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

<?php
/* See license terms in /license.txt */

/**
* EVENTS LIBRARY
*
* This is the events library for Chamilo.
* Include/require it in your code to use its functionality.
* Functions of this library are used to record informations when some kind
* of event occur. Each event has his own types of informations then each event
* use its own function.
*
* @package chamilo.library
*/

$TABLETRACK_LOGIN           = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_LOGIN);
$TABLETRACK_OPEN 		    = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_OPEN);
$TABLETRACK_ACCESS          = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ACCESS);
$course_tracking_table		= Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_COURSE_ACCESS);
$TABLETRACK_DOWNLOADS	    = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_DOWNLOADS);
$TABLETRACK_UPLOADS         = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_UPLOADS);
$TABLETRACK_LINKS 		    = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_LINKS);
$TABLETRACK_EXERCICES 	    = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
$TABLETRACK_LASTACCESS 	    = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_LASTACCESS); //for "what's new" notification
$TABLETRACK_DEFAULT         = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_DEFAULT);

/**
 * @author Sebastien Piraux <piraux_seb@hotmail.com>
 * @desc Record information for open event (when homepage is opened)
 */
function event_open()
{
    global $_configuration;
    global $TABLETRACK_OPEN;

    // @getHostByAddr($_SERVER['REMOTE_ADDR']) : will provide host and country information
    // $_SERVER['HTTP_USER_AGENT'] :  will provide browser and os information
    // $_SERVER['HTTP_REFERER'] : provide information about refering url
    if (isset($_SERVER['HTT_REFERER'])) {
        $referer = Database::escape_string($_SERVER['HTTP_REFERER']);
    } else {
        $referer = '';
    }
    // record informations only if user comes from another site
    //if(!eregi($_configuration['root_web'],$referer))
    $pos = strpos($referer, $_configuration['root_web']);
    if ($pos === false && $referer != '') {
        $ip = api_get_real_ip();
        $remhost = @ getHostByAddr($ip);
        if ($remhost == $ip)
        	$remhost = "Unknown"; // don't change this
        $reallyNow = api_get_utc_datetime();
        $sql = "INSERT INTO ".$TABLETRACK_OPEN."
        		(open_remote_host,
        		 open_agent,
        		 open_referer,
        		 open_date)
        		VALUES
        		('".$remhost."',
        		 '".Database::escape_string($_SERVER['HTTP_USER_AGENT'])."', '".Database::escape_string($referer)."', '$reallyNow')";
        $res = Database::query($sql);
    }
    return 1;
}

/**
 * @author Sebastien Piraux <piraux_seb@hotmail.com>
 * @desc Record information for login event
 * (when an user identifies himself with username & password)
 */
function event_login()
{
    global $TABLETRACK_LOGIN;
    global $_user;
    // @todo use api_get_user_info();
    //$userInfo = api_get_user_info();
    $userInfo = $_user;
    if (empty($userInfo)) {
        return false;
    }

    $userId = api_get_user_id();

    $reallyNow = api_get_utc_datetime();
    $sql = "INSERT INTO ".$TABLETRACK_LOGIN." (login_user_id, login_ip, login_date, logout_date) VALUES
            ('".$userId."',
            '".Database::escape_string(api_get_real_ip())."',
            '".$reallyNow."',
            '".$reallyNow."'
            )";
    Database::query($sql);

    // Auto subscribe
    $user_status = $userInfo['status']  == SESSIONADMIN ? 'sessionadmin' :
        $userInfo['status'] == COURSEMANAGER ? 'teacher' :
        $userInfo['status'] == DRH ? 'DRH' : 'student';
    $autoSubscribe = api_get_setting($user_status.'_autosubscribe');
    if ($autoSubscribe) {
        $autoSubscribe = explode('|', $autoSubscribe);
        foreach ($autoSubscribe as $code) {
            if (CourseManager::course_exists($code)) {
                CourseManager::subscribe_user($userId, $code);
            }
        }
    }
}

/**
 * @author Sebastien Piraux <piraux_seb@hotmail.com>
 * @desc Record information for access event for courses
 */
function event_access_course() {
    global $TABLETRACK_ACCESS, $TABLETRACK_LASTACCESS;

    $id_session = api_get_session_id();
    $now        = api_get_utc_datetime();
    $_cid       = api_get_course_id();
    $user_id    = api_get_user_id();

    if ($user_id) {
        $user_id = "'".$user_id."'";
    } else {
        $user_id = "0"; // no one
    }
    $sql = "INSERT INTO ".$TABLETRACK_ACCESS."  (access_user_id, access_cours_code, access_date, access_session_id) VALUES
            (".$user_id.", '".$_cid."', '".$now."','".$id_session."')";
    Database::query($sql);

    // added for "what's new" notification
    $sql = "UPDATE $TABLETRACK_LASTACCESS  SET access_date = '$now'
            WHERE access_user_id = $user_id AND access_cours_code = '$_cid' AND access_tool IS NULL AND access_session_id=".$id_session;
    Database::query($sql);

    if (Database::affected_rows() == 0) {
        $sql = "INSERT INTO $TABLETRACK_LASTACCESS (access_user_id, access_cours_code, access_date, access_session_id)
                VALUES (".$user_id.", '".$_cid."', '$now', '".$id_session."')";
        Database::query($sql);
    }
    // end "what's new" notification
    return 1;
}

/**
 * @param string $tool tool name of the tool (name in mainDb.accueil table)
 * @author Sebastien Piraux <piraux_seb@hotmail.com>
 * @desc Record information for access event for tools
 *
 *  $tool can take this values :
 *  Links, Calendar, Document, Announcements,
 *  Group, Video, Works, Users, Exercices, Course Desc
 *  ...
 *  Values can be added if new modules are created (15char max)
 *  I encourage to use $nameTool as $tool when calling this function
 *
 * 	Functionality for "what's new" notification is added by Toon Van Hoecke
 */
function event_access_tool($tool, $id_session = 0)
{
    global $_configuration;
    global $_cid;
    global $TABLETRACK_ACCESS;
    global $_course;
    global $TABLETRACK_LASTACCESS; //for "what's new" notification

    $id_session    = api_get_session_id();
    $tool          = Database::escape_string($tool);
    $reallyNow     = api_get_utc_datetime();
    $user_id       = api_get_user_id();
    // record information
    // only if user comes from the course $_cid
    //if( eregi($_configuration['root_web'].$_cid,$_SERVER['HTTP_REFERER'] ) )
    //$pos = strpos($_SERVER['HTTP_REFERER'],$_configuration['root_web'].$_cid);
    $coursePath = isset($_course['path']) ? $_course['path'] : null;

