'; print_r($list);
        return $list;
    }

    /**
     * Gets exercise results (NO Exercises in LPs) from a given exercise id, course, session
     * @param   int     exercise id
     * @param   string  course code
     * @param   int     session id
     * @return  array   with the results
     *
     */
    public static function get_exercise_results_by_attempt($exe_id, $status = null)
    {
        $table_track_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCISES);
        $table_track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
        $table_track_attempt_recording = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT_RECORDING);
        $exe_id = intval($exe_id);

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

        $sql = "SELECT * FROM $table_track_exercises
                WHERE status = '".$status."' AND exe_id = $exe_id";

        $res = Database::query($sql);
        $list = array();
        if (Database::num_rows($res)) {
            $row = Database::fetch_array($res, 'ASSOC');

            //Checking if this attempt was revised by a teacher
            $sql_revised = 'SELECT exe_id FROM '.$table_track_attempt_recording.'
                            WHERE author != "" AND exe_id = '.$exe_id.' LIMIT 1';
            $res_revised = Database::query($sql_revised);
            $row['attempt_revised'] = 0;
            if (Database::num_rows($res_revised) > 0) {
                $row['attempt_revised'] = 1;
            }
            $list[$exe_id] = $row;
            $sql = "SELECT * FROM $table_track_attempt
                    WHERE exe_id = $exe_id ORDER BY tms ASC";
            $res_question = Database::query($sql);
            while ($row_q = Database::fetch_array($res_question, 'ASSOC')) {
                $list[$exe_id]['question_list'][$row_q['question_id']] = $row_q;
            }
        }
        return $list;
    }

    /**
     * Gets exercise results (NO Exercises in LPs) from a given user, exercise id, course, session, lp_id, lp_item_id
     * @param   int     user id
     * @param   int     exercise id
     * @param   string  course code
     * @param   int     session id
     * @param   int     lp id
     * @param   int     lp item id
     * @param   string 	order asc or desc
     * @return  array   with the results
     *
     */
    public static function getExerciseResultsByUser($user_id, $exercise_id, $courseId, $session_id = 0, $lp_id = 0, $lp_item_id = 0, $order = null)
    {
        $table_track_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCISES);
        $table_track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
        $table_track_attempt_recording = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT_RECORDING);
        $courseId = intval($courseId);
        $exercise_id = intval($exercise_id);
        $session_id = intval($session_id);
        $user_id = intval($user_id);
        $lp_id = intval($lp_id);
        $lp_item_id = intval($lp_item_id);

        if (!in_array(strtolower($order), array('asc', 'desc'))) {
            $order = 'asc';
        }

        $sql = "SELECT * FROM $table_track_exercises
                WHERE
                    status 			= '' AND
                    exe_user_id 	= $user_id AND
                    c_id 	        = $courseId AND
                    exe_exo_id 		= $exercise_id AND
                    session_id 		= $session_id AND
                    orig_lp_id 		= $lp_id AND
                    orig_lp_item_id = $lp_item_id
                ORDER by exe_id $order ";

        $res = Database::query($sql);
        $list = array();
        while ($row = Database::fetch_array($res, 'ASSOC')) {
            //Checking if this attempt was revised by a teacher
            $sql = 'SELECT exe_id FROM '.$table_track_attempt_recording.'
                    WHERE author != "" AND exe_id = '.$row['exe_id'].'
                    LIMIT 1';
            $res_revised = Database::query($sql);
            $row['attempt_revised'] = 0;
            if (Database::num_rows($res_revised) > 0) {
                $row['attempt_revised'] = 1;
            }
            $list[$row['exe_id']] = $row;
            $sql = "SELECT * FROM $table_track_attempt
                    WHERE exe_id = {$row['exe_id']}";
            $res_question = Database::query($sql);
            while ($row_q = Database::fetch_array($res_question, 'ASSOC')) {
                $list[$row['exe_id']]['question_list'][$row_q['question_id']] = $row_q;
            }
        }
        return $list;
    }

    /**
     * Count exercise attempts (NO Exercises in LPs ) from a given exercise id, course, session
     * @param int $user_id
     * @param   int     exercise id
     * @param   int     $courseId
     * @param   int     session id
     * @return  array   with the results
     *
     */
    public static function count_exercise_attempts_by_user($user_id, $exercise_id, $courseId, $session_id = 0)
    {
        $TABLETRACK_EXERCICES = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCISES);
        $courseId = intval($courseId);
        $exercise_id = intval($exercise_id);
        $session_id = intval($session_id);
        $user_id = intval($user_id);

