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

<?php
/* For licensing terms, see /license.txt */
/**
 *    This is the tracking library for Chamilo
 *    Include/require it in your code to use its functionality.
 *
 *    @package chamilo.library
 *    @author Julio Montoya <gugli100@gmail.com> (Score average fixes)
 */
/**
 * Code
 */
define('SESSION_LINK_TARGET','_self');

require_once api_get_path(SYS_CODE_PATH).'exercice/exercise.lib.php';
//require_once api_get_path(SYS_CODE_PATH).'exercice/exercise.class.php'; moved to autoload
require_once api_get_path(SYS_CODE_PATH).'newscorm/learnpathList.class.php';

/**
 * Class
 * @package chamilo.library
 */
class Tracking
{
    /**
     * @param int $userId
     *
     * @return array
     */
    public static function getStats($userId)
    {
        if (api_is_drh() && api_drh_can_access_all_session_content()) {
            $studentList = SessionManager::getAllUsersFromCoursesFromAllSessionFromStatus(
                'drh_all',
                $userId,
                false,
                null,
                null,
                null,
                null,
                null,
                null,
                null,
                array(),
                array(),
                STUDENT
            );
            $students = array();
            foreach ($studentList as $studentData) {
                $students[] = $studentData['user_id'];
            }

            $teacherList = SessionManager::getAllUsersFromCoursesFromAllSessionFromStatus(
                'drh_all',
                $userId,
                false,
                null,
                null,
                null,
                null,
                null,
                null,
                null,
                array(),
                array(),
                COURSEMANAGER
            );
            $teachers = array();
            foreach ($teacherList as $teacherData) {
                $teachers[] = $teacherData['user_id'];
            }

            $humanResources = SessionManager::getAllUsersFromCoursesFromAllSessionFromStatus(
                'drh_all',
                $userId,
                false,
                null,
                null,
                null,
                null,
                null,
                null,
                null,
                array(),
                array(),
                DRH
            );

            $humanResourcesList = array();
            foreach ($humanResources as $item) {
                $humanResourcesList[] = $item['user_id'];
            }

            $platformCourses = SessionManager::getAllCoursesFollowedByUser(
                $userId,
                null,
                null,
                null,
                null,
                null
            );

            //$platformCourses = SessionManager::getAllCoursesFromAllSessionFromDrh($userId);
            $courses = array();
            foreach ($platformCourses as $course) {
                $courses[$course['code']] = $course['code'];
            }
            $sessions = SessionManager::get_sessions_followed_by_drh($userId);
        } else {

            $studentList = UserManager::getUsersFollowedByUser(
                $userId,
                STUDENT,
                false,
                false,
                false,
                null,
                null,
                null,
                null,
                null,
                null,
                COURSEMANAGER
            );

            $students = array();
            foreach ($studentList as $studentData) {
                $students[] = $studentData['user_id'];
            }

            $teacherList = UserManager::getUsersFollowedByUser(
                $userId,
                COURSEMANAGER,
                false,
                false,
                false,
                null,
                null,
                null,
                null,
                null,
                null,
                COURSEMANAGER
            );

            $teachers = array();
            foreach ($teacherList as $teacherData) {
                $teachers[] = $teacherData['user_id'];
            }

            $humanResources = UserManager::getUsersFollowedByUser(
                $userId,
                DRH,
                false,
                false,
                false,
                null,
                null,
                null,
                null,
                null,
                null,
                COURSEMANAGER
            );

            $humanResourcesList = array();
            foreach ($humanResources as $item) {
                $humanResourcesList[] = $item['user_id'];
            }

            $platformCourses = CourseManager::getCoursesFollowedByUser(
                $userId,
                COURSEMANAGER
            );
            foreach ($platformCourses as $course) {
                $courses[$course['code']] = $course['code'];
            }

            $sessions = SessionManager::getSessionsFollowedByUser(
                $userId,
                COURSEMANAGER
            );
        }

        return array(
            'drh' => $humanResourcesList,
            'teachers' => $teachers,
            'students' => $students,
            'courses' => $courses,
            'sessions' => $sessions
        );
    }

    /**
     * Calculates the time spent on the platform by a user
     * @param   int|array User id
     * @param   string type of time filter: 'last_week' or 'custom'
     * @param   strgin  start date date('Y-m-d H:i:s')
     * @param   strgin  end date date('Y-m-d H:i:s')
     * @return timestamp $nb_seconds
     */
    public static function get_time_spent_on_the_platform(
        $userId,
        $timeFilter = 'last_7_days',
        $start_date = null,
        $end_date = null
    ) {
        $tbl_track_login = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_LOGIN);
        $condition_time = '';

        if (is_array($userId)) {
            $userList = array_map('intval', $userId);
            $userCondition = " login_user_id IN ('".implode("','", $userList)."')";
        } else {
            $userCondition = " login_user_id = ".intval($userId);
        }

        if (empty($timeFilter)) {
            $timeFilter = 'last_week';
        }

        $today = date('Y-m-d H:i:s');

        switch ($timeFilter) {
            case 'last_7_days':
                $new_date = date('Y-m-d H:i:s', strtotime('-7 day'));
                $condition_time = ' AND (login_date >= "'.$new_date.'" AND logout_date <= "'.$today.'") ';
                break;
            case 'last_30_days':
                $new_date = date('Y-m-d H:i:s', strtotime('-30 day'));
                $condition_time = ' AND (login_date >= "'.$new_date.'" AND logout_date <= "'.$today.'") ';
               break;
            case 'custom':
                if (!empty($start_date) && !empty($end_date)) {
                    $start_date = Database::escape_string($start_date);
                    $end_date = Database::escape_string($end_date);
                    $condition_time = ' AND (login_date >= "'.$start_date.'" AND logout_date <= "'.$end_date.'" ) ';
                }
                break;
        }

    	$sql = 'SELECT SUM(TIMESTAMPDIFF(SECOND, login_date, logout_date)) diff
    	        FROM '.$tbl_track_login.'
                WHERE '.$userCondition.$condition_time;
    	$rs = Database::query($sql);
        $row = Database::fetch_array($rs, 'ASSOC');
        $diff = $row['diff'];

        if ($diff >= 0) {
            return $diff;
        } else {
            return -1;
        }
    }

    /**
     * Calculates the time spent on the course
     * @param integer $user_id
     * @param string  $course_code
     * @param int Session id (optional)
     * @return timestamp     Time in seconds
     */
    public static function get_time_spent_on_the_course($user_id, $course_code, $session_id = 0)
    {
    	$course_code = Database::escape_string($course_code);
    	$session_id  = intval($session_id);

    	$tbl_track_course = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_COURSE_ACCESS);
    	if (is_array($user_id)) {
    	    $user_id = array_map('intval', $user_id);
    		$condition_user = " AND user_id IN (".implode(',',$user_id).") ";
    	} else {
    		$user_id = intval($user_id);
    		$condition_user = " AND user_id = '$user_id' ";
    	}

    	$sql = "SELECT SUM(UNIX_TIMESTAMP(logout_course_date) - UNIX_TIMESTAMP(login_course_date)) as nb_seconds
                FROM $tbl_track_course
                WHERE
                    UNIX_TIMESTAMP(logout_course_date) > UNIX_TIMESTAMP(login_course_date) AND
                    course_code='$course_code' AND
                    session_id = '$session_id' $condition_user";

        $rs = Database::query($sql);
    	$row = Database::fetch_array($rs);
    	return $row['nb_seconds'];
    }

    /**
     * Get first connection date for a student
     * @param    int                  Student id
     * @return    string|bool     Date format long without day or false if there are no connections
     */
    public static function get_first_connection_date($student_id)
    {
    	$tbl_track_login = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_LOGIN);
    	$sql = 'SELECT login_date FROM ' . $tbl_track_login . '
                WHERE login_user_id = ' . intval($student_id) . '
                ORDER BY login_date ASC LIMIT 0,1';

    	$rs = Database::query($sql);
    	if (Database::num_rows($rs)>0) {
    		if ($first_login_date = Database::result($rs, 0, 0)) {
    			return api_convert_and_format_date($first_login_date, DATE_FORMAT_SHORT, date_default_timezone_get());
    		}
    	}
    	return false;
    }

    /**
     * Get las connection date for a student
     * @param int Student id
     * @param bool Show a warning message (optional)
     * @param bool True for returning results in timestamp (optional)
     * @return string|int|bool Date format long without day, false if there are no connections or
     * timestamp if parameter $return_timestamp is true
     */
    public static function get_last_connection_date($student_id, $warning_message = false, $return_timestamp = false)
    {
    	$tbl_track_login = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_LOGIN);
    	$sql = 'SELECT login_date FROM ' . $tbl_track_login . '
                WHERE login_user_id = ' . intval($student_id) . '
                ORDER BY login_date DESC LIMIT 0,1';

    	$rs = Database::query($sql);
    	if (Database::num_rows($rs) > 0) {
    		if ($last_login_date = Database::result($rs, 0, 0)) {
    			$last_login_date = api_get_local_time($last_login_date);
    			if ($return_timestamp) {
    				return api_strtotime($last_login_date,'UTC');
    			} else {
    				if (!$warning_message) {
    					return api_format_date($last_login_date, DATE_FORMAT_SHORT);
    				} else {
    					$timestamp = api_strtotime($last_login_date,'UTC');
    					$currentTimestamp = time();

    					//If the last connection is > than 7 days, the text is red
    					//345600 = 7 days in seconds
    					if ($currentTimestamp - $timestamp > 604800) {
    						return '<span style="color: #F00;">' . api_format_date($last_login_date, DATE_FORMAT_SHORT) . '</span>';
    					} else {
    						return api_format_date($last_login_date, DATE_FORMAT_SHORT);
    					}
    				}
    			}
    		}
    	}
    	return false;
    }

    /**
     * Get las connection date for a student
     * @param array Student id array
     * @param int $days
     * @param bool $getCount
     * @return int
     */
    public static function getInactiveUsers($studentList, $days, $getCount = true)
    {
        if (empty($studentList)) {
            return 0;
        }
        $days = intval($days);
        $date = api_get_utc_datetime(strtotime($days.' days ago'));
        $studentList = array_map('intval', $studentList);

        $tbl_track_login = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_LOGIN);
        $select = " SELECT login_user_id ";
        if ($getCount) {
            $select = " SELECT count(DISTINCT login_user_id) as count";
        }
        $sql = "$select
                FROM $tbl_track_login
                WHERE
                    login_user_id IN (' ". implode("','", $studentList) . "' ) AND
                    login_date < '$date'
                ";
        $rs = Database::query($sql);
        if (Database::num_rows($rs) > 0) {
            if ($getCount) {
                $count = Database::fetch_array($rs);
                return $count['count'];
            }
            return Database::store_result($rs, 'ASSOC');
        }
        return false;
    }

    /**
     * Get first user's connection date on the course
     * @param     int         User id
     * @param    string        Course code
     * @param    int            Session id (optional, default=0)
     * @return    string|bool    Date with format long without day or false if there is no date
     */
    public static function get_first_connection_date_on_the_course($student_id, $course_code, $session_id = 0, $convert_date = true)
    {
    	// protect data
    	$student_id  = intval($student_id);
    	$course_code = Database::escape_string($course_code);
    	$session_id  = intval($session_id);

    	$tbl_track_login = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_COURSE_ACCESS);
    	$sql = 'SELECT login_course_date FROM '.$tbl_track_login.'
                        WHERE user_id = '.$student_id.'
                        AND course_code = "'.$course_code.'"
                        AND session_id = '.$session_id.'
                        ORDER BY login_course_date ASC LIMIT 0,1';
    	$rs = Database::query($sql);
    	if (Database::num_rows($rs) > 0) {
    		if ($first_login_date = Database::result($rs, 0, 0)) {
    			if ($convert_date) {
    				return api_convert_and_format_date($first_login_date, DATE_FORMAT_SHORT);
    			} else {
    				return $first_login_date;
    			}
    		}
    	}
    	return false;
    }

    /**
     * Get last user's connection date on the course
     * @param     int         User id
     * @param    string        Course code
     * @param    int            Session id (optional, default=0)
     * @return    string|bool    Date with format long without day or false if there is no date
     */
    public static function get_last_connection_date_on_the_course($student_id, $course_code, $session_id = 0, $convert_date = true)
    {
    	// protect data
    	$student_id  = intval($student_id);
    	$course_code = Database::escape_string($course_code);
    	$session_id  = intval($session_id);

    	$tbl_track_e_course_access = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_COURSE_ACCESS);
    	$sql = 'SELECT login_course_date
                FROM '.$tbl_track_e_course_access.'
                WHERE   user_id = '.$student_id.' AND
                        course_code = "'.$course_code.'" AND
                        session_id = '.$session_id.'
                ORDER BY login_course_date DESC
                LIMIT 0,1';

    	$rs = Database::query($sql);
    	if (Database::num_rows($rs) > 0) {
    		if ($last_login_date = Database::result($rs, 0, 0)) {
                if (empty($last_login_date) || $last_login_date == '0000-00-00 00:00:00') {
                    return false;
                }
                //$last_login_date_timestamp = api_strtotime($last_login_date, 'UTC');
                //see #5736
                $last_login_date_timestamp = api_strtotime($last_login_date);
    			$now = time();
    			//If the last connection is > than 7 days, the text is red
    			//345600 = 7 days in seconds
    			if ($now - $last_login_date_timestamp > 604800) {
    				if ($convert_date) {
                        $last_login_date = api_convert_and_format_date($last_login_date, DATE_FORMAT_SHORT);
                        $icon = api_is_allowed_to_edit() ? '<a href="'.api_get_path(REL_CODE_PATH).'announcements/announcements.php?action=add&remind_inactive='.$student_id.'" title="'.get_lang('RemindInactiveUser').'"><img src="'.api_get_path(WEB_IMG_PATH).'messagebox_warning.gif" /> </a>': null;
    					return $icon. Display::label($last_login_date, 'warning');
    				} else {
    					return $last_login_date;
    				}
    			} else {
    				if ($convert_date) {
    					return api_convert_and_format_date($last_login_date, DATE_FORMAT_SHORT);
    				} else {
    					return $last_login_date;
    				}
    			}
    		}
    	}
    	return false;
    }

    /**
     * Get count of the connections to the course during a specified period
     * @param   string  Course code
     * @param   int     Session id (optional)
     * @param   int     Datetime from which to collect data (defaults to 0)
     * @param   int     Datetime to which to collect data (defaults to now)
     * @return  int     count connections
     */
    public static function get_course_connections_count($course_code, $session_id = 0, $start = 0, $stop = null)
    {

    	if ($start < 0) {
    		$start = 0;
    	}
    	if (!isset($stop) or ($stop < 0)) {
    		$stop = api_get_utc_datetime();
    	}

        $start = Database::escape_string($start);
        $stop = Database::escape_string($stop);

    	$month_filter = " AND login_course_date > '$start' AND login_course_date < '$stop' ";

    	$course_code = Database::escape_string($course_code);
    	$session_id  = intval($session_id);
    	$count = 0;

    	$tbl_track_e_course_access = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_COURSE_ACCESS);
    	$sql = "SELECT count(*) as count_connections
                FROM $tbl_track_e_course_access
                WHERE
                    course_code = '$course_code' AND
                    session_id = $session_id
                    $month_filter";
    	$rs = Database::query($sql);
    	if (Database::num_rows($rs)>0) {
    		$row = Database::fetch_object($rs);
    		$count = $row->count_connections;
    	}
    	return $count;
    }

    /**
     * Get count courses per student
     * @param     int        Student id
     * @param    bool    Include sessions (optional)
     * @return  int        count courses
     */
    public static function count_course_per_student($user_id, $include_sessions = true)
    {
    	$user_id = intval($user_id);
    	$tbl_course_rel_user = Database :: get_main_table(TABLE_MAIN_COURSE_USER);
    	$tbl_session_course_rel_user = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE_USER);

    	$sql = 'SELECT DISTINCT course_code
                FROM ' . $tbl_course_rel_user . '
                WHERE user_id = ' . $user_id.' AND relation_type<>'.COURSE_RELATION_TYPE_RRHH;
    	$rs = Database::query($sql);
    	$nb_courses = Database::num_rows($rs);

    	if ($include_sessions) {
    		$sql = 'SELECT DISTINCT course_code
                    FROM ' . $tbl_session_course_rel_user . '
                    WHERE id_user = ' . $user_id;
    		$rs = Database::query($sql);
    		$nb_courses += Database::num_rows($rs);
    	}

    	return $nb_courses;
    }

    /**
     * Gets the score average from all tests in a course by student
     *
     * @param    mixed		Student(s) id
     * @param    string 	Course code
     * @param    int    	Exercise id (optional), filtered by exercise
     * @param    int    	Session id (optional), if param $session_id is null it'll return results including sessions, 0 = session is not filtered
     * @return   string 	value (number %) Which represents a round integer about the score average.
     */
    public static function get_avg_student_exercise_score($student_id, $course_code, $exercise_id = 0, $session_id = null)
    {
    	$course_info = api_get_course_info($course_code);
    	if (!empty($course_info)) {
    		// table definition
    		$tbl_course_quiz     = Database::get_course_table(TABLE_QUIZ_TEST);
    		$tbl_stats_exercise  = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);

