')' : $session_condition = ' WHERE g.session_id = 0';

        if ($in_get_empty_group == 0) {
            // get only groups that are not empty
            $sql = "SELECT DISTINCT g.id, g.name
                FROM ".Database::get_course_table(TABLE_GROUP)." AS g
                INNER JOIN ".Database::get_course_table(TABLE_GROUP_USER)." gu
                ON (g.id = gu.group_id AND g.c_id = $course_id AND gu.c_id = $course_id)
                $session_condition
                ORDER BY g.name";
        } else {
            // get all groups even if they are empty
            $sql = "SELECT g.id, g.name
                    FROM ".Database::get_course_table(TABLE_GROUP)." AS g
                    $session_condition
                    AND c_id = $course_id";
        }
        $result = Database::query($sql);

        while ($group_data = Database::fetch_array($result)) {
            $group_data['userNb'] = GroupManager::number_of_students($group_data['id'], $course_id);
            $group_list[$group_data['id']] = $group_data;
        }
        return $group_list;
    }

    /**
     * Delete a course
     * This function deletes a whole course-area from the platform. When the
     * given course is a virtual course, the database and directory will not be
     * deleted.
     * When the given course is a real course, also all virtual courses refering
     * to the given course will be deleted.
     * Considering the fact that we remove all traces of the course in the main
     * database, it makes sense to remove all tracking as well (if stats databases exist)
     * so that a new course created with this code would not use the remains of an older
     * course.
     *
     * @param string The code of the course to delete
     * course from the groups in the real course if they are not subscribed in
     * that real course.
     */
    public static function delete_course($code)
    {
        $table_course                       = Database::get_main_table(TABLE_MAIN_COURSE);
        $table_course_user                  = Database::get_main_table(TABLE_MAIN_COURSE_USER);
        $table_course_class                 = Database::get_main_table(TABLE_MAIN_COURSE_CLASS);

        $table_session_course               = Database::get_main_table(TABLE_MAIN_SESSION_COURSE);
        $table_session_course_user          = Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
        $table_course_survey                = Database::get_main_table(TABLE_MAIN_SHARED_SURVEY);
        $table_course_survey_question       = Database::get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION);
        $table_course_survey_question_option= Database::get_main_table(TABLE_MAIN_SHARED_SURVEY_QUESTION_OPTION);

        $table_stats_hotpots        = Database::get_main_table(TABLE_STATISTIC_TRACK_E_HOTPOTATOES);
        $table_stats_attempt        = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
        $table_stats_exercises      = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
        $table_stats_access         = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ACCESS);
        $table_stats_lastaccess     = Database::get_main_table(TABLE_STATISTIC_TRACK_E_LASTACCESS);
        $table_stats_course_access  = Database::get_main_table(TABLE_STATISTIC_TRACK_E_COURSE_ACCESS);
        $table_stats_online         = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ONLINE);
        $table_stats_default        = Database::get_main_table(TABLE_STATISTIC_TRACK_E_DEFAULT);
        $table_stats_downloads      = Database::get_main_table(TABLE_STATISTIC_TRACK_E_DOWNLOADS);
        $table_stats_links          = Database::get_main_table(TABLE_STATISTIC_TRACK_E_LINKS);
        $table_stats_uploads        = Database::get_main_table(TABLE_STATISTIC_TRACK_E_UPLOADS);

        $courseInfo = api_get_course_info($code);

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

        self::create_database_dump($courseInfo);

        $code = Database::escape_string($code);
        $courseId = $courseInfo['real_id'];

        $course_tables = self::get_course_tables();

        // Cleaning c_x tables
        if (!empty($courseInfo['id'])) {
            foreach ($course_tables as $table) {
                $table = Database::get_course_table($table);
                $sql = "DELETE FROM $table WHERE c_id = $courseId ";
                Database::query($sql);
            }
        }

        if (!empty($courseInfo['directory'])) {
            $course_dir = api_get_path(SYS_COURSE_PATH).$courseInfo['directory'];
            $archive_dir = api_get_path(SYS_ARCHIVE_PATH).$courseInfo['directory'].'_'.time();
            if (is_dir($course_dir)) {
                rename($course_dir, $archive_dir);
            }
        }

        // Unsubscribe all classes from the course
        $sql = "DELETE FROM $table_course_class WHERE course_code='".$code."'";
        Database::query($sql);
        // Unsubscribe all users from the course
        $sql = "DELETE FROM $table_course_user WHERE c_id ='".$courseId."'";
        Database::query($sql);
        // Delete the course from the sessions tables
        $sql = "DELETE FROM $table_session_course WHERE c_id='".$courseId."'";
        Database::query($sql);
        $sql = "DELETE FROM $table_session_course_user WHERE c_id='".$courseId."'";
        Database::query($sql);

        $sql = 'SELECT survey_id FROM '.$table_course_survey.' WHERE course_code="'.$code.'"';
        $result_surveys = Database::query($sql);
        while($surveys = Database::fetch_array($result_surveys)) {
            $survey_id = $surveys[0];
            $sql = 'DELETE FROM '.$table_course_survey_question.' WHERE survey_id="'.$survey_id.'"';
            Database::query($sql);
            $sql = 'DELETE FROM '.$table_course_survey_question_option.' WHERE survey_id="'.$survey_id.'"';
            Database::query($sql);
            $sql = 'DELETE FROM '.$table_course_survey.' WHERE survey_id="'.$survey_id.'"';
            Database::query($sql);
        }

        // Delete the course from the stats tables

        $sql = "DELETE FROM $table_stats_hotpots WHERE c_id = '".$courseId."'";
        Database::query($sql);
        $sql = "DELETE FROM $table_stats_attempt WHERE c_id = '".$courseId."'";
        Database::query($sql);
        $sql = "DELETE FROM $table_stats_exercises WHERE c_id = '".$courseId."'";
        Database::query($sql);
        $sql = "DELETE FROM $table_stats_access WHERE c_id = '".$courseId."'";
        Database::query($sql);
        $sql = "DELETE FROM $table_stats_lastaccess WHERE c_id = '".$courseId."'";
        Database::query($sql);
        $sql = "DELETE FROM $table_stats_course_access WHERE c_id = '".$courseId."'";
        Database::query($sql);
        $sql = "DELETE FROM $table_stats_online WHERE course = '".$code."'";
        Database::query($sql);
        $sql = "DELETE FROM $table_stats_default WHERE default_cours_code = '".$code."'";
        Database::query($sql);
        $sql = "DELETE FROM $table_stats_downloads WHERE c_id = '".$courseId."'";
        Database::query($sql);
        $sql = "DELETE FROM $table_stats_links WHERE c_id = '".$courseId."'";
        Database::query($sql);
        $sql = "DELETE FROM $table_stats_uploads WHERE upload_cours_id = '".$code."'";
        Database::query($sql);

        if (api_is_multiple_url_enabled()) {
            $url_id = 1;
            if (api_get_current_access_url_id() != -1) {
                $url_id = api_get_current_access_url_id();
            }
            UrlManager::delete_url_rel_course($courseId, $url_id);
        }

        // Delete the course from the database
        $sql = "DELETE FROM $table_course WHERE id = '".$courseId."'";
        Database::query($sql);

        // delete extra course fields
        $t_cf         = Database::get_main_table(TABLE_MAIN_COURSE_FIELD);
        $t_cfv        = Database::get_main_table(TABLE_MAIN_COURSE_FIELD_VALUES);

        $sql = "SELECT distinct field_id FROM $t_cfv WHERE course_code = '$code'";
        $res_field_ids = @Database::query($sql);
        $field_ids = array();
        while($row_field_id = Database::fetch_row($res_field_ids)){
            $field_ids[] = $row_field_id[0];
        }

        // Delete from table_course_field_value from a given course_code

        $sql_course_field_value = "DELETE FROM $t_cfv WHERE course_code = '$code'";
        @Database::query($sql_course_field_value);

        $sql = "SELECT distinct field_id FROM $t_cfv";
        $res_field_all_ids = @Database::query($sql);

        $field_all_ids = array();
        while($row_field_all_id = Database::fetch_row($res_field_all_ids)){
            $field_all_ids[] = $row_field_all_id[0];
        }

        if (isset($field_ids) && is_array($field_ids) && count($field_ids) > 0) {
            foreach ($field_ids as $field_id) {
                // check if field id is used into table field value
                if (!empty($field_all_ids) && is_array($field_all_ids)) {
                    if (in_array($field_id, $field_all_ids)) {
                        continue;
                    } else {
                        $sql_course_field = "DELETE FROM $t_cf WHERE id = '$field_id'";
                        Database::query($sql_course_field);
                    }
                }
            }
        }

        // Add event to system log
        $user_id = api_get_user_id();
        event_system(LOG_COURSE_DELETE, LOG_COURSE_CODE, $code, api_get_utc_datetime(), $user_id, $code);
    }

    /**
     * Creates a file called mysql_dump.sql in the course folder
     * @param array course info
     * @return
     */
    public static function create_database_dump($courseInfo)
    {
        $sql_dump = null;
        if (empty($courseInfo)) {
            return null;
        }
        $course_tables = self::get_course_tables();

        if (!empty($courseInfo['real_id'])) {
            // Cleaning c_x tables
            foreach ($course_tables as $table) {
                $table = Database::get_course_table($table);
                $sql = "SELECT * FROM $table WHERE c_id = {$courseInfo['real_id']} ";
                $res_table = Database::query($sql);

                while ($row = Database::fetch_array($res_table, 'ASSOC')) {
                    $row_to_save = array();
                    foreach ($row as $key => $value) {
                        $row_to_save[$key] = $key."='".Database::escape_string($row[$key])."'";
                    }
                    $sql_dump .= "INSERT INTO $table SET ".implode(', ', $row_to_save).';';
                }
            }
        }

        if (is_dir(api_get_path(SYS_COURSE_PATH).$courseInfo['directory'])) {
            $file_name = api_get_path(SYS_COURSE_PATH).$courseInfo['directory'].'/mysql_dump.sql';
            $handle = fopen($file_name, 'a+');
            if ($handle !== false) {
                fwrite($handle, $sql_dump);
                fclose($handle);
            }
        }
    }

    /**
     * Sort courses for a specific user ??
     * @param   int     User ID
     * @param   string  Course code
     * @return  int     Minimum course order
     * @todo Review documentation
     */
    public static function userCourseSort($user_id, $courseId) {

        if ($user_id != strval(intval($user_id))) {
            return false;
        }

        $courseId = Database::escape_string($courseId);
        $TABLECOURSE = Database::get_main_table(TABLE_MAIN_COURSE);
        $TABLECOURSUSER = Database::get_main_table(TABLE_MAIN_COURSE_USER);

        $course_title = Database::result(Database::query('SELECT title FROM '.$TABLECOURSE.' WHERE id = "'.$courseId.'"'), 0, 0);

        $sql = 'SELECT course.code as code, course.title as title, cu.sort as sort
                FROM '.$TABLECOURSUSER.' as cu, '.$TABLECOURSE.' as course
                WHERE   course.id = cu.c_id AND
                        user_id = "'.$user_id.'" AND
                        cu.relation_type<>'.COURSE_RELATION_TYPE_RRHH.' AND
                        user_course_cat = 0
                ORDER BY cu.sort';
        $result = Database::query($sql);

        $course_title_precedent = '';
        $counter = 0;
        $course_found = false;
        $course_sort = 1;

        if (Database::num_rows($result) > 0) {
            while ($courses = Database::fetch_array($result)) {

                if ($course_title_precedent == '') {
                    $course_title_precedent = $courses['title'];
                }

                if (api_strcasecmp($course_title_precedent, $course_title) < 0) {

                    $course_found = true;
                    $course_sort = $courses['sort'];

                    if ($counter == 0) {
                        $sql = 'UPDATE '.$TABLECOURSUSER.' SET sort = sort+1 WHERE user_id = "'.$user_id.'" AND relation_type<>'.COURSE_RELATION_TYPE_RRHH.' AND user_course_cat="0" AND sort > "'.$course_sort.'"';
                        $course_sort++;
                    } else {
                        $sql = 'UPDATE '.$TABLECOURSUSER.' SET sort = sort+1 WHERE user_id = "'.$user_id.'" AND relation_type<>'.COURSE_RELATION_TYPE_RRHH.' AND user_course_cat="0" AND sort >= "'.$course_sort.'"';
                    }

                    Database::query($sql);
                    break;

                } else {
                    $course_title_precedent = $courses['title'];
                }
                $counter++;
            }
            // We must register the course in the beginning of the list
            if (!$course_found) {
                $course_sort = Database::result(Database::query('SELECT min(sort) as min_sort FROM '.$TABLECOURSUSER.' WHERE user_id="'.$user_id.'" AND user_course_cat="0"'), 0, 0);
                Database::query('UPDATE '.$TABLECOURSUSER.' SET sort = sort+1 WHERE user_id= "'.$user_id.'" AND user_course_cat="0"');
            }
        }
        return $course_sort;
    }

    /**
     * create recursively all categories as option of the select passed in paramater.
     *
     * @param object $select_element the quickform select where the options will be added
     * @param string $category_selected_code the option value to select by default (used mainly for edition of courses)
     * @param string $parent_code the parent category of the categories added (default=null for root category)
     * @param string $padding the indent param (you shouldn't indicate something here)
     */
    public static function select_and_sort_categories($select_element, $category_selected_code = '', $parent_code = null , $padding = '') {

        $sql = "SELECT code, name, auth_course_child, auth_cat_child
                FROM ".Database::get_main_table(TABLE_MAIN_CATEGORY)."
                WHERE parent_id ".(is_null($parent_code) ? "IS NULL" : "='".Database::escape_string($parent_code)."'")."
                ORDER BY code";
        $res = Database::query($sql);

        while ($cat = Database::fetch_array($res)) {
            $params = $cat['auth_course_child'] == 'TRUE' ? '' : 'disabled';
            $params .= ($cat['code'] == $category_selected_code) ? ' selected' : '';
            $select_element->addOption($padding.'('.$cat['code'].') '.$cat['name'], $cat['code'], $params);
            if ($cat['auth_cat_child']) {
                self::select_and_sort_categories($select_element, $category_selected_code, $cat['code'], $padding.' - ');
            }
        }
    }

    /**
     * check if course exists
     * @param string course_code
     * @param string whether to accept virtual course codes or not
     * @return true if exists, false else
     */
    public static function course_exists($course_code, $accept_virtual = false) {
        if ($accept_virtual === true) {
            $sql = 'SELECT 1 FROM '.Database::get_main_table(TABLE_MAIN_COURSE).' WHERE code="'.Database::escape_string($course_code).'" OR visual_code="'.Database::escape_string($course_code).'"';
        } else {
            $sql = 'SELECT 1 FROM '.Database::get_main_table(TABLE_MAIN_COURSE).' WHERE code="'.Database::escape_string($course_code).'"';
        }
        return Database::num_rows(Database::query($sql));
    }


    /**
     * Send an email to tutor after the auth-suscription of a student in your course
     * @author Carlos Vargas <carlos.vargas@dokeos.com>, Dokeos Latino
     * @param  int $user_id the id of the user
     * @param  string $course_code the course code
     * @param  string $send_to_tutor_also
     * @return string we return the message that is displayed when the action is succesfull
     */
    public static function email_to_tutor($user_id, $course_code, $send_to_tutor_also = false)
    {
        if ($user_id != strval(intval($user_id))) {
            return false;
        }

        $course_code = Database::escape_string($course_code);

        $student = Database::fetch_array(Database::query("SELECT * FROM ".Database::get_main_table(TABLE_MAIN_USER)."
                WHERE user_id='".$user_id."'"));
        $courseInfo = api_get_course_info($course_code);
        $name_course = $courseInfo['title'];
        $sql = "SELECT * FROM ".Database::get_main_table(TABLE_MAIN_COURSE_USER)." WHERE c_id = '".$courseInfo['real_id']."'";

        // TODO: Ivan: This is a mistake, please, have a look at it. Intention here is diffcult to be guessed.
        //if ($send_to_tutor_also = true)
        // Proposed change:
        if ($send_to_tutor_also) {
        //
            $sql .= " AND tutor_id=1";
        } else {
            $sql .= " AND status=1";
        }

        $result = Database::query($sql);
        while ($row = Database::fetch_array($result)) {
            $tutor = Database::fetch_array(Database::query("SELECT * FROM ".Database::get_main_table(TABLE_MAIN_USER)."
                    WHERE user_id='".$row['user_id']."'"));
            $emailto         = $tutor['email'];
            $emailsubject     = get_lang('NewUserInTheCourse').': '.$name_course;
            $emailbody         = get_lang('Dear').': '. api_get_person_name($tutor['firstname'], $tutor['lastname'])."\n";
            $emailbody        .= get_lang('MessageNewUserInTheCourse').': '.$name_course."\n";
            $emailbody        .= get_lang('UserName').': '.$student['username']."\n";
            if (api_is_western_name_order()) {
                $emailbody    .= get_lang('FirstName').': '.$student['firstname']."\n";
                $emailbody    .= get_lang('LastName').': '.$student['lastname']."\n";
            } else {
                $emailbody    .= get_lang('LastName').': '.$student['lastname']."\n";
                $emailbody    .= get_lang('FirstName').': '.$student['firstname']."\n";
            }
            $emailbody        .= get_lang('Email').': '.$student['email']."\n\n";
            $recipient_name = api_get_person_name($tutor['firstname'], $tutor['lastname'], null, PERSON_NAME_EMAIL_ADDRESS);
            $sender_name = api_get_person_name(api_get_setting('administratorName'), api_get_setting('administratorSurname'), null, PERSON_NAME_EMAIL_ADDRESS);
            $email_admin = api_get_setting('emailAdministrator');
            @api_mail($recipient_name, $emailto, $emailsubject, $emailbody, $sender_name,$email_admin);
        }
    }

    /**
     * @return array
     */
    public static function get_special_course_list()
    {
        $tbl_course           = Database :: get_main_table(TABLE_MAIN_COURSE);
        $tbl_course_field           = Database :: get_main_table(TABLE_MAIN_COURSE_FIELD);
        $tbl_course_field_value     = Database :: get_main_table(TABLE_MAIN_COURSE_FIELD_VALUES);

          //we filter the courses from the URL
        $join_access_url = $where_access_url='';
        if (api_get_multiple_access_url()) {
            $access_url_id = api_get_current_access_url_id();
            if ($access_url_id != -1) {
                $tbl_url_course = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
                $join_access_url= " INNER JOIN $tbl_course course ON (course.code = tcfv.course_code)
                INNER JOIN $tbl_url_course url_rel_course
                ON url_rel_course.c_id = course.id ";
                $where_access_url =" AND access_url_id = $access_url_id ";
            }
        }