    $pos = isset($_SERVER['HTTP_REFERER']) ? strpos(strtolower($_SERVER['HTTP_REFERER']), strtolower(api_get_path(WEB_COURSE_PATH).$coursePath)) : false;
    // added for "what's new" notification
    $pos2 = isset($_SERVER['HTTP_REFERER']) ? strpos(strtolower($_SERVER['HTTP_REFERER']), strtolower($_configuration['root_web']."index")) : false;
    // end "what's new" notification
    if ($pos !== false || $pos2 !== false) {
        $sql = "INSERT INTO ".$TABLETRACK_ACCESS."
        			(access_user_id,
        			 access_cours_code,
        			 access_tool,
        			 access_date,
        			 access_session_id
        			 )
        		VALUES
        			(".$user_id.",".// Don't add ' ' around value, it's already done.
        			"'".$_cid."' ,
        			'".$tool."',
        			'".$reallyNow."',
        			'".$id_session."')";
        Database::query($sql);
    }
    // "what's new" notification
    $sql = "UPDATE $TABLETRACK_LASTACCESS
        	SET access_date = '$reallyNow'
        	WHERE access_user_id = ".$user_id." AND access_cours_code = '".$_cid."' AND access_tool = '".$tool."' AND access_session_id=".$id_session;
    Database::query($sql);
    if (Database::affected_rows() == 0) {
        $sql = "INSERT INTO $TABLETRACK_LASTACCESS (access_user_id,access_cours_code,access_tool, access_date, access_session_id)
        		VALUES (".$user_id.", '".$_cid."' , '$tool', '$reallyNow', $id_session)";
        Database::query($sql);
    }
    return 1;
}

/**
 * @param doc_id id of document (id in mainDb.document table)
 * @author Sebastien Piraux <piraux_seb@hotmail.com>
 * @desc Record information for download event
 * (when an user click to d/l a document)
 * it will be used in a redirection page
 * bug fixed: Roan Embrechts
 * Roan:
 * The user id is put in single quotes,
 * (why? perhaps to prevent sql insertion hacks?)
 * and later again.
 * Doing this twice causes an error, I remove one of them.
 */
function event_download($doc_url)
{
    $tbl_stats_downloads = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_DOWNLOADS);
    $doc_url = Database::escape_string($doc_url);

    $reallyNow = api_get_utc_datetime();
    $user_id = "'".api_get_user_id()."'";
    $_cid = api_get_course_id();

    $sql = "INSERT INTO $tbl_stats_downloads (
        		 down_user_id,
        		 down_cours_id,
        		 down_doc_path,
        		 down_date,
        		 down_session_id
        		)
        		VALUES (
        		 ".$user_id.",
        		 '".$_cid."',
        		 '".$doc_url."',
        		 '".$reallyNow."',
        		 '".api_get_session_id()."'
        		)";
    Database::query($sql);
    return 1;
}

/**
 * @param link_id (id in coursDb liens table)
 * @author Sebastien Piraux <piraux_seb@hotmail.com>
 * @desc Record information for link event (when an user click on an added link)
 * it will be used in a redirection page
*/
function event_link($link_id)
{
    global $TABLETRACK_LINKS;
    $reallyNow = api_get_utc_datetime();
    $user_id = api_get_user_id();
    $sql = "INSERT INTO ".$TABLETRACK_LINKS."
        		( links_user_id,
        		 links_cours_id,
        		 links_link_id,
        		 links_date,
        		 links_session_id
        		) VALUES (
        		 ".$user_id.",
        		 '".api_get_course_id()."',
        		 '".Database::escape_string($link_id)."',
        		 '".$reallyNow."',
        		 '".api_get_session_id()."'
        		)";
    Database::query($sql);
    return 1;
}

/**
 * Update the TRACK_E_EXERCICES exercises
 *
 * @param   int     exeid id of the attempt
 * @param   int     exo_id 	exercise id
 * @param   mixed   result 	score
 * @param   int     weighting ( higher score )
 * @param   int     duration ( duration of the attempt in seconds )
 * @param   int     session_id
 * @param   int     learnpath_id (id of the learnpath)
 * @param   int     learnpath_item_id (id of the learnpath_item)
 *
 * @author Sebastien Piraux <piraux_seb@hotmail.com>
 * @author Julio Montoya Armas <gugli100@gmail.com> Reworked 2010
 * @desc Record result of user when an exercice was done
*/
function update_event_exercice(
    $exeid,
    $exo_id,
    $score,
    $weighting,
    $session_id,
    $learnpath_id = 0,
    $learnpath_item_id = 0,
    $learnpath_item_view_id = 0,
    $duration = 0,
    $question_list = array(),
    $status = '',
    $remind_list = array(),
    $end_date = null
) {
    require_once api_get_path(SYS_CODE_PATH).'exercice/exercise.lib.php';
    global $debug;

    if ($debug) error_log('Called to update_event_exercice');
    if ($debug) error_log('duration:' . $duration);

    if ($exeid != '') {
        /*
         * Code commented due BT#8423 do not change the score to 0.
         *
         * Validation in case of fraud with actived control time
        if (!exercise_time_control_is_valid($exo_id, $learnpath_id, $learnpath_item_id)) {
        	$score = 0;
        }
        */
        if (!isset($status) || empty($status)) {
        	$status = '';
        } else {
        	$status = Database::escape_string($status);
        }

        $TABLETRACK_EXERCICES = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);

        if (!empty($question_list)) {
            $question_list = array_map('intval', $question_list);
        }

        if (!empty($remind_list)) {
        	$remind_list = array_map('intval', $remind_list);
        	$remind_list = array_filter($remind_list);
        	$remind_list = implode(",", $remind_list);
        } else {
        	$remind_list = '';
        }

        if (empty($end_date)) {
            $end_date = api_get_utc_datetime();
        }