    		// Compose a filter based on optional exercise given
    		$condition_quiz = "";
    		if (!empty($exercise_id)) {
    			$exercise_id = intval($exercise_id);
    			$condition_quiz =" AND id = $exercise_id ";
    		}

    		// Compose a filter based on optional session id given
    		$condition_session = "";
    		if (isset($session_id)) {
    			$session_id = intval($session_id);
    			$condition_session = " AND session_id = $session_id ";
    		}
    		$sql = "SELECT count(id) FROM $tbl_course_quiz
    				WHERE c_id = {$course_info['real_id']} AND active <> -1 $condition_quiz ";
    		$count_quiz = Database::fetch_row(Database::query($sql));

    		if (!empty($count_quiz[0]) && !empty($student_id)) {
    			if (is_array($student_id)) {
    				$condition_user = " AND exe_user_id IN (".implode(',',$student_id).") ";
    			} else {
    				$condition_user = " AND exe_user_id = '$student_id' ";
    			}

    			if (empty($exercise_id)) {
    				$sql = "SELECT id FROM $tbl_course_quiz
    						WHERE c_id = {$course_info['real_id']} AND active <> -1 $condition_quiz";
                    $result = Database::query($sql);
                    $exercise_list = array();
    				$exercise_id = null;
                    if (Database::num_rows($result)) {
                        while ($row = Database::fetch_array($result)) {
                            $exercise_list[] = $row['id'];
                        }
                    }
                    if (!empty($exercise_list)) {
                        $exercise_id = implode("','",$exercise_list);
                    }
    			}

    			$count_quiz = Database::fetch_row(Database::query($sql));

    			$sql = "SELECT SUM(exe_result/exe_weighting*100) as avg_score, COUNT(*) as num_attempts
                        FROM $tbl_stats_exercise
                        WHERE exe_exo_id IN ('".$exercise_id."')
    			        $condition_user AND
                        orig_lp_id = 0 AND
                        status = '' AND
                        exe_cours_id = '$course_code' AND
                        orig_lp_item_id = 0 $condition_session
                        ORDER BY exe_date DESC";

    			$res = Database::query($sql);
    			$row = Database::fetch_array($res);
    			$quiz_avg_score = 0;

    			if (!empty($row['avg_score'])) {
    				$quiz_avg_score = round($row['avg_score'],2);
    			}

    			if(!empty($row['num_attempts'])) {
    				$quiz_avg_score = round($quiz_avg_score / $row['num_attempts'], 2);
    			}
    			if (is_array($student_id)) {
    				$quiz_avg_score = round($quiz_avg_score / count($student_id), 2);
    			}
    			return $quiz_avg_score;
    		}
    	}
    	return null;
    }

    /**
     * Get count student's exercise COMPLETED attempts
     * @param    int     Student id
     * @param    string    Course code
     * @param    int        Exercise id
     * @param    int        Learning path id (optional), for showing attempts inside a learning path $lp_id and $lp_item_id params are required.
     * @param    int        Learning path item id (optional), for showing attempts inside a learning path $lp_id and $lp_item_id params are required.
     * @return  int     count of attempts
     */
    public static function count_student_exercise_attempts($student_id, $course_code, $exercise_id, $lp_id = 0, $lp_item_id = 0, $session_id = 0)
    {
    	$course_code = Database::escape_string($course_code);
    	$student_id  = intval($student_id);
    	$exercise_id = intval($exercise_id);
    	$session_id  = intval($session_id);

    	if (!empty($lp_id)) $lp_id = intval($lp_id);
    	if (!empty($lp_item_id)) $lp_id = intval($lp_item_id);

    	$tbl_stats_exercices = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);

    	$sql = "SELECT COUNT(ex.exe_id) as essais FROM $tbl_stats_exercices AS ex
                WHERE  ex.exe_cours_id = '$course_code'
                AND ex.exe_exo_id = $exercise_id
                AND status = ''
                AND orig_lp_id = $lp_id
                AND orig_lp_item_id = $lp_item_id
                AND exe_user_id= $student_id
                AND session_id = $session_id ";

    	$rs = Database::query($sql);
    	$row = Database::fetch_row($rs);
    	$count_attempts = $row[0];

    	return $count_attempts;
    }

    /**
     * Get count student's exercise progress
     * @param    int       user id
     * @param    string    course code
     * @param    int       session id
    */

    static function get_exercise_student_progress($exercise_list, $user_id, $course_code, $session_id)
    {
        $course_code    = Database::escape_string($course_code);
        $user_id        = intval($user_id);
        $session_id     = intval($session_id);

        if (empty($exercise_list)) {
            return '0%';
        }
        $tbl_stats_exercices = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
        $exercise_list = array_keys($exercise_list);
        $exercise_list = array_map('intval', $exercise_list);

        $exercise_list_imploded = implode("' ,'", $exercise_list);

        $sql = "SELECT COUNT(DISTINCT ex.exe_exo_id) FROM $tbl_stats_exercices AS ex
                WHERE ex.exe_cours_id = '$course_code' AND
                      ex.session_id  = $session_id AND
                      ex.exe_user_id = $user_id AND ex.exe_exo_id IN ('$exercise_list_imploded') ";

        $rs = Database::query($sql);
        $count = 0;
        if ($rs) {
            $row = Database::fetch_row($rs);
            $count = $row[0];
        }
        $count = ($count != 0 ) ? 100*round(intval($count)/count($exercise_list), 2) .'%' : '0%';
        return $count;
    }

    /**
     * @param array $exercise_list
     * @param int $user_id
     * @param string $course_code
     * @param int $session_id
     * @return string
     */
    static function get_exercise_student_average_best_attempt($exercise_list, $user_id, $course_code, $session_id) {
        $result = 0;
        if (!empty($exercise_list)) {
            foreach ($exercise_list as $exercise_data) {
                $exercise_id = $exercise_data['id'];
                $best_attempt = get_best_attempt_exercise_results_per_user($user_id, $exercise_id , $course_code, $session_id);

                if (!empty($best_attempt)) {
                    $result += $best_attempt['exe_result']/$best_attempt['exe_weighting'];
                }
            }
            $result = $result/ count($exercise_list);
            $result = round($result, 2)*100;
        }

        return $result.'%';
    }

    /**
     * Returns the average student progress in the learning paths of the given
     * course.
     * @param   int/array    Student id(s)
     * @param   string        Course code
     * @param     array         Limit average to listed lp ids
     * @param    int            Session id (optional), if parameter $session_id is null(default) it'll return results including sessions, 0 = session is not filtered
     * @param    bool        Will return an array of the type: [sum_of_progresses, number] if it is set to true
     * @return double        Average progress of the user in this course
     */
    public static function get_avg_student_progress($student_id, $course_code = null, $lp_ids = array(), $session_id = null, $return_array = false)
    {
        $conditions = array();
    	// Get the information of the course.
    	$course_info = api_get_course_info($course_code);
    	if (!empty($course_info)) {
            $conditions[] = " c_id = {$course_info['real_id']} ";
        }
        // table definition
        $tbl_course_lp_view = Database :: get_course_table(TABLE_LP_VIEW);

        // Compose a filter based on optional learning paths list given
        $condition_lp = null;
        if (!empty($lp_ids)) {
            if (count($lp_ids) > 0) {
                $lp_ids = array_map('intval', $lp_ids);
                $conditions[] = " lp_view.lp_id IN(".implode(',', $lp_ids).") ";
            }
        }

        // If there is at least one learning path and one student.
        if (!empty($student_id)) {
            if (is_array($student_id)) {
                $student_id = array_map('intval', $student_id);
                $conditions[] = " lp_view.user_id IN (".implode(',', $student_id).")  ";
            } else {
                $student_id = intval($student_id);
                $conditions[] = " lp_view.user_id = '$student_id' ";
            }
            if (!empty($session_id)) {
                $conditions[] = " session_id = $session_id ";
            }
            $conditionToString = implode('AND', $conditions);

            // Get last view for each student (in case of multi-attempt)
            // Also filter on LPs of this session
            $sql = " SELECT
                        MAX(view_count),
                        AVG(progress) average,
                        SUM(progress) sum_progress,
                        count(progress) count_progress
                      FROM $tbl_course_lp_view lp_view
                      WHERE
                      $conditionToString
                      GROUP BY lp_id";
            $result = Database::query($sql);
            $row = Database::fetch_array($result, 'ASSOC');
            if (!$return_array) {
                $avg_progress = round($row['average'], 1);
                return $avg_progress;
            } else {
                return array($row['sum_progress'], $row['count_progress']);
            }
        }
    }

    /**
     * This function gets:
     * 1. The score average from all SCORM Test items in all LP in a course-> All the answers / All the max scores.
     * 2. The score average from all Tests (quiz) in all LP in a course-> All the answers / All the max scores.
     * 3. And finally it will return the average between 1. and 2.
     * @todo improve performance, when loading 1500 users with 20 lps the script dies
     * This function does not take the results of a Test out of a LP
     *
     * @param   mixed       Array of user ids or an user id
     * @param   string      Course code
     * @param   array       List of LP ids
     * @param   int         Session id (optional), if param $session_id is null(default) it'll return results including sessions, 0 = session is not filtered
     * @param   bool        Returns an array of the type [sum_score, num_score] if set to true
     * @param   bool        get only the latest attempts or ALL attempts
     * @return  string      Value (number %) Which represents a round integer explain in got in 3.
     */
    public static function get_avg_student_score(
        $student_id,
        $course_code,
        $lp_ids = array(),
        $session_id = null,
        $return_array = false,
        $get_only_latest_attempt_results = false
    ) {
        $debug = false;
        if (empty($lp_ids)) {
            $debug = false;
        }

        if ($debug) echo '<h1>Tracking::get_avg_student_score</h1>';
        $tbl_stats_exercices        = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES);
        $tbl_stats_attempts         = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);

        $course = api_get_course_info($course_code);

        if (!empty($course)) {

            // get course tables names
            $tbl_quiz_questions = Database :: get_course_table(TABLE_QUIZ_QUESTION);
            $lp_table           = Database :: get_course_table(TABLE_LP_MAIN);
            $lp_item_table      = Database :: get_course_table(TABLE_LP_ITEM);
            $lp_view_table      = Database :: get_course_table(TABLE_LP_VIEW);
            $lp_item_view_table = Database :: get_course_table(TABLE_LP_ITEM_VIEW);

            $course_id = $course['real_id'];

            // Compose a filter based on optional learning paths list given

            $condition_lp = "";
            if (count($lp_ids) > 0) {
                $condition_lp =" AND id IN(".implode(',',$lp_ids).") ";
            }

            // Compose a filter based on optional session id
            $session_id = intval($session_id);
            if (count($lp_ids) > 0) {
                $condition_session = " AND session_id = $session_id ";
            } else {
                $condition_session = " WHERE session_id = $session_id ";
            }

            // Check the real number of LPs corresponding to the filter in the
            // database (and if no list was given, get them all)

            if (empty($session_id)) {
                $sql = "SELECT DISTINCT(id), use_max_score FROM $lp_table WHERE c_id = $course_id AND session_id = 0 $condition_lp ";
            } else {
                $sql = "SELECT DISTINCT(id), use_max_score FROM $lp_table WHERE c_id = $course_id $condition_lp ";
            }

            $res_row_lp   = Database::query($sql);
            $count_row_lp = Database::num_rows($res_row_lp);

            $lp_list = $use_max_score = array();
            while ($row_lp = Database::fetch_array($res_row_lp)) {
                $lp_list[] = $row_lp['id'];
                $use_max_score[$row_lp['id']]  = $row_lp['use_max_score'];
            }

            if ($debug) {
                echo 'Use max score or not list '; var_dump($use_max_score);
            }

            // Init local variables that will be used through the calculation
            $progress = 0;

            // prepare filter on users
            $condition_user1 = "";

            if (is_array($student_id)) {
                array_walk($student_id, 'intval');
                $condition_user1 =" AND user_id IN (".implode(',', $student_id).") ";
            } else {
                $condition_user1 =" AND user_id = $student_id ";
            }

            if ($count_row_lp > 0 && !empty($student_id)) {

                // Getting latest LP result for a student
                //@todo problem when a  course have more than 1500 users
                $sql = "SELECT MAX(view_count) as vc, id, progress, lp_id, user_id  FROM $lp_view_table
                        WHERE 	c_id = $course_id AND
                                lp_id IN (".implode(',',$lp_list).")
                                $condition_user1 AND
                                session_id = $session_id
                        GROUP BY lp_id, user_id";
                if ($debug) echo $sql;
                $rs_last_lp_view_id = Database::query($sql);

                $global_result = 0;

                if (Database::num_rows($rs_last_lp_view_id) > 0) {
                    // Cycle through each line of the results (grouped by lp_id, user_id)
                    while ($row_lp_view = Database::fetch_array($rs_last_lp_view_id)) {
                        $count_items = 0;
                        $lp_partial_total = 0;

                        $list = array();
                        $lp_view_id = $row_lp_view['id'];
                        $progress   = $row_lp_view['progress'];
                        $lp_id      = $row_lp_view['lp_id'];
                        $user_id    = $row_lp_view['user_id'];
                        if ($debug) echo '<h2>LP id '.$lp_id.'</h2>';

                        if ($get_only_latest_attempt_results) {
                            //Getting lp_items done by the user
                            $sql = "SELECT DISTINCT lp_item_id
                                    FROM $lp_item_view_table
                                    WHERE c_id = $course_id AND
                                          lp_view_id = $lp_view_id
                                    ORDER BY lp_item_id";
                            $res_lp_item = Database::query($sql);

                            while ($row_lp_item = Database::fetch_array($res_lp_item,'ASSOC')) {
                                $my_lp_item_id = $row_lp_item['lp_item_id'];

                                //Getting the most recent attempt
                                $sql = "SELECT  lp_iv.id as lp_item_view_id,
                                                lp_iv.score as score,
                                                lp_i.max_score,
                                                lp_iv.max_score as max_score_item_view,
                                                lp_i.path,
                                                lp_i.item_type,
                                                lp_i.id as iid
                                        FROM $lp_item_view_table as lp_iv
                                            INNER JOIN $lp_item_table as lp_i
                                            ON  lp_i.id = lp_iv.lp_item_id AND
                                                lp_iv.c_id = $course_id AND
                                                lp_i.c_id  = $course_id AND
                                                (lp_i.item_type='sco' OR lp_i.item_type='".TOOL_QUIZ."')
                                        WHERE 	lp_item_id = $my_lp_item_id AND
                                                lp_view_id = $lp_view_id
                                        ORDER BY view_count DESC
                                        LIMIT 1";
                                $res_lp_item_result = Database::query($sql);
                                while ($row_max_score = Database::fetch_array($res_lp_item_result,'ASSOC')) {
                                    $list[]= $row_max_score;
                                }
                            }
                        } else {
                            // For the currently analysed view, get the score and
                            // max_score of each item if it is a sco or a TOOL_QUIZ
                            $sql_max_score = "SELECT lp_iv.id as lp_item_view_id,
                                                     lp_iv.score as score,
                                                     lp_i.max_score,
                                                     lp_iv.max_score as max_score_item_view,
                                                     lp_i.path,
                                                     lp_i.item_type,
                                                     lp_i.id as iid
                                              FROM $lp_item_view_table as lp_iv
                                                  INNER JOIN $lp_item_table as lp_i
                                                  ON lp_i.id = lp_iv.lp_item_id AND
                                                     lp_iv.c_id = $course_id AND
                                                     lp_i.c_id  = $course_id AND
                                                     (lp_i.item_type='sco' OR lp_i.item_type='".TOOL_QUIZ."')
                                              WHERE lp_view_id = $lp_view_id ";
                            if ($debug) echo $sql_max_score.'<br />';

                            $res_max_score = Database::query($sql_max_score);

                            while ($row_max_score = Database::fetch_array($res_max_score,'ASSOC')) {
                                $list[]= $row_max_score;
                            }
                        }

                        // Go through each scorable element of this view

                        $score_of_scorm_calculate = 0;

                        foreach ($list as $row_max_score) {
                            $max_score              = $row_max_score['max_score'];  //Came from the original lp_item
                            $max_score_item_view    = $row_max_score['max_score_item_view']; //Came from the lp_item_view
                            $score                  = $row_max_score['score'];

                            if ($debug) echo '<h3>Item Type: ' .$row_max_score['item_type'].'</h3>';