        $sql = "SELECT count(*) as count FROM $TABLETRACK_EXERCICES
                WHERE status = ''  AND
                    exe_user_id = '$user_id' AND
                    c_id = '$courseId' AND
                    exe_exo_id = '$exercise_id' AND
                    session_id = $session_id AND
                    orig_lp_id =0 AND
                    orig_lp_item_id = 0
                ORDER BY exe_id";
        $res = Database::query($sql);
        $result = 0;
        if (Database::num_rows($res) > 0) {
            $row = Database::fetch_array($res, 'ASSOC');
            $result = $row['count'];
        }

        return $result;
    }

    /**
     * Gets all exercise BEST results attempts (NO Exercises in LPs ) from a given exercise id, course, session per user
     * @param   int     $exercise_id
     * @param   int     $courseId
     * @param   int     $session_id
     * @return  array   with the results
     * @todo rename this function
     */
    public static function get_best_exercise_results_by_user($exercise_id, $courseId, $session_id = 0)
    {
        $table_track_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCISES);
        $table_track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
        $courseId = intval($courseId);
        $exercise_id = intval($exercise_id);
        $session_id = intval($session_id);

        $sql = "SELECT * FROM $table_track_exercises
                WHERE
                    status = '' AND
                    c_id = $courseId AND
                    exe_exo_id = '$exercise_id' AND
                    session_id = $session_id AND
                    orig_lp_id = 0 AND
                    orig_lp_item_id = 0
                ORDER BY exe_id";

        $res = Database::query($sql);
        $list = array();
        while ($row = Database::fetch_array($res, 'ASSOC')) {
            $list[$row['exe_id']] = $row;
            $sql = "SELECT * FROM $table_track_attempt WHERE exe_id = {$row['exe_id']}";
            $res_question = Database::query($sql);
            while ($row_q = Database::fetch_array($res_question, 'ASSOC')) {
                $list[$row['exe_id']]['question_list'][$row_q['question_id']] = $row_q;
            }
        }

        // Getting the best results of every student
        $best_score_return = array();
        foreach ($list as $student_result) {
            $user_id = $student_result['exe_user_id'];
            $current_best_score[$user_id] = $student_result['exe_result'];

            //echo $current_best_score[$user_id].' - '.$best_score_return[$user_id]['exe_result'].'
';
            if (!isset($best_score_return[$user_id]['exe_result'])) {
                $best_score_return[$user_id] = $student_result;
            }

            if ($current_best_score[$user_id] > $best_score_return[$user_id]['exe_result']) {
                $best_score_return[$user_id] = $student_result;
            }
        }

        return $best_score_return;
    }

    /**
     * @param int $user_id
     * @param int $exercise_id
     * @param int $courseId
     * @param int $session_id
     * @return array
     */
    public static function get_best_attempt_exercise_results_per_user($user_id, $exercise_id, $courseId, $session_id = 0)
    {
        $table_track_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCISES);
        $courseId = intval($courseId);
        $exercise_id = intval($exercise_id);
        $session_id = intval($session_id);
        $user_id = intval($user_id);

        $sql = "SELECT * FROM $table_track_exercises
                WHERE
                    status = ''  AND
                    c_id = '$courseId' AND
                    exe_exo_id = '$exercise_id' AND
                    session_id = $session_id  AND
                    exe_user_id = $user_id AND
                    orig_lp_id =0 AND
                    orig_lp_item_id = 0
                ORDER BY exe_id";

        $res = Database::query($sql);
        $list = array();
        while ($row = Database::fetch_array($res, 'ASSOC')) {
            $list[$row['exe_id']] = $row;  /*
              $sql = "SELECT * FROM $table_track_attempt WHERE exe_id = {$row['exe_id']}";
              $res_question = Database::query($sql);
              while($row_q = Database::fetch_array($res_question,'ASSOC')) {
              $list[$row['exe_id']]['question_list'][$row_q['question_id']] = $row_q;
              } */
        }
        //Getting the best results of every student
        $best_score_return = array();
        $best_score_return['exe_result'] = 0;

        foreach ($list as $result) {
            $current_best_score = $result;
            if ($current_best_score['exe_result'] > $best_score_return['exe_result']) {
                $best_score_return = $result;
            }
        }
        if (!isset($best_score_return['exe_weighting'])) {
            $best_score_return = array();
        }
        return $best_score_return;
    }

    /**
     * @param int $exercise_id
     * @param int $courseId
     * @param int $session_id
     * @return mixed
     */
    public static function count_exercise_result_not_validated($exercise_id, $courseId, $session_id = 0)
    {
        $table_track_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCISES);
        $table_track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT_RECORDING);
        $courseId = intval($courseId);
        $session_id = intval($session_id);
        $exercise_id = intval($exercise_id);