        $sql = "UPDATE $TABLETRACK_EXERCICES SET
        		   exe_exo_id 			= '".Database::escape_string($exo_id)."',
        		   exe_result			= '".Database::escape_string($score)."',
        		   exe_weighting 		= '".Database::escape_string($weighting)."',
        		   session_id			= '".Database::escape_string($session_id)."',
        		   orig_lp_id 			= '".Database::escape_string($learnpath_id)."',
        		   orig_lp_item_id 		= '".Database::escape_string($learnpath_item_id)."',
                   orig_lp_item_view_id = '".Database::escape_string($learnpath_item_view_id)."',
        		   exe_duration 		= '".Database::escape_string($duration)."',
        		   exe_date				= '".$end_date."',
        		   status 				= '".$status."',
        		   questions_to_check 	= '".$remind_list."',
        		   data_tracking    	= '".implode(',', $question_list)."'
        		 WHERE exe_id = '".Database::escape_string($exeid)."'";
        $res = Database::query($sql);

        if ($debug) error_log('update_event_exercice called');
        if ($debug) error_log("$sql");

        //Deleting control time session track
        //exercise_time_control_delete($exo_id);
        return $res;
    } else {
        return false;
    }
}

/**
 * This function creates an empty Exercise in STATISTIC_TRACK_E_EXERCICES table.
 * After that in exercise_result.php we call the update_event_exercice() to update the exercise
 * @return $id the last id registered, or false on error
 * @author Julio Montoya <gugli100@gmail.com>
 * @desc Record result of user when an exercice was done
 * @deprecated this function seems to be deprecated
*/
function create_event_exercice($exo_id)
{
    if (empty($exo_id) or (intval($exo_id)!=$exo_id)) {
        return false;
    }
    $tbl_track_exe = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $tbl_exe = Database::get_course_table(TABLE_QUIZ_TEST);
    $uid = api_get_user_id();
    $course_id = api_get_course_int_id();

    // First, check the exercise exists
    $sql_exe_id="SELECT exercises.id FROM $tbl_exe as exercises WHERE c_id = $course_id AND exercises.id=$exo_id";
    $res_exe_id=Database::query($sql_exe_id);
    if ($res_exe_id === false) { return false; } //sql error
    if (Database::num_rows($res_exe_id)<1) { return false;} //exe not found
    $row_exe_id=Database::fetch_row($res_exe_id);
    $exercise_id = intval($row_exe_id[0]);
    // Second, check if the record exists in the database (looking for incomplete records)
    $sql = "SELECT exe_id FROM $tbl_track_exe WHERE exe_exo_id =   $exo_id AND " .
        		"exe_user_id =  $uid AND " .
        		"exe_cours_id = '".api_get_course_id()."' AND " .
        		"status = 'incomplete' AND ".
        		"session_id = ".api_get_session_id();
    $res = Database::query($sql);
    if ($res === false) {return false;}
    if (Database::num_rows($res) > 0) {
        $row = Database::fetch_array($res);
        return $row['exe_id'];
    }

    // No record was found, so create one
    // get expire time to insert into the tracking record
    require_once api_get_path(SYS_CODE_PATH).'exercice/exercise.lib.php';
    $current_expired_time_key = get_time_control_key($exercise_id);
    if (isset($_SESSION['expired_time'][$current_expired_time_key])) { //Only for exercice of type "One page"
        $expired_date = $_SESSION['expired_time'][$current_expired_time_key];
    } else {
        $expired_date = '0000-00-00 00:00:00';
    }
    $sql = "INSERT INTO $tbl_track_exe ( exe_user_id, exe_cours_id, expired_time_control, exe_exo_id, session_id)
        	VALUES (  $uid,  '".api_get_course_id()."' ,'$expired_date','$exo_id','".api_get_session_id()."')";
    Database::query($sql);
    $id= Database::insert_id();
    return $id;
}

/**
 * Record an event for this attempt at answering an exercise
 * @param	float	Score achieved
 * @param	string	Answer given
 * @param	integer	Question ID
 * @param	integer Exercise ID
 * @param	integer	Position
 * @return	boolean	Result of the insert query
 */
function exercise_attempt($score, $answer, $question_id, $exe_id, $position, $exercise_id = 0, $nano = null)
{
    require_once api_get_path(SYS_CODE_PATH).'exercice/exercise.lib.php';
    global $debug, $learnpath_id, $learnpath_item_id;
    $score          = Database::escape_string($score);
    $answer         = Database::escape_string($answer);
    $question_id    = Database::escape_string($question_id);
    $exe_id         = Database::escape_string($exe_id);
    $position 		= Database::escape_string($position);
    $now            = api_get_utc_datetime();
    $user_id        = api_get_user_id();

    $TBL_TRACK_ATTEMPT = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);

    if ($debug) error_log("----- entering exercise_attempt() function ------");
    if ($debug) error_log("answer: $answer");
    if ($debug) error_log("score: $score");
    if ($debug) error_log("question_id : $question_id");
    if ($debug) error_log("position: $position");

    //Validation in case of fraud with actived control time
    if (!exercise_time_control_is_valid($exercise_id, $learnpath_id, $learnpath_item_id)) {
        if ($debug) error_log("exercise_time_control_is_valid is false");
        /*$score = 0;
        $answer = 0;*/
    }

    if (!empty($user_id)) {
        $user_id = "'".$user_id."'";
    } else {
        // anonymous
        $user_id = api_get_anonymous_id();
    }

    $file = '';
    if (isset($nano)) {
        $file = Database::escape_string(basename($nano->load_filename_if_exists(false)));
    }

    $course_code = api_get_course_id();
    $session_id = api_get_session_id();

    if (!empty($question_id) && !empty($exe_id) && !empty($user_id)) {

        // Check if attempt exists
        $sql = "SELECT exe_id FROM $TBL_TRACK_ATTEMPT
                WHERE
                    course_code = '$course_code' AND
                    session_id = $session_id AND
                    exe_id = $exe_id AND
                    user_id = $user_id AND
                    question_id = $question_id AND
                    position = $position";
        $result = Database::query($sql);
        if (Database::num_rows($result)) {
            if ($debug) error_log("Attempt already exist: exe_id: $exe_id - user_id:$user_id - question_id:$question_id");
            //The attempt already exist do not update use  update_event_exercice() instead
            return false;
        }

        $sql = "INSERT INTO $TBL_TRACK_ATTEMPT (exe_id, user_id, question_id, answer, marks, course_code, session_id, position, tms, filename)
                  VALUES (
                  ".$exe_id.",
                  ".$user_id.",
                   '".$question_id."',
                   '".$answer."',
                   '".$score."',
                   '".$course_code."',
                   '".$session_id."',
                   '".$position."',
                   '".$now."',
                   '".$file."'
                )";

        if ($debug) error_log("Saving question attempt: ");
        if ($debug) error_log($sql);