                            if ($row_max_score['item_type'] == 'sco') {
                                // Check if it is sco (easier to get max_score)
                                //when there's no max score, we assume 100 as the max score, as the SCORM 1.2 says that the value should always be between 0 and 100.
                                if ($max_score == 0 || is_null($max_score) || $max_score == '') {
                                    //Chamilo style
                                    if ($use_max_score[$lp_id]) {
                                        $max_score = 100;
                                    } else {
                                        //Overwrites max score = 100 to use the one that came in the lp_item_view see BT#1613
                                        $max_score = $max_score_item_view;
                                    }
                                }
                                //Avoid division by zero errors
                                if (!empty($max_score)) {
                                    $lp_partial_total += $score/$max_score;
                                }
                                if ($debug) echo '<b>$lp_partial_total, $score, $max_score '.$lp_partial_total.' '.$score.' '.$max_score.'</b><br />';
                            } else {
                                // Case of a TOOL_QUIZ element
                                $item_id    = $row_max_score['iid'];
                                $item_path  = $row_max_score['path'];
                                $lp_item_view_id  = $row_max_score['lp_item_view_id'];

                                // Get last attempt to this exercise  through
                                // the current lp for the current user
                                $sql_last_attempt = "SELECT exe_id FROM $tbl_stats_exercices WHERE
                                        exe_exo_id           = '$item_path' AND
                                        exe_user_id          = $user_id AND
                                        orig_lp_item_id      = $item_id AND
                                        orig_lp_item_view_id = $lp_item_view_id AND
                                        exe_cours_id         = '$course_code'  AND
                                        session_id           = $session_id
                                        ORDER BY exe_date DESC LIMIT 1";
                                if ($debug) echo $sql_last_attempt .'<br />';
                                $result_last_attempt = Database::query($sql_last_attempt);
                                $num = Database :: num_rows($result_last_attempt);
                                if ($num > 0 ) {
                                    $id_last_attempt = Database :: result($result_last_attempt, 0, 0);
                                    if ($debug) echo $id_last_attempt.'<br />';

                                    // Within the last attempt number tracking, get the sum of
                                    // the max_scores of all questions that it was
                                    // made of (we need to make this call dynamic because of random questions selection)
                                    $sql = "SELECT SUM(t.ponderation) as maxscore FROM
                                            (
                                                SELECT DISTINCT question_id, marks, ponderation
                                                FROM $tbl_stats_attempts AS at INNER JOIN $tbl_quiz_questions AS q ON (q.id = at.question_id)
                                                WHERE exe_id ='$id_last_attempt' AND q.c_id = $course_id
                                            )
                                            AS t";
                                    if ($debug) echo '$sql: '.$sql.' <br />';
                                    $res_max_score_bis = Database::query($sql);
                                    $row_max_score_bis = Database::fetch_array($res_max_score_bis);

                                    if (!empty($row_max_score_bis['maxscore'])) {
                                        $max_score = $row_max_score_bis['maxscore'];
                                    }
                                    if (!empty($max_score) && floatval($max_score) > 0) {
                                        $lp_partial_total += $score/$max_score;
                                    }
                                    if ($debug) echo '$lp_partial_total, $score, $max_score <b>'.$lp_partial_total.' '.$score.' '.$max_score.'</b><br />';
                                }
                            }

                            if (in_array($row_max_score['item_type'], array('quiz','sco'))) {
                                // Normal way
                                if ($use_max_score[$lp_id]) {
                                    $count_items++;
                                } else {
                                    if ($max_score != '') {
                                        $count_items++;
                                    }
                                }
                                if ($debug) echo '$count_items: '.$count_items;
                            }
                        } //end for

                        $score_of_scorm_calculate += $count_items?(($lp_partial_total/$count_items)*100):0;

                        if ($debug) echo '<h3>$count_items '.$count_items.'</h3>';
                        if ($debug) echo '<h3>$score_of_scorm_calculate '.$score_of_scorm_calculate.'</h3>';

                        $global_result += $score_of_scorm_calculate;
                        if ($debug) echo '<h3>$global_result '.$global_result.'</h3>';
                    } // end while
                }

                $lp_with_quiz = 0;
                if ($debug) var_dump($lp_list);
                foreach ($lp_list as $lp_id) {
                    //Check if LP have a score we asume that all SCO have an score
                    $sql = "SELECT count(id) as count FROM $lp_item_table
                            WHERE c_id = $course_id AND  (item_type = 'quiz' OR item_type = 'sco') AND lp_id = ".$lp_id;
                    if ($debug) echo $sql;
                    $result_have_quiz = Database::query($sql);

                    if (Database::num_rows($result_have_quiz) > 0 ) {
                        $row = Database::fetch_array($result_have_quiz,'ASSOC');
                        if (is_numeric($row['count']) && $row['count'] != 0) {
                            $lp_with_quiz ++;
                        }
                    }
                }

                if ($debug) echo '<h3>$lp_with_quiz '.$lp_with_quiz.' </h3>';
                if ($debug) echo '<h3>Final return</h3>';

                if ($lp_with_quiz != 0 ) {
                    if (!$return_array) {
                        $score_of_scorm_calculate = round(($global_result/$lp_with_quiz),2);
                        if ($debug) var_dump($score_of_scorm_calculate);
                        if (empty($lp_ids)) {
                            //$score_of_scorm_calculate = round($score_of_scorm_calculate/count($lp_list),2);
                            if ($debug) echo '<h2>All lps fix: '.$score_of_scorm_calculate.'</h2>';
                        }
                        return $score_of_scorm_calculate;
                    } else {
                        if ($debug) var_dump($global_result, $lp_with_quiz);
                        return array($global_result, $lp_with_quiz);
                    }
                } else {
                    return '-';
                }
            }
        }
        return null;
    }

    /**
     * This function gets:
     * 1. The score average from all SCORM Test items in all LP in a course-> All the answers / All the max scores.
     * 2. The score average from all Tests (quiz) in all LP in a course-> All the answers / All the max scores.
     * 3. And finally it will return the average between 1. and 2.
     * This function does not take the results of a Test out of a LP
     *
     * @param   int|array   Array of user ids or an user id
     * @param   string      Course code
     * @param   array       List of LP ids
     * @param   int         Session id (optional), if param $session_id is null(default) it'll return results including sessions, 0 = session is not filtered
     * @param   bool        Returns an array of the type [sum_score, num_score] if set to true
     * @param   bool        get only the latest attempts or ALL attempts
     * @return  string      Value (number %) Which represents a round integer explain in got in 3.
     */
    public static function getAverageStudentScore(
        $student_id,
        $course_code = null,
        $lp_ids = array(),
        $session_id = null
    ) {
        if (empty($student_id)) {
            return 0;
        }

        $conditions = array();

        if (!empty($course_code)) {
            $course = api_get_course_info($course_code);
            $courseId = $course['real_id'];
            $conditions[] = " c_id = $courseId";
        }

        // get course tables names
        $tbl_quiz_questions = Database :: get_course_table(TABLE_QUIZ_QUESTION);
        $lp_table           = Database :: get_course_table(TABLE_LP_MAIN);
        $lp_item_table      = Database :: get_course_table(TABLE_LP_ITEM);
        $lp_view_table      = Database :: get_course_table(TABLE_LP_VIEW);
        $lp_item_view_table = Database :: get_course_table(TABLE_LP_ITEM_VIEW);

        // Compose a filter based on optional learning paths list given

        if (!empty($lp_ids) && count($lp_ids) > 0) {
            $conditions[] = " id IN(".implode(',', $lp_ids).") ";
        }

        // Compose a filter based on optional session id
        $session_id = intval($session_id);
        if (!empty($session_id)) {
            $conditions[] = " session_id = $session_id ";
        }

        if (is_array($student_id)) {
            array_walk($student_id, 'intval');
            $conditions[] =" lp_view.user_id IN (".implode(',', $student_id).") ";
        } else {
            $conditions[] =" lp_view.user_id = $student_id ";
        }

        $conditionsToString = implode('AND ', $conditions);
        $sql = "SELECT  SUM(lp_iv.score) sum_score,
                        SUM(lp_i.max_score) sum_max_score,
                        count(*) as count
                FROM $lp_table as lp
                INNER JOIN $lp_item_table as lp_i
                ON lp.id = lp_id AND lp.c_id = lp_i.c_id
                INNER JOIN $lp_view_table as lp_view
                ON lp_view.lp_id = lp_i.lp_id AND lp_view.c_id = lp_i.c_id
                INNER JOIN $lp_item_view_table as lp_iv
                ON lp_i.id = lp_iv.lp_item_id AND lp_view.c_id = lp_iv.c_id AND lp_iv.lp_view_id = lp_view.id
                WHERE (lp_i.item_type='sco' OR lp_i.item_type='".TOOL_QUIZ."') AND
                $conditionsToString
                ";
        $result = Database::query($sql);
        $row = Database::fetch_array($result, 'ASSOC');

        if (empty($row['sum_max_score'])) {
            return 0;
        }

        return ($row['sum_score'] / $row['sum_max_score'])*100;

    }

    /**
     * This function gets time spent in learning path for a student inside a course
     * @param     int|array    Student id(s)
     * @param     string         Course code
     * @param     array         Limit average to listed lp ids
     * @param     int            Session id (optional), if param $session_id is null(default) it'll return results including sessions, 0 = session is not filtered
     * @return     int         Total time
     */
    public static function get_time_spent_in_lp($student_id, $course_code, $lp_ids = array(), $session_id = null)
    {
        $course = CourseManager :: get_course_information($course_code);
        $student_id = intval($student_id);
        $total_time = 0;

        if (!empty($course)) {

            $lp_table   = Database :: get_course_table(TABLE_LP_MAIN);
            $t_lpv      = Database :: get_course_table(TABLE_LP_VIEW);
            $t_lpiv     = Database :: get_course_table(TABLE_LP_ITEM_VIEW);

            $course_id	 = $course['real_id'];

            // Compose a filter based on optional learning paths list given
            $condition_lp = "";
            if(count($lp_ids) > 0) {
                $condition_lp =" AND id IN(".implode(',',$lp_ids).") ";
            }

            // Compose a filter based on optional session id
            $condition_session = "";
            $session_id = intval($session_id);

            if (isset($session_id)) {
                $condition_session = " AND session_id = $session_id ";
            }

            // Check the real number of LPs corresponding to the filter in the
            // database (and if no list was given, get them all)
            //$res_row_lp = Database::query("SELECT DISTINCT(id) FROM $lp_table $condition_lp $condition_session");
            $res_row_lp = Database::query("SELECT DISTINCT(id) FROM $lp_table WHERE c_id = $course_id $condition_lp");
            $count_row_lp = Database::num_rows($res_row_lp);

            // calculates time
            if ($count_row_lp > 0) {
                while ($row_lp = Database::fetch_array($res_row_lp)) {
                    $lp_id = intval($row_lp['id']);
                    $sql = 'SELECT SUM(total_time)
                        FROM '.$t_lpiv.' AS item_view
                        INNER JOIN '.$t_lpv.' AS view
                            ON item_view.lp_view_id = view.id
                            WHERE
                            item_view.c_id 		= '.$course_id.' AND
                            view.c_id 			= '.$course_id.' AND
                            view.lp_id 			= '.$lp_id.'
                            AND view.user_id 	= '.$student_id.' AND
                            session_id 			= '.$session_id;

                    $rs = Database::query($sql);
                    if (Database :: num_rows($rs) > 0) {
                        $total_time += Database :: result($rs, 0, 0);
                    }
                }
            }
        }
        return $total_time;
    }

    /**
     * This function gets last connection time to one learning path
     * @param     int|array    Student id(s)
     * @param     string         Course code
     * @param     int         Learning path id
     * @return     int         Total time
     */
    public static function get_last_connection_time_in_lp($student_id, $course_code, $lp_id, $session_id = 0)
    {
        $course = CourseManager :: get_course_information($course_code);
        $student_id = intval($student_id);
        $lp_id = intval($lp_id);
        $last_time = 0;
        $session_id = intval($session_id);

        if (!empty($course)) {

            $course_id	 = $course['real_id'];

            $lp_table    = Database :: get_course_table(TABLE_LP_MAIN);
            $t_lpv       = Database :: get_course_table(TABLE_LP_VIEW);
            $t_lpiv      = Database :: get_course_table(TABLE_LP_ITEM_VIEW);

            // Check the real number of LPs corresponding to the filter in the
            // database (and if no list was given, get them all)
            $res_row_lp = Database::query("SELECT id FROM $lp_table WHERE c_id = $course_id AND id = $lp_id ");
            $count_row_lp = Database::num_rows($res_row_lp);

            // calculates last connection time
            if ($count_row_lp > 0) {
                $sql = 'SELECT MAX(start_time)
                    FROM ' . $t_lpiv . ' AS item_view
                    INNER JOIN ' . $t_lpv . ' AS view
                        ON item_view.lp_view_id = view.id
                        WHERE
                        item_view.c_id 		= '.$course_id.' AND
                        view.c_id 			= '.$course_id.' AND
                        view.lp_id 			= '.$lp_id.'
                        AND view.user_id 	= '.$student_id.'
                        AND view.session_id = '.$session_id;
                $rs = Database::query($sql);
                if (Database :: num_rows($rs) > 0) {
                    $last_time = Database :: result($rs, 0, 0);
                }
            }
        }
        return $last_time;
    }

    /**
     * gets the list of students followed by coach
     * @param     int     Coach id
     * @return     array     List of students
     */
    public static function get_student_followed_by_coach($coach_id)
    {
        $coach_id = intval($coach_id);

        $tbl_session_course_user = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
        $tbl_session_course = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE);
        $tbl_session_user = Database :: get_main_table(TABLE_MAIN_SESSION_USER);
        $tbl_session = Database :: get_main_table(TABLE_MAIN_SESSION);

        $a_students = array ();

        // At first, courses where $coach_id is coach of the course //
        $sql = 'SELECT id_session, course_code
                FROM ' . $tbl_session_course_user . '
                WHERE id_user=' . $coach_id.' AND status=2';

        if (api_is_multiple_url_enabled()) {
            $tbl_session_rel_access_url= Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_SESSION);
            $access_url_id = api_get_current_access_url_id();
            if ($access_url_id != -1) {
                $sql = 'SELECT scu.id_session, scu.course_code
                    FROM ' . $tbl_session_course_user . ' scu
                    INNER JOIN '.$tbl_session_rel_access_url.'  sru
                    ON (scu.id_session=sru.session_id)
                    WHERE
                        scu.id_user=' . $coach_id.' AND
                        scu.status=2 AND
                        sru.access_url_id = '.$access_url_id;
            }
        }

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

        while ($a_courses = Database::fetch_array($result)) {
            $course_code = $a_courses["course_code"];
            $id_session = $a_courses["id_session"];

            $sql = "SELECT distinct    srcru.id_user
                    FROM $tbl_session_course_user AS srcru, $tbl_session_user sru
                    WHERE
                        srcru.id_user = sru.id_user AND
                        sru.relation_type<>".SESSION_RELATION_TYPE_RRHH." AND
                        srcru.id_session = sru.id_session AND
                        srcru.course_code='$course_code' AND
                        srcru.id_session='$id_session'";

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

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

        // Then, courses where $coach_id is coach of the session    //

        $sql = 'SELECT session_course_user.id_user
                    FROM ' . $tbl_session_course_user . ' as session_course_user
                    INNER JOIN     '.$tbl_session_user.' sru ON session_course_user.id_user = sru.id_user AND session_course_user.id_session = sru.id_session
                    INNER JOIN ' . $tbl_session_course . ' as session_course
                        ON session_course.course_code = session_course_user.course_code
                        AND session_course_user.id_session = session_course.id_session
                    INNER JOIN ' . $tbl_session . ' as session
                        ON session.id = session_course.id_session
                        AND session.id_coach = ' . $coach_id;
        if (api_is_multiple_url_enabled()) {
            $tbl_session_rel_access_url= Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_SESSION);
            $access_url_id = api_get_current_access_url_id();
            if ($access_url_id != -1){
                $sql = 'SELECT session_course_user.id_user
            FROM ' . $tbl_session_course_user . ' as session_course_user
            INNER JOIN     '.$tbl_session_user.' sru
                ON session_course_user.id_user = sru.id_user AND
                   session_course_user.id_session = sru.id_session
            INNER JOIN ' . $tbl_session_course . ' as session_course
                ON session_course.course_code = session_course_user.course_code AND
                session_course_user.id_session = session_course.id_session
            INNER JOIN ' . $tbl_session . ' as session
                ON session.id = session_course.id_session AND
                session.id_coach = ' . $coach_id.'
            INNER JOIN '.$tbl_session_rel_access_url.' session_rel_url
                ON session.id = session_rel_url.session_id WHERE access_url_id = '.$access_url_id;
            }
        }
        $result = Database::query($sql);
        while ($row = Database::fetch_array($result)) {
            $a_students[$row['id_user']] = $row['id_user'];
        }
        return $a_students;
    }

    /**
     * Get student followed by a coach inside a session
     * @param    int        Session id
     * @param    int        Coach id
     * @return     array    students list
     */
    public static function get_student_followed_by_coach_in_a_session($id_session, $coach_id)
    {
        $coach_id = intval($coach_id);
        $tbl_session_course_user = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
        $tbl_session = Database :: get_main_table(TABLE_MAIN_SESSION);