        // get course list auto-register
        $sql = "SELECT DISTINCT(tcfv.course_code) FROM $tbl_course_field_value tcfv INNER JOIN $tbl_course_field tcf
                ON tcfv.field_id =  tcf.id $join_access_url
                WHERE tcf.field_variable = 'special_course' AND tcfv.field_value = 1  $where_access_url";
        $special_course_result = Database::query($sql);

        $special_course_list = array();

        if (Database::num_rows($special_course_result)>0) {
            $special_course_list = array();
            while ($result_row = Database::fetch_array($special_course_result)) {
                $special_course_list[] = $result_row['course_code'];
            }
        }
        return $special_course_list;
    }

    /**
     * Get list of courses for a given user
     * @param int       user ID
     * @param boolean   Whether to include courses from session or not
     * @return array    List of codes and db names
     * @author isaac flores paz
     */
    public static function get_courses_list_by_user_id($user_id, $include_sessions = false) {
        $user_id = intval($user_id);
        $course_list = array();
        $codes = array();
        $tbl_course                 = Database::get_main_table(TABLE_MAIN_COURSE);
        $tbl_course_user            = Database::get_main_table(TABLE_MAIN_COURSE_USER);
        $tbl_user_course_category   = Database::get_main_table(TABLE_USER_COURSE_CATEGORY);

        $special_course_list = self::get_special_course_list();

        $with_special_courses = $without_special_courses = '';
        if (!empty($special_course_list)) {
            $sc_string = '"'.implode('","',$special_course_list).'"';
            $with_special_courses = ' course.code IN ('.$sc_string.')';
            $without_special_courses = ' AND course.code NOT IN ('.$sc_string.')';
        }

        if (!empty($with_special_courses)) {
            $sql = "SELECT DISTINCT(course.code), course.id as real_id
                        FROM    ".$tbl_course_user." course_rel_user
                        LEFT JOIN ".$tbl_course." course
                        ON course.id = course_rel_user.c_id
                        LEFT JOIN ".$tbl_user_course_category." user_course_category
                        ON course_rel_user.user_course_cat = user_course_category.id
                        WHERE  $with_special_courses
                        GROUP BY course.code
                        ORDER BY user_course_category.sort,course.title,course_rel_user.sort ASC";
            $rs_special_course = Database::query($sql);
            if (Database::num_rows($rs_special_course) > 0) {
                while ($result_row = Database::fetch_array($rs_special_course)) {
                    $result_row['special_course'] = 1;
                    $course_list[] = $result_row;
                    $codes[] = $result_row['real_id'];
                }
            }
        }

        // get course list not auto-register. Use Distinct to avoid multiple
        // entries when a course is assigned to a HRD (DRH) as watcher
        $sql = "SELECT DISTINCT(course.code), course.id as real_id
                FROM $tbl_course course
                INNER JOIN $tbl_course_user cru ON course.id = cru.c_id
                WHERE cru.user_id='$user_id' $without_special_courses";

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

        if (Database::num_rows($result)) {
            while ($row = Database::fetch_array($result, 'ASSOC')) {
                $course_list[] = $row;
                $codes[] = $row['real_id'];
            }
        }

        if ($include_sessions === true) {
            $sql = "SELECT DISTINCT(c.code), c.id as real_id
                    FROM ".Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER)." s, ".Database::get_main_table(TABLE_MAIN_COURSE)." c
                    WHERE id_user = $user_id AND s.c_id =c.id";
            $r = Database::query($sql);
            while ($row = Database::fetch_array($r, 'ASSOC')) {
                if (!in_array($row['real_id'], $codes)) {
                    $course_list[] = $row;
                }
            }
        }
        return $course_list;
    }

    /**
     * Get course ID from a given course directory name
     * @param   string  Course directory (without any slash)
     * @return  string  Course code, or false if not found
     */
    public static function get_course_id_from_path($path) {
        $path = Database::escape_string(str_replace('.', '', str_replace('/', '', $path)));
        $res = Database::query("SELECT code FROM ".Database::get_main_table(TABLE_MAIN_COURSE)."
                WHERE directory LIKE BINARY '$path'");
        if ($res === false) {
            return false;
        }
        if (Database::num_rows($res) != 1) {
            return false;
        }
        $row = Database::fetch_array($res);
        return $row['code'];
    }

    /**
     * Get course code(s) from visual code
     * @param   string  Visual code
     * @return  array   List of codes for the given visual code
     */
    public static function get_courses_info_from_visual_code($code) {
        $result = array();
        $sql_result = Database::query("SELECT * FROM ".Database::get_main_table(TABLE_MAIN_COURSE)."
                WHERE visual_code = '".Database::escape_string($code)."'");
        while ($virtual_course = Database::fetch_array($sql_result)) {
            $result[] = $virtual_course;
        }
        return $result;
    }

    /**
     * Get coachs' emails by session
     * @param int session id
     * @param int  course id
     * @return array  array(email => name_tutor)  by coach
     * @author Carlos Vargas <carlos.vargas@dokeos.com>
     */
    public static function get_email_of_tutor_to_session($session_id, $courseId) {

        $tbl_session_course_user = Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
        $tbl_user = Database::get_main_table(TABLE_MAIN_USER);
        $coachs_emails = array();

        $courseId = Database::escape_string($courseId);
        $session_id = intval($session_id);

        $sql = "SELECT id_user FROM $tbl_session_course_user WHERE id_session='$session_id' AND c_id ='$courseId' AND status =2";
        $rs  = Database::query($sql);

        if (Database::num_rows($rs) > 0) {

            $user_ids = array();
            while ($row = Database::fetch_array($rs)) {
                $user_ids[] = $row['id_user'];
            }

            $sql = "SELECT firstname, lastname, email FROM $tbl_user WHERE user_id IN (".implode(",",$user_ids).")";
            $rs_user = Database::query($sql);

            while ($row_emails = Database::fetch_array($rs_user)) {
                $mail_tutor = array('email' => $row_emails['email'], 'complete_name' => api_get_person_name($row_emails['firstname'], $row_emails['lastname']));
                $coachs_emails[] = $mail_tutor;
            }
        }
        return $coachs_emails;
    }

    /**
     * Creates a new extra field for a given course
      * @param    string    Field's internal variable name
      * @param    int        Field's type
      * @param    string    Field's language var name
      * @return int     new extra field id
      */
    public static function create_course_extra_field($fieldvarname, $fieldtype, $fieldtitle) {
        // database table definition
        $t_cfv            = Database::get_main_table(TABLE_MAIN_COURSE_FIELD_VALUES);
        $t_cf             = Database::get_main_table(TABLE_MAIN_COURSE_FIELD);
        $fieldvarname     = Database::escape_string($fieldvarname);
        $fieldtitle     = Database::escape_string($fieldtitle);
        $fieldtype = (int)$fieldtype;
        $time = time();
        $sql_field = "SELECT id FROM $t_cf WHERE field_variable = '$fieldvarname'";
        $res_field = Database::query($sql_field);

        $r_field = Database::fetch_row($res_field);

        if (Database::num_rows($res_field) > 0) {
            return $r_field[0];
        }

        // save new fieldlabel into course_field table
        $sql = "SELECT MAX(field_order) FROM $t_cf";
        $res = Database::query($sql);

        $order = 0;
        if (Database::num_rows($res) > 0) {
            $row = Database::fetch_row($res);
            $order = $row[0] + 1;
        }

        $sql = "INSERT INTO $t_cf
                                    SET field_type = '$fieldtype',
                                    field_variable = '$fieldvarname',
                                    field_display_text = '$fieldtitle',
                                    field_order = '$order',
                                    tms = FROM_UNIXTIME($time)";
        Database::query($sql);

        return Database::insert_id();
    }

    /**
     * Updates course attribute. Note that you need to check that your attribute is valid before you use this function
     *
     * @param int Course id
     * @param string Attribute name
     * @param string Attribute value
     * @return bool True if attribute was successfully updated, false if course was not found or attribute name is invalid
     */
    public static function update_attribute($id, $name, $value) {
        $id = (int)$id;
        $table = Database::get_main_table(TABLE_MAIN_COURSE);
        $sql = "UPDATE $table SET $name = '".Database::escape_string($value)."' WHERE id = '$id';";
        return Database::query($sql);
    }

    /**
     * Update course attributes. Will only update attributes with a non-empty value. Note that you NEED to check that your attributes are valid before using this function
     *
     * @param int Course id
     * @param array Associative array with field names as keys and field values as values
     * @return bool True if update was successful, false otherwise
     */
    public static function update_attributes($id, $attributes) {
        $id = (int)$id;
        $table = Database::get_main_table(TABLE_MAIN_COURSE);
        $sql = "UPDATE $table SET ";
        $i = 0;
        foreach($attributes as $name => $value) {
            if($value != '') {
                if($i > 0) {
                    $sql .= ", ";
                }
                $sql .= " $name = '".Database::escape_string($value)."'";
                $i++;
            }
        }
        $sql .= " WHERE id = '$id';";
        return Database::query($sql);
    }


    /**
     * Update an extra field value for a given course
     * @param    integer    Course ID
     * @param    string    Field variable name
     * @param    string    Field value
     * @return    boolean    true if field updated, false otherwise
     */
    public static function update_course_extra_field_value($course_code, $fname, $fvalue = '') {

        $t_cfv            = Database::get_main_table(TABLE_MAIN_COURSE_FIELD_VALUES);
        $t_cf             = Database::get_main_table(TABLE_MAIN_COURSE_FIELD);
        $fname = Database::escape_string($fname);
        $course_code = Database::escape_string($course_code);
        $fvalues = '';
        if (is_array($fvalue)) {
            foreach ($fvalue as $val) {
                $fvalues .= Database::escape_string($val).';';
            }
            if (!empty($fvalues)) {
                $fvalues = substr($fvalues, 0, -1);
            }
        } else {
            $fvalues = Database::escape_string($fvalue);
        }

        $sqlcf = "SELECT * FROM $t_cf WHERE field_variable='$fname'";
        $rescf = Database::query($sqlcf);
        if (Database::num_rows($rescf) == 1) {
            // Ok, the field exists
            // Check if enumerated field, if the option is available
            $rowcf = Database::fetch_array($rescf);

            $tms = time();
            $sqlcfv = "SELECT * FROM $t_cfv WHERE course_code = '$course_code' AND field_id = '".$rowcf['id']."' ORDER BY id";
            $rescfv = Database::query($sqlcfv);
            $n = Database::num_rows($rescfv);
            if ($n > 1) {
                //problem, we already have to values for this field and user combination - keep last one
                while ($rowcfv = Database::fetch_array($rescfv)) { // See the TODO note below.
                    if ($n > 1) {
                        $sqld = "DELETE FROM $t_cfv WHERE id = ".$rowcfv['id'];
                        $resd = Database::query($sqld);
                        $n--;
                    }
                    $rowcfv = Database::fetch_array($rescfv);
                    if ($rowcfv['field_value'] != $fvalues) {
                        $sqlu = "UPDATE $t_cfv SET field_value = '$fvalues', tms = FROM_UNIXTIME($tms) WHERE id = ".$rowcfv['id'];
                        $resu = Database::query($sqlu);
                        return ($resu ? true : false);
                    }
                    return true; // TODO: Sure exit from the function occures in this "while" cycle. Logic should checked. Maybe "if" instead of "while"? It is not clear...
                }
            } elseif ($n == 1) {
                //we need to update the current record
                $rowcfv = Database::fetch_array($rescfv);
                if ($rowcfv['field_value'] != $fvalues) {
                    $sqlu = "UPDATE $t_cfv SET field_value = '$fvalues', tms = FROM_UNIXTIME($tms) WHERE id = ".$rowcfv['id'];
                    $resu = Database::query($sqlu);
                    return ($resu ? true : false);
                }
                return true;
            } else {
                $sqli = "INSERT INTO $t_cfv (course_code,field_id,field_value,tms) " .
                    "VALUES ('$course_code',".$rowcf['id'].",'$fvalues',FROM_UNIXTIME($tms))";
                $resi = Database::query($sqli);
                return ($resi ? true : false);
            }
        } else {
            return false; //field not found
        }
    }

    /**
     * Get the course id of an course by the database name
     * @param string The database name
     * @return string The course id
     */
    public static function get_course_id_by_database_name($db_name) {
        return Database::result(Database::query('SELECT code FROM '.Database::get_main_table(TABLE_MAIN_COURSE).
                ' WHERE db_name="'.Database::escape_string($db_name).'"'), 0, 'code');
    }

    public static function get_session_category_id_by_session_id($session_id) {
        return Database::result(Database::query('SELECT  sc.id session_category
                FROM '.Database::get_main_table(TABLE_MAIN_SESSION_CATEGORY).' sc
                INNER JOIN '.Database::get_main_table(TABLE_MAIN_SESSION).' s
                ON sc.id=s.session_category_id WHERE s.id="'.Database::escape_string($session_id).'"'),
            0, 'session_category');
    }

    /**
     * Get the course id of an course by the database name
     * @param string The database name
     * @return string The course id
     */
    public static function get_course_extra_field_list($code) {
        $tbl_course_field = Database::get_main_table(TABLE_MAIN_COURSE_FIELD);
        $tbl_course_field_value    = Database::get_main_table(TABLE_MAIN_COURSE_FIELD_VALUES);
        $sql_field = "SELECT id, field_type, field_variable, field_display_text, field_default_value
            FROM $tbl_course_field  WHERE field_visible = '1' ";
        $res_field = Database::query($sql_field);
        $extra_fields = array();
        while($rowcf = Database::fetch_array($res_field)) {
            $extra_field_id = $rowcf['id'];
            $sql_field_value = "SELECT field_value FROM $tbl_course_field_value WHERE course_code = '$code' AND field_id = '$extra_field_id' ";
            $res_field_value = Database::query($sql_field_value);
            if(Database::num_rows($res_field_value) > 0 ) {
                $r_field_value = Database::fetch_row($res_field_value);
                $rowcf['extra_field_value'] = $r_field_value[0];
            }
            $extra_fields[] = $rowcf;
        }
        return $extra_fields;
    }

    /**
     * Gets the value of a course extra field. Returns null if it was not found
     *
     * @param string Name of the extra field
     * @param string Course code
     * @return string Value
     */
    public static function get_course_extra_field_value($field_name, $code) {
        $tbl_course_field = Database::get_main_table(TABLE_MAIN_COURSE_FIELD);
        $tbl_course_field_value    = Database::get_main_table(TABLE_MAIN_COURSE_FIELD_VALUES);
        $sql = "SELECT id FROM $tbl_course_field WHERE field_visible = '1' AND field_variable = '$field_name';";
        $res = Database::query($sql);
        $row = Database::fetch_object($res);
        if(!$row) {
            return null;
        } else {
            $sql_field_value = "SELECT field_value FROM $tbl_course_field_value WHERE course_code = '$code' AND field_id = '{$row->id}';";
            $res_field_value = Database::query($sql_field_value);
            $row_field_value = Database::fetch_object($res_field_value);
            if(!$row_field_value) {
                return null;
            } else {
                return $row_field_value['field_value'];
            }
        }
    }


    /**
     * Get the database name of a course by the code
     * @param string The course code
     * @return string The database name
     */
    public static function get_name_database_course($course_code) {
        return Database::result(Database::query('SELECT db_name FROM '.Database::get_main_table(TABLE_MAIN_COURSE).
                ' WHERE code="'.Database::escape_string($course_code).'"'), 0, 'db_name');
    }

    /**
     * Lists details of the course description
     * @param array        The course description
     * @param string    The encoding
     * @param bool        If true is displayed if false is hidden
     * @return string     The course description in html
     */
    public static function get_details_course_description_html($descriptions, $charset, $action_show = true) {
        if (isset($descriptions) && count($descriptions) > 0) {
            $data = '';
            foreach ($descriptions as $id => $description) {
                $data .= '<div class="sectiontitle">';
                if (api_is_allowed_to_edit() && $action_show) {
                    //delete
                    $data .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&amp;action=delete&amp;description_id='.$description->id.'" onclick="javascript:if(!confirm(\''.addslashes(api_htmlentities(get_lang('ConfirmYourChoice'), ENT_QUOTES, $charset)).'\')) return false;">';
                    $data .= Display::return_icon('delete.gif', get_lang('Delete'), array('style' => 'vertical-align:middle;float:right;'));
                    $data .= '</a> ';
                    //edit
                    $data .= '<a href="'.api_get_self().'?'.api_get_cidreq().'&amp;description_id='.$description->id.'">';
                    $data .= Display::return_icon('edit.png', get_lang('Edit'), array('style' => 'vertical-align:middle;float:right; padding-right:4px;'), ICON_SIZE_SMALL);
                    $data .= '</a> ';
                }
                $data .= $description->title;
                $data .= '</div>';
                $data .= '<div class="sectioncomment">';
                $data .= $description->content;
                $data .= '</div>';
            }
        } else {
            $data .= '<em>'.get_lang('ThisCourseDescriptionIsEmpty').'</em>';
        }

        return $data;
    }

    /**
     * Returns the details of a course category
     *
     * @param string Category code
     * @return array Course category
     */
    public static function get_course_category($code) {
        $table_categories = Database::get_main_table(TABLE_MAIN_CATEGORY);
        $sql = "SELECT * FROM $table_categories WHERE code = '$code';";
        return Database::fetch_array(Database::query($sql));
    }

    /**
     *     Get count rows of a table inside a course database
     *  @param  string    The table of which the rows should be counted
     *  @param  int        optionally count rows by session id
     *  @return int     The number of rows in the given table.
     */
    public static function count_rows_course_table($table, $session_id = '', $course_id = null) {
        $condition_session = '';
        if ($session_id !== '') {
            $session_id = intval($session_id);
            $condition_session = " AND session_id = '$session_id' ";
        }
        if (!empty($course_id)) {
            $course_id = intval($course_id);
        } else {
            $course_id = api_get_course_int_id();
        }
        $condition_session .= " AND c_id = '$course_id' ";

        $sql    = "SELECT COUNT(*) AS n FROM $table WHERE 1=1 $condition_session ";
        $rs     = Database::query($sql);
        $row     = Database::fetch_row($rs);
        return $row[0];
    }

    /**
      * Subscribes courses to human resource manager (Dashboard feature)
      *    @param    int         Human Resource Manager id
      * @param    array        Courses code
      * @param    int            Relation type
      **/
    public static function suscribe_courses_to_hr_manager($hr_manager_id, $courses_list) {

        // Database Table Definitions
        $tbl_course             =   Database::get_main_table(TABLE_MAIN_COURSE);
        $tbl_course_rel_user    =   Database::get_main_table(TABLE_MAIN_COURSE_USER);
        $tbl_course_rel_access_url =  Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);

        $hr_manager_id = intval($hr_manager_id);
        $affected_rows = 0;