        $res = Database::query($sql);
        if (defined('ENABLED_LIVE_EXERCISE_TRACKING')){
        	$recording_table = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT_RECORDING);
            if ($debug) error_log("Saving e attempt recording ");
        	$recording_changes = "INSERT INTO $recording_table (exe_id, question_id, marks, insert_date, author, session_id)
            VALUES ('$exe_id','$question_id','$score','".api_get_utc_datetime()."','', '".api_get_session_id()."') ";
        	Database::query($recording_changes);
        }
        return $res;
    } else {
        return false;
    }
}

/**
 * Record an hotspot spot for this attempt at answering an hotspot question
 * @param	int		Exercise ID
 * @param	int		Question ID
 * @param	int		Answer ID
 * @param	int		Whether this answer is correct (1) or not (0)
 * @param	string	Coordinates of this point (e.g. 123;324)
 * @return	boolean	Result of the insert query
 * @uses Course code and user_id from global scope $_cid and $_user
 */
function exercise_attempt_hotspot($exe_id, $question_id, $answer_id, $correct, $coords, $exerciseId = 0)
{
    require_once api_get_path(SYS_CODE_PATH).'exercice/exercise.lib.php';
    global $safe_lp_id, $safe_lp_item_id;
    //Validation in case of fraud  with actived control time
    if (!exercise_time_control_is_valid($exerciseId, $safe_lp_id, $safe_lp_item_id)) {
        //$correct = 0;
    }

    $tbl_track_e_hotspot = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_HOTSPOT);
    $sql = "INSERT INTO $tbl_track_e_hotspot (hotspot_user_id, hotspot_course_code, hotspot_exe_id, hotspot_question_id, hotspot_answer_id, hotspot_correct, hotspot_coordinate)".
        	" VALUES ('" . api_get_user_id() . "'," .
        	" '" . api_get_course_id() . "', " .
        	" '" . Database :: escape_string($exe_id) . "', " .
        	" '" . Database :: escape_string($question_id) . "'," .
        	" '" . Database :: escape_string($answer_id) . "'," .
        	" '" . Database :: escape_string($correct) . "'," .
        	" '" . Database :: escape_string($coords) . "')";
    return $result = Database::query($sql);
}

/**
 * Records information for common (or admin) events (in the track_e_default table)
 * @author Yannick Warnier <yannick.warnier@beeznest.com>
 * @param	string	Type of event
 * @param	string	Type of value
 * @param	string	Value
 * @param	string	Timestamp (defaults to null)
 * @param	integer	User ID (defaults to null)
 * @param	string	Course code (defaults to null)
 * @param	integer	Session ID (defaults to null - only stored from 1.10 onwards)
 * @assert ('','','') === false
 */
function event_system(
    $event_type,
    $event_value_type,
    $event_value,
    $datetime = null,
    $user_id = null,
    $course_code = null,
    $session_id = null
) {
    global $TABLETRACK_DEFAULT;
    if (empty($event_type)) {
        return false;
    }
    $event_type         = Database::escape_string($event_type);
    $event_value_type   = Database::escape_string($event_value_type);

    // Clean the user_info.
    if ($event_value_type == LOG_USER_OBJECT) {
        if (is_array($event_value)) {
            unset($event_value['complete_name']);
            unset($event_value['firstName']);
            unset($event_value['lastName']);
            unset($event_value['avatar_small']);
            unset($event_value['avatar']);
            unset($event_value['password']);
            unset($event_value['lastLogin']);
            unset($event_value['picture_uri']);
        }
    }

    if (in_array(
        $event_type,
        array(
            LOG_SESSION_ADD_USER_COURSE,
            LOG_SESSION_DELETE_USER_COURSE,
            LOG_SESSION_DELETE_USER,
            LOG_SESSION_ADD_COURSE,
            LOG_SESSION_DELETE_COURSE,
        )
    )
    ){
        $event_value = array(
            'user_id' => $event_value,
            'course_code' => $course_code,
            'session_id' => $session_id,
        );

        if (in_array($event_type, array(LOG_SESSION_ADD_COURSE, LOG_SESSION_DELETE_COURSE))) {
            $event_value['user_id'] = api_get_user_id();
        }
    }

    if (is_array($event_value)) {
        $event_value = serialize($event_value);
    }

    $event_value        = Database::escape_string($event_value);
    $course_info        = api_get_course_info($course_code);

    if (!empty($course_info)) {
        $course_id      = $course_info['real_id'];
        $course_code    = $course_info['code'];
        $course_code    = Database::escape_string($course_code);
    } else {
        $course_id = null;
        $course_code = null;
    }

    if (!isset($datetime)) {
        $datetime = api_get_utc_datetime();
    }

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

    if (!isset($user_id)) {
        $user_id = api_get_user_id();
    }

    $user_id = intval($user_id);

    $sql = "INSERT INTO $TABLETRACK_DEFAULT (default_user_id, default_cours_code, c_id, default_date, default_event_type, default_value_type, default_value)
            VALUES ('$user_id', '$course_code', '$course_id', '$datetime', '$event_type', '$event_value_type', '$event_value')";
    Database::query($sql);
    return true;
}

/**
 * Get every email stored in the database
 *
 * @param int $etId
 * @return array
 * @assert () !== false
 */
function get_all_event_types() {
    global $event_config;

    $sql = 'SELECT etm.id, event_type_name, activated, language_id, message, subject, dokeos_folder
            FROM '.Database::get_main_table(TABLE_EVENT_EMAIL_TEMPLATE).' etm
            INNER JOIN '.Database::get_main_table(TABLE_MAIN_LANGUAGE).' l
            ON etm.language_id = l.id';

    $events_types = Database::store_result(Database::query($sql), 'ASSOC');

    $to_return = array();
    foreach ($events_types as $et) {
        $et['nameLangVar'] = $event_config[$et["event_type_name"]]["name_lang_var"];
        $et['descLangVar'] = $event_config[$et["event_type_name"]]["desc_lang_var"];
        $to_return[] = $et;
    }
    return $to_return;
}