        $a_students = array ();
        // At first, courses where $coach_id is coach of the course //
        $sql = 'SELECT course_code FROM ' . $tbl_session_course_user . ' WHERE id_session="' . $id_session . '" AND id_user=' . $coach_id.' AND status=2';
        $result = Database::query($sql);

        while ($a_courses = Database::fetch_array($result)) {
            $course_code = $a_courses["course_code"];

            $sql = "SELECT distinct    srcru.id_user
                    FROM $tbl_session_course_user AS srcru
                    WHERE
                        course_code='$course_code' AND
                        id_session = '" . $id_session . "'";
            $rs = Database::query($sql);
            while ($row = Database::fetch_array($rs)) {
                $a_students[$row['id_user']] = $row['id_user'];
            }
        }

        // Then, courses where $coach_id is coach of the session
        $sql = 'SELECT id_coach FROM ' . $tbl_session . '
                WHERE id="' . $id_session.'" AND id_coach="' . $coach_id . '"';
        $result = Database::query($sql);
        //He is the session_coach so we select all the users in the session
        if (Database::num_rows($result) > 0) {
            $sql = 'SELECT DISTINCT srcru.id_user
                    FROM ' . $tbl_session_course_user . ' AS srcru
                    WHERE id_session="' . $id_session . '"';
            $result = Database::query($sql);
            while ($row = Database::fetch_array($result)) {
                $a_students[$row['id_user']] = $row['id_user'];
            }
        }
        return $a_students;
    }

    /**
     * Check if a coach is allowed to follow a student
     * @param    int        Coach id
     * @param    int        Student id
     * @return    bool
     */
    public static function is_allowed_to_coach_student($coach_id, $student_id)
    {
        $coach_id = intval($coach_id);
        $student_id = intval($student_id);

        $tbl_session_course_user = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
        $tbl_session_course = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE);
        $tbl_session = Database :: get_main_table(TABLE_MAIN_SESSION);

        // At first, courses where $coach_id is coach of the course //

        $sql = 'SELECT 1 FROM ' . $tbl_session_course_user . ' WHERE id_user=' . $coach_id .' AND status=2';
        $result = Database::query($sql);
        if (Database::num_rows($result) > 0) {
            return true;
        }
        // Then, courses where $coach_id is coach of the session
        $sql = 'SELECT session_course_user.id_user
                    FROM ' . $tbl_session_course_user . ' as session_course_user
                    INNER JOIN ' . $tbl_session_course . ' as session_course
                        ON session_course.course_code = session_course_user.course_code
                    INNER JOIN ' . $tbl_session . ' as session
                        ON session.id = session_course.id_session
                        AND session.id_coach = ' . $coach_id . '
                    WHERE id_user = ' . $student_id;
        $result = Database::query($sql);
        if (Database::num_rows($result) > 0) {
            return true;
        }
        return false;
    }

    /**
     * Get courses followed by coach
     * @param     int        Coach id
     * @param    int        Session id (optional)
     * @return    array    Courses list
     */
    public static function get_courses_followed_by_coach($coach_id, $id_session = null)
    {
        $coach_id = intval($coach_id);
        if (!empty($id_session)) {
            $id_session = intval($id_session);
        }

        $tbl_session_course_user = Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
        $tbl_session_course = Database::get_main_table(TABLE_MAIN_SESSION_COURSE);
        $tbl_session = Database::get_main_table(TABLE_MAIN_SESSION);
        $tbl_course = Database::get_main_table(TABLE_MAIN_COURSE);

        // At first, courses where $coach_id is coach of the course.

        $sql = 'SELECT DISTINCT course_code
                FROM ' . $tbl_session_course_user . '
                WHERE id_user = ' . $coach_id.' AND status = 2';
        if (api_is_multiple_url_enabled()) {
            $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 = 'SELECT DISTINCT scu.course_code
                        FROM ' . $tbl_session_course_user . ' scu
                        INNER JOIN '.$tbl_course_rel_access_url.' cru
                        ON (scu.course_code = cru.course_code)
                        WHERE
                            scu.id_user=' . $coach_id.' AND
                            scu.status=2 AND
                            cru.access_url_id = '.$access_url_id;
            }
        }

        if (!empty($id_session)) {
            $sql .= ' AND id_session=' . $id_session;
        }

        $courseList = array();
        $result = Database::query($sql);
        while ($row = Database::fetch_array($result)) {
            $courseList[$row['course_code']] = $row['course_code'];
        }

        // Then, courses where $coach_id is coach of the session

        $sql = 'SELECT DISTINCT session_course.course_code
                FROM ' . $tbl_session_course . ' as session_course
                INNER JOIN ' . $tbl_session . ' as session
                    ON session.id = session_course.id_session
                    AND session.id_coach = ' . $coach_id . '
                INNER JOIN ' . $tbl_course . ' as course
                    ON course.code = session_course.course_code';

        if (api_is_multiple_url_enabled()) {
            $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 = 'SELECT DISTINCT session_course.course_code
                    FROM ' . $tbl_session_course . ' as session_course
                    INNER JOIN ' . $tbl_session . ' as session
                        ON session.id = session_course.id_session
                        AND session.id_coach = ' . $coach_id . '
                    INNER JOIN ' . $tbl_course . ' as course
                        ON course.code = session_course.course_code
                     INNER JOIN '.$tbl_course_rel_access_url.' course_rel_url
                    ON (session_course.course_code = course_rel_url.course_code)';
            }
        }

        if (!empty ($id_session)) {
            $sql .= ' WHERE session_course.id_session=' . $id_session;
            if (api_is_multiple_url_enabled())
            $sql .=  ' AND access_url_id = '.$access_url_id;
        }  else {
            if (api_is_multiple_url_enabled())
            $sql .=  ' WHERE access_url_id = '.$access_url_id;
        }

        $result = Database::query($sql);
        while ($row = Database::fetch_array($result)) {
            $courseList[$row['course_code']] = $row['course_code'];
        }

        return $courseList;
    }

    /**
     * Get sessions coached by user
     * @param    int        Coach id
     * @return    array    Sessions list
     */
    public static function get_sessions_coached_by_user($coach_id, $start = 0, $limit = 0, $getCount = false)
    {
        // table definition
        $tbl_session = Database :: get_main_table(TABLE_MAIN_SESSION);
        $tbl_session_course_user = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE_USER);

        $coach_id = intval($coach_id);

        $select = " SELECT * FROM ";

        if ($getCount) {
            $select = " SELECT count(DISTINCT id) as count FROM ";
        }

        $limitCondition = null;
        if (!empty($start) && !empty($limit)) {
            $limitCondition = " LIMIT ".intval($start).", ".intval($limit);
        }

        // session where we are general coach
        $sql = " $select

                (
                    SELECT DISTINCT id, name, date_start, date_end
                    FROM $tbl_session
                    WHERE id_coach = $coach_id
                UNION
                    SELECT DISTINCT session.id, session.name, session.date_start, session.date_end
                    FROM $tbl_session as session
                    INNER JOIN $tbl_session_course_user as session_course_user
                        ON session.id = session_course_user.id_session AND
                        session_course_user.id_user= $coach_id AND
                        session_course_user.status=2
                )
                as sessions $limitCondition
                ";

        if (api_is_multiple_url_enabled()) {
            $tbl_session_rel_access_url= Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_SESSION);
            $access_url_id = api_get_current_access_url_id();
            if ($access_url_id != -1){
                $sql = "
                    $select
                    (
                        SELECT DISTINCT id, name, date_start, date_end
                        FROM $tbl_session session INNER JOIN $tbl_session_rel_access_url session_rel_url
                        ON (session.id = session_rel_url.session_id)
                        WHERE id_coach = $coach_id AND access_url_id = $access_url_id
                    UNION
                        SELECT DISTINCT session.id, session.name, session.date_start, session.date_end
                        FROM $tbl_session as session
                        INNER JOIN $tbl_session_course_user as session_course_user
                            ON session.id = session_course_user.id_session AND
                            session_course_user.id_user= $coach_id AND
                            session_course_user.status=2
                        INNER JOIN $tbl_session_rel_access_url session_rel_url
                        ON (session.id = session_rel_url.session_id)
                        WHERE access_url_id = $access_url_id
                    ) as sessions $limitCondition
                    ";
            }
        }

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

        while ($row = Database::fetch_array($rs)) {
            $a_sessions[$row["id"]] = $row;
        }

        if (is_array($a_sessions)) {
            foreach ($a_sessions as & $session) {
                if ($session['date_start'] == '0000-00-00') {
                    $session['status'] = get_lang('SessionActive');
                }
                else {
                    $date_start = explode('-', $session['date_start']);
                    $time_start = mktime(0, 0, 0, $date_start[1], $date_start[2], $date_start[0]);
                    $date_end = explode('-', $session['date_end']);
                    $time_end = mktime(0, 0, 0, $date_end[1], $date_end[2], $date_end[0]);
                    if ($time_start < time() && time() < $time_end) {
                        $session['status'] = get_lang('SessionActive');
                    } else {
                        if (time() < $time_start) {
                            $session['status'] = get_lang('SessionFuture');
                        } else {
                            if (time() > $time_end) {
                                $session['status'] = get_lang('SessionPast');
                            }
                        }
                    }
                }
            }
        }

        return $a_sessions;
    }

    /**
     * Get courses list from a session
     * @param    int        Session id
     * @return    array    Courses list
     */
    public static function get_courses_list_from_session($session_id)
    {
        $session_id = intval($session_id);

        // table definition
        $tbl_session_course = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE);

        $sql = 'SELECT DISTINCT course_code
                    FROM ' . $tbl_session_course . '
                    WHERE id_session=' . $session_id;

        $rs = Database::query($sql);
        $a_courses = array ();
        while ($row = Database::fetch_array($rs)) {
            $a_courses[$row['course_code']] = $row;
        }
        return $a_courses;
    }

    /**
     * Count the number of documents that an user has uploaded to a course
     * @param    int|array   Student id(s)
     * @param    string      Course code
     * @param    int         Session id (optional), if param $session_id is null(default) return count of assignments including sessions, 0 = session is not filtered
     * @return    int        Number of documents
     */

    public static function count_student_uploaded_documents($student_id, $course_code, $session_id = null)
    {
        // get the information of the course
        $a_course = CourseManager::get_course_information($course_code);
        if (!empty($a_course)) {
            // table definition
            $tbl_item_property = Database :: get_course_table(TABLE_ITEM_PROPERTY);
            $tbl_document = Database :: get_course_table(TABLE_DOCUMENT);
            $course_id	 = $a_course['real_id'];
            if (is_array($student_id)) {
                $studentList = array_map('intval', $student_id);
                $condition_user = " AND ip.insert_user_id IN ('".implode(',', $studentList)."') ";
            } else {
                $student_id = intval($student_id);
                $condition_user = " AND ip.insert_user_id = '$student_id' ";
            }

            $condition_session = null;
            if (isset($session_id)) {
                $session_id = intval($session_id);
                $condition_session = " AND pub.session_id = $session_id ";
            }

            $sql = "SELECT count(ip.tool) AS count
                    FROM $tbl_item_property ip INNER JOIN $tbl_document pub
                            ON ip.ref = pub.id
                    WHERE 	ip.c_id  = $course_id AND
                            pub.c_id  = $course_id AND
                            pub.filetype ='file' AND
                            ip.tool = 'document'
                            $condition_user $condition_session ";
            $rs = Database::query($sql);
            $row = Database::fetch_row($rs);
            return $row['count'];
        }
        return null;
    }

    /**
     * Count assignments per student
     * @param    int|array   Student id(s)
     * @param    string        Course code
     * @param    int            Session id (optional), if param $session_id is null(default) return count of assignments including sessions, 0 = session is not filtered
     * @return    int            Count of assignments
     */
    public static function count_student_assignments($student_id, $course_code = null, $session_id = null)
    {
        if (empty($student_id)) {
            return 0;
        }

        $conditions = array();

        // Get the information of the course
        $a_course = CourseManager::get_course_information($course_code);
        if (!empty($a_course)) {
            $course_id = $a_course['real_id'];
            $conditions[]= " ip.c_id  = $course_id AND pub.c_id  = $course_id ";
        }

        // table definition
        $tbl_item_property = Database :: get_course_table(TABLE_ITEM_PROPERTY);
        $tbl_student_publication = Database :: get_course_table(TABLE_STUDENT_PUBLICATION);

        if (is_array($student_id)) {
            $studentList = array_map('intval', $student_id);
            $conditions[]= " ip.insert_user_id IN ('".implode("','", $studentList)."') ";
        } else {
            $student_id = intval($student_id);
            $conditions[]= " ip.insert_user_id = '$student_id' ";
        }
        if (isset($session_id)) {
            $session_id = intval($session_id);
            $conditions[]= " pub.session_id = $session_id ";
        }
        $conditionToString = implode('AND', $conditions);

        $sql = "SELECT count(ip.tool) as count
                FROM $tbl_item_property ip
                INNER JOIN $tbl_student_publication pub ON ip.ref = pub.id
                WHERE
                    ip.tool='work' AND
                    $conditionToString";
        $rs = Database::query($sql);
        $row = Database::fetch_array($rs, 'ASSOC');
        return $row['count'];
    }

    /**
     * Count messages per student inside forum tool
     * @param    int|array        Student id
     * @param    string    Course code
     * @param    int        Session id (optional), if param $session_id is
     * null(default) return count of messages including sessions, 0 = session is not filtered
     * @return    int        Count of messages
     */
    public static function count_student_messages($student_id, $courseCode = null, $session_id = null)
    {
        if (empty($student_id)) {
            return 0;
        }

        $courseInfo = api_get_course_info($courseCode);
        $courseCondition = null;
        $conditions = array();
        if (!empty($courseInfo)) {
            $course_id	    = $courseInfo['real_id'];
            $conditions[]= " post.c_id  = $course_id AND forum.c_id = $course_id ";
        }

        // Table definition.
        $tbl_forum_post = Database :: get_course_table(TABLE_FORUM_POST);
        $tbl_forum      = Database :: get_course_table(TABLE_FORUM);

        if (is_array($student_id)) {
            $studentList = array_map('intval', $student_id);
            $conditions[]= " post.poster_id IN ('".implode("','", $studentList)."') ";
        } else {
            $student_id = intval($student_id);
            $conditions[]= " post.poster_id = '$student_id' ";
        }

        if (isset($session_id)) {
            $session_id = intval($session_id);
            $conditions[]= " forum.session_id = $session_id";
        }

        $conditionsToString = implode('AND ', $conditions);
        $sql = "SELECT count(poster_id) as count
                FROM $tbl_forum_post post INNER JOIN $tbl_forum forum
                ON forum.forum_id = post.forum_id
                WHERE $conditionsToString";

        $rs = Database::query($sql);
        $row = Database::fetch_array($rs, 'ASSOC');
        $count = $row['count'];
        return $count;
    }

    /**
     * This function counts the number of post by course
     * @param      string     Course code
     * @param    int        Session id (optional), if param $session_id is null(default) it'll return results including sessions, 0 = session is not filtered
     * @return    int     The number of post by course
     */
    public static function count_number_of_posts_by_course($course_code, $session_id = null)
    {
        $a_course = CourseManager :: get_course_information($course_code);
        if (!empty($a_course)) {
            $tbl_posts 		= Database :: get_course_table(TABLE_FORUM_POST);
            $tbl_forums 	= Database :: get_course_table(TABLE_FORUM);

            $condition_session = '';
            if (isset($session_id)) {
                $session_id = intval($session_id);
                $condition_session = ' AND f.session_id = '. $session_id;
            }

            $course_id	 = $a_course['real_id'];

            $sql = "SELECT count(*) FROM $tbl_posts p INNER JOIN $tbl_forums f
                    ON f.forum_id = p.forum_id
                    WHERE 	p.c_id = $course_id AND
                            f.c_id = $course_id
                            $condition_session
                    ";
            $result = Database::query($sql);
            $row = Database::fetch_row($result);
            $count = $row[0];
            return $count;
        } else {
            return null;
        }
    }

    /**
     * This function counts the number of threads by course
     * @param      string     Course code
     * @param    int        Session id (optional), if param $session_id is null(default) it'll return results including sessions, 0 = session is not filtered
     * @return    int     The number of threads by course
     */
    public static function count_number_of_threads_by_course($course_code, $session_id = null)
    {
        $course_info = api_get_course_info($course_code);
        if (empty($course_info)) {
            return null;
        }
        $course_id = $course_info['real_id'];
        $tbl_threads = Database :: get_course_table(TABLE_FORUM_THREAD);
        $tbl_forums  = Database :: get_course_table(TABLE_FORUM);
        $condition_session = '';
        if (isset($session_id)) {
            $session_id = intval($session_id);
            $condition_session = '  AND f.session_id = '. $session_id;
        }