        //Deleting assigned courses to hrm_id
        if (api_is_multiple_url_enabled()) {
            $sql = "SELECT s.c_id FROM $tbl_course_rel_user s INNER JOIN $tbl_course_rel_access_url a ON (a.c_id = s.c_id)
                    WHERE user_id = $hr_manager_id AND relation_type=".COURSE_RELATION_TYPE_RRHH." AND access_url_id = ".api_get_current_access_url_id()."";
        } else {
            $sql = "SELECT c_id FROM $tbl_course_rel_user
                    WHERE user_id = $hr_manager_id AND relation_type=".COURSE_RELATION_TYPE_RRHH." ";
        }
        $result = Database::query($sql);
        if (Database::num_rows($result) > 0) {
            while ($row = Database::fetch_array($result))   {
                $sql = "DELETE FROM $tbl_course_rel_user WHERE c_id = '{$row['c_id']}' AND user_id = $hr_manager_id AND relation_type=".COURSE_RELATION_TYPE_RRHH." ";
                Database::query($sql);
            }
        }

        // inserting new courses list
        if (is_array($courses_list)) {
            foreach ($courses_list as $courseId) {
                $courseId = Database::escape_string($courseId);
                $insert_sql = "INSERT IGNORE INTO $tbl_course_rel_user(c_id, user_id, status, relation_type) VALUES('$courseId', $hr_manager_id, '".DRH."', '".COURSE_RELATION_TYPE_RRHH."')";
                $result = Database::query($insert_sql);
                if (Database::affected_rows($result)) {
                    $affected_rows++;
                }
            }
        }
        return $affected_rows;

    }

    /**
     * get courses followed by human resources manager
     * @param int         human resources manager id
     * @return array    courses
     */
    public static function get_courses_followed_by_drh($user_id) {
        // Database Table Definitions
        $tbl_course             =     Database::get_main_table(TABLE_MAIN_COURSE);
        $tbl_course_rel_user     =     Database::get_main_table(TABLE_MAIN_COURSE_USER);
        $tbl_course_rel_access_url =   Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);

        $user_id = intval($user_id);
        $assigned_courses_to_hrm = array();

        if (api_get_multiple_access_url()) {
           $sql = "SELECT *, id as real_id FROM $tbl_course c
                    INNER JOIN $tbl_course_rel_user cru ON (cru.c_id = c.id)
                    LEFT JOIN $tbl_course_rel_access_url a ON (a.c_id = c.id)
                    WHERE cru.user_id = '$user_id' AND status = ".DRH." AND relation_type = '".COURSE_RELATION_TYPE_RRHH."' AND access_url_id = ".api_get_current_access_url_id()."";
        } else {
            $sql = "SELECT *, id as real_id FROM $tbl_course c
                    INNER JOIN $tbl_course_rel_user cru ON cru.c_id = c.c_id AND cru.user_id = '$user_id' AND status = ".DRH." AND relation_type = '".COURSE_RELATION_TYPE_RRHH."' ";
        }
        $rs_assigned_courses = Database::query($sql);
        if (Database::num_rows($rs_assigned_courses) > 0) {
            while ($row_assigned_courses = Database::fetch_array($rs_assigned_courses))    {
                $assigned_courses_to_hrm[$row_assigned_courses['code']] = $row_assigned_courses;
            }
        }
        return $assigned_courses_to_hrm;
    }

    /**
     * check if a course is special (autoregister)
     * @param string course code
     */
    public static function is_special_course($course_code){
        $tbl_course_field_value        = Database::get_main_table(TABLE_MAIN_COURSE_FIELD_VALUES);
        $tbl_course_field             = Database::get_main_table(TABLE_MAIN_COURSE_FIELD);
        $is_special = false;
        $sql = "SELECT course_code FROM $tbl_course_field_value tcfv INNER JOIN $tbl_course_field tcf ON " .
                " tcfv.field_id =  tcf.id WHERE tcf.field_variable = 'special_course' AND tcfv.field_value = 1 AND course_code='$course_code'";
        $result = Database::query($sql);
        $num_rows = Database::num_rows($result);
        if ($num_rows > 0){
            $is_special = true;

        }
        return $is_special;
    }

    /**
     * Update course picture
     * @param   string  Course code
     * @param   string  File name
     * @param   string  The full system name of the image from which course picture will be created.
     * @return  bool    Returns the resulting. In case of internal error or negative validation returns FALSE.
     */
    public static function update_course_picture($course_code, $filename, $source_file = null) {

        $course_info          = api_get_course_info($course_code);
        $store_path           = api_get_path(SYS_COURSE_PATH).$course_info['path'];   // course path
        $course_image         = $store_path.'/course-pic.png';                      // image name for courses
        $course_medium_image  = $store_path.'/course-pic85x85.png';
        //$extension            = strtolower(substr(strrchr($filename, '.'), 1));

        if (file_exists($course_image)) {
            @unlink($course_image);
        }
        if (file_exists($course_medium_image)) {
            @unlink($course_medium_image);
        }

        $my_course_image = new Image($source_file);
        $result = $my_course_image->send_image($course_image, -1, 'png');
        //Redimension image to 100x85
        if ($result) {
            $medium = new Image($course_image);
            //$picture_infos = $medium->get_image_size();
            $medium->resize(100, 85, 0, false);
            $medium->send_image($store_path.'/course-pic85x85.png', -1, 'png');
        }
        return $result;
    }

    /**
     * Builds the course block in user_portal.php
     * @todo use Twig
     */
    public static function course_item_html($params, $is_sub_content = false) {
        global $app;
        if ($app['full_width']) {
            $rowDiv = '<div class="row-fluid">';
        } else {
            $rowDiv = '<div class="row">';
        }
        $html = '';
        $class = "well course-box";
        if ($is_sub_content) {
            $class = "course_item";
        }
        if (!empty($params['is_session'])) {
            $class .= " session-item";
        }
        $html .= '<div class="'.$class.'">';
            $html .= $rowDiv;
            $html .= '<div class="span7">';
                $html .= $rowDiv;
                    $html .= '<div class="span1 course-box-thumbnail-box">';
                    if (!empty($params['link'])) {
                        $html .= '<a class="thumbnail" href="'.$params['link'].'">';
                        $html .= $params['icon'];
                        $html .= '</a>';
                    } else {
                        $html .= '<div class="thumbnail">';
                        $html .= $params['icon'];
                        $html .= '</div>';
                    }

                    $html .= '</div>';
                    $notifications = isset($params['notifications']) ? $params['notifications'] : null;
                    $param_class = isset($params['class']) ? $params['class'] : '';
                    if (!empty($params['is_session'])) {
                        $param_class .= ' session-box-text';
                    } else {
                        $param_class .= ' course-box-text';
                    }

                    $html .= '<div class="span6 '.$param_class.'">';
                        $html .='<h3>'.$params['title'].$notifications.'</h3> ';

                        if (!empty($params['subtitle'])) {
                            $html .= '<small>'.$params['subtitle'].'</small>';
                        }
                        if (!empty($params['teachers'])) {
                            $html .= '<h5>'.Display::return_icon('teacher.png', get_lang('Teacher'), array(), ICON_SIZE_TINY).$params['teachers'].'</h5>';
                        }
                        if (!empty($params['coaches'])) {
                            $html .= '<h5>'.Display::return_icon('teacher.png', get_lang('Coach'), array(), ICON_SIZE_TINY).$params['coaches'].'</h5>';
                        }

                    $html .= '</div>';
                $html .= '</div>';

            $html .= '</div>';
            $params['right_actions'] = isset($params['right_actions']) ? $params['right_actions'] : null;
            $html .= '<div class="span1 pull-right course-box-actions">'.$params['right_actions'].'</div>';
        $html .= '</div>';
        $html .= '</div>';
        return $html;
    }

    public static function course_item_parent($main_content, $sub_content, $sub_sub_content = null) {
        return '<div class="well">'.$main_content.$sub_content.$sub_sub_content.'</div>';
    }

    /**
     * Display special courses (and only these) as several HTML divs of class userportal-course-item
     *
     * Special courses are courses that stick on top of the list and are "auto-registerable"
     * in the sense that any user clicking them is registered as a student
     * @param int       User id
     * @param bool      Whether to show the document quick-loader or not
     * @return void
     */
    public static function displaySpecialCourses($user_id, $filter, $load_dirs, $getCount, $start = null, $maxPerPage = null) {
        $user_id = intval($user_id);
        $tbl_course                 = Database::get_main_table(TABLE_MAIN_COURSE);
        $tbl_course_user            = Database::get_main_table(TABLE_MAIN_COURSE_USER);

        $special_course_list        = self::get_special_course_list();
        $html = null;

        if (!empty($special_course_list)) {
            $with_special_courses = ' course.code IN ("'.implode('","',$special_course_list).'")';
        } else {
            return null;
        }

        $select = " course.id,
                    course.code,
                    course.subscribe subscr,
                    course.unsubscribe unsubscr,
                    course_rel_user.status status,
                    course_rel_user.sort sort,
                    course_rel_user.user_course_cat user_course_cat,
                    course_rel_user.user_id";

        if ($getCount) {
            $select = "COUNT(course.id) as total";
        }

        $sql = "SELECT $select
                FROM $tbl_course course
                LEFT JOIN $tbl_course_user course_rel_user
                  ON course.id = course_rel_user.c_id AND course_rel_user.user_id = '$user_id'
                WHERE $with_special_courses ";

        if ($getCount) {
            $result = Database::query($sql);
            $row = Database::fetch_array($result);
            return $row['total'];
        }

        $group = " GROUP BY course.code ";

        $sql .= $group;

        $rs_special_course = Database::query($sql);
        $number_of_courses = Database::num_rows($rs_special_course);
        $key = 0;

        if ($number_of_courses > 0) {
            while ($course = Database::fetch_array($rs_special_course)) {
                $course_info = api_get_course_info($course['code']);
                $params = array();

                $course_info['id_session']  = null;
                $course_info['status']      = $course['status'];
                $show_notification = Display::show_notification($course_info);

                if (empty($course['user_id'])) {
                    $course['status'] = STUDENT;
                }

                $params['icon'] = Display::return_icon('blackboard.png', $course_info['title'], array(), ICON_SIZE_LARGE);

                $params['right_actions'] = '';

                if (api_is_platform_admin()) {
                    if ($load_dirs) {
                        $params['right_actions'] .= '<a id="document_preview_'.$course['real_id'].'_0" class="document_preview" href="javascript:void(0);">'.Display::return_icon('folder.png', get_lang('Documents'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                        $params['right_actions'] .= '<a href="'.api_get_path(WEB_CODE_PATH).'course_info/infocours.php?cidReq='.$course['code'].'">'.Display::return_icon('edit.png', get_lang('Edit'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                        $params['right_actions'] .= Display::div('', array('id' => 'document_result_'.$course['real_id'].'_0', 'class'=>'document_preview_container'));
                    } else {
                        $params['right_actions'] .= '<a href="'.api_get_path(WEB_CODE_PATH).'course_info/infocours.php?cidReq='.$course['code'].'">'.Display::return_icon('edit.png', get_lang('Edit'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                    }
                    if ($course['status'] == COURSEMANAGER) {
                        //echo Display::return_icon('teachers.gif', get_lang('Status').': '.get_lang('Teacher'), array('style'=>'width: 11px; height: 11px;'));
                    }
                } else {
                    if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED) {
                        if ($load_dirs) {
                            $params['right_actions'] .=  '<a id="document_preview_'.$course['real_id'].'_0" class="document_preview" href="javascript:void(0);">'.Display::return_icon('folder.png', get_lang('Documents'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                            $params['right_actions'] .=  Display::div('', array('id' => 'document_result_'.$course['real_id'].'_0', 'class'=>'document_preview_container'));
                        }
                    }
                }

                if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED || $course['status'] == COURSEMANAGER) {
                    $course_title = '<a href="'.api_get_path(WEB_COURSE_PATH).$course_info['path'].'/index.php?id_session=0&amp;autoreg=1">'.$course_info['title'].'</a>';
                } else {
                    $course_title = $course_info['title']." ".Display::tag('span',get_lang('CourseClosed'), array('class'=>'item_closed'));
                }

                if (api_get_setting('display_coursecode_in_courselist') == 'true') {
                    $course_title .= ' ('.$course_info['visual_code'].') ';
                }
                if (api_get_setting('display_teacher_in_courselist') == 'true') {
                    $params['teachers'] = CourseManager::get_teacher_list_from_course_code_to_string($course['real_id'], self::USER_SEPARATOR, true);
                }
                $course_title .= '&nbsp;';
                $course_title .= Display::return_icon('klipper.png', get_lang('CourseAutoRegister'));

                $params['title'] = $course_title;
                $params['link'] = api_get_path(WEB_COURSE_PATH).$course_info['path'].'/index.php?id_session=0&amp;autoreg=1';

                if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED) {
                    $params['notifications'] = $show_notification;
                }
                $html .= self::course_item_html($params, false);
                $key++;
            }
        }

        return $html;
    }

    public static function displayPersonalCourseCategories($user_id, $filter, $load_dirs, $getCount, $start = null, $maxPerPage = null) {
        $tableUserCourseCategory = Database::get_main_table(TABLE_USER_COURSE_CATEGORY);

        // Table definitions
        $TABLECOURS                     = Database :: get_main_table(TABLE_MAIN_COURSE);
        $TABLECOURSUSER                 = Database :: get_main_table(TABLE_MAIN_COURSE_USER);
        $TABLE_ACCESS_URL_REL_COURSE    = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
        $current_url_id                 = api_get_current_access_url_id();

        $sql = "SELECT * FROM $tableUserCourseCategory
                WHERE user_id = $user_id";

        if ($getCount) {
            $sql = "SELECT COUNT(id) as total FROM $tableUserCourseCategory WHERE user_id = $user_id";
            $result = Database::query($sql);
            $row = Database::fetch_array($result);
            return $row['total'];
        }

        $order = " ORDER BY sort";

        $sql .= $order;

        if (isset($start) && isset($maxPerPage)) {
            $start = intval($start);
            $maxPerPage = intval($maxPerPage);
            $limitCondition = " LIMIT $start, $maxPerPage";
            $sql .= $limitCondition;
        }

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

        $html = null;

        if (Database::num_rows($result)) {
            while ($category = Database::fetch_array($result)) {
                $categoryId = $category['id'];

                $select = " SELECT DISTINCT
                        course.id,
                        course.title,
                        course.code,
                        course.subscribe subscr,
                        course.unsubscribe unsubscr,
                        course_rel_user.status status,
                        course_rel_user.sort sort,
                        course_rel_user.user_course_cat user_course_cat";

                $from = "$TABLECOURS course, $TABLECOURSUSER  course_rel_user, $TABLE_ACCESS_URL_REL_COURSE url, $tableUserCourseCategory user_cat";

                $where = " course.id = course_rel_user.c_id AND
                    url.c_id = course.id AND
                    user_cat.user_id = $user_id AND
                    course_rel_user.user_id = $user_id AND
                    course_rel_user.user_course_cat = $categoryId ";

                // Use user's classification for courses (if any).
                $order = " ORDER BY user_cat.sort  ASC";

                $sql = "$select FROM $from WHERE $where ";

                // corresponding to the current URL.
                if (api_get_multiple_access_url() && $current_url_id != -1) {
                    $sql .= " AND url.course_code=course.code AND access_url_id='".$current_url_id."'";
                }
                $sql .= $order;

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

                $course_list = array();

                $courseHTML = null;

                // Browse through all courses.
                while ($course = Database::fetch_array($resultCourse)) {
                    $course_info = api_get_course_info($course['code']);
                    //$course['id_session'] = null;
                    $course_info['id_session'] = null;
                    $course_info['status'] = $course['status'];

                    //In order to avoid doubles
                    if (in_array($course_info['real_id'], $course_list)) {
                        continue;
                    } else {
                        $course_list[] = $course_info['real_id'];
                    }

                    // For each course, get if there is any notification icon to show
                    // (something that would have changed since the user's last visit).
                    $show_notification = Display :: show_notification($course_info);

                    // New code displaying the user's status in respect to this course.
                    $status_icon = Display::return_icon('blackboard.png', $course_info['title'], array(), ICON_SIZE_LARGE);

                    $params = array();
                    $params['right_actions'] = '';

                    if (api_is_platform_admin()) {
                        if ($load_dirs) {
                            $params['right_actions'] .= '<a id="document_preview_'.$course_info['real_id'].'_0" class="document_preview" href="javascript:void(0);">'.Display::return_icon('folder.png', get_lang('Documents'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                            $params['right_actions'] .= '<a href="'.api_get_path(WEB_CODE_PATH).'course_info/infocours.php?cidReq='.$course['code'].'">'.Display::return_icon('edit.png', get_lang('Edit'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                            $params['right_actions'] .= Display::div('', array('id' => 'document_result_'.$course_info['real_id'].'_0', 'class'=>'document_preview_container'));
                        } else {
                            $params['right_actions'].= '<a href="'.api_get_path(WEB_CODE_PATH).'course_info/infocours.php?cidReq='.$course['code'].'">'.Display::return_icon('edit.png', get_lang('Edit'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                        }

                        if ($course_info['status'] == COURSEMANAGER) {
                            //echo Display::return_icon('teachers.gif', get_lang('Status').': '.get_lang('Teacher'), array('style'=>'width: 11px; height: 11px;'));
                        }
                    } else {
                        if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED) {
                            if ($load_dirs) {
                                $params['right_actions'] .= '<a id="document_preview_'.$course_info['real_id'].'_0" class="document_preview" href="javascript:void(0);">'.Display::return_icon('folder.png', get_lang('Documents'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                                $params['right_actions'] .= Display::div('', array('id' => 'document_result_'.$course_info['real_id'].'_0', 'class'=>'document_preview_container'));
                            } else {
                                if ($course_info['status'] == COURSEMANAGER) {
                                    $params['right_actions'].= '<a href="'.api_get_path(WEB_CODE_PATH).'course_info/infocours.php?cidReq='.$course['code'].'">'.Display::return_icon('edit.png', get_lang('Edit'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                                }
                            }
                        }
                    }

                    $course_title_url = '';
                    if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED || $course['status'] == COURSEMANAGER) {
                        $course_title_url = api_get_path(WEB_COURSE_PATH).$course_info['path'].'/index.php?id_session=0';
                        $course_title = Display::url($course_info['title'], $course_title_url);
                    } else {
                        $course_title = $course_info['title']." ".Display::tag('span',get_lang('CourseClosed'), array('class'=>'item_closed'));
                    }

                    // Start displaying the course block itself
                    if (api_get_setting('display_coursecode_in_courselist') == 'true') {
                        $course_title .= ' ('.$course_info['visual_code'].') ';
                    }
                    if (api_get_setting('display_teacher_in_courselist') == 'true') {
                        $teachers = CourseManager::get_teacher_list_from_course_code_to_string($course['real_id'], self::USER_SEPARATOR, true);
                    }