/**
 * Get users linked to an event
 *
 * @param string $event_name
 *
 * @return string
 */
function get_users_subscribed_to_event($event_name) {
    $event_name = Database::escape_string($event_name);
    $sql = 'SELECT u.*
            FROM '.Database::get_main_table(TABLE_MAIN_USER).' u,'
                  .Database::get_main_table(TABLE_MAIN_EVENT_TYPE).' e,'
                  .Database::get_main_table(TABLE_EVENT_TYPE_REL_USER).' ue
        	WHERE ue.user_id = u.user_id
        	AND e.name = "'.$event_name.'"
        	AND e.id = ue.event_type_id';
    $return = Database::store_result(Database::query($sql),'ASSOC');
    return json_encode($return);
}

/**
 * Get the users related to one event
 *
 * @param string $event_name
 */
function get_event_users($event_name)
{
    $event_name = Database::escape_string($event_name);
    $sql = 'SELECT user.user_id,  user.firstname, user.lastname
            FROM '.Database::get_main_table(TABLE_MAIN_USER).' user
            JOIN '.Database::get_main_table(TABLE_EVENT_TYPE_REL_USER).' relUser
            ON relUser.user_id = user.user_id
            WHERE user.status <> '.ANONYMOUS.' AND relUser.event_type_name = "'.$event_name.'"';
    $user_list = Database::store_result(Database::query($sql), 'ASSOC');
    return json_encode($user_list);
}

/**
 * @param int $user_id
 * @param string $event_type
 * @return array|bool
 */
function get_events_by_user_and_type($user_id, $event_type) {
    global $TABLETRACK_DEFAULT;
    $user_id = intval($user_id);
    $event_type = Database::escape_string($event_type);

    $sql = "SELECT * FROM $TABLETRACK_DEFAULT
            WHERE default_value_type = 'user_id' AND
                  default_value = $user_id AND
                  default_event_type = '$event_type'
            ORDER BY default_date ";
    $result = Database::query($sql);
    if ($result) {
        return Database::store_result($result, 'ASSOC');
    }
    return false;
}

/**
 * @param int $user_id
 * @param string $event_type
 * @return mixed
 */
function get_latest_event_by_user_and_type($user_id, $event_type) {
    $result = get_events_by_user_and_type($user_id, $event_type);
    if ($result && !empty($result)) {
        return $result[0];
    }
}

/**
 * Save the new message for one event and for one language
 *
 * @param string $eventName
 * @param array $users
 * @param string $message
 * @param string $subject
 * @param string $eventMessageLanguage
 * @param int $activated
 */
function save_event_type_message($event_name, $users, $message, $subject, $event_message_language, $activated)
{
    $event_name = Database::escape_string($event_name);
    $activated = intval($activated);
    $event_message_language = Database::escape_string($event_message_language);

    // Deletes then re-adds the users linked to the event
    $sql = 'DELETE FROM '.Database::get_main_table(TABLE_EVENT_TYPE_REL_USER).' WHERE event_type_name = "'.$event_name.'"	';
    Database::query($sql);

    foreach ($users as $user) {
        $sql = 'INSERT INTO '.Database::get_main_table(TABLE_EVENT_TYPE_REL_USER).' (user_id,event_type_name) VALUES('.intval($user).',"'.  $event_name.'")';
        Database::query($sql);
    }
    $language_id = api_get_language_id($event_message_language);
    // check if this template in this language already exists or not
    $sql = 'SELECT COUNT(id) as total FROM '.Database::get_main_table(TABLE_EVENT_EMAIL_TEMPLATE).'
            WHERE event_type_name = "'.$event_name.'" AND language_id = '.$language_id;

    $sql = Database::store_result(Database::query($sql),'ASSOC');

    // if already exists, we update
    if ($sql[0]["total"] > 0) {
        $sql = 'UPDATE '.Database::get_main_table(TABLE_EVENT_EMAIL_TEMPLATE).'
            SET message = "'.Database::escape_string($message).'",
            subject = "'.Database::escape_string($subject).'",
            activated = '.$activated.'
            WHERE event_type_name = "'.$event_name.'" AND language_id = (SELECT id FROM '.Database::get_main_table(TABLE_MAIN_LANGUAGE).'
                WHERE dokeos_folder = "'.$event_message_language.'")';
        Database::query($sql);
    } else { // else we create a new record
        // gets the language_-_id
        $lang_id = '(SELECT id FROM '.Database::get_main_table(TABLE_MAIN_LANGUAGE).'
                    WHERE dokeos_folder = "'.$event_message_language.'")';
        $lang_id = Database::store_result(Database::query($lang_id),'ASSOC');

        if (!empty($lang_id[0]["id"])) {
            $sql = 'INSERT INTO '.Database::get_main_table(TABLE_EVENT_EMAIL_TEMPLATE).' (event_type_name, language_id, message, subject, activated)
                VALUES("'.$event_name.'", '.$lang_id[0]["id"].', "'.Database::escape_string($message).'", "'.Database::escape_string($subject).'", '.$activated.')';
            Database::query($sql);
        }
    }

    // set activated at every save
    $sql = 'UPDATE '.Database::get_main_table(TABLE_EVENT_EMAIL_TEMPLATE).'
                SET activated = '.$activated.'
            WHERE event_type_name = "'.$event_name.'"';
    Database::query($sql);
}

/**
 * @param $etId
 * @param $users
 * @param $message
 * @param $subject
 */
function eventType_mod($etId, $users, $message, $subject) {
    $etId = intval($etId);

    $sql = 'DELETE FROM '.Database::get_main_table(TABLE_EVENT_TYPE_REL_USER).' WHERE event_type_id = '.$etId.'	';
    Database::query($sql);

    foreach ($users as $user) {
        $sql = 'INSERT INTO '.Database::get_main_table(TABLE_EVENT_TYPE_REL_USER).' (user_id,event_type_id)
            VALUES('.intval($user).','.$etId.') ';
        Database::query($sql);
    }

    $sql = 'UPDATE '.Database::get_main_table(TABLE_MAIN_EVENT_TYPE_MESSAGE).'
            SET message = "'.Database::escape_string($message).'",
                subject = "'.Database::escape_string($subject).'"
                WHERE event_type_id = '.$etId.'';
    Database::query($sql);
}

/**
 * Gets the last attempt of an exercise based in the exe_id
 *
 * @param $exe_id
 * @return mixed
 */
function get_last_attempt_date_of_exercise($exe_id)
{
    $exe_id = intval($exe_id);
    $track_attempts = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
    $sql = 'SELECT max(tms) as last_attempt_date FROM '.$track_attempts.'
            WHERE exe_id='.$exe_id;
    $rs_last_attempt 		= Database::query($sql);
    $row_last_attempt 		= Database::fetch_array($rs_last_attempt);
    //Get the date of last attempt
    $last_attempt_date 		= $row_last_attempt['last_attempt_date'];
    return $last_attempt_date;
}