        $sql = "SELECT count(*) FROM $tbl_threads t INNER JOIN $tbl_forums f ON f.forum_id = t.forum_id
                WHERE t.c_id = $course_id AND f.c_id = $course_id  $condition_session ";
        $result = Database::query($sql);
        if (Database::num_rows($result)) {
            $row = Database::fetch_row($result);
            $count = $row[0];
            return $count;
        } else {
            return null;
        }
    }

    /**
     * This function counts the number of forums by course
     * @param      string     Course code
     * @param    int        Session id (optional), if param $session_id is null(default) it'll return results including sessions, 0 = session is not filtered
     * @return    int     The number of forums by course
     */
    public static function count_number_of_forums_by_course($course_code, $session_id = null)
    {
        $course_info = api_get_course_info($course_code);
        if (empty($course_info)) {
            return null;
        }
        $course_id = $course_info['real_id'];

        $condition_session = '';
        if (isset($session_id)) {
             $session_id = intval($session_id);
             $condition_session = '  session_id = '. $session_id;
        }

        $tbl_forums = Database :: get_course_table(TABLE_FORUM);
        $sql = "SELECT count(*) FROM $tbl_forums WHERE c_id = $course_id AND $condition_session";
        $result = Database::query($sql);
        if (Database::num_rows($result)) {
            $row = Database::fetch_row($result);
            $count = $row[0];
            return $count;
        } else {
            return null;
        }
    }

    /**
     * This function counts the chat last connections by course in x days
     * @param      string     Course code
     * @param      int     Last x days
     * @param    int        Session id (optional)
     * @return     int     Chat last connections by course in x days
     */
    public static function chat_connections_during_last_x_days_by_course($course_code, $last_days, $session_id = 0)
    {
        $course_info = api_get_course_info($course_code);
        if (empty($course_info)) {
            return null;
        }
        $course_id = $course_info['real_id'];

        //protect data
        $last_days   = intval($last_days);
        $course_code = Database::escape_string($course_code);
        $session_id  = intval($session_id);
        $tbl_stats_access = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_ACCESS);

        $sql = "SELECT count(*) FROM $tbl_stats_access WHERE DATE_SUB(NOW(),INTERVAL $last_days DAY) <= access_date
                AND access_cours_code = '$course_code' AND access_tool='".TOOL_CHAT."' AND access_session_id='$session_id' ";
        $result = Database::query($sql);
        if (Database::num_rows($result)) {
            $row = Database::fetch_row($result);
            $count = $row[0];
            return $count;
        } else {
            return null;
        }
    }

    /**
     * This function gets the last student's connection in chat
     * @param      int     Student id
     * @param      string     Course code
     * @param    int        Session id (optional)
     * @return     string    datetime formatted without day (e.g: February 23, 2010 10:20:50 )
     */
    public static function chat_last_connection($student_id, $course_code, $session_id = 0)
    {
        $student_id = intval($student_id);
        $course_code= Database::escape_string($course_code);
        $session_id    = intval($session_id);
        $date_time  = '';

        // table definition
        $tbl_stats_access = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_LASTACCESS);
        $sql = "SELECT access_date
                FROM $tbl_stats_access
                WHERE
                     access_tool='".TOOL_CHAT."' AND
                     access_user_id='$student_id' AND
                     access_cours_code = '$course_code' AND
                     access_session_id = '$session_id'
                ORDER BY access_date DESC limit 1";
        $rs = Database::query($sql);
        if (Database::num_rows($rs) > 0) {
            $row = Database::fetch_array($rs);
            $date_time = api_convert_and_format_date($row['access_date'], null, date_default_timezone_get());
        }
        return $date_time;
    }

    /**
     * Get count student's visited links
     * @param    int        Student id
     * @param    string    Course code
     * @param    int        Session id (optional)
     * @return    int        count of visited links
     */
    public static function count_student_visited_links($student_id, $course_code, $session_id = 0)
    {

        // protect datas
        $student_id  = intval($student_id);
        $course_code = Database::escape_string($course_code);
        $session_id  = intval($session_id);

        // table definition
        $tbl_stats_links = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_LINKS);

        $sql = 'SELECT 1
                FROM '.$tbl_stats_links.'
                WHERE
                    links_user_id= '.$student_id.' AND
                    links_cours_id = "'.$course_code.'" AND
                    links_session_id = '.$session_id.' ';

        $rs = Database::query($sql);
        return Database::num_rows($rs);
    }

    /**
     * Get count student downloaded documents
     * @param    int        Student id
     * @param    string    Course code
     * @param    int        Session id (optional)
     * @return    int        Count downloaded documents
     */
    public static function count_student_downloaded_documents($student_id, $course_code, $session_id = 0)
    {
        // protect datas
        $student_id  = intval($student_id);
        $course_code = Database::escape_string($course_code);
        $session_id  = intval($session_id);

        // table definition
        $tbl_stats_documents = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_DOWNLOADS);

        $sql = 'SELECT 1
                FROM ' . $tbl_stats_documents . '
                WHERE down_user_id = '.$student_id.'
                AND down_cours_id  = "'.$course_code.'"
                AND down_session_id = '.$session_id.' ';
        $rs = Database::query($sql);
        return Database::num_rows($rs);
    }

    /**
     * Get course list inside a session from a student
     * @param    int        Student id
     * @param    int        Session id (optional)
     * @return    array    Courses list
     */
    public static function get_course_list_in_session_from_student($user_id, $id_session = 0)
    {
        $user_id = intval($user_id);
        $id_session = intval($id_session);
        $tbl_session_course_user = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
        $sql = 'SELECT course_code
                FROM ' . $tbl_session_course_user . '
                WHERE
                    id_user="' . $user_id . '" AND
                    id_session="' . $id_session . '"';
        $result = Database::query($sql);
        $a_courses = array ();
        while ($row = Database::fetch_array($result)) {
            $a_courses[$row['course_code']] = $row['course_code'];
        }
        return $a_courses;
    }

    /**
     * Get inactives students in course
     * @param    string    Course code
     * @param    string    Since login course date (optional, default = 'never')
     * @param    int        Session id    (optional)
     * @return    array    Inactives users
     */
    public static function get_inactives_students_in_course($course_code, $since = 'never', $session_id=0)
    {
        $tbl_track_login         = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_COURSE_ACCESS);
        $tbl_session_course_user = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
        $table_course_rel_user   = Database :: get_main_table(TABLE_MAIN_COURSE_USER);
        $inner = '';
        if ($session_id!=0) {
            $inner = ' INNER JOIN '.$tbl_session_course_user.' session_course_user
                    ON stats_login.course_code = session_course_user.course_code
                    AND session_course_user.id_session = '.intval($session_id).'
                    AND session_course_user.id_user = stats_login.user_id ';
        }
        $sql = 'SELECT user_id, MAX(login_course_date) max_date FROM'.$tbl_track_login.' stats_login'.$inner.'
            GROUP BY user_id
            HAVING DATE_SUB( NOW(), INTERVAL '.$since.' DAY) > max_date ';
        //HAVING DATE_ADD(max_date, INTERVAL '.$since.' DAY) < NOW() ';

        if ($since == 'never') {
            $sql = 'SELECT course_user.user_id FROM '.$table_course_rel_user.' course_user
                    LEFT JOIN '. $tbl_track_login.' stats_login
                    ON course_user.user_id = stats_login.user_id AND relation_type<>'.COURSE_RELATION_TYPE_RRHH.' '.
            $inner.'
                WHERE course_user.course_code = \''.Database::escape_string($course_code).'\'
                AND stats_login.login_course_date IS NULL
                GROUP BY course_user.user_id';
        }
        $rs = Database::query($sql);
        $inactive_users = array();
        while($user = Database::fetch_array($rs)) {
            $inactive_users[] = $user['user_id'];
        }
        return $inactive_users;
    }

    /**
     * Get count login per student
     * @param    int        Student id
     * @param    string    Course code
     * @param    int        Session id (optional)
     * @return    int        count login
     */
    public static function count_login_per_student($student_id, $course_code, $session_id = 0)
    {
        $student_id  = intval($student_id);
        $course_code = Database::escape_string($course_code);
        $session_id  = intval($session_id);
        $tbl_course_rel_user = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ACCESS);

        $sql = 'SELECT '.$student_id.'
                FROM ' . $tbl_course_rel_user . '
                WHERE access_user_id=' . $student_id . '
                AND access_cours_code="' . $course_code . '" AND access_session_id = "'.$session_id.'" ';

        $rs = Database::query($sql);
        $nb_login = Database::num_rows($rs);

        return $nb_login;
    }

    /**
     * Get students followed by a human resources manager
     * @param    int        Drh id
     * @return    array    Student list
     */
    public static function get_student_followed_by_drh($hr_dept_id)
    {
        $hr_dept_id = intval($hr_dept_id);
        $a_students = array();
        $tbl_user     = Database :: get_main_table(TABLE_MAIN_USER);

        $sql = 'SELECT DISTINCT user_id FROM '.$tbl_user.' as user
            WHERE hr_dept_id='.$hr_dept_id;
        $rs = Database::query($sql);

        while($user = Database :: fetch_array($rs)) {
            $a_students[$user['user_id']] = $user['user_id'];
        }

        return $a_students;
    }

    /**
     * Gets the average of test and scorm inside a learning path
     * @param    int     User id
     * @param     string     Course id
     * @return    float    average of test
     * @author     isaac flores paz
     * @deprecated get_avg_student_score should be use
     */
    public static function get_average_test_scorm_and_lp ($user_id, $course_id)
    {

        //the score inside the Reporting table
        $course_info      = api_get_course_info($course_id);
        $course_id        = $course_info['real_id'];

        $lp_table         = Database :: get_course_table(TABLE_LP_MAIN);
        $lp_view_table    = Database  :: get_course_table(TABLE_LP_VIEW);
        $lp_item_view_table = Database  :: get_course_table(TABLE_LP_ITEM_VIEW);
        $lp_item_table = Database  :: get_course_table(TABLE_LP_ITEM);

        $sql_type = "SELECT id, lp_type FROM $lp_table WHERE c_id = $course_id";
        $rs_type=Database::query($sql_type);
        $average_data=0;
        $count_loop=0;
        $lp_list = array();
        while ($row_type = Database::fetch_array($rs_type)) {
            $lp_list[] = $row_type['id'];
            if ($row_type['lp_type']==1) {
                //lp chamilo

                $sql = "SELECT id FROM $lp_view_table  WHERE c_id = $course_id AND user_id = '".intval($user_id)."' and lp_id='".$row_type['id']."'";
                $rs_last_lp_view_id = Database::query($sql);
                $lp_view_id = intval(Database::result($rs_last_lp_view_id,0,'id'));

                $sql_list_view="SELECT li.max_score,lv.user_id,liw.score,(liw.score/li.max_score) as sum_data
                                FROM $lp_item_table li
                                INNER JOIN $lp_view_table lv
                                ON li.lp_id=lv.lp_id
                                INNER JOIN $lp_item_view_table liw
                                ON liw.lp_item_id=li.id
                                WHERE   li.c_id = $course_id AND
                                        liw.c_id = $course_id AND
                                        lv.c_id = $course_id AND
                                        lv.user_id= $user_id AND
                                        li.item_type = 'quiz' AND
                                        liw.lp_view_id= $lp_view_id";
                $sum=0;
                $tot=0;
                $rs_list_view1=Database::query($sql_list_view);
                while ($row_list_view=Database::fetch_array($rs_list_view1)) {
                    $sum=$sum+$row_list_view['sum_data'];
                    $tot++;
                }
                if ($tot==0) {
                    $tot=1;
                }
                $average_data1=$sum/$tot;
                $sql_list_view='';
                $rs_last_lp_view_id='';

            } elseif ($row_type['lp_type']==2) {
                //lp scorm
                $sql = "SELECT id FROM $lp_view_table  WHERE c_id = $course_id AND user_id = '".intval($user_id)."' and lp_id='".$row_type['id']."'";
                $rs_last_lp_view_id = Database::query($sql);
                $lp_view_id = intval(Database::result($rs_last_lp_view_id,0,'id'));

                $sql_list_view = "SELECT li.max_score,lv.user_id,liw.score,((liw.score/li.max_score)*100) as sum_data
                                   FROM $lp_item_table li
                                   INNER JOIN $lp_view_table lv
                                   ON li.lp_id=lv.lp_id
                                   INNER JOIN $lp_item_view_table liw ON liw.lp_item_id=li.id
                                   WHERE li.c_id = $course_id AND
                                        liw.c_id = $course_id AND
                                        lv.c_id = $course_id AND
                                        lv.user_id= $user_id AND
                                        (li.item_type = 'sco' OR li.item_type='quiz') AND
                                        liw.lp_view_id = $lp_view_id";
                $tot=0;
                $sum=0;

                $rs_list_view2=Database::query($sql_list_view);
                while ($row_list_view=Database::fetch_array($rs_list_view2)) {
                    $sum=$sum+$row_list_view['sum_data'];
                    $tot++;
                }
                if ($tot==0) {
                    $tot=1;
                }
                $average_data2=$sum/$tot;
            }
            $average_data_sum = $average_data_sum+$average_data1+$average_data2;
            $average_data2=0;
            $average_data1=0;
            $count_loop++;
        }

        //We only count the LP that have an exercise to get the average
        $lp_with_quiz = 0;
        foreach($lp_list as $lp_id) {

            //check if LP have a score
            $sql = "SELECT count(id) as count FROM $lp_item_table
                    WHERE c_id = $course_id AND item_type = 'quiz' AND lp_id = ".$lp_id." ";
            $result_have_quiz = Database::query($sql);

            if (Database::num_rows($result_have_quiz) > 0 ) {
                $row = Database::fetch_array($result_have_quiz,'ASSOC');
                if (is_numeric($row['count']) && $row['count'] != 0) {
                    $lp_with_quiz++;
                }
            }
        }

        if ($lp_with_quiz > 0) {
            $avg_student_score = round(($average_data_sum / $lp_with_quiz * 100), 2);
        }
        return $avg_student_score;
    }

    /**
     * get count clicks about tools most used by course
     * @param      string     Course code
     * @param    int        Session id (optional), if param $session_id is null(default) it'll return results including sessions, 0 = session is not filtered
     * @return    array     tools data
     */
    public static function get_tools_most_used_by_course($course_code, $session_id = null)
    {
        //protect data
        $course_code = Database::escape_string($course_code);
        $data = array();
        $TABLETRACK_ACCESS = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_LASTACCESS);
        $condition_session     = '';
        if (isset($session_id)) {
            $session_id = intval($session_id);
            $condition_session = ' AND access_session_id = '. $session_id;
        }
        $sql = "SELECT access_tool, COUNT(DISTINCT access_user_id),count( access_tool ) as count_access_tool
                FROM $TABLETRACK_ACCESS
                WHERE
                    access_tool IS NOT NULL AND
                    access_tool != '' AND
                    access_cours_code = '$course_code'
                    $condition_session
                GROUP BY access_tool
                ORDER BY count_access_tool DESC
                LIMIT 0, 3";
        $rs = Database::query($sql);
        if (Database::num_rows($rs) > 0) {
            while ($row = Database::fetch_array($rs)) {
                $data[] = $row;
            }
        }
        return $data;
    }
    /**
     * Get total clicks by session
     * @param    int        Session id (optional), if param $session_id is null(default) it'll return results including sessions, 0 = session is not filtered
     * @return    array     data
     * @todo    implement total click by $course_id
     */
    public static function get_total_clicks_by_session($session_id = null)
    {
        $tables = array(
            TABLE_STATISTIC_TRACK_E_LASTACCESS => array('access_session_id','access_user_id'),
            TABLE_STATISTIC_TRACK_E_ACCESS => array('access_session_id', 'access_user_id'),
            #TABLE_STATISTIC_TRACK_E_LOGIN,
            TABLE_STATISTIC_TRACK_E_DOWNLOADS => array('down_session_id', 'down_user_id'),
            TABLE_STATISTIC_TRACK_E_LINKS => array('links_session_id', 'links_user_id'),
            TABLE_STATISTIC_TRACK_E_ONLINE => array('session_id', 'login_user_id'),
            #TABLE_STATISTIC_TRACK_E_HOTPOTATOES,
            TABLE_STATISTIC_TRACK_E_COURSE_ACCESS => array('session_id', 'user_id'),
            TABLE_STATISTIC_TRACK_E_EXERCICES => array('session_id', 'exe_user_id'),
            TABLE_STATISTIC_TRACK_E_ATTEMPT => array('session_id', 'user_id'),
            #TABLE_STATISTIC_TRACK_E_ATTEMPT_RECORDING,
            #TABLE_STATISTIC_TRACK_E_DEFAULT,
            TABLE_STATISTIC_TRACK_E_UPLOADS => array('upload_session_id', 'upload_user_id'),
            #TABLE_STATISTIC_TRACK_E_HOTSPOT,
            #TABLE_STATISTIC_TRACK_E_ITEM_PROPERTY,
            #TABLE_STATISTIC_TRACK_E_OPEN,
        );

        if (isset($_GET['session_id']) && !empty($_GET['session_id'])) {
            $sessionId = intval($_GET['session_id']);
        }

        foreach ($tables as $tableName => $fields) {
            $sql = sprintf('SELECT %s as user, count(*) as total FROM %s WHERE %s = %s GROUP BY %s', $fields[1], $tableName, $fields[0], $sessionId, $fields[1]);
            $rs = Database::query($sql);
            if (Database::num_rows($rs) > 0) {
                while ($row = Database::fetch_array($rs)) {
                    $data[$row['user']] = (isset($data[$row['user']])) ?  $data[$row['user']] + $row[total]: $row['total'];
                }
            }
        }

        return $data;
    }

    /**
     * get documents most downloaded by course
     * @param      string     Course code
     * @param    int        Session id (optional), if param $session_id is null(default) it'll return results including sessions, 0 = session is not filtered
     * @param    int        Limit (optional, default = 0, 0 = without limit)
     * @return    array     documents downloaded
     */
    public static function get_documents_most_downloaded_by_course($course_code, $session_id = null, $limit = 0)
    {
        //protect data
        $course_code = Database::escape_string($course_code);
        $data = array();