                    $params['link'] = $course_title_url;
                    $params['icon'] = $status_icon;
                    $params['title'] = $course_title;
                    $params['teachers'] = $teachers;

                    if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED) {
                        $params['notifications'] = $show_notification;
                    }
                    $courseHTML .= self::course_item_html($params, true);
                }

                $params = array();

                $params['icon'] = Display::return_icon('folder_yellow.png', $category['title'], array(), ICON_SIZE_LARGE);
                $params['title'] = $category['title'];
                $params['class'] = 'table_user_course_category';
                $html .= self::course_item_parent(self::course_item_html($params, true), $courseHTML);
            }
        }
        return $html;
    }

    /**
     * @param int $user_id
     * @param $filter
     * @param bool $load_dirs
     * @param int $getCount
     * @param int $start
     * @param null $maxPerPage
     * @return null|string
     */
    static function displayCourses($user_id, $filter, $load_dirs, $getCount, $start = null, $maxPerPage = null)
    {

        // Table definitions
        $TABLECOURS                     = Database :: get_main_table(TABLE_MAIN_COURSE);
        $TABLECOURSUSER                 = Database :: get_main_table(TABLE_MAIN_COURSE_USER);
        $TABLE_ACCESS_URL_REL_COURSE    = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
        $current_url_id                 = api_get_current_access_url_id();

        // Get course list auto-register
        $special_course_list            = self::get_special_course_list();

        $without_special_courses = '';

        if (!empty($special_course_list)) {
            //$without_special_courses = ' AND course.code NOT IN ("'.implode('","',$special_course_list).'")';
        }

        $select = " SELECT DISTINCT course.id,
                course.title,
                course.code,
                course.subscribe subscr,
                course.unsubscribe unsubscr,
                course_rel_user.status status,
                course_rel_user.sort sort,
                course_rel_user.user_course_cat user_course_cat,
                course.id as real_id
                ";

        $from = "$TABLECOURS course, $TABLECOURSUSER  course_rel_user, $TABLE_ACCESS_URL_REL_COURSE url ";

        $where = "  course.id = course_rel_user.c_id AND
                    url.c_id = course.id AND
                    course_rel_user.user_id = '".$user_id."' AND
                    course_rel_user.user_course_cat = 0
                    ";

        $order = " ORDER BY course_rel_user.user_course_cat, course_rel_user.sort ASC";


        if ($getCount) {
            $select = "SELECT count(course.id) as total";
        }

        $sql = "$select FROM $from WHERE $where $without_special_courses ";

        // corresponding to the current URL.
        if (api_get_multiple_access_url() && $current_url_id != -1) {
            $sql .= " AND url.c_id = course.id AND access_url_id='".$current_url_id."'";
        }

        $sql .= $order;

        if (isset($start) && isset($maxPerPage)) {
            $start = intval($start);
            $maxPerPage = intval($maxPerPage);
            $limitCondition = " LIMIT $start, $maxPerPage";
            $sql .= $limitCondition;
        }

        if ($getCount) {
            $result = Database::query($sql);
            $row = Database::fetch_array($result);
            return $row['total'];
        }

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

        $html = null;
        $course_list = array();

        // Browse through all courses.
        while ($course = Database::fetch_array($result)) {
            $course_info = api_get_course_info($course['code']);
            //$course['id_session'] = null;
            $course_info['id_session'] = null;
            $course_info['status'] = $course['status'];

            //In order to avoid doubles
            if (in_array($course_info['real_id'], $course_list)) {
                continue;
            } else {
                $course_list[] = $course_info['real_id'];
            }

            // For each course, get if there is any notification icon to show
            // (something that would have changed since the user's last visit).
            $show_notification = Display :: show_notification($course_info);

            // New code displaying the user's status in respect to this course.
            $status_icon = Display::return_icon('blackboard.png', $course_info['title'], array(), ICON_SIZE_LARGE);

            $params = array();
            $params['right_actions'] = '';

            if (api_is_platform_admin()) {
                if ($load_dirs) {
                    $params['right_actions'] .= '<a id="document_preview_'.$course_info['real_id'].'_0" class="document_preview" href="javascript:void(0);">'.Display::return_icon('folder.png', get_lang('Documents'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                    $params['right_actions'] .= '<a href="'.api_get_path(WEB_CODE_PATH).'course_info/infocours.php?cidReq='.$course['code'].'">'.Display::return_icon('edit.png', get_lang('Edit'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                    $params['right_actions'] .= Display::div('', array('id' => 'document_result_'.$course_info['real_id'].'_0', 'class'=>'document_preview_container'));
                } else {
                    $params['right_actions'].= '<a href="'.api_get_path(WEB_CODE_PATH).'course_info/infocours.php?cidReq='.$course['code'].'">'.Display::return_icon('edit.png', get_lang('Edit'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                }

                if ($course_info['status'] == COURSEMANAGER) {
                    //echo Display::return_icon('teachers.gif', get_lang('Status').': '.get_lang('Teacher'), array('style'=>'width: 11px; height: 11px;'));
                }
            } else {
                if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED) {
                    if ($load_dirs) {
                        $params['right_actions'] .= '<a id="document_preview_'.$course_info['real_id'].'_0" class="document_preview" href="javascript:void(0);">'.Display::return_icon('folder.png', get_lang('Documents'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                        $params['right_actions'] .= Display::div('', array('id' => 'document_result_'.$course_info['real_id'].'_0', 'class'=>'document_preview_container'));
                    } else {
                        if ($course_info['status'] == COURSEMANAGER) {
                            $params['right_actions'].= '<a href="'.api_get_path(WEB_CODE_PATH).'course_info/infocours.php?cidReq='.$course['code'].'">'.Display::return_icon('edit.png', get_lang('Edit'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                        }
                    }
                }
            }

            $course_title = $course_info['title'];

            $course_title_url = '';
            if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED || $course['status'] == COURSEMANAGER) {
                $course_title_url = api_get_path(WEB_COURSE_PATH).$course_info['path'].'/index.php?id_session=0';
                $course_title = Display::url($course_info['title'], $course_title_url);
            } else {
                $course_title = $course_info['title']." ".Display::tag('span',get_lang('CourseClosed'), array('class'=>'item_closed'));
            }

            // Start displaying the course block itself
            if (api_get_setting('display_coursecode_in_courselist') == 'true') {
                $course_title .= ' ('.$course_info['visual_code'].') ';
            }
            $teachers = null;
            if (api_get_setting('display_teacher_in_courselist') == 'true') {
                $teachers = $course_info['teacher_list_formatted'];
            }

            $params['link'] = $course_title_url;
            $params['icon'] = $status_icon;
            $params['title'] = $course_title;
            $params['teachers'] = $teachers;

            if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED) {
                $params['notifications'] = $show_notification;
            }

            $is_subcontent = true;
            if (empty($user_category_id)) {
                $is_subcontent = false;
            }
            $html .= self::course_item_html($params, $is_subcontent);
        }
        return $html;
    }

    /**
     * Display courses (without special courses) as several HTML divs
     * of course categories, as class userportal-catalog-item.
     * @uses display_courses_in_category() to display the courses themselves
     * @param int        user id
     * @param bool      Whether to show the document quick-loader or not
     * @return void
     */
    public static function display_courses($user_id, $load_dirs = false) {
        $user_id = intval($user_id);
        if (empty($user_id)) {
            $user_id = api_get_user_id();
        }
        $html = null;

        // Step 1: We get all the categories of the user
        $tucc = Database::get_main_table(TABLE_USER_COURSE_CATEGORY);
        $sql = "SELECT id, title FROM $tucc WHERE user_id='".$user_id."' ORDER BY sort ASC";
        $result = Database::query($sql);
        while ($row = Database::fetch_array($result)) {
            $params = array();
            // We simply display the title of the category.
            $params['icon'] = Display::return_icon('folder_yellow.png', $row['title'], array(), ICON_SIZE_LARGE);
            $params['title'] = $row['title'];
            $params['class'] = 'table_user_course_category';
            $html .= self::course_item_parent(self::course_item_html($params, true), self :: display_courses_in_category($row['id'], $load_dirs));
        }

        // Step 2: We display the course without a user category.
        $html .= self :: display_courses_in_category(0, $load_dirs);
        return $html;
    }

    /**
     *  Display courses inside a category (without special courses) as HTML dics of
     *  class userportal-course-item.
     *  @param int      User category id
     * @param bool      Whether to show the document quick-loader or not
     *  @return void
     */
    public static function display_courses_in_category($user_category_id, $load_dirs = false)
    {
        $user_id = api_get_user_id();
        // Table definitions
        $TABLECOURS                     = Database :: get_main_table(TABLE_MAIN_COURSE);
        $TABLECOURSUSER                 = Database :: get_main_table(TABLE_MAIN_COURSE_USER);
        $TABLE_ACCESS_URL_REL_COURSE    = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
        $current_url_id                 = api_get_current_access_url_id();

        // Get course list auto-register
        $special_course_list            = self::get_special_course_list();

        $without_special_courses = '';
        if (!empty($special_course_list)) {
            $without_special_courses = ' AND course.code NOT IN ("'.implode('","',$special_course_list).'")';
        }

        //AND course_rel_user.relation_type<>".COURSE_RELATION_TYPE_RRHH."
        $sql = "SELECT  course.id,
                        course.title,
                        course.code,
                        course.subscribe subscr,
                        course.unsubscribe unsubscr,
                        course_rel_user.status status,
                        course_rel_user.sort sort,
                        course_rel_user.user_course_cat user_course_cat
                FROM    $TABLECOURS      course,
                        $TABLECOURSUSER  course_rel_user, ".$TABLE_ACCESS_URL_REL_COURSE." url
                WHERE   course.code = course_rel_user.course_code AND
                        url.c_id = course.id AND
                        course_rel_user.user_id = '".$user_id."' AND
                        course_rel_user.user_course_cat='".$user_category_id."' $without_special_courses ";
        // If multiple URL access mode is enabled, only fetch courses

        // corresponding to the current URL.
        if (api_get_multiple_access_url() && $current_url_id != -1) {
            $sql .= " AND url.course_code=course.code AND access_url_id='".$current_url_id."'";
        }


        // Use user's classification for courses (if any).
        $sql .= " ORDER BY course_rel_user.user_course_cat, course_rel_user.sort ASC";

        $result = Database::query($sql);
        $status_icon = '';
        $html = '';

        $course_list = array();

        // Browse through all courses.
        while ($course = Database::fetch_array($result)) {
            $course_info = api_get_course_info($course['code']);
            //$course['id_session'] = null;
            $course_info['id_session'] = null;
            $course_info['status'] = $course['status'];

            //In order to avoid doubles
            if (in_array($course_info['real_id'], $course_list)) {
                continue;
            } else {
                $course_list[] = $course_info['real_id'];
            }

            // For each course, get if there is any notification icon to show
            // (something that would have changed since the user's last visit).
            $show_notification = Display :: show_notification($course_info);

            // New code displaying the user's status in respect to this course.
            $status_icon = Display::return_icon('blackboard.png', $course_info['title'], array(), ICON_SIZE_LARGE);

            $params = array();
            $params['right_actions'] = '';

            if (api_is_platform_admin()) {
                if ($load_dirs) {
                    $params['right_actions'] .= '<a id="document_preview_'.$course_info['real_id'].'_0" class="document_preview" href="javascript:void(0);">'.Display::return_icon('folder.png', get_lang('Documents'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                    $params['right_actions'] .= '<a href="'.api_get_path(WEB_CODE_PATH).'course_info/infocours.php?cidReq='.$course['code'].'">'.Display::return_icon('edit.png', get_lang('Edit'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                    $params['right_actions'] .= Display::div('', array('id' => 'document_result_'.$course_info['real_id'].'_0', 'class'=>'document_preview_container'));
                } else {
                    $params['right_actions'].= '<a href="'.api_get_path(WEB_CODE_PATH).'course_info/infocours.php?cidReq='.$course['code'].'">'.Display::return_icon('edit.png', get_lang('Edit'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                }

                if ($course_info['status'] == COURSEMANAGER) {
                    //echo Display::return_icon('teachers.gif', get_lang('Status').': '.get_lang('Teacher'), array('style'=>'width: 11px; height: 11px;'));
                }
            } else {
                if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED) {
                    if ($load_dirs) {
                        $params['right_actions'] .= '<a id="document_preview_'.$course_info['real_id'].'_0" class="document_preview" href="javascript:void(0);">'.Display::return_icon('folder.png', get_lang('Documents'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                        $params['right_actions'] .= Display::div('', array('id' => 'document_result_'.$course_info['real_id'].'_0', 'class'=>'document_preview_container'));
                    } else {
                        if ($course_info['status'] == COURSEMANAGER) {
                            $params['right_actions'].= '<a href="'.api_get_path(WEB_CODE_PATH).'course_info/infocours.php?cidReq='.$course['code'].'">'.Display::return_icon('edit.png', get_lang('Edit'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                        }
                    }
                }
            }

            $course_title = $course_info['title'];

            $course_title_url = '';
            if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED || $course['status'] == COURSEMANAGER) {
                $course_title_url = api_get_path(WEB_COURSE_PATH).$course_info['path'].'/index.php?id_session=0';
                $course_title = Display::url($course_info['title'], $course_title_url);
            } else {
                $course_title = $course_info['title']." ".Display::tag('span',get_lang('CourseClosed'), array('class'=>'item_closed'));
            }

            // Start displaying the course block itself
            if (api_get_setting('display_coursecode_in_courselist') == 'true') {
                $course_title .= ' ('.$course_info['visual_code'].') ';
            }
            if (api_get_setting('display_teacher_in_courselist') == 'true') {
                $teachers = CourseManager::get_teacher_list_from_course_code_to_string($course['real_id'], self::USER_SEPARATOR, true);
            }

            $params['link'] = $course_title_url;
            $params['icon'] = $status_icon;
            $params['title'] = $course_title;
            $params['teachers'] = $teachers;

            if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED) {
                $params['notifications'] = $show_notification;
            }

            $is_subcontent = true;
            if (empty($user_category_id)) {
                $is_subcontent = false;
            }
            $html .= self::course_item_html($params, $is_subcontent);
        }
        return $html;
    }

    /**
     * Retrieves the user defined course categories
     * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
     * @return array containing all the titles of the user defined courses with the id as key of the array
     */
    function get_user_course_categories()
    {
        $output = array();
        $table_category = Database::get_main_table(TABLE_USER_COURSE_CATEGORY);
        $sql = "SELECT * FROM ".$table_category." WHERE user_id='".Database::escape_string(api_get_user_id())."'";
        $result = Database::query($sql);
        while ($row = Database::fetch_array($result)) {
            $output[$row['id']] = $row['title'];
        }
        return $output;
    }

    /**
     * Get the course id based on the original id and field name in the extra fields. Returns 0 if course was not found
     *
     * @param string Original course id
     * @param string Original field name
     * @return int Course id
     */
    public static function get_course_id_from_original_id($original_course_id_value, $original_course_id_name)
    {
        $t_cfv = Database::get_main_table(TABLE_MAIN_COURSE_FIELD_VALUES);
        $table_field = Database::get_main_table(TABLE_MAIN_COURSE_FIELD);
        $courseTable = Database::get_main_table(TABLE_MAIN_COURSE);
        $sql_course = "SELECT c.id FROM $table_field cf INNER JOIN $t_cfv cfv ON cfv.field_id = cf.id
                       INNER JOIN $courseTable as c on c.code = cfv.course_code
                       WHERE field_variable='$original_course_id_name' AND field_value='$original_course_id_value'";
        $res = Database::query($sql_course);
        $row = Database::fetch_object($res);
        if ($row != false) {
            return $row->id;
        } else {
            return 0;
        }
    }

    /**
     * Display code for one specific course a logged in user is subscribed to.
     * Shows a link to the course, what's new icons...
     *
     * $my_course['d'] - course directory
     * $my_course['i'] - course title
     * $my_course['c'] - visual course code
     * $my_course['k']  - system course code
     *
     * @param   array       Course details
     * @param   integer     Session ID
     * @param   string      CSS class to apply to course entry
     * @param   boolean     Whether the session is supposedly accessible now (not in the case it has passed and is in invisible/unaccessible mode)
     * @param   bool      Whether to show the document quick-loader or not
     * @return  string      The HTML to be printed for the course entry
     *
     * @version 1.0.3
     * @todo refactor into different functions for database calls | logic | display
     * @todo replace single-character $my_course['d'] indices
     * @todo move code for what's new icons to a separate function to clear things up
     * @todo add a parameter user_id so that it is possible to show the courselist of other users (=generalisation). This will prevent having to write a new function for this.
     */
    public static function get_logged_user_course_html($course, $session_id = 0, $load_dirs = false)
    {
        $course_info = api_get_course_info_by_id($course['id']);
        $course_info['id_session'] = $session_id;

        // Display course entry.
        // Show a link to the course, unless the course is closed and user is not course admin.
        $session_url = '';

        if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED || $course_info['user_status_in_course'] == COURSEMANAGER) {
            $session_url = api_get_path(WEB_COURSE_PATH).$course_info['path'].'/index.php?id_session='.$course_info['id_session'];
            $session_title = '<a href="'.api_get_path(WEB_COURSE_PATH).$course_info['path'].'/index.php?id_session='.$course_info['id_session'].'">'.$course_info['name'].'</a>';
        } else {
            $session_title = $course_info['name'].' '.Display::tag('span',get_lang('CourseClosed'), array('class'=>'item_closed'));
        }

        $params = array();
        $params['icon'] = Display::return_icon('blackboard_blue.png', $course_info['name'], array(), ICON_SIZE_LARGE);
        $params['link'] = $session_url;
        $params['title'] = $session_title;
        $params['right_actions'] = '';

        if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED) {
            if ($load_dirs) {
                $params['right_actions'] .= '<a id="document_preview_'.$course_info['real_id'].'_'.$course_info['id_session'].'" class="document_preview" href="javascript:void(0);">'.
                                            Display::return_icon('folder.png', get_lang('Documents'), array('align' => 'absmiddle'),ICON_SIZE_SMALL).'</a>';
                $params['right_actions'] .= Display::div('', array('id' => 'document_result_'.$course_info['real_id'].'_'.$course_info['id_session'], 'class'=>'document_preview_container'));
            }
        }

        if (api_get_setting('display_coursecode_in_courselist') == 'true') {
            $session_title .= ' ('.$course_info['visual_code'].') ';
        }

        if (api_get_setting('display_teacher_in_courselist') == 'true') {
            $teacher_list = CourseManager::get_teacher_list_from_course_code_to_string($course_info['real_id'], self::USER_SEPARATOR, true);
            $course_coachs = CourseManager::get_coachs_from_course_to_string($course_info['id_session'], $course_info['real_id'], self::USER_SEPARATOR, true);
            $params['teachers'] = $teacher_list;
            $params['coaches'] = $course_coachs;
        }
        $session_title .= isset($course['special_course']) ? ' '.Display::return_icon('klipper.png', get_lang('CourseAutoRegister')) : '';