/**
 * Gets how many attempts exists by user, exercise, learning path
 * @param   int user id
 * @param   int exercise id
 * @param   int lp id
 * @param   int lp item id
 * @param   int lp item view id
 */
function get_attempt_count($user_id, $exerciseId, $lp_id, $lp_item_id,$lp_item_view_id) {
    $stat_table 	= Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $user_id 		= intval($user_id);
    $exerciseId 	= intval($exerciseId);
    $lp_id 			= intval($lp_id);
    $lp_item_id 	= intval($lp_item_id);
    $lp_item_view_id= intval($lp_item_view_id);

    $sql = "SELECT count(*) as count FROM $stat_table WHERE
        		exe_exo_id 				= $exerciseId AND
        		exe_user_id 			= $user_id AND
        		status 			   	   != 'incomplete' AND
        		orig_lp_id 				= $lp_id AND
        		orig_lp_item_id 		= $lp_item_id AND
        		orig_lp_item_view_id 	= $lp_item_view_id AND
        		exe_cours_id 			= '".api_get_course_id()."' AND
        		session_id 				= '" . api_get_session_id() . "'";

    $query = Database::query($sql);
    if (Database::num_rows($query) > 0 ) {
        $attempt = Database :: fetch_array($query,'ASSOC');
        return $attempt['count'];
    } else {
        return 0;
    }
}

/**
 * @param int $user_id
 * @param int $exerciseId
 * @param int $lp_id
 * @param int $lp_item_id
 * @return int
 */
function get_attempt_count_not_finished($user_id, $exerciseId, $lp_id, $lp_item_id)
{
    $stat_table 	= Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $user_id 		= intval($user_id);
    $exerciseId 	= intval($exerciseId);
    $lp_id 			= intval($lp_id);
    $lp_item_id 	= intval($lp_item_id);
    //$lp_item_view_id= intval($lp_item_view_id);

    $sql = "SELECT count(*) as count FROM $stat_table WHERE
        		exe_exo_id 			= $exerciseId AND
        		exe_user_id 		= $user_id AND
        		status 				!= 'incomplete' AND
        		orig_lp_id 			= $lp_id AND
        		orig_lp_item_id 	= $lp_item_id AND
        		exe_cours_id = '".api_get_course_id()."' AND
        		session_id = '" . api_get_session_id() . "'";

    $query = Database::query($sql);
    if (Database::num_rows($query) > 0 ) {
        $attempt = Database :: fetch_array($query,'ASSOC');
        return $attempt['count'];
    } else {
        return 0;
    }
}

/**
 * Deletes a learning path view for a student
 * @param int $user_id
 * @param int $lp_id
 * @param array $course
 * @param int $session_id
 */
function delete_student_lp_events($user_id, $lp_id, $course, $session_id)
{
    $lp_view_table = Database::get_course_table(TABLE_LP_VIEW);
    $lp_item_view_table = Database::get_course_table(TABLE_LP_ITEM_VIEW);
    $lpInteraction = Database::get_course_table(TABLE_LP_IV_INTERACTION);
    $lpObjective = Database::get_course_table(TABLE_LP_IV_OBJECTIVE);

    $course_id = $course['real_id'];

    if (empty($course_id)) {
        $course_id = api_get_course_int_id();
    }

    $track_e_exercises = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $track_attempts = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
    $recording_table = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT_RECORDING);
    $user_id = intval($user_id);
    $lp_id = intval($lp_id);
    $session_id = intval($session_id);

    //Make sure we have the exact lp_view_id
    $sql = "SELECT id FROM $lp_view_table
            WHERE
                c_id = $course_id AND
                user_id = $user_id AND
                lp_id = $lp_id AND
                session_id = $session_id ";
    $result = Database::query($sql);

    if (Database::num_rows($result)) {
        $view = Database::fetch_array($result, 'ASSOC');
        $lp_view_id = $view['id'];
        $sql = "DELETE FROM $lp_item_view_table
                WHERE c_id = $course_id AND lp_view_id = $lp_view_id ";
        Database::query($sql);

        $sql = "DELETE FROM $lpInteraction
                WHERE c_id = $course_id AND lp_iv_id = $lp_view_id ";
        Database::query($sql);

        $sql = "DELETE FROM $lpObjective
                WHERE c_id = $course_id AND lp_iv_id = $lp_view_id ";
        Database::query($sql);
    }

    $sql = "DELETE FROM $lp_view_table
            WHERE
                c_id = $course_id AND
                user_id = $user_id AND
                lp_id= $lp_id AND
                session_id = $session_id
            ";
    Database::query($sql);

    $sql = "SELECT exe_id FROM $track_e_exercises
            WHERE
                exe_user_id = $user_id AND
                session_id = $session_id AND
                exe_cours_id = '{$course['code']}' AND
                orig_lp_id = $lp_id
            ";

    $result = Database::query($sql);
    $exe_list = array();
    while ($row = Database::fetch_array($result, 'ASSOC')) {
        $exe_list[] = $row['exe_id'];
    }

    if (!empty($exe_list) && is_array($exe_list) && count($exe_list) > 0) {
        $sql = "DELETE FROM $track_e_exercises WHERE exe_id IN (".implode(',',$exe_list).")";
        Database::query($sql);

        $sql = "DELETE FROM $track_attempts WHERE exe_id IN (".implode(',',$exe_list).")";
        Database::query($sql);

        $sql = "DELETE FROM $recording_table WHERE exe_id IN (".implode(',',$exe_list).")";
        Database::query($sql);
    }
    event_system(
        LOG_LP_ATTEMPT_DELETE,
        LOG_LP_ID,
        $lp_id,
        null,
        null,
        $course['code'],
        $session_id
    );
}