        $sql = "SELECT count(e.exe_id) as count
                FROM $table_track_exercises e
                LEFT JOIN $table_track_attempt a
                ON e.exe_id = a.exe_id
                WHERE
                    exe_exo_id = $exercise_id AND
                    c_id = '$courseId' AND
                    e.session_id = $session_id  AND
                    orig_lp_id = 0 AND
                    marks IS NULL AND
                    status = '' AND
                    orig_lp_item_id = 0
                ORDER BY e.exe_id";
        $res = Database::query($sql);
        $row = Database::fetch_array($res, 'ASSOC');

        return $row['count'];
    }

    /**
     * Gets all exercise BEST results attempts (NO Exercises in LPs ) from a given exercise id, course, session per user
     * @param   int     exercise id
     * @param   int   course id
     * @param   int     session id
     * @return  array   with the results
     *
     */
    public static function get_count_exercises_attempted_by_course($courseId, $session_id = 0)
    {
        $table_track_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCISES);
        $courseId = intval($courseId);
        $session_id = intval($session_id);

        $sql = "SELECT DISTINCT exe_exo_id, exe_user_id
                FROM $table_track_exercises
                WHERE
                    status = '' AND
                    c_id = '$courseId' AND
                    session_id = $session_id AND
                    orig_lp_id =0 AND
                    orig_lp_item_id = 0
                ORDER BY exe_id";
        $res = Database::query($sql);
        $count = 0;
        if (Database::num_rows($res) > 0) {
            $count = Database::num_rows($res);
        }
        return $count;
    }

    /**
     * Gets all exercise events from a Learning Path within a Course 	nd Session
     * @param	int		exercise id
     * @param	int	$courseId
     * @param 	int		session id
     * @return 	array
     */
    public static function get_all_exercise_event_from_lp($exercise_id, $courseId, $session_id = 0)
    {
        $table_track_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCISES);
        $table_track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
        $courseId = intval($courseId);
        $exercise_id = intval($exercise_id);
        $session_id = intval($session_id);

        $sql = "SELECT * FROM $table_track_exercises
                WHERE
                    status = '' AND
                    c_id = $courseId AND
                    exe_exo_id = '$exercise_id' AND
                    session_id = $session_id AND
                    orig_lp_id !=0 AND
                    orig_lp_item_id != 0";

        $res = Database::query($sql);
        $list = array();
        while ($row = Database::fetch_array($res, 'ASSOC')) {
            $list[$row['exe_id']] = $row;
            $sql = "SELECT * FROM $table_track_attempt WHERE exe_id = {$row['exe_id']}";
            $res_question = Database::query($sql);
            while ($row_q = Database::fetch_array($res_question, 'ASSOC')) {
                $list[$row['exe_id']]['question_list'][$row_q['question_id']] = $row_q;
            }
        }
        return $list;
    }

    /**
     * @param int $lp_id
     * @param int $course_id
     *
     * @return array
     */
    public static function get_all_exercises_from_lp($lp_id, $course_id)
    {
        $lp_item_table = Database :: get_course_table(TABLE_LP_ITEM);
        $course_id = intval($course_id);
        $lp_id = intval($lp_id);
        $sql = "SELECT * FROM $lp_item_table
                WHERE
                    c_id = $course_id AND
                    lp_id = '".$lp_id."' AND
                    item_type = 'quiz'
                ORDER BY parent_item_id, display_order";
        $res = Database::query($sql);

        $my_exercise_list = array();
        while ($row = Database::fetch_array($res, 'ASSOC')) {
            $my_exercise_list[] = $row;
        }

        return $my_exercise_list;
    }

    /**
     * This function gets the comments of an exercise
     *
     * @param int $id
     * @param int $question_id
     *
     * @return string the comment
     */
    public static function get_comments($exe_id, $question_id)
    {
        $table_track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
        $sql = "SELECT teacher_comment FROM ".$table_track_attempt."
                WHERE exe_id='".Database::escape_string($exe_id)."' AND question_id = '".Database::escape_string($question_id)."'
                ORDER by question_id";
        $sqlres = Database::query($sql);
        $comm = Database::result($sqlres, 0, "teacher_comment");
        return $comm;
    }

    /**
     * @param int $exe_id
     *
     * @return array
     */
    public static function getAllExerciseEventByExeId($exe_id)
    {
        $table_track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
        $exe_id = intval($exe_id);
        $list = array();

        $sql = "SELECT * FROM $table_track_attempt
                WHERE exe_id = $exe_id ORDER BY position";
        $res_question = Database::query($sql);
        if (Database::num_rows($res_question)) {
            while ($row = Database::fetch_array($res_question, 'ASSOC')) {
                $list[$row['question_id']][] = $row;
            }
        }
        return $list;
    }

    /**
     *
     * @param int $exe_id
     * @param int $user_id
     * @param int $courseId
     * @param int $session_id
     * @param int $question_id
     */
    public static function delete_attempt($exe_id, $user_id, $courseId, $session_id, $question_id)
    {
        $table_track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);

        $exe_id = intval($exe_id);
        $user_id = intval($user_id);
        $courseId = intval($courseId);
        $session_id = intval($session_id);
        $question_id = intval($question_id);