        // Display the "what's new" icons
        if ($course_info['visibility'] != COURSE_VISIBILITY_CLOSED) {
            $session_title .= Display :: show_notification($course_info);
        }
        $params['title'] = $session_title;
        $params['extra'] = '';
        $html = self::course_item_html($params, true);
        return $html;
    }

    /**
     *
     * @param    string    source course code
     * @param     int        source session id
     * @param    string    destination course code
     * @param     int        destination session id
     * @return  bool
     */
    public static function copy_course($source_course_code, $source_session_id, $destination_course_code, $destination_session_id, $params = array()) {
        require_once api_get_path(SYS_CODE_PATH).'coursecopy/classes/CourseBuilder.class.php';
        require_once api_get_path(SYS_CODE_PATH).'coursecopy/classes/CourseRestorer.class.php';
        require_once api_get_path(SYS_CODE_PATH).'coursecopy/classes/CourseSelectForm.class.php';

        $course_info = api_get_course_info($source_course_code);

        if (!empty($course_info)) {
            $cb = new CourseBuilder('', $course_info);
            $course = $cb->build($source_session_id, $source_course_code, true);
            $course_restorer = new CourseRestorer($course);
            $course_restorer->skip_content = $params;
            $course_restorer->restore($destination_course_code, $destination_session_id, true, true);
            return true;
        }
        return false;
    }


    /**
     * A simpler version of the copy_course, the function creates an empty course with an autogenerated course code
     *
     * @param    string    new course title
     * @param    string    source course code
     * @param     int        source session id
     * @param     int        destination session id
     * @param    bool    new copied tools (Exercises and LPs)will be set to invisible by default?
     *
     * @return     array
     */
    public static function copy_course_simple($new_title, $source_course_code, $source_session_id = 0, $destination_session_id = 0, $params = array())
    {
        $source_course_info = api_get_course_info($source_course_code);
        if (!empty($source_course_info)) {
            $new_course_code = self::generate_nice_next_course_code($source_course_code);
            if ($new_course_code) {
                $new_course_info = self::create_course($new_title, $new_course_code, false);
                if (!empty($new_course_info['code'])) {
                    $result = self::copy_course($source_course_code, $source_session_id, $new_course_info['code'], $destination_session_id, $params);
                    if ($result) {
                        return $new_course_info;
                    }
                }
            }
        }
        return false;
    }

    /**
     * Creates a new course code based in a given code
     *
     * @param string    wanted code
     * <code>    $wanted_code = 'curse' if there are in the DB codes like curse1 curse2 the function will return: course3</code>
     * if the course code doest not exist in the DB the same course code will be returned
     * @return string    wanted unused code
     */
    public static function generate_nice_next_course_code($wanted_code)
    {
        $course_code_ok = !self::course_code_exists($wanted_code);
        if (!$course_code_ok) {
           $wanted_code = self::generate_course_code($wanted_code);
           $table = Database::get_main_table(TABLE_MAIN_COURSE);
           $wanted_code = Database::escape_string($wanted_code);
           $sql = "SELECT count(*) as count FROM $table WHERE code LIKE '$wanted_code%'";
           $result = Database::query($sql);
           if (Database::num_rows($result) > 0 ) {
               $row = Database::fetch_array($result);
               $count = $row['count'] + 1;
               $wanted_code = $wanted_code.'_'.$count;
               $result = api_get_course_info($wanted_code);
               if (empty($result)) {
                   return $wanted_code;
               }
           }
           return false;
        }
        return $wanted_code;
    }


    /**
     * Gets the status of the users agreement in a course course-session
     *
     * @param int user id
     * @param string course code
     * @param int session id
     * @return boolean
     */
    public static function is_user_accepted_legal($user_id, $courseInfo, $session_id = null)
    {
        $user_id    = intval($user_id);
        $course_code = $courseInfo['code'];
        $course_id = $courseInfo['real_id'];
        $course_code = Database::escape_string($course_code);
        $session_id = intval($session_id);
        if (empty($session_id)) {
            $table = Database::get_main_table(TABLE_MAIN_COURSE_USER);
            $sql = "SELECT legal_agreement FROM $table
                    WHERE user_id =  $user_id AND c_id  = '$course_id' ";
            $result = Database::query($sql);
            if (Database::num_rows($result) > 0 ) {
                $result = Database::fetch_array($result);
                if ($result['legal_agreement'] == 1 ) {
                    return true;
                }
            }
            return false;
        } else {
            $table = Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
            $sql = "SELECT legal_agreement FROM $table
                    WHERE id_user =  $user_id AND c_id  ='$course_id' AND id_session = $session_id";
            $result = Database::query($sql);
            if (Database::num_rows($result) > 0 ) {
                $result = Database::fetch_array($result);
                if ($result['legal_agreement'] == 1 ) {
                    return true;
                }
            }
            return false;
        }
        return false;
    }

    /**
     * Saves the user-course legal agreement
     * @param   int user id
     * @param   string course code
     * @param   int session id
     */
    function save_user_legal($user_id, $courseInfo, $session_id = null)
    {

        $user_id    = intval($user_id);
        $course_code  = $courseInfo['code'];
        $course_id  = $courseInfo['real_id'];

        $course_code = Database::escape_string($course_code);
        $session_id = intval($session_id);
        if (empty($session_id)) {
            $table = Database::get_main_table(TABLE_MAIN_COURSE_USER);
            $sql = "UPDATE $table SET legal_agreement = '1'
                    WHERE user_id =  $user_id AND c_id  ='$course_id' ";
            $result = Database::query($sql);
        } else {
            $table = Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
            $sql = "UPDATE  $table SET legal_agreement = '1'
                    WHERE id_user =  $user_id AND c_id  = '$course_id' AND id_session = $session_id";
            $result = Database::query($sql);
        }
    }

    public static function get_user_course_vote($user_id, $course_id, $session_id = null, $url_id = null) {
        $table_user_course_vote     = Database::get_main_table(TABLE_MAIN_USER_REL_COURSE_VOTE);

        $session_id = !isset($session_id)   ? api_get_session_id()                : intval($session_id);
        $url_id     = empty($url_id)        ? api_get_current_access_url_id()    : intval($url_id);

        $user_id = intval($user_id);

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

        $params = array(
            'user_id'        => $user_id,
            'c_id'          => $course_id,
            'session_id'    => $session_id,
            'url_id'        => $url_id
        );

        $result = Database::select('vote', $table_user_course_vote, array('where' => array('user_id = ? AND c_id = ? AND session_id = ? AND url_id = ?' => $params)), 'first');
        if (!empty($result)) {
            return $result['vote'];
        }
        return false;
    }

    public static function get_course_ranking($course_id, $session_id = null, $url_id = null) {
        $table_course_ranking = Database::get_main_table(TABLE_STATISTIC_TRACK_COURSE_RANKING);

        $session_id = !isset($session_id)   ? api_get_session_id() : intval($session_id);
        $url_id     = empty($url_id)        ? api_get_current_access_url_id() : intval($url_id);

        $params = array(
            'c_id'          => $course_id,
            'session_id'    => $session_id,
            'url_id'        => $url_id
        );

        $result = Database::select('c_id, accesses, total_score, users', $table_course_ranking, array('where' => array('c_id = ? AND session_id = ? AND url_id = ?' => $params)), 'first');

        $point_average_in_percentage = 0;
        $point_average_in_star = 0;
        $users_who_voted = 0;

        if (!empty($result['users'])) {
            $users_who_voted                = $result['users'];
            $point_average_in_percentage    = round($result['total_score']/$result['users'] * 100 / 5, 2);
            $point_average_in_star            = round($result['total_score']/$result['users'], 1);
        }

        $result['user_vote'] = false;

        if (!api_is_anonymous()) {
            $result['user_vote'] = self::get_user_course_vote(api_get_user_id(), $course_id, $session_id,$url_id);
        }

        $result['point_average']        = $point_average_in_percentage;
        $result['point_average_star']   = $point_average_in_star;
        $result['users_who_voted']        = $users_who_voted;

        return $result;
    }

    /**
     *
     * Updates the course ranking
     * @param int   course id
     * @param int   session id
     * @param id    url id
     *
     **/
    public static function update_course_ranking($course_id = null, $session_id = null, $url_id = null, $points_to_add = null, $add_access = true, $add_user = true)
    {
        //Course catalog stats modifications see #4191
        $table_course_ranking       = Database::get_main_table(TABLE_STATISTIC_TRACK_COURSE_RANKING);

        $now = api_get_utc_datetime();
        $course_id  = empty($course_id)     ? api_get_course_int_id() : intval($course_id);
        $session_id = !isset($session_id)   ? api_get_session_id() : intval($session_id);
        $url_id     = empty($url_id)        ? api_get_current_access_url_id() : intval($url_id);

        $params = array(
            'c_id'          => $course_id,
            'session_id'    => $session_id,
            'url_id'        => $url_id,
            'creation_date' => $now,
        );

        $result = Database::select('id, accesses, total_score, users', $table_course_ranking, array('where' => array('c_id = ? AND session_id = ? AND url_id = ?' => $params)), 'first');

        // Problem here every thime we load the courses/XXXX/index.php course home page we update the access

        if (empty($result)) {
            if ($add_access) {
                $params['accesses'] = 1;
            }
            //The votes and users are empty
            if (isset($points_to_add) && !empty($points_to_add)) {
               $params['total_score'] = intval($points_to_add);
            }
            if ($add_user) {
                $params['users'] = 1;
            }
            $result = Database::insert($table_course_ranking, $params);
        } else {
            $my_params = array();

            if ($add_access) {
                $my_params['accesses'] = intval($result['accesses']) + 1;
            }
            if (isset($points_to_add) && !empty($points_to_add)) {
               $my_params['total_score'] = $result['total_score'] + $points_to_add;
            }
            if ($add_user) {
                $my_params['users']  = $result['users'] + 1;
            }

            if (!empty($my_params)) {
                $result = Database::update($table_course_ranking, $my_params, array('c_id = ? AND session_id = ? AND url_id = ?' => $params));
            }
        }
        return $result;
    }


    /**
     * Add user vote to a course
     *
     * @param   int user id
     * @param   int vote [1..5]
     * @param   int course id
     * @param   int session id
     * @param   int url id (access_url_id)
     * @return    mixed 'added', 'updated' or 'nothing'
     *
     */

    public static function add_course_vote($user_id, $vote, $course_id, $session_id = null, $url_id = null)
    {
        $table_user_course_vote     = Database::get_main_table(TABLE_MAIN_USER_REL_COURSE_VOTE);
        $course_id  = empty($course_id) ? api_get_course_int_id() : intval($course_id);

        if (empty($course_id) || empty($user_id)) {
            return false;
        }

        if (!in_array($vote, array(1,2,3,4,5))) {
            return false;
        }

        $session_id = !isset($session_id)   ? api_get_session_id() : intval($session_id);
        $url_id     = empty($url_id)        ? api_get_current_access_url_id() : intval($url_id);
        $vote       = intval($vote);

        $params = array(
            'user_id'       => intval($user_id),
            'c_id'          => $course_id,
            'session_id'    => $session_id,
            'url_id'        => $url_id,
            'vote'          => $vote
        );

        $action_done = 'nothing';

        $result = Database::select('id, vote', $table_user_course_vote, array('where' => array('user_id = ? AND c_id = ? AND session_id = ? AND url_id = ?' => $params)), 'first');

        if (empty($result)) {
            $result = Database::insert($table_user_course_vote, $params);
            $points_to_add = $vote;
            $add_user = true;
            $action_done = 'added';
        } else {
            $my_params = array('vote' => $vote);
            $points_to_add = $vote - $result['vote'];
            $add_user = false;

            $result = Database::update($table_user_course_vote, $my_params, array('user_id = ? AND c_id = ? AND session_id = ? AND url_id = ?' => $params));
            $action_done = 'updated';
        }

        //Current points
        if (!empty($points_to_add)) {
            self::update_course_ranking($course_id, $session_id, $url_id, $points_to_add, false, $add_user);
        }
        return $action_done;
    }

    /**
     * Remove course ranking + user votes
     *
     * @param   int course id
     * @param   int session id
     * @param   int url id
     *
     */
    public function remove_course_ranking($course_id, $session_id, $url_id = null) {
        $table_course_ranking       = Database::get_main_table(TABLE_STATISTIC_TRACK_COURSE_RANKING);
        $table_user_course_vote     = Database::get_main_table(TABLE_MAIN_USER_REL_COURSE_VOTE);
        if (!empty($course_id) && isset($session_id)) {

            $url_id     = empty($url_id) ? api_get_current_access_url_id() : intval($url_id);
            $params = array(
                'c_id'          => $course_id,
                'session_id'    => $session_id,
                'url_id'        => $url_id,
            );
            Database::delete($table_course_ranking,   array('c_id = ? AND session_id = ? AND url_id = ?' => $params));
            Database::delete($table_user_course_vote, array('c_id = ? AND session_id = ? AND url_id = ?' => $params));
        }
    }

    /**
     * Returns an array with the hottest courses
     * @param   int number of days
     * @param   int number of hottest courses
     */
    public static function return_hot_courses($days = 30, $limit = 5)
    {
        $urlId = api_get_current_access_url_id();
        $limit  = intval($limit);

        //Getting my courses
        $my_course_list = CourseManager::get_courses_list_by_user_id(api_get_user_id());

        $my_course_code_list = array();
        foreach ($my_course_list as $course) {
            $my_course_code_list[$course['real_id']] = $course['real_id'];
        }

        if (api_is_drh()) {
            $courses = CourseManager::get_courses_followed_by_drh(api_get_user_id());
            foreach ($courses as $course) {
                $my_course_code_list[$course['real_id']] = $course['real_id'];
            }
        }

        $table_course_access = Database::get_main_table(TABLE_STATISTIC_TRACK_E_COURSE_ACCESS);
        $table_course = Database::get_main_table(TABLE_MAIN_COURSE);
        $table_course_url = Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);

        //@todo all dates in the tracking_course_access, last_access are in the DB time (NOW) not UTC
        /*
        $today                    = api_get_utc_datetime();
        $today_diff                = time() -intval($days)*24*60*60;
        $today_diff                = api_get_utc_datetime($today_diff);
         * */

       $sql = "SELECT COUNT(course_access_id) course_count, a.c_id, visibility ".
              "FROM $table_course c INNER JOIN $table_course_access a ".
              "  ON (c.id = a.c_id) INNER JOIN $table_course_url u ON u.c_id = c.id ".
              "  WHERE   u.access_url_id = ".$urlId." AND".
              "          login_course_date <= now() AND ".
              "          login_course_date > DATE_SUB(now(), INTERVAL $days DAY) AND".
              "          visibility <> '".COURSE_VISIBILITY_CLOSED."'".
              "  GROUP BY a.c_id".
              "  ORDER BY course_count DESC".
              "  LIMIT $limit";

        $result = Database::query($sql);
        $courses = array();
        if (Database::num_rows($result)) {
            $courses = Database::store_result($result, 'ASSOC');
            $courses = self::process_hot_course_item($courses, $my_course_code_list);
        }
        return $courses;
    }

    public static function process_hot_course_item($courses, $my_course_code_list = array()) {
        $ajax_url = api_get_path(WEB_AJAX_PATH).'course.ajax.php?a=add_course_vote';

        foreach ($courses as &$my_course) {
            $course_info = api_get_course_info_by_id($my_course['c_id']);
            $my_course['extra_info'] = $course_info;
            $my_course['extra_info']['go_to_course_button'] = '';
            $my_course['extra_info']['register_button'] = '';
            $access_link = self::get_access_link_by_user(api_get_user_id(), $course_info, $my_course_code_list);

            //Course visibility
            if ($access_link && in_array('register', $access_link)) {
                $stok = Security::get_token();
                $my_course['extra_info']['register_button'] = Display::url(get_lang('Subscribe'), api_get_path(WEB_COURSE_PATH).$course_info['path'].'/index.php?action=subscribe&amp;sec_token='.$stok, array('class' => 'btn btn-primary'));
            }

            if ($access_link && in_array('enter', $access_link)) {
                $my_course['extra_info']['go_to_course_button'] = Display::url(get_lang('GoToCourse'), api_get_path(WEB_COURSE_PATH).$course_info['path'].'/index.php', array('class' => 'btn btn-primary'));
            }

            //Description
            $my_course['extra_info']['description_button'] = '';
            if ($course_info['visibility'] == COURSE_VISIBILITY_OPEN_WORLD || in_array($course_info['real_id'], $my_course_code_list) ) {
                $my_course['extra_info']['description_button'] = Display::url(get_lang('Description'), api_get_path(WEB_AJAX_PATH).'course_home.ajax.php?a=show_course_information&amp;code='.$course_info['code'], array('class' => 'ajax btn'));
            }

            $my_course['extra_info']['teachers'] = CourseManager::get_teacher_list_from_course_code_to_string($course_info['real_id']);
            $point_info = self::get_course_ranking($course_info['real_id'], 0);
            $my_course['extra_info']['rating_html'] = Display::return_rating_system('star_'.$course_info['real_id'], $ajax_url.'&amp;course_id='.$course_info['real_id'], $point_info);
        }
        return $courses;
    }

    public static function return_most_accessed_courses($limit = 5) {
        $table_course_ranking    = Database::get_main_table(TABLE_STATISTIC_TRACK_COURSE_RANKING);
        $params['url_id']        = api_get_current_access_url_id();

        $result = Database::select('c_id, accesses, total_score, users', $table_course_ranking, array('where' => array('url_id = ?' => $params), 'order' => 'accesses DESC', 'limit' => $limit), 'all', true);
        return $result;
    }

    /**
     *
     * @return ResultSet
     */
    static function list_inactive_courses($ceiling, $visibility_level = COURSE_VISIBILITY_REGISTERED) {
        $ceiling = is_numeric($ceiling) ? (int) $ceiling : strtotime($ceiling);
        $ceiling = date('Y-m-d H:i:s', $ceiling);
        $visibility_level = $visibility_level ? $visibility_level : '0';