        $TABLETRACK_DOWNLOADS   = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_DOWNLOADS);
        $condition_session = '';
        if (isset($session_id)) {
            $session_id = intval($session_id);
            $condition_session = ' AND down_session_id = '. $session_id;
        }
        $sql = "SELECT down_doc_path, COUNT(DISTINCT down_user_id), COUNT(down_doc_path) as count_down
                FROM $TABLETRACK_DOWNLOADS
                WHERE down_cours_id = '$course_code'
                $condition_session
                GROUP BY down_doc_path
                ORDER BY count_down DESC
                LIMIT 0,  $limit";
        $rs = Database::query($sql);

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

    /**
     * get links most visited by course
     * @param      string     Course code
     * @param    int        Session id (optional), if param $session_id is null(default) it'll return results including sessions, 0 = session is not filtered
     * @return    array     links most visited
     */
    public static function get_links_most_visited_by_course($course_code, $session_id = null)
    {
        $course_code = Database::escape_string($course_code);
        $course_info = api_get_course_info($course_code);

        $course_id = $course_info['real_id'];

        $data = array();

        $TABLETRACK_LINKS       = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_LINKS);
        $TABLECOURSE_LINKS      = Database::get_course_table(TABLE_LINK);

        $condition_session = '';
        if (isset($session_id)) {
            $session_id = intval($session_id);
            $condition_session = ' AND cl.session_id = '.$session_id;
        }

        $sql = "SELECT cl.title, cl.url,count(DISTINCT sl.links_user_id), count(cl.title) as count_visits
                FROM $TABLETRACK_LINKS AS sl, $TABLECOURSE_LINKS AS cl
                WHERE cl.c_id = $course_id AND
                      sl.links_link_id = cl.id
                      AND sl.links_cours_id = '$course_code'
                      $condition_session
                GROUP BY cl.title, cl.url
                ORDER BY count_visits DESC
                LIMIT 0, 3";
        $rs = Database::query($sql);
        if (Database::num_rows($rs) > 0) {
            while ($row = Database::fetch_array($rs)) {
                $data[] = $row;
            }
        }
        return $data;
    }

    /**
     * Shows the user progress (when clicking in the Progress tab)
     * @param   int     user id
     * @return  string  html code
     */
    static function show_user_progress($user_id, $session_id = 0, $extra_params = '', $show_courses = true)
    {
        $tbl_course		            = Database :: get_main_table(TABLE_MAIN_COURSE);
        $tbl_session		        = Database :: get_main_table(TABLE_MAIN_SESSION);
        $tbl_course_user            = Database :: get_main_table(TABLE_MAIN_COURSE_USER);
        $tbl_access_rel_course      = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
        $tbl_session_course_user    = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
        $tbl_access_rel_session     = Database :: get_main_table(TABLE_MAIN_ACCESS_URL_REL_SESSION);
        $user_id = intval($user_id);

        // get course list
        if (api_is_multiple_url_enabled()) {
            $sql = 'SELECT cu.course_code as code, title
                    FROM '.$tbl_course_user.' cu INNER JOIN '.$tbl_access_rel_course.' a
                    ON(a.course_code = cu.course_code)
                    INNER JOIN '.$tbl_course.' c ON( cu.course_code = c.code)
                    WHERE
                        user_id='.$user_id.' AND
                        relation_type<>'.COURSE_RELATION_TYPE_RRHH.' AND
                        access_url_id = '.api_get_current_access_url_id().'
                    ORDER BY title ';
        } else {
            $sql = 'SELECT course_code as code, title
                    FROM '.$tbl_course_user.' u
                    INNER JOIN '.$tbl_course.' c ON(course_code = c.code)
                    WHERE
                        u.user_id='.$user_id.' AND
                        relation_type<>'.COURSE_RELATION_TYPE_RRHH.'
                    ORDER BY title ';
        }

        $rs = Database::query($sql);
        $courses = $course_in_session = $temp_course_in_session = array();
        while($row = Database :: fetch_array($rs, 'ASSOC')) {
            $courses[$row['code']] = $row['title'];
        }

        // Get the list of sessions where the user is subscribed as student
        if (api_is_multiple_url_enabled()) {
            $sql = 'SELECT DISTINCT cu.course_code, id_session as session_id, name
                    FROM '.$tbl_session_course_user.' cu
                    INNER JOIN '.$tbl_access_rel_session.' a
                        ON(a.session_id = cu.id_session)
                    INNER JOIN '.$tbl_session.' s  ON(s.id = a.session_id)
                    WHERE
                        id_user='.$user_id.' AND
                        access_url_id = '.api_get_current_access_url_id().'
                    ORDER BY name ';
        } else {
            $sql = 'SELECT DISTINCT course_code, id_session as session_id, name
                    FROM '.$tbl_session_course_user.' u
                    INNER JOIN '.$tbl_session.' s ON(s.id = u.id_session)
                    WHERE id_user='.$user_id.'
                    ORDER BY name ';
        }

        $rs = Database::query($sql);
        $simple_session_array = array();
        while ($row = Database :: fetch_array($rs)) {
            $course_info = CourseManager::get_course_information($row['course_code']);
            $temp_course_in_session[$row['session_id']]['course_list'][$course_info['id']]  = $course_info;
            $temp_course_in_session[$row['session_id']]['name'] = $row['name'];
            $simple_session_array[$row['session_id']] = $row['name'];
        }
        foreach($simple_session_array as $my_session_id => $session_name) {
            $course_list = $temp_course_in_session[$my_session_id]['course_list'];
            $my_course_data = array();
            foreach ($course_list as $course_data) {
                $my_course_data[$course_data['id']] = $course_data['title'];
            }
            $my_course_data = utf8_sort($my_course_data);
            $final_course_data = array();

            foreach($my_course_data as $course_id => $value) {
                $final_course_data[$course_id] = $course_list[$course_id];
            }
            $course_in_session[$my_session_id]['course_list'] = $final_course_data;
            $course_in_session[$my_session_id]['name'] = $session_name;
        }

        $html = '';

        // Course list

        if ($show_courses) {
            if (!empty($courses)) {
                $html .= Display::page_subheader(
                    Display::return_icon('course.png', get_lang('MyCourses'), array(), ICON_SIZE_SMALL).' '.get_lang('MyCourses')
                );
                $html .= '<table class="data_table" width="100%">';
                $html .= '<tr>
                          '.Display::tag('th', get_lang('Course'),          		array('width'=>'300px')).'
                          '.Display::tag('th', get_lang('TimeSpentInTheCourse'),    array('class'=>'head')).'
                          '.Display::tag('th', get_lang('Progress'),        		array('class'=>'head')).'
                          '.Display::tag('th', get_lang('Score').Display::return_icon('info3.gif', get_lang('ScormAndLPTestTotalAverage'), array('align' => 'absmiddle', 'hspace' => '3px')),array('class'=>'head')).'
                          '.Display::tag('th', get_lang('LastConnexion'),   		array('class'=>'head')).'
                          '.Display::tag('th', get_lang('Details'),         		array('class'=>'head')).'
                        </tr>';

                foreach ($courses as $course_code => $course_title) {
                    $weighting = 0;

                    $total_time_login      = Tracking :: get_time_spent_on_the_course($user_id, $course_code);
                    $time                  = api_time_to_hms($total_time_login);
                    $progress              = Tracking :: get_avg_student_progress($user_id, $course_code);
                    $percentage_score      = Tracking :: get_avg_student_score($user_id, $course_code, array());
                    $last_connection       = Tracking :: get_last_connection_date_on_the_course($user_id, $course_code);

                    if (is_null($progress)) {
                        $progress = '0%';
                    } else {
                        $progress = $progress.'%';
                    }

                    if ($course_code == $_GET['course'] && empty($_GET['session_id'])) {
                        $html .= '<tr class="row_odd" style="background-color:#FBF09D">';
                    } else {
                        $html .= '<tr class="row_even">';
                    }
                    $url = api_get_course_url($course_code, $session_id);
                    $course_url = Display::url($course_title, $url, array('target'=>SESSION_LINK_TARGET));
                    $html .= '<td>'.$course_url.'</td>';

                    $html .= '<td align="center">'.$time.'</td>';
                    $html .= '<td align="center">'.$progress.'</td>';

                    $html .= '<td align="center">';
                    if (is_numeric($percentage_score)) {
                        $html .= $percentage_score.'%';
                    } else {
                        $html .= '0%';
                    }
                    $html .= '</td>';
                    $html .= '<td align="center">'.$last_connection.'</td>';
                    $html .= '<td align="center">';
                    if ($course_code == $_GET['course'] && empty($_GET['session_id'])) {
                        $html .= '<a href="#">';
                        $html .= Display::return_icon('2rightarrow_na.gif', get_lang('Details'));
                    } else {
                        $html .= '<a href="'.api_get_self().'?course='.$course_code.$extra_params.'">';
                        $html .= Display::return_icon('2rightarrow.gif', get_lang('Details'));
                    }
                    $html .= '</a>';
                    $html .= '</td></tr>';
                }
                $html .= '</table>';
            }
        }

        // Session list
        if (!empty($course_in_session)) {
            $main_session_graph = '';

            //if (!isset($_GET['session_id']) && !isset($_GET['course'])) {

                //Load graphics only when calling to an specific session
                $session_graph = array();

                $all_exercise_graph_name_list = array();
                $my_results = array();
                $all_exercise_graph_list = array();

                $all_exercise_start_time = array();

                foreach ($course_in_session as $my_session_id => $session_data) {

                    $course_list  = $session_data['course_list'];
                    $session_name = $session_data['name'];

                    $user_count = count(SessionManager::get_users_by_session($my_session_id));

                    $exercise_graph_name_list = array();
                    //$user_results = array();
                    $exercise_graph_list = array();

                    foreach ($course_list as $course_data) {

                        $exercise_list = get_all_exercises($course_data, $my_session_id);

                        foreach ($exercise_list as $exercise_data) {
                            $exercise_obj = new Exercise($course_data['id']);
                            $exercise_obj->read($exercise_data['id']);
                            //Exercise is not necessary to be visible to show results check the result_disable configuration instead
                            //$visible_return = $exercise_obj->is_visible();

                            if ($exercise_data['results_disabled'] == 0 || $exercise_data['results_disabled'] == 2) {
                            //if ($visible_return['value'] == true) {
                                $best_average = intval(get_best_average_score_by_exercise($exercise_data['id'], $course_data['code'], $my_session_id, $user_count));
                                $exercise_graph_list[] 		= $best_average;
                                $all_exercise_graph_list[] 	= $best_average;

                                $user_result_data 	   		= get_best_attempt_by_user(api_get_user_id(), $exercise_data['id'], $course_data['code'], $my_session_id);
                                $score = 0;
                                if (!empty($user_result_data['exe_weighting']) && intval($user_result_data['exe_weighting']) != 0) {
                                    $score = intval($user_result_data['exe_result']/$user_result_data['exe_weighting'] * 100);
                                }
                                //$user_results[] = $score;
                                $time = api_strtotime($exercise_data['start_time']) ? api_strtotime($exercise_data['start_time'], 'UTC') : 0;
                                $all_exercise_start_time[] = $time;
                                $my_results[] = $score;
                                if (count($exercise_list)<=10) {
                                    $title = cut($course_data['title'], 30)." \n ".cut($exercise_data['title'], 30);
                                    $exercise_graph_name_list[]= $title;
                                    $all_exercise_graph_name_list[] = $title;
                                } else {
                                    // if there are more than 10 results, space becomes difficult to find, so only show the title of the exercise, not the tool
                                    $title = cut($exercise_data['title'], 30);
                                    $exercise_graph_name_list[]= $title;
                                    $all_exercise_graph_name_list[]= $title;
                                }
                            }
                        }
                    }
                }

                //Complete graph
                if (!empty($my_results) && !empty($all_exercise_graph_list)) {
                    asort($all_exercise_start_time);

                    //Fix exams order
                    $final_all_exercise_graph_name_list = array();
                    $my_results_final = array();
                    $final_all_exercise_graph_list = array();

                    foreach ($all_exercise_start_time as $key => $time) {
                        $label_time = '';
                        if (!empty($time)) {
                            $label_time = date('d-m-y', $time);
                            //$label_time = api_format_date($time, DATE_FORMAT_NUMBER);
                        }
                        $final_all_exercise_graph_name_list[] 	= $all_exercise_graph_name_list[$key].' '.$label_time;
                        $my_results_final[]                     = $my_results[$key];
                        $final_all_exercise_graph_list[] 		= $all_exercise_graph_list[$key];
                    }
                    $main_session_graph = self::generate_session_exercise_graph($final_all_exercise_graph_name_list, $my_results_final, $final_all_exercise_graph_list);
                }
            //}


            $html .= Display::page_subheader(Display::return_icon('session.png', get_lang('Sessions'), array(), ICON_SIZE_SMALL).' '.get_lang('Sessions'));

            $html .= '<table class="data_table" width="100%">';
            //'.Display::tag('th', get_lang('DoneExercises'),            array('class'=>'head')).'
            $html .= '<tr>
                  '.Display::tag('th', get_lang('Session'),                  array('width'=>'300px')).'
                  '.Display::tag('th', get_lang('PublishedExercises'),       array('width'=>'300px')).'
                  '.Display::tag('th', get_lang('NewExercises'),            array('class'=>'head')).'
                  '.Display::tag('th', get_lang('AverageExerciseResult'),    array('class'=>'head')).'
                  '.Display::tag('th', get_lang('Details'),                  array('class'=>'head')).'
                  </tr>';

            foreach ($course_in_session as $my_session_id => $session_data) {
                $course_list  = $session_data['course_list'];
                $session_name = $session_data['name'];

                if (isset($session_id) && !empty($session_id)) {
                    if ($session_id != $my_session_id) {
                        continue;
                    }
                }

                $all_exercises = 0;
                $all_unanswered_exercises_by_user = 0;
                $all_average = 0;

                $stats_array = array();

                foreach($course_list as $course_data) {
                    //All exercises in the course @todo change for a real count
                    $exercises          = get_all_exercises($course_data, $my_session_id);
                    $count_exercises = 0;
                    if (is_array($exercises) && !empty($exercises)) {
                        $count_exercises 	= count($exercises);
                    }

                    //Count of user results
                    //$done_exercises     = get_count_exercises_attempted_by_course($course_data['code'], $my_session_id);
                    $done_exercises     = null;

                    $answered_exercises = 0;
                    if (!empty($exercises)) {
                        foreach($exercises as $exercise_item) {
                            $attempts = count_exercise_attempts_by_user(api_get_user_id(), $exercise_item['id'], $course_data['code'], $my_session_id);
                            if ($attempts > 1)  {
                                $answered_exercises++;
                            }
                        }
                    }

                    //Average
                    $average            = get_average_score_by_course($course_data['code'], $my_session_id);

                    $all_exercises     += $count_exercises;

                    $all_unanswered_exercises_by_user += $count_exercises - $answered_exercises;
                    //$all_done_exercise += $done_exercises;
                    $all_average       += $average;
                    //$stats_array[$course_data['code']] = array('exercises'=>$count_exercises, 'unanswered_exercises_by_user'=>$answered_exercises,'done_exercises'=>$done_exercises, 'average'=>$average);
                }

                $all_average = $all_average /  count($course_list);

                if (isset($_GET['session_id']) && $my_session_id == $_GET['session_id']) {
                    $html .= '<tr style="background-color:#FBF09D">';
                } else {
                    $html .= '<tr>';
                }
                $url = api_get_path(WEB_CODE_PATH)."session/?session_id={$my_session_id}";

                $html .= Display::tag('td', Display::url($session_name, $url, array('target'=>SESSION_LINK_TARGET)));
                $html .= Display::tag('td', $all_exercises);
                $html .= Display::tag('td', $all_unanswered_exercises_by_user);