/**
 * Delete all exercise attempts (included in LP or not)
 *
 * @param 	int		user id
 * @param 	int		exercise id
 * @param 	string	course code
 * @param 	int		session id
  */
function delete_all_incomplete_attempts($user_id, $exercise_id, $course_code, $session_id = 0)
{
    $track_e_exercises    = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $user_id              = intval($user_id);
    $exercise_id          = intval($exercise_id);
    $course_code          = Database::escape_string($course_code);
    $session_id           = intval($session_id);
    if (!empty($user_id) && !empty($exercise_id) && !empty($course_code)) {
        $sql = "DELETE FROM $track_e_exercises
                WHERE exe_user_id = $user_id AND exe_exo_id = $exercise_id AND exe_cours_id = '$course_code' AND session_id = $session_id AND status = 'incomplete' ";
        Database::query($sql);
    }
    event_system(LOG_EXERCISE_RESULT_DELETE, LOG_EXERCISE_AND_USER_ID, $exercise_id.'-'.$user_id, null, null, $course_code, $session_id);
}

/**
 * Gets all 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
 */
function get_all_exercise_results($exercise_id, $course_code, $session_id = 0, $load_question_list = true, $user_id = null) {
    $TABLETRACK_EXERCICES  = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $TBL_TRACK_ATTEMPT     = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
    $course_code           = Database::escape_string($course_code);
    $exercise_id           = intval($exercise_id);
    $session_id            = intval($session_id);

    $user_condition =  null;
    if (!empty($user_id)) {
        $user_id = intval($user_id);
        $user_condition  = "AND exe_user_id = $user_id ";
    }
    $sql = "SELECT * FROM $TABLETRACK_EXERCICES
            WHERE
                status = ''  AND
                exe_cours_id = '$course_code' AND
                exe_exo_id = '$exercise_id' AND
                session_id = $session_id  AND
                orig_lp_id =0 AND
                orig_lp_item_id = 0
                $user_condition
            ORDER BY exe_id";
    $res = Database::query($sql);
    $list = array();
    while($row = Database::fetch_array($res,'ASSOC')) {
        $list[$row['exe_id']] = $row;
        if ($load_question_list) {
        	$sql = "SELECT * FROM $TBL_TRACK_ATTEMPT WHERE exe_id = {$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;
}

/**
 * Gets all exercise results (NO Exercises in LPs ) from a given exercise id, course, session
 * @param   string  course code
 * @param   int     session id
 * @return  array   with the results
 *
 */
function get_all_exercise_results_by_course($course_code, $session_id = 0, $get_count = true)
{
    $table_track_exercises = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $table_track_attempt   = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
    $course_code           = Database::escape_string($course_code);

    $session_id = intval($session_id);
    $select = '*';
    if ($get_count) {
        $select = 'count(*) as count';
    }
    $sql = "SELECT $select FROM $table_track_exercises
            WHERE status = ''  AND exe_cours_id = '$course_code' AND session_id = $session_id  AND orig_lp_id = 0 AND orig_lp_item_id = 0
            ORDER BY exe_id";
    $res = Database::query($sql);
    if ($get_count) {
        $row = Database::fetch_array($res,'ASSOC');
        return $row['count'];
    } else {
        $list = array();
        while($row = Database::fetch_array($res,'ASSOC')) {
        	$list[$row['exe_id']] = $row;
        }
        return $list;
    }
}

/**
* Gets all 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
*
*/
function get_all_exercise_results_by_user($user_id,  $course_code, $session_id = 0)
{
    $table_track_exercises = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $table_track_attempt   = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
    $course_code = Database::escape_string($course_code);
    //$exercise_id = intval($exercise_id);
    $session_id = intval($session_id);
    $user_id    = intval($user_id);

    $sql = "SELECT * FROM $table_track_exercises
            WHERE
              status = '' AND
              exe_user_id = $user_id AND
              exe_cours_id = '$course_code' 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;
        }
    }
    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
*
*/
function get_exercise_results_by_attempt($exe_id)
{
    $table_track_exercises = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $table_track_attempt   = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
    $table_track_attempt_recording  = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT_RECORDING);
    $exe_id = intval($exe_id);

    $sql = "SELECT * FROM $table_track_exercises WHERE 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']] = $row_q;
        }
    }
    // echo '<pre>'; print_r($list); echo "</pre>";
    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
 *
 */
function get_exercise_results_by_user(
    $user_id,
    $exercise_id,
    $course_code,
    $session_id = 0,
    $lp_id = 0,
    $lp_item_id = 0,
    $order = null
) {
    $table_track_exercises = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $table_track_attempt   = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
    $table_track_attempt_recording   = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT_RECORDING);
    $course_code 	= Database::escape_string($course_code);
    $exercise_id 	= intval($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 	= $user_id AND
        			exe_cours_id 	= '$course_code' 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_revised = 'SELECT exe_id FROM ' . $table_track_attempt_recording . '
                        WHERE author != "" AND exe_id = '.$row['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;
        }
        $list[$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     exercise id
 * @param   string  course code
 * @param   int     session id
 * @return  array   with the results
 *
 */
function count_exercise_attempts_by_user($user_id, $exercise_id, $course_code, $session_id = 0)
{
    $TABLETRACK_EXERCICES  = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $course_code           = Database::escape_string($course_code);
    $exercise_id           = intval($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 exe_cours_id = '$course_code' AND exe_exo_id = '$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   string  course code
 * @param   int     session id
 * @return  array   with the results
 * @todo rename this function
 *
 */
function get_best_exercise_results_by_user($exercise_id, $course_code, $session_id = 0)
{
    $table_track_exercises = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $table_track_attempt   = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
    $course_code           = Database::escape_string($course_code);
    $exercise_id           = intval($exercise_id);
    $session_id            = intval($session_id);

    $sql = "SELECT * FROM $table_track_exercises
            WHERE status = ''  AND exe_cours_id = '$course_code' 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'].'<br />';
        if (isset($current_best_score[$user_id]) &&
            isset($best_score_return[$user_id]['exe_result']) &&
            $current_best_score[$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 string $course_code
 * @param int $session_id
 * @return array
 */
function get_best_attempt_exercise_results_per_user($user_id, $exercise_id, $course_code, $session_id = 0)
{
    $table_track_exercises = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $course_code           = Database::escape_string($course_code);
    $exercise_id           = intval($exercise_id);
    $session_id            = intval($session_id);
    $user_id               = intval($user_id);

    $sql = "SELECT * FROM $table_track_exercises
            WHERE
                status = ''  AND
                exe_cours_id = '$course_code' 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;
    }
    //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 string $course_code
 * @param int $session_id
 * @return mixed
 */
function count_exercise_result_not_validated($exercise_id, $course_code, $session_id = 0)
{
    $table_track_exercises = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $table_track_attempt   = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT_RECORDING);
    $course_code           = Database::escape_string($course_code);
    $session_id     = intval($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 = $exercise_id AND
                    exe_cours_id = '$course_code' 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   string  course code
 * @param   int     session id
 * @return  array   with the results
 *
 */
function get_count_exercises_attempted_by_course($course_code, $session_id = 0)
{
    $table_track_exercises = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $course_code           = Database::escape_string($course_code);
    $session_id            = intval($session_id);