        $table_course = Database::get_main_table(TABLE_MAIN_COURSE);
        $table_category = Database::get_main_table(TABLE_MAIN_CATEGORY);
        $sql = "SELECT
                    c.*,
                    cat.name AS category
                FROM
                    $table_course AS c
                LEFT JOIN
                    $table_category AS cat
                ON
                    c.category_code = cat.code
                WHERE
                    c.visibility >= $visibility_level AND
                    c.last_visit<='$ceiling'
        ";

        return ResultSet::create($sql);
    }

    /**
     * Get courses count
     * @param int Access URL ID (optional)
     * @return int Number of courses
     */
    public static function count_courses($access_url_id = null)
    {
        $table_course = Database::get_main_table(TABLE_MAIN_COURSE);
        $table_course_rel_access_url = Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
        $sql = "SELECT count(id) FROM $table_course c";
        if (!empty($access_url_id) && $access_url_id == intval($access_url_id)) {
            $sql .= ", $table_course_rel_access_url u WHERE c.id = u.c_id AND u.access_url_id = $access_url_id";
        }
        $res = Database::query($sql);
        $row = Database::fetch_row($res);
        return $row[0];
    }

    /**
     * Return a link to go to the course, validating the visibility of the
     * course and the user status
     * @param int User ID
     * @param array Course details array
     * @param array  List of courses to which the user is subscribed (if not provided, will be generated)
     * @return mixed 'enter' for a link to go to the course or 'register' for a link to subscribe, or false if no access
     */
    static function get_access_link_by_user($uid, $course, $user_courses = array())
    {
        if (empty($uid) or empty($course)) { return false; }
        if (empty($user_courses)) {
            // get the array of courses to which the user is subscribed
            $user_courses = CourseManager::get_courses_list_by_user_id($uid);
            foreach ($user_courses as $k => $v) {
                $user_courses[$k] = $v['real_id'];
            }
        }

        if (!isset($course['real_id']) && empty($course['real_id'])) {
            $course = api_get_course_info($course['code']);
        }

        $is_admin = api_is_platform_admin_by_id($uid);
        $options =  array();

        // Register button
        if (!api_is_anonymous($uid) &&
            !$is_admin &&
            (
                ($course['visibility'] == COURSE_VISIBILITY_OPEN_WORLD || $course['visibility'] == COURSE_VISIBILITY_OPEN_PLATFORM) ||
                $course['visibility'] == COURSE_VISIBILITY_REGISTERED && $course['subscribe'] == SUBSCRIBE_ALLOWED
            ) &&
            $course['subscribe'] == SUBSCRIBE_ALLOWED &&
            (!in_array($course['real_id'], $user_courses) || empty($user_courses))
          ) {
            $options[]= 'register';
        }

         // Go To Course button (only if admin, if course public or if student already subscribed)
        if ($is_admin ||
            $course['visibility'] == COURSE_VISIBILITY_OPEN_WORLD && empty($course['registration_code']) ||
            (api_user_is_login($uid) && $course['visibility'] == COURSE_VISIBILITY_OPEN_PLATFORM && empty($course['registration_code']) ) ||
            (in_array($course['real_id'], $user_courses) && $course['visibility'] != COURSE_VISIBILITY_CLOSED)
        ) {
            $options[]=  'enter';
        }
        return $options;
    }

    // TODO: Such a function might be useful in other places too. It might be moved in the CourseManager class.
    // Also, the function might be upgraded for avoiding code duplications.
    static function generate_course_code($course_title, $encoding = null) {
        if (empty($encoding)) {
            $encoding = api_get_system_encoding();
        }
        return substr(preg_replace('/[^A-Z0-9]/', '', strtoupper(api_transliterate($course_title, 'X', $encoding))), 0, CourseManager::MAX_COURSE_LENGTH_CODE);
    }


    /**
     * Defines the four needed keys to create a course based on several parameters.
     * @param string    The code you want for this course
     * @param string    Prefix added for ALL keys
     * @param string    Prefix added for databases only
     * @param string    Prefix added for paths only
     * @param bool      Add unique prefix
     * @param bool      Use code-independent keys
     * @return array    An array with the needed keys ['currentCourseCode'], ['currentCourseId'], ['currentCourseDbName'], ['currentCourseRepository']
     * @todo Eliminate the global variables.
     */
    static function define_course_keys($wanted_code, $prefix_for_all = '', $prefix_for_base_name = '', $prefix_for_path = '', $add_unique_prefix = false, $use_code_indepedent_keys = true)
    {
        global $prefixAntiNumber, $_configuration;
        $course_table = Database :: get_main_table(TABLE_MAIN_COURSE);
        $wanted_code = self::generate_course_code($wanted_code);
        $keys_course_code = $wanted_code;
        if (!$use_code_indepedent_keys) {
            $wanted_code = '';
        }

        if ($add_unique_prefix) {
            $unique_prefix = substr(md5(uniqid(rand())), 0, 10);
        } else {
            $unique_prefix = '';
        }

        $keys = array();
        $final_suffix = array('CourseId' => '', 'CourseDb' => '', 'CourseDir' => '');
        $limit_numb_try = 100;
        $keys_are_unique = false;
        $try_new_fsc_id = $try_new_fsc_db = $try_new_fsc_dir = 0;

        while (!$keys_are_unique) {

            $keys_course_id = $prefix_for_all . $unique_prefix . $wanted_code . $final_suffix['CourseId'];
            //$keys_course_db_name = $prefix_for_base_name . $unique_prefix . strtoupper($keys_course_id) . $final_suffix['CourseDb'];
            $keys_course_repository = $prefix_for_path . $unique_prefix . $wanted_code . $final_suffix['CourseDir'];
            $keys_are_unique = true;

            // Check whether they are unique.
            $query = "SELECT 1 FROM ".$course_table." WHERE code='".$keys_course_id."' LIMIT 0,1";
            $result = Database::query($query);

            //if ($keys_course_id == DEFAULT_COURSE || Database::num_rows($result)) {
            if (Database::num_rows($result)) {
                $keys_are_unique = false;
                $try_new_fsc_id ++;
                $final_suffix['CourseId'] = substr(md5(uniqid(rand())), 0, 4);
            }
            if (file_exists(api_get_path(SYS_COURSE_PATH).$keys_course_repository)) {
                $keys_are_unique = false;
                $try_new_fsc_dir ++;
                $final_suffix['CourseDir'] = substr(md5(uniqid(rand())), 0, 4);
            }

            if (($try_new_fsc_id + $try_new_fsc_db + $try_new_fsc_dir) > $limit_numb_try) {
                return $keys;
            }
        }

        $keys['currentCourseCode'] = $keys_course_code;
        $keys['currentCourseId'] = $keys_course_id;
        $keys['currentCourseRepository'] = $keys_course_repository;

        return $keys;
    }

    /**
     * Initializes a file repository for a newly created course.
     */
    static function prepare_course_repository($course_repository, $course_code)
    {
        $perm = api_get_permissions_for_new_directories();
        $perm_file = api_get_permissions_for_new_files();
        $htmlpage = "<!DOCTYPE html>\n<html lang=\"en\">\n  <head>\n    <meta charset=\"utf-8\">\n    <title>Not authorized</title>\n  </head>\n  <body>\n  </body>\n</html>";
        $cp = api_get_path(SYS_COURSE_PATH).$course_repository;

        //Creating document folder
        mkdir($cp, $perm);
        mkdir($cp . '/document', $perm);
        $cpt = $cp.'/document/index.html';
        $fd = fopen($cpt, 'w');
        fwrite($fd, $htmlpage);
        fclose($fd);

        /*
        @chmod($cpt, $perm_file);
        @copy($cpt, $cp . '/document/index.html');
        mkdir($cp . '/document/images', $perm);
        @copy($cpt, $cp . '/document/images/index.html');
        mkdir($cp . '/document/images/gallery/', $perm);
        @copy($cpt, $cp . '/document/images/gallery/index.html');
        mkdir($cp . '/document/shared_folder/', $perm);
        @copy($cpt, $cp . '/document/shared_folder/index.html');
        mkdir($cp . '/document/audio', $perm);
        @copy($cpt, $cp . '/document/audio/index.html');
        mkdir($cp . '/document/flash', $perm);
        @copy($cpt, $cp . '/document/flash/index.html');
        mkdir($cp . '/document/video', $perm);
        @copy($cpt, $cp . '/document/video/index.html');    */

        // Creating dropbox folder
        mkdir($cp . '/dropbox', $perm);
        $cpt = $cp.'/dropbox/index.html';
        $fd = fopen($cpt, 'w');
        fwrite($fd, $htmlpage);
        fclose($fd);
        @chmod($cpt, $perm_file);
        mkdir($cp . '/group', $perm);
        @copy($cpt, $cp . '/group/index.html');
        mkdir($cp . '/page', $perm);
        @copy($cpt, $cp . '/page/index.html');
        mkdir($cp . '/scorm', $perm);
        @copy($cpt, $cp . '/scorm/index.html');
        mkdir($cp . '/upload', $perm);
        @copy($cpt, $cp . '/upload/index.html');
        mkdir($cp . '/upload/forum', $perm);
        @copy($cpt, $cp . '/upload/forum/index.html');
        mkdir($cp . '/upload/forum/images', $perm);
        @copy($cpt, $cp . '/upload/forum/images/index.html');
        mkdir($cp . '/upload/test', $perm);
        @copy($cpt, $cp . '/upload/test/index.html');
        mkdir($cp . '/upload/blog', $perm);
        @copy($cpt, $cp . '/upload/blog/index.html');
        mkdir($cp . '/upload/learning_path', $perm);
        @copy($cpt, $cp . '/upload/learning_path/index.html');
        mkdir($cp . '/upload/learning_path/images', $perm);
        @copy($cpt, $cp . '/upload/learning_path/images/index.html');
        mkdir($cp . '/upload/calendar', $perm);
        @copy($cpt, $cp . '/upload/calendar/index.html');
        mkdir($cp . '/upload/calendar/images', $perm);
        @copy($cpt, $cp . '/upload/calendar/images/index.html');
        mkdir($cp . '/work', $perm);
        @copy($cpt, $cp . '/work/index.html');
        mkdir($cp . '/upload/announcements', $perm);
        @copy($cpt, $cp . '/upload/announcements/index.html');
        mkdir($cp . '/upload/announcements/images', $perm);
        @copy($cpt, $cp . '/upload/announcements/images/index.html');

        //Oral expression question type
        mkdir($cp . '/exercises', $perm);
        @copy($cpt, $cp . '/exercises/index.html');

        // Create .htaccess in the dropbox directory.
        $fp = fopen($cp . '/dropbox/.htaccess', 'w');
        fwrite($fp, "AuthName AllowLocalAccess
                       AuthType Basic

                       order deny,allow
                       deny from all

                       php_flag zlib.output_compression off");
        fclose($fp);
        return 0;
    }

    /**
     * Get current courses
     * */
    static function get_course_tables()
    {
        $tables = array();

        $tables[]= 'tool';
        $tables[]= 'tool_intro';
        $tables[]= 'group_info';
        $tables[]= 'group_category';
        $tables[]= 'group_rel_user';
        $tables[]= 'group_rel_tutor';
        $tables[]= 'item_property';
        $tables[]= 'userinfo_content';
        $tables[]= 'userinfo_def';
        $tables[]= 'course_description';
        $tables[]= 'calendar_event';
        $tables[]= 'calendar_event_repeat';
        $tables[]= 'calendar_event_repeat_not';
        $tables[]= 'calendar_event_attachment';
        $tables[]= 'announcement';
        $tables[]= 'announcement_attachment';
        $tables[]= 'resource';
        $tables[]= 'student_publication';
        $tables[]= 'student_publication_assignment';
        $tables[]= 'document';
        $tables[]= 'forum_category';
        $tables[]= 'forum_forum';
        $tables[]= 'forum_thread';
        $tables[]= 'forum_post';
        $tables[]= 'forum_mailcue';
        $tables[]= 'forum_attachment';
        $tables[]= 'forum_notification';
        $tables[]= 'forum_thread_qualify';
        $tables[]= 'forum_thread_qualify_log';
        $tables[]= 'link';
        $tables[]= 'link_category';
        $tables[]= 'online_connected';
        $tables[]= 'online_link';
        $tables[]= 'chat_connected';
        $tables[]= 'quiz';
        $tables[]= 'quiz_rel_question';
        $tables[]= 'quiz_question';
        $tables[]= 'quiz_answer';
        $tables[]= 'quiz_question_option';
        $tables[]= 'quiz_category';
        $tables[]= 'quiz_question_rel_category';
        $tables[]= 'dropbox_post';
        $tables[]= 'dropbox_file';
        $tables[]= 'dropbox_person';
        $tables[]= 'dropbox_category';
        $tables[]= 'dropbox_feedback';
        $tables[]= 'lp';
        $tables[]= 'lp_item';
        $tables[]= 'lp_view';
        $tables[]= 'lp_item_view';
        $tables[]= 'lp_iv_interaction';
        $tables[]= 'lp_iv_objective';
        $tables[]= 'blog';
        $tables[]= 'blog_comment';
        $tables[]= 'blog_post';
        $tables[]= 'blog_rating';
        $tables[]= 'blog_rel_user';
        $tables[]= 'blog_task';
        $tables[]= 'blog_task_rel_user';
        $tables[]= 'blog_attachment';
        $tables[]= 'permission_group';
        $tables[]= 'permission_user';
        $tables[]= 'permission_task';
        $tables[]= 'role';
        $tables[]= 'role_group';
        $tables[]= 'role_permissions';
        $tables[]= 'role_user';
        $tables[]= 'survey';
        $tables[]= 'survey_question';
        $tables[]= 'survey_question_option';
        $tables[]= 'survey_invitation';
        $tables[]= 'survey_answer';
        $tables[]= 'survey_group';
        $tables[]= 'wiki';
        $tables[]= 'wiki_conf';
        $tables[]= 'wiki_discuss';
        $tables[]= 'wiki_mailcue';
        $tables[]= 'course_setting';
        $tables[]= 'glossary';
        $tables[]= 'notebook';
        $tables[]= 'attendance';
        $tables[]= 'attendance_sheet';
        $tables[]= 'attendance_calendar';
        $tables[]= 'attendance_result';
        $tables[]= 'attendance_sheet_log';
        $tables[]= 'thematic';
        $tables[]= 'thematic_plan';
        $tables[]= 'thematic_advance';
        $tables[]= 'metadata';
        return $tables;
    }

    static function browse_folders($path, $files, $media)
    {
        $defaultCourseDocumentPath = api_get_path(SYS_DEFAULT_COURSE_DOCUMENT_PATH);
        if ($media == 'images') {
            $code_path = $defaultCourseDocumentPath.'images/';
        }
        if ($media == 'audio') {
            $code_path = $defaultCourseDocumentPath.'audio/';
        }
        if ($media == 'flash') {
            $code_path = $defaultCourseDocumentPath.'flash/';
        }
        if ($media == 'video') {
            $code_path = $defaultCourseDocumentPath.'video/';
        }
        if ($media == 'certificates') {
            $code_path = $defaultCourseDocumentPath.'certificates/';
        }

        if (is_dir($path)) {
            $handle = opendir($path);
            while (false !== ($file = readdir($handle))) {
                if (is_dir($path.$file) && strpos($file, '.') !== 0) {
                    $files[]['dir'] = str_replace($code_path, '', $path.$file.'/');
                    $files = self::browse_folders($path.$file.'/', $files, $media);
                } elseif (is_file($path.$file) && strpos($file, '.') !== 0) {
                    $files[]['file'] = str_replace($code_path, '', $path.$file);
                }
            }
        }

        return $files;
    }

    /**
     * @param $files
     * @param $type
     * @return array
     */
    static function sort_pictures($files, $type)
    {
        $pictures = array();
        foreach ($files as $key => $value){
            if (isset($value[$type]) && !empty($value[$type])) {
                $pictures[][$type] = $value[$type];
            }
        }
        return $pictures;
    }

    /**
     * Fills the course database with some required content and example content.
     * @version 1.2
     */
    static function fill_db_course($course_id, $course_repository, $language, $fill_with_exemplary_content = null)
    {
        if (is_null($fill_with_exemplary_content)) {
            $fill_with_exemplary_content = api_get_setting('example_material_course_creation') != 'false';
        }
        $course_id = intval($course_id);

        if (empty($course_id)) {
            return false;
        }
        $now = api_get_utc_datetime(time());

        $tbl_course_homepage 	= Database::get_course_table(TABLE_TOOL_LIST);
        $TABLEINTROS 			= Database::get_course_table(TABLE_TOOL_INTRO);
        $TABLEGROUPCATEGORIES 	= Database::get_course_table(TABLE_GROUP_CATEGORY);
        $TABLEITEMPROPERTY 		= Database::get_course_table(TABLE_ITEM_PROPERTY);
        $TABLETOOLAGENDA 		= Database::get_course_table(TABLE_AGENDA);
        $TABLETOOLANNOUNCEMENTS = Database::get_course_table(TABLE_ANNOUNCEMENT);
        $TABLETOOLDOCUMENT 		= Database::get_course_table(TABLE_DOCUMENT);
        $TABLETOOLLINK 			= Database::get_course_table(TABLE_LINK);
        $TABLEQUIZ 				= Database::get_course_table(TABLE_QUIZ_TEST);
        $TABLEQUIZQUESTION 		= Database::get_course_table(TABLE_QUIZ_TEST_QUESTION);
        $TABLEQUIZQUESTIONLIST 	= Database::get_course_table(TABLE_QUIZ_QUESTION);
        $TABLEQUIZANSWERSLIST 	= Database::get_course_table(TABLE_QUIZ_ANSWER);
        $TABLESETTING 			= Database::get_course_table(TABLE_COURSE_SETTING);

        $TABLEFORUMCATEGORIES 	= Database::get_course_table(TABLE_FORUM_CATEGORY);
        $TABLEFORUMS 			= Database::get_course_table(TABLE_FORUM);
        $TABLEFORUMTHREADS 		= Database::get_course_table(TABLE_FORUM_THREAD);
        $TABLEFORUMPOSTS 		= Database::get_course_table(TABLE_FORUM_POST);
        $TABLEGRADEBOOK 		= Database::get_main_table(TABLE_MAIN_GRADEBOOK_CATEGORY);
        $TABLEGRADEBOOKLINK		= Database::get_main_table(TABLE_MAIN_GRADEBOOK_LINK);
        $TABLEGRADEBOOKCERT		= Database::get_main_table(TABLE_MAIN_GRADEBOOK_CERTIFICATE);

        include api_get_path(SYS_CODE_PATH).'lang/english/create_course.inc.php';
        $file_to_include = api_get_path(SYS_CODE_PATH).'lang/'.$language.'/create_course.inc.php';

        if (file_exists($file_to_include)) {
            include $file_to_include;
        }

        $visible_for_all = 1;
        $visible_for_course_admin = 0;
        $visible_for_platform_admin = 2;