        $sql = "DELETE FROM $table_track_attempt
                WHERE
                    exe_id = $exe_id AND
                    user_id = $user_id AND
                    c_id = $courseId AND
                    session_id = $session_id AND
                    question_id = $question_id ";
        Database::query($sql);

        Event::addEvent(
            LOG_QUESTION_RESULT_DELETE,
            LOG_EXERCISE_ATTEMPT_QUESTION_ID,
            $exe_id . '-' . $question_id,
            null,
            null,
            $courseId,
            $session_id
        );
    }

    /**
     * @param $exe_id
     * @param $user_id
     * @param int $courseId
     * @param $question_id
     * @param int $sessionId
     */
    public static function delete_attempt_hotspot($exe_id, $user_id, $courseId, $question_id, $sessionId = null)
    {
        $table_track_attempt = Database::get_main_table(TABLE_STATISTIC_TRACK_E_HOTSPOT);

        $exe_id = intval($exe_id);
        $user_id = intval($user_id);
        $courseId = intval($courseId);
        $question_id = intval($question_id);
        if (!isset($sessionId)) {
            $sessionId = api_get_session_id();
        }

        $sql = "DELETE FROM $table_track_attempt
                WHERE   hotspot_exe_id = $exe_id AND
                        hotspot_user_id = $user_id AND
                        c_id = $courseId AND
                        hotspot_question_id = $question_id ";
        Database::query($sql);
        Event::addEvent(
            LOG_QUESTION_RESULT_DELETE,
            LOG_EXERCISE_ATTEMPT_QUESTION_ID,
            $exe_id . '-' . $question_id,
            null,
            null,
            $courseId,
            $sessionId
        );
    }

    /**
     * User logs in for the first time to a course
     * @param int $courseId
     * @param int $user_id
     * @param int $session_id
     */
    public static function event_course_login($courseId, $user_id, $session_id)
    {
        $course_tracking_table = Database::get_main_table(TABLE_STATISTIC_TRACK_E_COURSE_ACCESS);
        $time = api_get_datetime();

        $courseId = intval($courseId);
        $user_id = intval($user_id);
        $session_id = intval($session_id);

        $sql = "INSERT INTO $course_tracking_table(c_id, user_id, login_course_date, logout_course_date, counter, session_id)
                VALUES('".$courseId."', '".$user_id."', '$time', '$time', '1', '".$session_id."')";
        Database::query($sql);

        //Course catalog stats modifications see #4191
        CourseManager::update_course_ranking(null, null, null, null, true, false);
    }

    /**
     * For the sake of genericity, this function is a switch.
     * It's called by EventsDispatcher and fires the good function
     * with the good require_once.
     *
     * @param string $event_name
     * @param array $params
     */
    public static function event_send_mail($event_name, $params)
    {
        EventsMail::send_mail($event_name, $params);
    }

    /**
     * Internal function checking if the mail was already sent from that user to that user
     * @param string $event_name
     * @param int $user_from
     * @param int $user_to
     * @return boolean
     */
    public static function check_if_mail_already_sent($event_name, $user_from, $user_to = null)
    {
        if ($user_to == null) {
            $sql = 'SELECT COUNT(*) as total FROM '.Database::get_main_table(TABLE_EVENT_SENT).'
                    WHERE user_from = '.$user_from.' AND event_type_name = "'.$event_name.'"';
        } else {
            $sql = 'SELECT COUNT(*) as total FROM '.Database::get_main_table(TABLE_EVENT_SENT).'
                    WHERE user_from = '.$user_from.' AND user_to = '.$user_to.' AND event_type_name = "'.$event_name.'"';
        }
        $result = Database::store_result(Database::query($sql), 'ASSOC');
        return $result[0]["total"];
    }

    /**
     *
     * Filter EventEmailTemplate Filters see the main/inc/conf/events.conf.dist.php
     *
     */

    /**
     * Basic template event message filter (to be used by other filters as default)
     * @param array $values (passing by reference)
     * @return boolean True if everything is OK, false otherwise
     */
    function event_send_mail_filter_func(&$values)
    {
        return true;
    }

    /**
     * user_registration - send_mail filter
     * @param array $values (passing by reference)
     * @return boolean True if everything is OK, false otherwise
     */
    function user_registration_event_send_mail_filter_func(&$values)
    {
        $res = _event_send_mail_filter_func($values);
        // proper logic for this filter
        return $res;
    }

    /**
     * portal_homepage_edited - send_mail filter
     * @param array $values (passing by reference)
     * @return boolean True if everything is OK, false otherwise
     */
    function portal_homepage_edited_event_send_mail_filter_func(&$values)
    {
        $res = self::event_send_mail_filter_func($values);
        // proper logic for this filter
        return $res;
    }
}