    $sql = "SELECT DISTINCT exe_exo_id, exe_user_id
            FROM $table_track_exercises
            WHERE status = '' AND exe_cours_id = '$course_code' 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	string	course_code
 * @param 	int		session id
 * @return 	array
 */
function get_all_exercise_event_from_lp($exercise_id, $course_code, $session_id = 0)
{
    $table_track_exercises = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
    $table_track_attempt   = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
    $course_code = Database::escape_string($course_code);
    $exercise_id = intval($exercise_id);
    $session_id = intval($session_id);

    $sql = "SELECT * FROM $table_track_exercises
            WHERE status = '' AND exe_cours_id = '$course_code' 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 $course_id
 * @return array
 */
function get_all_exercises_from_lp($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."'
            ORDER BY parent_item_id, display_order";
    $res = Database::query($sql);
    $my_exercise_list = array();
    while($row = Database::fetch_array($res,'ASSOC')) {
        if ($row['item_type'] == 'quiz') {
        	$my_exercise_list[] = $row;
        }
    }
    return $my_exercise_list;
}

/**
 * This function gets the comments of an exercise
 *
 * @param int $id
 * @param int $question_id
 * @return string the comment
 */
function get_comments($exe_id, $question_id)
{
    $table_track_attempt = Database::get_statistic_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 $exe_id
 * @return array
 */
function get_all_exercise_event_by_exe_id($exe_id)
{
    $table_track_attempt   = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
    $exe_id = intval($exe_id);
    $sql = "SELECT * FROM $table_track_attempt
            WHERE exe_id = $exe_id
            ORDER BY position";
    $res_question = Database::query($sql);
    $list = array();
    if (Database::num_rows($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 string $course_code
 * @param int $session_id
 * @param int $question_id
 */
function delete_attempt($exe_id, $user_id, $course_code, $session_id, $question_id)
{
    $table_track_attempt   = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);

    $exe_id          = intval($exe_id);
    $user_id         = intval($user_id);
    $course_code     = Database::escape_string($course_code);
    $session_id      = intval($session_id);
    $question_id     = intval($question_id);

    $sql = "DELETE FROM $table_track_attempt
            WHERE exe_id = $exe_id AND user_id = $user_id AND course_code = '$course_code' AND session_id = $session_id AND question_id = $question_id ";
    Database::query($sql);
    event_system(
        LOG_QUESTION_RESULT_DELETE,
        LOG_EXERCISE_ATTEMPT_QUESTION_ID,
        $exe_id . '-' . $question_id,
        null,
        null,
        $course_code,
        $session_id
    );
}

/**
 * @param int $exe_id
 * @param int $user_id
 * @param string $course_code
 * @param int $question_id
 * @todo add session_id for 10
 */
function delete_attempt_hotspot($exe_id, $user_id, $course_code, $session_id = 0, $question_id) {
    $table_track_attempt   = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_HOTSPOT);

    $exe_id          = intval($exe_id);
    $user_id         = intval($user_id);
    $course_code     = Database::escape_string($course_code);
    $session_id      = intval($session_id);
    $question_id     = intval($question_id);

    $sql = "DELETE FROM $table_track_attempt
            WHERE hotspot_exe_id = $exe_id AND hotspot_user_id = $user_id AND hotspot_course_code = '$course_code' AND hotspot_question_id = $question_id ";
    Database::query($sql);
    event_system(
        LOG_QUESTION_RESULT_DELETE,
        LOG_EXERCISE_ATTEMPT_QUESTION_ID,
        $exe_id . '-' . $question_id,
        null,
        null,
        $course_code,
        $session_id
    );
}

/**
 * User logs in for the first time to a course
 * @param string $course_code
 * @param int $user_id
 * @param int $session_id
 */
function event_course_login($course_code, $user_id, $session_id)
{
    $course_tracking_table = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_COURSE_ACCESS);

    //@todo use api_get_utc_datetime
    $time = api_get_utc_datetime();

    $course_code = Database::escape_string($course_code);
    $user_id	 = intval($user_id);
    $session_id  = intval($session_id);
    $session_lifetime = 3600;

    //We select the last record for the current course in the course tracking table
    $sql = "SELECT course_access_id
            FROM $course_tracking_table
            WHERE
                user_id     = $user_id AND
                course_code = '$course_code' AND
                session_id  = $session_id AND
                login_course_date > '$time' - INTERVAL $session_lifetime SECOND
            ORDER BY login_course_date DESC LIMIT 0,1";
    $result = Database::query($sql);

    if (Database::num_rows($result) > 0) {
        $i_course_access_id = Database::result($result,0,0);
        //We update the course tracking table
        $sql = "UPDATE $course_tracking_table  SET logout_course_date = '$time', counter = counter+1
            WHERE course_access_id = ".intval($i_course_access_id)." AND session_id = ".$session_id;
        Database::query($sql);
    } else {
        $sql="INSERT INTO $course_tracking_table (course_code, user_id, login_course_date, logout_course_date, counter, session_id)" .
            "VALUES('".$course_code."', '".$user_id."', '$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 $params
 */
function event_send_mail($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 $user_to
 * @return boolean
 */
function check_if_mail_already_sent($event_name, $user_from, $user_to = null) {
    $event_name = Database::escape_string($event_name);
    $user_to = intval($user_to);
    $user_from = intval($user_from);
    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) {
    $res = _event_send_mail_filter_func($values);
    // proper logic for this filter
    return $res;
}

/*  End of filters   */



/**
 * Gets the last attempt of an exercise based in the exe_id
 * @param int $exe_id
 * @return mixed
 */
function getLatestQuestionIdFromAttempt($exe_id)
{
    $exe_id = intval($exe_id);
    $track_attempts = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
    $sql = 'SELECT question_id FROM '.$track_attempts.'
            WHERE exe_id='.$exe_id.'
            ORDER BY tms DESC
            LIMIT 1';
    $result = Database::query($sql);
    if (Database::num_rows($result)) {
        $row = Database::fetch_array($result);
        return $row['question_id'];
    } else {
        return false;
    }
}