                //$html .= Display::tag('td', $all_done_exercise);
                $html .= Display::tag('td', convert_to_percentage($all_average));

                if (isset($_GET['session_id']) && $my_session_id == $_GET['session_id']) {
                    $icon = Display::url(Display::return_icon('2rightarrow_na.gif', get_lang('Details')), '?session_id='.$my_session_id);
                } else {
                    $icon = Display::url(Display::return_icon('2rightarrow.gif', get_lang('Details')), '?session_id='.$my_session_id);
                }
                $html .= Display::tag('td', $icon);
                $html .= '</tr>';
            }
            $html .= '</table><br />';
            $html .= Display::div($main_session_graph, array('id'=>'session_graph','class'=>'chart-session', 'style'=>'position:relative; text-align: center;') );

            //Checking selected session

            if (isset($_GET['session_id'])) {
                $session_id_from_get = intval($_GET['session_id']);

                $session_data 	= $course_in_session[$session_id_from_get];
                $course_list 	= $session_data['course_list'];

                $html .= Display::tag('h3',$session_data['name'].' - '.get_lang('CourseList'));

                $html .= '<table class="data_table" width="100%">';
                //'.Display::tag('th', get_lang('DoneExercises'),         array('class'=>'head')).'
                $html .= '
                    <tr>
                      <th width="300px">'.get_lang('Course').'</th>
                      '.Display::tag('th', get_lang('PublishedExercises'),    	array('class'=>'head')).'
                      '.Display::tag('th', get_lang('NewExercises'),    		array('class'=>'head')).'
                      '.Display::tag('th', get_lang('MyAverage'), 				array('class'=>'head')).'
                      '.Display::tag('th', get_lang('AverageExerciseResult'), 	array('class'=>'head')).'
                      '.Display::tag('th', get_lang('TimeSpentInTheCourse'),    array('class'=>'head')).'
                      '.Display::tag('th', get_lang('LPProgress')     ,      	array('class'=>'head')).'
                      '.Display::tag('th', get_lang('Score').Display::return_icon('info3.gif', get_lang('ScormAndLPTestTotalAverage'), array ('align' => 'absmiddle', 'hspace' => '3px')), array('class'=>'head')).'
                      '.Display::tag('th', get_lang('LastConnexion'),         	array('class'=>'head')).'
                      '.Display::tag('th', get_lang('Details'),               	array('class'=>'head')).'
                    </tr>';

                foreach ($course_list as $course_data) {
                    $course_code 	= $course_data['code'];
                    $course_title 	= $course_data['title'];

                    //All exercises in the course @todo change for a real count
                    $exercises          = get_all_exercises($course_data, $session_id_from_get);
                    $count_exercises = 0;
                    if (!empty($exercises)) {
                        $count_exercises 	= count($exercises);
                    }
                    //Count of user results
                    //$done_exercises     = get_best_exercise_results_by_course($course_code, $session_id_from_get);

                    //From course exercises NOT from LP exercises!!!
                    //$done_exercises     = get_count_exercises_attempted_by_course($course_code, $session_id_from_get);
                    $answered_exercises = 0;
                    foreach($exercises as $exercise_item) {
                        $attempts = count_exercise_attempts_by_user(api_get_user_id(), $exercise_item['id'], $course_code, $session_id_from_get);
                        if ($attempts > 1)  {
                            $answered_exercises++;
                        }
                    }

                    $unanswered_exercises = $count_exercises - $answered_exercises;

                    // Average
                    $average = get_average_score_by_course($course_code, $session_id_from_get);
                    $my_average	= get_average_score_by_course_by_user(api_get_user_id(), $course_code, $session_id_from_get);

                    $stats_array[$course_code] = array(
                        'exercises'						=> $count_exercises,
                        'unanswered_exercises_by_user'	=> $unanswered_exercises,
                        'done_exercises'				=> $done_exercises,
                        'average'						=> $average,
                        'my_average'					=> $my_average
                    );

                    $weighting = 0;
                    $last_connection       = Tracking :: get_last_connection_date_on_the_course($user_id, $course_code, $session_id_from_get);
                    $progress              = Tracking :: get_avg_student_progress($user_id, $course_code,array(), $session_id_from_get);
                    $total_time_login      = Tracking :: get_time_spent_on_the_course($user_id, $course_code, $session_id_from_get);
                    $time                  = api_time_to_hms($total_time_login);
                    $percentage_score      = Tracking :: get_avg_student_score($user_id, $course_code, array(), $session_id_from_get);

                    if ($course_code == $_GET['course'] && $_GET['session_id'] == $session_id_from_get) {
                        $html .= '<tr class="row_odd" style="background-color:#FBF09D" >';
                    } else {
                        $html .= '<tr class="row_even">';
                    }

                    $url        = api_get_course_url($course_code, $session_id_from_get);
                    $course_url = Display::url($course_title, $url, array('target'=>SESSION_LINK_TARGET));

                    $html .= Display::tag('td', $course_url);
                    $html .= Display::tag('td', $stats_array[$course_code]['exercises']);
                    $html .= Display::tag('td', $stats_array[$course_code]['unanswered_exercises_by_user']);
                    //$html .= Display::tag('td', $stats_array[$course_code]['done_exercises']);
                    $html .= Display::tag('td', convert_to_percentage($stats_array[$course_code]['my_average']));

                    $html .= Display::tag('td', $stats_array[$course_code]['average'] == 0 ? '-' : '('.convert_to_percentage($stats_array[$course_code]['average']).')');
                    $html .= Display::tag('td', $time, array('align'=>'center'));

                    if (is_numeric($progress)) {
                        $progress = $progress.'%';
                    } else {
                        $progress = '0%';
                    }
                    //Progress
                    $html .= Display::tag('td', $progress, array('align'=>'center'));
                    if (is_numeric($percentage_score)) {
                        $percentage_score = $percentage_score.'%';
                    } else {
                        $percentage_score = '0%';
                    }
                    //Score
                    $html .= Display::tag('td', $percentage_score, array('align'=>'center'));
                    $html .= Display::tag('td', $last_connection,  array('align'=>'center'));

                    if ($course_code == $_GET['course'] && $_GET['session_id'] == $session_id_from_get) {
                        $details = '<a href="#">';
                        $details .=Display::return_icon('2rightarrow_na.gif', get_lang('Details'));
                    } else {
                        $details = '<a href="'.api_get_self().'?course='.$course_code.'&session_id='.$session_id_from_get.$extra_params.'">';
                        $details .=Display::return_icon('2rightarrow.gif', get_lang('Details'));
                    }
                    $details .= '</a>';
                    $html .= Display::tag('td', $details, array('align'=>'center'));
                    $html .= '</tr>';
                }
                $html .= '</table>';

                if (!empty($session_graph[$session_id_from_get])) {
                    //$html .= Display::div($session_graph[$session_id_from_get], array('id'=>'session_graph','class'=>'chart-session', 'style'=>'position:relative; text-align: center;') );
                }
            }
        }
        return $html;
    }

    /**
     * Shows the user detail progress (when clicking in the details link)
     * @param   int     user id
     * @param   string  course code
     * @param   int     session id
     * @return  string  html code
     */
    static function show_course_detail($user_id, $course_code, $session_id)
    {
        $html = '';
        if (isset($course_code)) {

            $user_id                    = intval($user_id);
            $session_id                 = intval($session_id);
            $course                     = Database::escape_string($course_code);
            $course_info                = CourseManager::get_course_information($course);

            //$course_id                  = $course_info['real_id'];
            //$session_name               = api_get_session_name($session_id);

            $html .= Display::page_subheader($course_info['title']);

            $html .= '<table class="data_table" width="100%">';

            //Course details
            $html .= '
                <tr>
                <th class="head" style="color:#000">'.get_lang('Exercices').'</th>
                <th class="head" style="color:#000">'.get_lang('Attempts').'</th>
                <th class="head" style="color:#000">'.get_lang('BestAttempt').'</th>
                <th class="head" style="color:#000">'.get_lang('Ranking').'</th>
                <th class="head" style="color:#000">'.get_lang('BestResultInCourse').'</th>
                <th class="head" style="color:#000">'.get_lang('Statistics').' '.Display :: return_icon('info3.gif', get_lang('OnlyBestResultsPerStudent'), array('align' => 'absmiddle', 'hspace' => '3px')).'</th>
                </tr>';

            if (empty($session_id)) {
                $user_list  = CourseManager::get_user_list_from_course_code($course, $session_id, null, null, STUDENT);
            } else {
                $user_list  = CourseManager::get_user_list_from_course_code($course, $session_id, null, null, 0);
            }

            //$exercise_list = get_all_exercises($course_info, $session_id, true);
            // Show exercise results of invisible exercises? see BT#4091
            $exercise_list = get_all_exercises($course_info, $session_id, false);

            $to_graph_exercise_result = array();

            if (!empty($exercise_list)) {
                $score = $weighting = $exe_id = 0;
                foreach ($exercise_list as $exercices) {

                    $exercise_obj = new Exercise($course_info['real_id']);
                    $exercise_obj->read($exercices['id']);
                    $visible_return = $exercise_obj->is_visible();

                    $score = $weighting = $attempts = 0;

                    //Getting count of attempts by user
                    $attempts      = count_exercise_attempts_by_user(api_get_user_id(), $exercices['id'], $course_info['code'], $session_id);

                    $html .= '<tr class="row_even">';
                    $url = api_get_path(WEB_CODE_PATH)."exercice/overview.php?cidReq={$course_info['code']}&id_session=$session_id&exerciseId={$exercices['id']}";

                    if ($visible_return['value'] == true) {
                        $exercices['title'] = Display::url($exercices['title'], $url, array('target'=>SESSION_LINK_TARGET));
                    }

                    $html .= Display::tag('td', $exercices['title']);

                    //Exercise configuration show results or show only score
                    if ($exercices['results_disabled'] == 0 || $exercices['results_disabled'] == 2) {
                        //For graphics
                        $best_exercise_stats = get_best_exercise_results_by_user($exercices['id'], $course_info['code'], $session_id);
                        $to_graph_exercise_result[$exercices['id']] = array('title'=>$exercices['title'], 'data'=>$best_exercise_stats);

                        $latest_attempt_url = '';
                        $best_score = $position = $percentage_score_result  = '-';
                        $graph = $normal_graph = null;

                        //Getting best results
                        $best_score_data = get_best_attempt_in_course($exercices['id'], $course_info['code'], $session_id);
                        $best_score      = show_score($best_score_data['exe_result'], $best_score_data['exe_weighting']);

                        if ($attempts > 0) {
                            $exercise_stat = get_best_attempt_by_user(api_get_user_id(), $exercices['id'], $course_info['code'], $session_id);
                            if (!empty($exercise_stat)) {

                                //Always getting the BEST attempt
                                $score          = $exercise_stat['exe_result'];
                                $weighting      = $exercise_stat['exe_weighting'];
                                $exe_id         = $exercise_stat['exe_id'];

                                $latest_attempt_url .= api_get_path(WEB_CODE_PATH).'exercice/result.php?id='.$exe_id.'&cidReq='.$course_info['code'].'&show_headers=1&id_session='.$session_id;
                                $percentage_score_result = Display::url(show_score($score, $weighting), $latest_attempt_url);
                                $my_score = 0;
                                if (!empty($weighting) && intval($weighting) != 0) {
                                    $my_score = $score/$weighting;
                                }
                                //@todo this function slows the page
                                $position = get_exercise_result_ranking($my_score, $exe_id, $exercices['id'], $course_info['code'], $session_id, $user_list);

                                $graph         = self::generate_exercise_result_thumbnail_graph($to_graph_exercise_result[$exercices['id']]);
                                $normal_graph  = self::generate_exercise_result_graph($to_graph_exercise_result[$exercices['id']]);
                            }
                        }

                        $html .= Display::div($normal_graph, array('id'=>'main_graph_'.$exercices['id'],'class'=>'dialog', 'style'=>'display:none') );

                        if (empty($graph)) {
                            $graph = '-';
                        } else {
                            $graph = Display::url($graph, '#', array('id'=>$exercices['id'], 'class'=>'opener'));
                        }

                        $html .= Display::tag('td', $attempts,                 array('align'=>'center'));
                        $html .= Display::tag('td', $percentage_score_result,  array('align'=>'center'));
                        $html .= Display::tag('td', $position,                 array('align'=>'center'));
                        $html .= Display::tag('td', $best_score,               array('align'=>'center'));
                        $html .= Display::tag('td', $graph,                    array('align'=>'center'));
                        //$html .= Display::tag('td', $latest_attempt_url,       array('align'=>'center', 'width'=>'25'));

                    } else {
                        // Exercise configuration NO results
                        $html .= Display::tag('td', $attempts,    array('align'=>'center'));
                        $html .= Display::tag('td', '-',          array('align'=>'center'));
                        $html .= Display::tag('td', '-',          array('align'=>'center'));
                        $html .= Display::tag('td', '-',          array('align'=>'center'));
                        $html .= Display::tag('td', '-',          array('align'=>'center'));
                    }
                    $html .= '</tr>';
                }
            } else {
                $html .= '<tr><td colspan="5" align="center">'.get_lang('NoEx').'</td></tr>';
            }
            $html .= '</table>';


            //LP table results
            $html .='<table class="data_table">';
            $html .= Display::tag('th', get_lang('Learnpaths'),         array('class'=>'head', 'style'=>'color:#000'));
            $html .= Display::tag('th', get_lang('LatencyTimeSpent'),   array('class'=>'head', 'style'=>'color:#000'));
            $html .= Display::tag('th', get_lang('Progress'),           array('class'=>'head', 'style'=>'color:#000'));
            $html .= Display::tag('th', get_lang('Score'),              array('class'=>'head', 'style'=>'color:#000'));
            $html .= Display::tag('th', get_lang('LastConnexion'),      array('class'=>'head', 'style'=>'color:#000'));
            $html .= '</tr>';

            $list = new LearnpathList(api_get_user_id(), $course_info['code'], $session_id, 'publicated_on ASC', true);
            $lp_list        = $list->get_flat_list();

            if (!empty($lp_list) > 0) {
                foreach($lp_list as $lp_id => $learnpath) {

                    $progress               = Tracking::get_avg_student_progress($user_id, $course, array($lp_id), $session_id);
                    $last_connection_in_lp  = Tracking::get_last_connection_time_in_lp($user_id, $course, $lp_id, $session_id);
                    $time_spent_in_lp       = Tracking::get_time_spent_in_lp($user_id, $course, array($lp_id), $session_id);
                    $percentage_score 		= Tracking::get_avg_student_score($user_id, $course, array($lp_id), $session_id);
                    if (is_numeric($percentage_score)) {
                        $percentage_score = $percentage_score.'%';
                    } else {
                        $percentage_score = '0%';
                    }

                    $time_spent_in_lp       = api_time_to_hms($time_spent_in_lp);

                    $html .= '<tr class="row_even">';
                    $url = api_get_path(WEB_CODE_PATH)."newscorm/lp_controller.php?cidReq={$course_code}&id_session=$session_id&lp_id=$lp_id&action=view";
                    $html .= Display::tag('td', Display::url($learnpath['lp_name'], $url, array('target'=>SESSION_LINK_TARGET)));
                    $html .= Display::tag('td', $time_spent_in_lp, array('align'=>'center'));
                    if (is_numeric($progress)) {
                        $progress = $progress.'%';
                    }
                    $html .= Display::tag('td', $progress, array('align'=>'center'));
                    $html .= Display::tag('td', $percentage_score);

                    $last_connection = '-';
                    if (!empty($last_connection_in_lp)) {
                        $last_connection = api_convert_and_format_date($last_connection_in_lp, DATE_TIME_FORMAT_LONG);
                    }
                    $html .= Display::tag('td', $last_connection, array('align'=>'center','width'=>'180px'));
                    $html .= "</tr>";
                }
            } else {
                $html .= '<tr>
                        <td colspan="4" align="center">
                            '.get_lang('NoLearnpath').'
                        </td>
                      </tr>';
            }
            $html .='</table>';
        }
        return $html;
    }

    /**
     * Generates an histogram
     *
     * @param 	array	list of exercise names
     * @param 	array	my results 0 to 100
     * @param 	array	average scores 0-100
     */
    static function generate_session_exercise_graph($names, $my_results, $average)
    {
        require_once api_get_path(LIBRARY_PATH).'pchart/pData.class.php';
        require_once api_get_path(LIBRARY_PATH).'pchart/pChart.class.php';
        require_once api_get_path(LIBRARY_PATH).'pchart/pCache.class.php';

        $cache = new pCache();

        // Dataset definition
        $data_set = new pData();