        /*    Course tools  */

        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_COURSE_DESCRIPTION . "','course_description/','info.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'course_description')) . "','0','squaregrey.gif','NO','_self','authoring','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_CALENDAR_EVENT . "','calendar/agenda.php','agenda.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'agenda')) . "','0','squaregrey.gif','NO','_self','interaction','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_DOCUMENT . "','document/document.php','folder_document.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'documents')) . "','0','squaregrey.gif','NO','_self','authoring','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_LEARNPATH . "','newscorm/lp_controller.php','scorms.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'learning_path')) . "','0','squaregrey.gif','NO','_self','authoring','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_LINK . "','link/link.php','links.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'links')) . "','0','squaregrey.gif','NO','_self','authoring','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_QUIZ . "','exercice/exercice.php','quiz.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'quiz')) . "','0','squaregrey.gif','NO','_self','authoring','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_ANNOUNCEMENT . "','announcements/announcements.php','valves.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'announcements')) . "','0','squaregrey.gif','NO','_self','authoring','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_FORUM . "','forum/index.php','forum.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'forums')) . "','0','squaregrey.gif','NO','_self','interaction','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_DROPBOX . "','dropbox/index.php','dropbox.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'dropbox')) . "','0','squaregrey.gif','NO','_self','interaction','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_USER . "','user/user.php','members.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'users')) . "','0','squaregrey.gif','NO','_self','interaction','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_GROUP . "','group/group.php','group.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'groups')) . "','0','squaregrey.gif','NO','_self','interaction','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_CHAT . "','chat/chat.php','chat.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'chat')) . "','0','squaregrey.gif','NO','_self','interaction','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_STUDENTPUBLICATION . "','work/work.php','works.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'student_publications')) . "','0','squaregrey.gif','NO','_self','interaction','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_SURVEY."','survey/survey_list.php','survey.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'survey')) . "','0','squaregrey.gif','NO','_self','interaction','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_WIKI ."','wiki/index.php','wiki.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'wiki')) . "','0','squaregrey.gif','NO','_self','interaction','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_GRADEBOOK."','gradebook/index.php','gradebook.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'gradebook')). "','0','squaregrey.gif','NO','_self','authoring','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_GLOSSARY."','glossary/index.php','glossary.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'glossary')). "','0','squaregrey.gif','NO','_self','authoring','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_NOTEBOOK."','notebook/index.php','notebook.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'notebook'))."','0','squaregrey.gif','NO','_self','interaction','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_ATTENDANCE."','attendance/index.php','attendance.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'attendances'))."','0','squaregrey.gif','NO','_self','authoring','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_COURSE_PROGRESS."','course_progress/index.php','course_progress.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'course_progress'))."','0','squaregrey.gif','NO','_self','authoring','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_CURRICULUM."','curriculum','cv.png','".Text::string2binary(api_get_setting('course_create_active_tools', 'curriculum'))."','0','squaregrey.gif','NO','_self','authoring','0')");

        if (api_get_setting('service_visio', 'active') == 'true') {
            $mycheck = api_get_setting('service_visio', 'visio_host');
            if (!empty($mycheck)) {
                Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_VISIO_CONFERENCE . "','conference/index.php?type=conference','visio_meeting.gif','1','0','squaregrey.gif','NO','_self','interaction','0')");
                Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_VISIO_CLASSROOM . "','conference/index.php?type=classroom','visio.gif','1','0','squaregrey.gif','NO','_self','authoring','0')");
            }
        }

        if (api_get_setting('search_enabled') == 'true') {
            Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '" . TOOL_SEARCH. "','search/','info.gif','".Text::string2binary(api_get_setting('course_create_active_tools', 'enable_search')) . "','0','search.gif','NO','_self','authoring','0')");
        }

        // Blogs (Kevin Van Den Haute :: kevin@develop-it.be)
        $sql = "INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL,'" . TOOL_BLOGS . "','blog/blog_admin.php','blog_admin.gif','" . Text::string2binary(api_get_setting('course_create_active_tools', 'blogs')) . "','1','squaregrey.gif','NO','_self','admin','0')";
        Database::query($sql);

        /*  Course homepage tools for course admin only    */

        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '".TOOL_TRACKING . "','tracking/courseLog.php','statistics.gif','$visible_for_course_admin','1','', 'NO','_self','admin','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '".TOOL_COURSE_SETTING . "','course_info/infocours.php','reference.gif','$visible_for_course_admin','1','', 'NO','_self','admin','0')");
        Database::query("INSERT INTO $tbl_course_homepage VALUES ($course_id, NULL, '".TOOL_COURSE_MAINTENANCE."','course_info/maintenance.php','backup.gif','$visible_for_course_admin','1','','NO','_self', 'admin','0')");

        /* Course_setting table (courseinfo tool)   */

        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'email_alert_manager_on_new_doc',0,'work')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'email_alert_on_new_doc_dropbox',0,'dropbox')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'allow_user_edit_agenda',0,'agenda')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'allow_user_edit_announcement',0,'announcement')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'email_alert_manager_on_new_quiz',1,'quiz')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'allow_user_image_forum',1,'forum')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'course_theme','','theme')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'allow_learning_path_theme','1','theme')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'allow_open_chat_window',1,'chat')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'email_alert_to_teacher_on_new_user_in_course',0,'registration')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'allow_user_view_user_list',1,'user')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'display_info_advance_inside_homecourse',1,'thematic_advance')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'email_alert_students_on_new_homework',0,'work')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'enable_lp_auto_launch',0,'learning_path')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'pdf_export_watermark_text','','learning_path')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'allow_public_certificates','','certificates')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'allow_fast_exercise_edition', 0 ,'exercise')");
        Database::query("INSERT INTO $TABLESETTING (c_id, variable,value,category) VALUES ($course_id, 'enable_exercise_auto_launch', 0 ,'exercise')");

        /* Course homepage tools for platform admin only */

        /* Group tool */

        Database::query("INSERT INTO $TABLEGROUPCATEGORIES  (c_id,  id , title , description , max_student , self_reg_allowed , self_unreg_allowed , groups_per_user , display_order )
                VALUES ($course_id, '2', '".Database::escape_string(get_lang('DefaultGroupCategory')) . "', '', '8', '0', '0', '0', '0');");

        /*    Example Material  */
        global $language_interface;
        $language_interface = !empty($language_interface) ? $language_interface : api_get_setting('platformLanguage');

        // Example material should be in the same language as the course is.
        $language_interface_original = $language_interface;
        $language_interface          = $language;

        //Share folder
        Database::query("INSERT INTO $TABLETOOLDOCUMENT (c_id, path,title,filetype,size) VALUES ($course_id,'/shared_folder','".get_lang('UserFolders')."','folder','0')");
        $example_doc_id = Database :: insert_id();
        Database::query("INSERT INTO $TABLEITEMPROPERTY (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility) VALUES ($course_id,'document',1,NOW(),NOW(),$example_doc_id,'DocumentAdded',1,0,NULL,0)");

        //Chat folder
        Database::query("INSERT INTO $TABLETOOLDOCUMENT (c_id, path,title,filetype,size) VALUES ($course_id,'/chat_files','".get_lang('ChatFiles')."','folder','0')");
        $example_doc_id = Database :: insert_id();
        Database::query("INSERT INTO $TABLEITEMPROPERTY (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility) VALUES ($course_id,'document',1,NOW(),NOW(),$example_doc_id,'DocumentAdded',1,0,NULL,0)");

        $sys_course_path = api_get_path(SYS_COURSE_PATH);
        $perm = api_get_permissions_for_new_directories();
        $perm_file = api_get_permissions_for_new_files();

        $chat_path = $sys_course_path.$course_repository.'/document/chat_files';

        if (!is_dir($chat_path)) {
            @mkdir($chat_path, api_get_permissions_for_new_directories());
        }

        /*    Documents   */
        if ($fill_with_exemplary_content) {

            Database::query("INSERT INTO $TABLETOOLDOCUMENT (c_id,path,title,filetype,size) VALUES ($course_id,'/images','".get_lang('Images')."','folder','0')");
            $example_doc_id = Database :: insert_id();
            Database::query("INSERT INTO $TABLEITEMPROPERTY  (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility) VALUES ($course_id,'document',1,NOW(),NOW(),$example_doc_id,'DocumentAdded',1,0,NULL,0)");

            Database::query("INSERT INTO $TABLETOOLDOCUMENT (c_id, path,title,filetype,size) VALUES ($course_id,'/images/gallery','".get_lang('DefaultCourseImages')."','folder','0')");
            $example_doc_id = Database :: insert_id();
            Database::query("INSERT INTO $TABLEITEMPROPERTY  (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility) VALUES ($course_id,'document',1,NOW(),NOW(),$example_doc_id,'DocumentAdded',1,0,NULL,0)");

            Database::query("INSERT INTO $TABLETOOLDOCUMENT (c_id, path,title,filetype,size) VALUES ($course_id,'/audio','".get_lang('Audio')."','folder','0')");
            $example_doc_id = Database :: insert_id();
            Database::query("INSERT INTO $TABLEITEMPROPERTY  (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility) VALUES ($course_id,'document',1,NOW(),NOW(),$example_doc_id,'DocumentAdded',1,0,NULL,0)");

            Database::query("INSERT INTO $TABLETOOLDOCUMENT (c_id, path,title,filetype,size) VALUES ($course_id,'/flash','".get_lang('Flash')."','folder','0')");
            $example_doc_id = Database :: insert_id();
            Database::query("INSERT INTO $TABLEITEMPROPERTY  (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility) VALUES ($course_id,'document',1,NOW(),NOW(),$example_doc_id,'DocumentAdded',1,0,NULL,0)");

            Database::query("INSERT INTO $TABLETOOLDOCUMENT (c_id, path,title,filetype,size) VALUES ($course_id,'/video','".get_lang('Video')."','folder','0')");
            $example_doc_id = Database :: insert_id();
            Database::query("INSERT INTO $TABLEITEMPROPERTY  (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility) VALUES ($course_id,'document',1,NOW(),NOW(),$example_doc_id,'DocumentAdded',1,0,NULL,0)");

            Database::query("INSERT INTO $TABLETOOLDOCUMENT (c_id, path,title,filetype,size) VALUES ($course_id,'/certificates','".get_lang('Certificates')."','folder','0')");
            $example_doc_id = Database :: insert_id();
            Database::query("INSERT INTO $TABLEITEMPROPERTY  (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility) VALUES ($course_id,'document',1,NOW(),NOW(),$example_doc_id,'DocumentAdded',1,0,NULL,0)");

            // FILL THE COURSE DOCUMENT WITH DEFAULT COURSE PICTURES

            $folders_to_copy_from_default_course =  array(
                'images',
                'audio',
                'flash',
                'video',
                'certificates',
            );

            $default_course_path = api_get_path(SYS_DEFAULT_COURSE_DOCUMENT_PATH);

            $default_document_array = array();
            foreach ($folders_to_copy_from_default_course as $folder) {
                $default_course_folder_path = $default_course_path.$folder.'/';
                $files = self::browse_folders($default_course_folder_path, array(), $folder);
                $sorted_array = self::sort_pictures($files, 'dir');
                $sorted_array = array_merge($sorted_array, self::sort_pictures($files, 'file'));
                $default_document_array[$folder] = $sorted_array;
            }

            //Light protection (adding index.html in every document folder)
            $htmlpage = "<!DOCTYPE html>\n<html lang=\"en\">\n <head>\n <meta charset=\"utf-8\">\n <title>Not authorized</title>\n  </head>\n  <body>\n  </body>\n</html>";

            $example_cert_id = 0;
            if (is_array($default_document_array) && count($default_document_array) > 0) {
                foreach ($default_document_array as $media_type => $array_media) {
                    $path_documents = "/$media_type/";

                    //hack until feature #5242 is implemented
                    if ($media_type == 'images') {
                        $media_type = 'images/gallery';
                        $images_folder = $sys_course_path.$course_repository."/document/images/";

                        if (!is_dir($images_folder)) {
                            //Creating index.html
                            mkdir($images_folder, $perm);
                            $fd = fopen($images_folder.'index.html', 'w');
                            fwrite($fd, $htmlpage);
                            @chmod($images_folder.'index.html', $perm_file);
                        }
                    }

                    $course_documents_folder = $sys_course_path.$course_repository."/document/$media_type/";
                    $default_course_path = api_get_path(SYS_DEFAULT_COURSE_DOCUMENT_PATH).$path_documents;

                    //echo 'try '.$course_documents_folder; echo '<br />';

                    if (!is_dir($course_documents_folder)) {
                        //Creating index.html
                        mkdir($course_documents_folder, $perm);
                        $fd = fopen($course_documents_folder.'index.html', 'w');
                        fwrite($fd, $htmlpage);
                        @chmod($course_documents_folder.'index.html', $perm_file);
                    }

                    if (is_array($array_media) && count($array_media)>0) {
                        foreach ($array_media as $key => $value) {
                            if (isset($value['dir']) && !empty($value['dir'])) {

                                if (!is_dir($course_documents_folder.$value['dir'])) {
                                    //Creating folder
                                    mkdir($course_documents_folder.$value['dir'], $perm);

                                    //Creating index.html (for light protection)
                                    $index_html = $course_documents_folder.$value['dir'].'/index.html';
                                    $fd = fopen($index_html, 'w');
                                    fwrite($fd, $htmlpage);
                                    @chmod($index_html, $perm_file);

                                    //Inserting folder in the DB
                                    $folder_path = substr($value['dir'], 0, strlen($value['dir']) - 1);
                                    $temp = explode('/', $folder_path);
                                    $title = $temp[count($temp)-1];

                                    //hack until feature #5242 is implemented
                                    if ($title == 'gallery') {
                                        $title = get_lang('DefaultCourseImages');
                                    }

                                    if ($media_type == 'images/gallery') {
                                        $folder_path = 'gallery/'.$folder_path;
                                    }

                                    Database::query("INSERT INTO $TABLETOOLDOCUMENT (c_id, path,title,filetype,size) VALUES ($course_id,'$path_documents".$folder_path."','".$title."','folder','0')");
                                    $image_id = Database :: insert_id();
                                    Database::query("INSERT INTO $TABLEITEMPROPERTY (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility) VALUES ($course_id,'document',1,NOW(),NOW(),$image_id,'DocumentAdded',1,0,NULL,0)");
                                }
                            }

                            if (isset($value['file']) && !empty($value['file'])) {
                                if (!file_exists($course_documents_folder.$value['file'])) {
                                    //Copying file
                                    copy($default_course_path.$value['file'], $course_documents_folder.$value['file']);
                                    chmod($course_documents_folder.$value['file'], $perm_file);
                                    //echo $default_course_path.$value['file']; echo ' - '; echo $course_documents_folder.$value['file']; echo '<br />';
                                    $temp = explode('/', $value['file']);
                                    $file_size = filesize($course_documents_folder.$value['file']);

                                    //hack until feature #5242 is implemented
                                    if ($media_type == 'images/gallery') {
                                        $value["file"] = 'gallery/'.$value["file"];
                                    }

                                    //Inserting file in the DB
                                    Database::query("INSERT INTO $TABLETOOLDOCUMENT (c_id, path,title,filetype,size) VALUES ($course_id,'$path_documents".$value["file"]."','".$temp[count($temp)-1]."','file','$file_size')");
                                    $image_id = Database :: insert_id();
                                    if ($path_documents.$value['file'] == '/certificates/default.html') {
                                      $example_cert_id = $image_id;
                                    }
                                    Database::query("INSERT INTO $TABLEITEMPROPERTY (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility) VALUES ($course_id,'document',1,NOW(),NOW(),$image_id,'DocumentAdded',1,0,NULL,1)");
                                }
                            }
                        }
                    }
                }
            }

            /* Agenda tool */

            Database::query("INSERT INTO $TABLETOOLAGENDA VALUES ($course_id, NULL, '".Database::escape_string(get_lang('AgendaCreationTitle')) . "', '".Database::escape_string(get_lang('AgendaCreationContenu')) . "', now(), now(), NULL, 0, 0)");
            // We need to add the item properties too!
            $insert_id = Database :: insert_id();
            $sql = "INSERT INTO $TABLEITEMPROPERTY (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility) VALUES ($course_id, '" . TOOL_CALENDAR_EVENT . "',1,NOW(),NOW(),$insert_id,'AgendaAdded',1,0,NULL,1)";
            Database::query($sql);

            /*  Links tool */
            $add_google_link_sql = "INSERT INTO $TABLETOOLLINK  (c_id, url, title, description, category_id, display_order, on_homepage, target)
                    VALUES ($course_id, 'http://www.google.com','Google','".Database::escape_string(get_lang('Google')) . "','0','0','0','_self')";
            Database::query($add_google_link_sql);

            // We need to add the item properties too!
            $insert_id = Database :: insert_id();
            $sql = "INSERT INTO $TABLEITEMPROPERTY  (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility)
                    VALUES ($course_id, '" . TOOL_LINK . "',1,NOW(),NOW(),$insert_id,'LinkAdded',1,0,NULL,1)";
            Database::query($sql);

            $add_wikipedia_link_sql = "INSERT INTO $TABLETOOLLINK  (c_id, url, title, description, category_id, display_order, on_homepage, target)
                    VALUES ($course_id, 'http://www.wikipedia.org','Wikipedia','".Database::escape_string(get_lang('Wikipedia')) . "','0','1','0','_self')";
            Database::query($add_wikipedia_link_sql);

            // We need to add the item properties too!
            $insert_id = Database :: insert_id();
            $sql = "INSERT INTO $TABLEITEMPROPERTY  (tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility) VALUES ('" . TOOL_LINK . "',1,NOW(),NOW(),$insert_id,'LinkAdded',1,0,NULL,1)";
            Database::query($sql);

            /* Announcement tool */

            $sql = "INSERT INTO $TABLETOOLANNOUNCEMENTS  (c_id, title,content,end_date,display_order,email_sent)
                    VALUES ($course_id, '".Database::escape_string(get_lang('AnnouncementExampleTitle')) . "', '".Database::escape_string(get_lang('AnnouncementEx')) . "', NOW(), '1','0')";
            Database::query($sql);

            // We need to add the item properties too!
            $insert_id = Database :: insert_id();
            $sql = "INSERT INTO $TABLEITEMPROPERTY (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility)
                    VALUES ($course_id, '" . TOOL_ANNOUNCEMENT . "',1,NOW(),NOW(),$insert_id,'AnnouncementAdded',1,0,NULL,1)";
            Database::query($sql);

            /* Introduction text */

            $intro_text='<p style="text-align: center;">
                            <img src="'.api_get_path(REL_CODE_PATH).'img/mascot.png" alt="Mr. Chamilo" title="Mr. Chamilo" />
                            <h2>'.Database::escape_string(get_lang('IntroductionText')).'</h2>
                         </p>';
            Database::query("INSERT INTO $TABLEINTROS VALUES ($course_id, '" . TOOL_COURSE_HOMEPAGE . "','".$intro_text."', 0)");
            Database::query("INSERT INTO $TABLEINTROS VALUES ($course_id, '" . TOOL_STUDENTPUBLICATION . "','".Database::escape_string(get_lang('IntroductionTwo')) . "', 0)");

            // Wiki intro
            $intro_wiki='<table width="100%" border="0" cellpadding="0" cellspacing="0"><tr><td width="110" valign="top" align="left"></td><td valign="top" align="left">'.Database::escape_string(get_lang('IntroductionWiki')).'</td></tr></table>';
            Database::query("INSERT INTO $TABLEINTROS VALUES ($course_id, '" . TOOL_WIKI . "','".$intro_wiki. "', 0)");

            /*  Exercise tool */

            $html = Database::escape_string('<table width="100%" border="0" cellpadding="0" cellspacing="0">
                                                <tr><td width="110" valign="top" align="left">
                                                <img src="'.api_get_path(WEB_DEFAULT_COURSE_DOCUMENT_PATH).'images/mr_dokeos/thinking.jpg"></td><td valign="top" align="left">'.get_lang('Antique').'
                                            </td></tr></table>');

            // Insert exercise
            Database::query('INSERT INTO '.$TABLEQUIZ .' (c_id, title, description, type, random, random_answers, active, results_disabled ) ' .
              ' VALUES ('.$course_id.', "'.Database::escape_string(get_lang('ExerciceEx')) . '", "'.$html.'", "1", "0", "0", "1", "0")');
            $exercise_id = Database :: insert_id();

            // Insert question
            Database::query("INSERT INTO $TABLEQUIZQUESTIONLIST (c_id, question, description, ponderation, position, type, picture, level)
                            VALUES ( '.$course_id.', '".Database::escape_string(get_lang('SocraticIrony')) . "', '".Database::escape_string(get_lang('ManyAnswers')) . "', '10', '1', '2','',1)");
            $questionId = Database :: insert_id();
            Database::query("INSERT INTO $TABLEQUIZQUESTION  (c_id, question_id, exercice_id, question_order) VALUES ($course_id,$questionId , $exercise_id, 1)");

            // Insert answers
            Database::query("INSERT INTO $TABLEQUIZANSWERSLIST (c_id, question_id, answer, correct, comment, ponderation, position) VALUES ($course_id, '$questionId', '".Database::escape_string(get_lang('Ridiculise')) . "', '0', '".Database::escape_string(get_lang('NoPsychology')) . "', '-5', '1')");
            Database::query("INSERT INTO $TABLEQUIZANSWERSLIST (c_id, question_id, answer, correct, comment, ponderation, position) VALUES ($course_id, '$questionId', '".Database::escape_string(get_lang('AdmitError')) . "', '0', '".Database::escape_string(get_lang('NoSeduction')) . "', '-5', '2')");
            Database::query("INSERT INTO $TABLEQUIZANSWERSLIST (c_id, question_id, answer, correct, comment, ponderation, position) VALUES ($course_id, '$questionId', '".Database::escape_string(get_lang('Force')) . "', '1', '".Database::escape_string(get_lang('Indeed')) . "', '5', '3')");
            Database::query("INSERT INTO $TABLEQUIZANSWERSLIST (c_id, question_id, answer, correct, comment, ponderation, position) VALUES ($course_id, '$questionId', '".Database::escape_string(get_lang('Contradiction')) . "', '1', '".Database::escape_string(get_lang('NotFalse')) . "', '5', '4')");

            /* Forum tool */

            Database::query("INSERT INTO $TABLEFORUMCATEGORIES VALUES ($course_id, 1,'".Database::escape_string(get_lang('ExampleForumCategory'))."', '', 1, 0, 0)");
            $insert_id = Database :: insert_id();

            Database::query("INSERT INTO $TABLEITEMPROPERTY  (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility)
                            VALUES ($course_id, 'forum_category',1,NOW(),NOW(),$insert_id,'ForumCategoryAdded',1,0,NULL,1)");

            Database::query("INSERT INTO $TABLEFORUMS (c_id, forum_title, forum_comment, forum_threads,forum_posts,forum_last_post,forum_category, allow_anonymous, allow_edit,allow_attachments, allow_new_threads,default_view,forum_of_group,forum_group_public_private, forum_order,locked,session_id )
                            VALUES ($course_id, '".Database::escape_string(get_lang('ExampleForum'))."', '', 0, 0, 0, 1, 0, 1, '0', 1, 'flat','0', 'public', 1, 0,0)");
            $insert_id = Database :: insert_id();
            Database::query("INSERT INTO $TABLEITEMPROPERTY  (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility)
                             VALUES ($course_id, '".TOOL_FORUM."', 1,NOW(),NOW(),$insert_id,'ForumAdded',1,0,NULL,1)");

            Database::query("INSERT INTO $TABLEFORUMTHREADS (c_id, thread_id, thread_title, forum_id, thread_replies, thread_poster_id, thread_poster_name, thread_views, thread_last_post, thread_date, locked, thread_qualify_max, session_id)
                            VALUES ($course_id, 1, '".Database::escape_string(get_lang('ExampleThread'))."', 1, 0, 1, '', 0, 1, NOW(), 0, 10, 0)");
            $insert_id = Database :: insert_id();

            Database::query("INSERT INTO $TABLEITEMPROPERTY  (c_id, tool,insert_user_id,insert_date,lastedit_date,ref,lastedit_type,lastedit_user_id,to_group_id,to_user_id,visibility)
                            VALUES ($course_id, 'forum_thread',1,NOW(),NOW(),$insert_id,'ForumThreadAdded',1,0,NULL,1)");

            Database::query("INSERT INTO $TABLEFORUMPOSTS VALUES ($course_id, 1, '".Database::escape_string(get_lang('ExampleThread'))."', '".Database::escape_string(get_lang('ExampleThreadContent'))."', 1, 1, 1, '', NOW(), 0, 0, 1)");

            /* Gradebook tool */
            $course = api_get_course_info_by_id($course_id);
            $course_code = $course['code'];
            // father gradebook
            Database::query("INSERT INTO $TABLEGRADEBOOK (name, description, user_id, course_code, parent_id, weight, visible, certif_min_score, session_id, document_id) VALUES ('$course_code','',1,'$course_code',0,100,0,NULL,NULL,$example_cert_id)");
            $gbid = Database :: insert_id();
            Database::query("INSERT INTO $TABLEGRADEBOOK (name, description, user_id, course_code, parent_id, weight, visible, certif_min_score, session_id, document_id) VALUES ('$course_code','',1,'$course_code',$gbid,100,1,75,NULL,$example_cert_id)");
            $gbid = Database :: insert_id();
            Database::query("INSERT INTO $TABLEGRADEBOOKLINK (type, ref_id, user_id, course_code, category_id, created_at, weight, visible, locked) VALUES (1,$exercise_id,1,'$course_code',$gbid,'$now',100,1,0)");
        }

        //Installing plugins in course
        $app_plugin = new AppPlugin();
        $app_plugin->install_course_plugins($course_id);

        $language_interface = $language_interface_original;
        return true;
    }


    /**
     * function register_course to create a record in the course table of the main database
     * @param string    $course_sys_code
     * @param string    $course_screen_code
     * @param string    $course_repository
     * @param string    $course_db_name
     * @param string    $tutor_name
     * @param string    $category
     * @param string    $title              complete name of course
     * @param string    $course_language    lang for this course
     * @param string    $uid                uid of owner
     * @param integer                       Expiration date in unix time representation
     * @param array                         Optional array of teachers' user ID
     * @return int      0
     * @todo use an array called $params instead of lots of params
     */
    static function register_course($params)
    {
        global $error_msg, $firstExpirationDelay;

        $title              = $params['title'];
        $code               = $params['code'];
        $visual_code        = $params['visual_code'];
        $directory          = isset($params['directory']) ? $params['directory'] : null;
        $tutor_name         = isset($params['tutor_name']) ? $params['tutor_name'] : null;
        //$description        = $params['description'];

        $category_code      = isset($params['category_code']) ? $params['category_code'] : null;
        $course_language    = isset($params['course_language']) && !empty($params['course_language']) ? $params['course_language'] : api_get_setting('platformLanguage');
        $user_id            = empty($params['user_id']) ? api_get_user_id() : intval($params['user_id']);
        $department_name    = isset($params['department_name']) ? $params['department_name'] : null;
        $department_url     = isset($params['department_url']) ? $params['department_url'] : null;
        $disk_quota         = isset($params['disk_quota']) ? $params['disk_quota'] : null;

        if (!isset($params['visibility'])) {
            $default_course_visibility = api_get_setting('courses_default_creation_visibility');
            if (isset($default_course_visibility)) {
                $visibility         = $default_course_visibility;
            } else {
                $visibility         = COURSE_VISIBILITY_OPEN_PLATFORM;
            }
        } else {
            $visibility         = $params['visibility'];
        }

        $subscribe          = isset($params['subscribe']) ? intval($params['subscribe']) : ($visibility == COURSE_VISIBILITY_OPEN_PLATFORM ? 1 : 0);
        $unsubscribe        = isset($params['unsubscribe']) ? intval($params['unsubscribe']) : 0;
        $expiration_date    = isset($params['expiration_date']) ? $params['expiration_date'] : null;
        $teachers           = isset($params['teachers']) ? $params['teachers'] : null;
        $status             = isset($params['status']) ? $params['status'] : null;

        $TABLECOURSE		 	= Database :: get_main_table(TABLE_MAIN_COURSE);
        $TABLECOURSUSER 		= Database :: get_main_table(TABLE_MAIN_COURSE_USER);

        $ok_to_register_course = true;

        // Check whether all the needed parameters are present.
        if (empty($code)) {
            $error_msg[] = 'courseSysCode is missing';
            $ok_to_register_course = false;
        }
        if (empty($visual_code)) {
            $error_msg[] = 'courseScreenCode is missing';
            $ok_to_register_course = false;
        }
        if (empty($directory)) {
            $error_msg[] = 'courseRepository is missing';
            $ok_to_register_course = false;
        }

        if (empty($title)) {
            $error_msg[] = 'title is missing';
            $ok_to_register_course = false;
        }

        if (empty($expiration_date)) {
            $expiration_date = api_get_utc_datetime(time() + $firstExpirationDelay);
        } else {
            $expiration_date = api_get_utc_datetime($expiration_date);
        }

        if ($visibility < 0 || $visibility > 3) {
            $error_msg[] = 'visibility is invalid';
            $ok_to_register_course = false;
        }

        if (empty($disk_quota)) {
            $disk_quota = api_get_setting('default_document_quotum');
        }

        $time = api_get_utc_datetime();

        if (stripos($department_url, 'http://') === false && stripos($department_url, 'https://') === false) {
            $department_url = 'http://'.$department_url;
        }
        //just in case
        if ($department_url == 'http://') {
            $department_url = '';
        }
        $course_id = 0;

        if ($ok_to_register_course) {

           // Here we must add 2 fields.
          $sql = "INSERT INTO ".$TABLECOURSE . " SET
                code            = '".Database :: escape_string($code) . "',
                directory       = '".Database :: escape_string($directory) . "',
                course_language = '".Database :: escape_string($course_language) . "',
                title           = '".Database :: escape_string($title) . "',
                description     = '".Database::escape_string(get_lang('CourseDescription')) . "',
                category_code   = '".Database :: escape_string($category_code) . "',
                visibility      = '".$visibility . "',
                show_score      = '1',
                disk_quota      = '".intval($disk_quota) . "',
                creation_date   = '$time',
                expiration_date = '".$expiration_date . "',
                last_edit       = '$time',
                last_visit      = NULL,
                tutor_name      = '".Database :: escape_string($tutor_name) . "',
                department_name = '".Database :: escape_string($department_name) . "',
                department_url  = '".Database :: escape_string($department_url) . "',
                subscribe       = '".intval($subscribe) . "',
                unsubscribe     = '".intval($unsubscribe) . "',
                visual_code     = '".Database :: escape_string($visual_code) . "'";

            Database::query($sql);
            $course_id  = Database::insert_id();

            if ($course_id) {

                $sort = api_max_sort_value('0', api_get_user_id());

                $i_course_sort = CourseManager :: userCourseSort($user_id, $code);
                if (!empty($user_id)) {
                    $sql = "INSERT INTO ".$TABLECOURSUSER . " SET
                            c_id     = '".Database :: escape_string($course_id). "',
                            user_id         = '".intval($user_id) . "',
                            status          = '1',
                            role            = '".Database::escape_string(get_lang('Professor')) . "',
                            tutor_id        = '0',
                            sort            = '". ($i_course_sort) . "',
                            user_course_cat = '0'";
                    Database::query($sql);
                }

                if (!empty($teachers)) {
                    if (!is_array($teachers)) {
                        $teachers = array($teachers);
                    }
                    foreach ($teachers as $key) {
                        //just in case
                        if ($key == $user_id) {
                            continue;
                        }
                        if (empty($key)) {
                            continue;
                        }
                        $sql = "INSERT INTO ".$TABLECOURSUSER . " SET
                            course_code     = '".Database::escape_string($code) . "',
                            user_id         = '".Database::escape_string($key) . "',
                            status          = '1',
                            role            = '',
                            tutor_id        = '0',
                            sort            = '". ($sort +1) . "',
                            user_course_cat = '0'";
                        Database::query($sql);
                    }
                }

                // Adding the course to an URL
                if (api_is_multiple_url_enabled()) {
                    $url_id = 1;
                    if (api_get_current_access_url_id() != -1) {
                        $url_id = api_get_current_access_url_id();
                    }
                    UrlManager::add_course_to_url($course_id, $url_id);
                } else {
                    UrlManager::add_course_to_url($course_id, 1);
                }

                // Add event to the system log.
                $user_id = api_get_user_id();
                event_system(LOG_COURSE_CREATE, LOG_COURSE_CODE, $code, api_get_utc_datetime(), $user_id, $code);

                $send_mail_to_admin = api_get_setting('send_email_to_admin_when_create_course');

                // @todo Improve code to send to all current portal administrators.
                if ($send_mail_to_admin == 'true') {
                    $siteName = api_get_setting('siteName');
                    $recipient_email = api_get_setting('emailAdministrator');
                    $recipient_name = api_get_person_name(api_get_setting('administratorName'), api_get_setting('administratorSurname'));
                    $iname = api_get_setting('Institution');
                    $subject = get_lang('NewCourseCreatedIn').' '.$siteName.' - '.$iname;
                    $message =  get_lang('Dear').' '.$recipient_name.",\n\n".get_lang('MessageOfNewCourseToAdmin').' '.$siteName.' - '.$iname."\n";
                    $message .= get_lang('CourseName').' '.$title."\n";
                    $message .= get_lang('Category').' '.$category_code."\n";
                    $message .= get_lang('Tutor').' '.$tutor_name."\n";
                    $message .= get_lang('Language').' '.$course_language;

                    @api_mail_html($recipient_name, $recipient_email, $subject, $message, $siteName, $recipient_email);
                }
            }
        }
        return $course_id;
    }


    /**
     * This function returns information about coachs from a course in session
     * @param int       - optional, session id
     * @param string    - optional, course code
     * @return array    - array containing user_id, lastname, firstname, username
     */
    public static function get_coaches_from_course($session_id=0, $courseId = null) {

        if (!empty($session_id)) {
            $session_id = intval($session_id);
        } else {
            $session_id = api_get_session_id();
        }

        if (!empty($courseId)) {
            $courseId = Database::escape_string($courseId);
        } else {
            $courseId = api_get_course_int_id();
        }

        $tbl_user                   = Database :: get_main_table(TABLE_MAIN_USER);
        $tbl_session_course_user    = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
        $coaches = array();

        $sql = "SELECT u.user_id,u.lastname,u.firstname,u.username
               FROM $tbl_user u,$tbl_session_course_user scu
                WHERE u.user_id = scu.id_user AND scu.id_session = '$session_id' AND scu.c_id = '$courseId' AND scu.status = 2";
        $rs = Database::query($sql);

        if (Database::num_rows($rs) > 0) {
            while ($row = Database::fetch_array($rs)) {
                $coaches[] = $row;
            }
            return $coaches;
        } else {
            return false;
        }
    }

    /**
     * @return a list (array) of all courses.
     * This function was originally in the Database class
     */
    public static function get_course_list()
    {
        $table = Database::get_main_table(TABLE_MAIN_COURSE);

        return Database::store_result(Database::query("SELECT *, id as real_id FROM $table"));
    }


    /**
     * Returns course code from a given gradebook category's id
     * @param int  Category ID
     * @return string  Course code
     */
    public static function get_course_by_category($category_id)
    {
        $category_id = intval($category_id);
        $info = Database::fetch_array(
            Database::query(
                'SELECT course_code FROM '.Database::get_main_table(TABLE_MAIN_GRADEBOOK_CATEGORY).' WHERE id='.$category_id
            ),
            'ASSOC'
        );

        return $info ? $info['course_code'] : false;
    }

    /**
     * @param $courseId
     * @return array
     */
    public static function getCourseSettings($courseId)
    {
        $settingTable = Database::get_course_table(TABLE_COURSE_SETTING);
        $courseId = intval($courseId);
        $sql = "SELECT * FROM $settingTable WHERE c_id = $courseId";
        $result = Database::query($sql);
        $settings = array();
        if (Database::num_rows($result)) {
            while ($row = Database::fetch_array($result, 'ASSOC')) {
                $settings[$row['variable']] = $row;
            }
        }
        return $settings;
    }


    function updateTeachers($course_code, $teachers)
    {
        if (empty($teachers)) {
            return false;
        }
        if (!is_array($teachers)) {
            $teachers = array($teachers);
        }

        $course_user_table  = Database::get_main_table(TABLE_MAIN_COURSE_USER);

        // Delete only teacher relations that doesn't match the selected teachers
        $cond = null;
        if (count($teachers)>0) {
            foreach($teachers as $key) {
                $cond.= " AND user_id <> '".$key."'";
            }
        }
        $sql = 'DELETE FROM '.$course_user_table.' WHERE course_code="'.Database::escape_string($course_code).'" AND status="1"'.$cond;
        Database::query($sql);

        if (count($teachers) > 0) {
            foreach ($teachers as $key) {

                //We check if the teacher is already subscribed in this course
                $sql_select_teacher = 'SELECT 1 FROM '.$course_user_table.' WHERE user_id = "'.$key.'" AND course_code = "'.$course_code.'" ';
                $result = Database::query($sql_select_teacher);

                if (Database::num_rows($result) == 1) {
                    $sql = 'UPDATE '.$course_user_table.' SET status = "1" WHERE course_code = "'.$course_code.'" AND user_id = "'.$key.'"  ';
                } else {
                    $sql = "INSERT INTO ".$course_user_table . " SET
                        course_code = '".Database::escape_string($course_code). "',
                        user_id = '".$key . "',
                        status = '1',
                        role = '',
                        tutor_id='0',
                        sort='0',
                        user_course_cat='0'";
                }
                Database::query($sql);
            }
        }
    }

} //end class CourseManager