        // Dataset definition
        $data_set->AddPoint($average,	 "Serie1");
        $data_set->AddPoint($my_results, "Serie2");
        $data_set->AddPoint($names,		 "Serie3");
        $data_set->AddAllSeries();
        $data_set->SetAbsciseLabelSerie('Serie3');
        $data_set->SetSerieName(get_lang('AverageScore'),"Serie1");
        $data_set->SetSerieName(get_lang('MyResults'),	 "Serie2");

        //$data_set->SetYAxisName(get_lang("Percentage"));

        $data_set->SetYAxisUnit("%");

        // Initialise the graph
        $main_width    = 860;
        $main_height   = 500;
        $y_label_angle = 50;
        $data_set->RemoveSerie("Serie3");
        $graph = new pChart($main_width, $main_height);
        //See 3.2 BT#2797
        $graph->setFixedScale(0,100);

        $graph->setFontProperties(api_get_path(LIBRARY_PATH).'pchart/fonts/tahoma.ttf',8);
        $graph->setGraphArea(65,50,$main_width-20, $main_height-140);

        $graph->drawFilledRoundedRectangle(7,7,$main_width-7,$main_height-7,5,240,240,240);
        $graph->drawRoundedRectangle(5,5,$main_width-5,$main_height -5,5,230,230,230);
        $graph->drawGraphArea(255,255,255,TRUE);

        //SCALE_NORMAL, SCALE_START0, SCALE_ADDALLSTART0, SCALE_ADDALL
        $graph->drawScale($data_set->GetData(),$data_set->GetDataDescription(),SCALE_NORMAL ,150,150,150,TRUE,$y_label_angle,1, TRUE);
        $graph->drawGrid(4,TRUE,230,230,230,70);

        // Draw the 0 line
        $graph->setFontProperties(api_get_path(LIBRARY_PATH).'pchart/fonts/tahoma.ttf',6);
        $graph->drawTreshold(0,143,55,72,TRUE,TRUE);

        // Draw the cubic curve graph
        $graph->drawLineGraph($data_set->GetData(),$data_set->GetDataDescription());
        $graph->drawPlotGraph($data_set->GetData(),$data_set->GetDataDescription(),1,1,230,255,255);

        // Finish the graph
        $graph->setFontProperties(api_get_path(LIBRARY_PATH).'pchart/fonts/tahoma.ttf',10);
        $graph->drawLegend($main_width - 150,70,$data_set->GetDataDescription(),255,255,255);

        $graph->setFontProperties(api_get_path(LIBRARY_PATH).'pchart/fonts/tahoma.ttf',11);
        $graph->drawTitle(50, 30, get_lang('ExercisesInTimeProgressChart'), 50,50,50,$main_width-110, true);

        // $main_graph = new pChart($main_width,$main_height);

        $graph_id = 'generate_session_exercise_graph'.Security::remove_XSS($_GET['course']).'-'.intval($_GET['session_id']).'-'.api_get_user_id();
        if ($cache->IsInCache($graph_id, $data_set->GetData())) {
        //if (0) {
            //if we already created the img
            //echo 'in cache';
            $img_file = $cache->GetHash($graph_id,$data_set->GetData());
        } else {
            $cache->WriteToCache($graph_id, $data_set->GetData(), $graph);
            ob_start();
            $graph->Stroke();
            ob_end_clean();
            $img_file = $cache->GetHash($graph_id, $data_set->GetData());
        }
        $html = '<img src="'.api_get_path(WEB_ARCHIVE_PATH).$img_file.'">';
        return $html;
    }

    /**
     *
     * Returns a thumbnail of the function generate_exercise_result_graph
     * @param 	array attempts
     */
    static function generate_exercise_result_thumbnail_graph($attempts)
    {
        require_once api_get_path(LIBRARY_PATH).'pchart/pData.class.php';
        require_once api_get_path(LIBRARY_PATH).'pchart/pChart.class.php';
        require_once api_get_path(LIBRARY_PATH).'pchart/pCache.class.php';

        $exercise_title = $attempts['title'];
        $attempts       = $attempts['data'];
        $my_exercise_result_array = $exercise_result = array();
        if (empty($attempts)) {
            return null;
        }

        foreach ($attempts as $attempt) {
            if (api_get_user_id() == $attempt['exe_user_id']) {
                if ($attempt['exe_weighting'] != 0 ) {
                    $my_exercise_result_array[]= $attempt['exe_result']/$attempt['exe_weighting'];
                }
            } else {
                if ($attempt['exe_weighting'] != 0 ) {
                    $exercise_result[]=  $attempt['exe_result']/$attempt['exe_weighting'];
                }
            }
        }

        //Getting best result
        rsort($my_exercise_result_array);
        $my_exercise_result = 0;
        if (isset($my_exercise_result_array[0])) {
            $my_exercise_result = $my_exercise_result_array[0] *100;
        }

        $max     = 100;
        $pieces  = 5 ;
        $part    = round($max / $pieces);
        $x_axis = array();
        $final_array = array();
        $my_final_array = array();

        for ($i=1; $i <=$pieces; $i++) {
            $sum = 1;
            if ($i == 1) {
                $sum = 0;
            }
            $min = ($i-1)*$part + $sum;
            $max = ($i)*$part;
            $x_axis[]= $min." - ".$max;
            $count = 0;
            foreach($exercise_result as $result) {
                $percentage = $result*100;
                //echo $percentage.' - '.$min.' - '.$max."<br />";
                if ($percentage >= $min && $percentage <= $max) {
                    //echo ' is > ';
                    $count++;
                }
            }
            //echo '<br />';
            $final_array[]= $count;

            if ($my_exercise_result >= $min && $my_exercise_result <= $max) {
                $my_final_array[] = 1;
            } else {
                $my_final_array[] = 0;
            }
        }

        //Fix to remove the data of the user with my data
        for($i = 0; $i<=count($my_final_array); $i++) {
            if (!empty($my_final_array[$i])) {
                $my_final_array[$i] =  $final_array[$i] + 1; //Add my result
                $final_array[$i] = 0;
            }
        }

        $cache = new pCache();

        // Dataset definition
        $data_set = new pData();
        $data_set->AddPoint($final_array,"Serie1");
        $data_set->AddPoint($my_final_array,"Serie2");
        //$data_set->AddPoint($x_axis,"Serie3");
        $data_set->AddAllSeries();

        // Initialise the graph

        $main_width  = 80;
        $main_height = 35;

        $thumbnail_graph = new pChart($main_width, $main_height);

        $thumbnail_graph->setFontProperties(api_get_path(LIBRARY_PATH).'pchart/fonts/tahoma.ttf',8);
        //$thumbnail_graph->setGraphArea(50,30,680,200);
        $thumbnail_graph->drawFilledRoundedRectangle(2,2,$main_width-2,$main_height-2,2,230,230,230);
        $thumbnail_graph->setGraphArea(5,5,$main_width-5,$main_height-5);
        $thumbnail_graph->drawGraphArea(255,255,255);

        //SCALE_NORMAL, SCALE_START0, SCALE_ADDALLSTART0
        $thumbnail_graph->drawScale($data_set->GetData(),$data_set->GetDataDescription(),SCALE_ADDALLSTART0, 150,150,150,FALSE,0,1,TRUE);

        $thumbnail_graph->drawOverlayBarGraph($data_set->GetData(),$data_set->GetDataDescription(), 100);

        // Finish the graph
        $graph_id = 'thumbnail_exercise_result_graph_'.Security::remove_XSS($_GET['course']).'-'.intval($_GET['session_id']).'-'.api_get_user_id();

        if ($cache->IsInCache($graph_id, $data_set->GetData())) {
            //if (0) {
            //if we already created the img
            //echo 'in cache';
            $img_file = $cache->GetHash($graph_id,$data_set->GetData());
        } else {
            $cache->WriteToCache($graph_id, $data_set->GetData(), $thumbnail_graph);
            ob_start();
            $thumbnail_graph->Stroke();
            ob_end_clean();
            $img_file = $cache->GetHash($graph_id, $data_set->GetData());
        }
        $html = '<img src="'.api_get_path(WEB_ARCHIVE_PATH).$img_file.'">';
        return $html;
    }

    /**
     * Generates a big graph with the number of best results
     * @param	array
     */
    static function generate_exercise_result_graph($attempts)
    {
        require_once api_get_path(LIBRARY_PATH).'pchart/pData.class.php';
        require_once api_get_path(LIBRARY_PATH).'pchart/pChart.class.php';
        require_once api_get_path(LIBRARY_PATH).'pchart/pCache.class.php';

        $exercise_title = strip_tags($attempts['title']);
        $attempts       = $attempts['data'];
        $my_exercise_result_array = $exercise_result = array();
        if (empty($attempts)) {
            return null;
        }
        foreach ($attempts as $attempt) {
            if (api_get_user_id() == $attempt['exe_user_id']) {
                if ($attempt['exe_weighting'] != 0 ) {
                    $my_exercise_result_array[]= $attempt['exe_result']/$attempt['exe_weighting'];
                }
            } else {
                if ($attempt['exe_weighting'] != 0 ) {
                    $exercise_result[]=  $attempt['exe_result']/$attempt['exe_weighting'];
                }
            }
        }

        //Getting best result
        rsort($my_exercise_result_array);
        $my_exercise_result = 0;
        if (isset($my_exercise_result_array[0])) {
            $my_exercise_result = $my_exercise_result_array[0] *100;
        }

        $max = 100;
        $pieces = 5 ;
        $part = round($max / $pieces);
        $x_axis = array();
        $final_array = array();
        $my_final_array = array();

        for ($i=1; $i <=$pieces; $i++) {
            $sum = 1;
            if ($i == 1) {
                $sum = 0;
            }
            $min = ($i-1)*$part + $sum;
            $max = ($i)*$part;
            $x_axis[]= $min." - ".$max;
            $count = 0;
            foreach($exercise_result as $result) {
                $percentage = $result*100;
                //echo $percentage.' - '.$min.' - '.$max."<br />";
                if ($percentage >= $min && $percentage <= $max) {
                    //echo ' is > ';
                    $count++;
                }
            }
            //echo '<br />';
            $final_array[]= $count;

            if ($my_exercise_result >= $min && $my_exercise_result <= $max) {
                $my_final_array[] = 1;
            } else {
                $my_final_array[] = 0;
            }
        }

        //Fix to remove the data of the user with my data

        for($i = 0; $i<=count($my_final_array); $i++) {
            if (!empty($my_final_array[$i])) {
                $my_final_array[$i] =  $final_array[$i] + 1; //Add my result
                $final_array[$i] = 0;
            }
        }

        $cache = new pCache();

        // Dataset definition
        $data_set = new pData();
        $data_set->AddPoint($final_array,"Serie1");
        $data_set->AddPoint($my_final_array,"Serie2");
        $data_set->AddPoint($x_axis,"Serie3");
        $data_set->AddAllSeries();

        $data_set->SetAbsciseLabelSerie('Serie3');
        $data_set->SetSerieName(get_lang('Score'),"Serie1");
        $data_set->SetSerieName(get_lang('MyResults'),"Serie2");

        $data_set->SetXAxisName(get_lang("Score"));

        // Initialise the graph
        $main_width  = 500;
        $main_height = 250;

        $main_graph = new pChart($main_width,$main_height);

        $main_graph->setFontProperties(api_get_path(LIBRARY_PATH).'pchart/fonts/tahoma.ttf',8);
        $main_graph->setGraphArea(50,30, $main_width -20,$main_height -50);

        $main_graph->drawFilledRoundedRectangle(10,10, $main_width- 10,$main_height -10,5,240,240,240);
        $main_graph->drawRoundedRectangle(7,7,$main_width - 7,$main_height  - 7,5,230,230,230);

        $main_graph->drawGraphArea(255,255,255,TRUE);

        //SCALE_NORMAL, SCALE_START0, SCALE_ADDALLSTART0
        $main_graph->drawScale($data_set->GetData(),$data_set->GetDataDescription(),SCALE_ADDALLSTART0, 150,150,150,TRUE,0,1,TRUE);

        $main_graph->drawGrid(4,TRUE,230,230,230,50);

        // Draw the 0 line
        $main_graph->setFontProperties(api_get_path(LIBRARY_PATH).'pchart/fonts/tahoma.ttf',6);
        //  $main_graph->drawTreshold(0,143,55,72,TRUE,TRUE);

        // Draw the bar graph
        $data_set->RemoveSerie("Serie3");

        //$main_graph->drawBarGraph($data_set->GetData(),$data_set->GetDataDescription(),TRUE);

        //$main_graph->drawStackedBarGraph($data_set->GetData(),$data_set->GetDataDescription(),TRUE);
        $main_graph->drawOverlayBarGraph($data_set->GetData(),$data_set->GetDataDescription(), 100);

        // Finish the graph
        $main_graph->setFontProperties(api_get_path(LIBRARY_PATH).'pchart/fonts/tahoma.ttf',8);
        $main_graph->drawLegend($main_width - 120,$main_height -100,$data_set->GetDataDescription(),255,255,255);
        $main_graph->setFontProperties(api_get_path(LIBRARY_PATH).'pchart/fonts/tahoma.ttf',8);
        $main_graph->drawTitle(180,22,$exercise_title,50,50,50);
        $graph_id = 'exercise_result_graph'.Security::remove_XSS($_GET['course']).'-'.intval($_GET['session_id']).'-'.api_get_user_id();
        if ($cache->IsInCache($graph_id, $data_set->GetData())) {
            //if (0) {
            //if we already created the img
            //echo 'in cache';
            $img_file = $cache->GetHash($graph_id,$data_set->GetData());
        } else {
            $cache->WriteToCache($graph_id, $data_set->GetData(), $main_graph);
            ob_start();
            $main_graph->Stroke();
            ob_end_clean();
            $img_file = $cache->GetHash($graph_id, $data_set->GetData());
        }
        $html = '<img src="'.api_get_path(WEB_ARCHIVE_PATH).$img_file.'">';
        return $html;
    }
}

/**
 * @todo move into a proper file
 * @package chamilo.tracking
 */
class TrackingCourseLog
{

    function count_item_resources()
    {
    	global $session_id;
        $course_id = api_get_course_int_id();

    	$table_item_property = Database :: get_course_table(TABLE_ITEM_PROPERTY);
    	$table_user = Database :: get_main_table(TABLE_MAIN_USER);

    	$sql = "SELECT count(tool) AS total_number_of_items FROM $table_item_property track_resource, $table_user user" .
                " WHERE track_resource.c_id = $course_id AND track_resource.insert_user_id = user.user_id AND id_session = $session_id ";

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

    	$sql .= " AND tool IN ('document', 'learnpath', 'quiz', 'glossary', 'link', 'course_description', 'announcement', 'thematic', 'thematic_advance', 'thematic_plan')";
    	$res = Database::query($sql);
    	$obj = Database::fetch_object($res);
    	return $obj->total_number_of_items;
    }

    function get_item_resources_data($from, $number_of_items, $column, $direction)
    {
    	global $dateTimeFormatLong, $session_id;
        $course_id = api_get_course_int_id();

    	$table_item_property = Database :: get_course_table(TABLE_ITEM_PROPERTY);
    	$table_user = Database :: get_main_table(TABLE_MAIN_USER);
    	$table_session = Database :: get_main_table(TABLE_MAIN_SESSION);

    	$session_id = intval($session_id);

    	$sql = "SELECT
                    tool as col0,
                    lastedit_type as col1,
                    ref as ref,
                    user.username as col3,
                    insert_date as col5,
                    visibility as col6,
                    user.user_id as user_id
                FROM $table_item_property track_resource, $table_user user
                WHERE   track_resource.c_id = $course_id AND
                        track_resource.insert_user_id = user.user_id AND
                        id_session = $session_id ";

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

    	$sql .= " AND tool IN ('document', 'learnpath', 'quiz', 'glossary', 'link', 'course_description', 'announcement', 'thematic', 'thematic_advance', 'thematic_plan')";

    	if ($column == 0) {
    		$column = '0';
    	}
    	if ($column != '' && $direction != '') {
    		if ($column != 2 && $column != 4) {
    			$sql .= " ORDER BY col$column $direction";
    		}
    	} else {
    		$sql .= " ORDER BY col5 DESC ";
    	}

    	$sql .= " LIMIT $from, $number_of_items ";

    	$res = Database::query($sql);
    	$resources = array ();
    	$thematic_tools = array('thematic', 'thematic_advance', 'thematic_plan');
    	while ($row = Database::fetch_array($res)) {
    		$ref = $row['ref'];
    		$table_name = TrackingCourseLog::get_tool_name_table($row['col0']);
    		$table_tool = Database :: get_course_table($table_name['table_name']);

    		$id = $table_name['id_tool'];
    		$recorset = false;

    		if (in_array($row['col0'], array('thematic_plan', 'thematic_advance'))) {
    			$tbl_thematic = Database :: get_course_table(TABLE_THEMATIC);
    			$sql = "SELECT thematic_id FROM $table_tool WHERE c_id = $course_id AND id = $ref";
    			$rs_thematic  = Database::query($sql);
    			if (Database::num_rows($rs_thematic)) {
    				$row_thematic = Database::fetch_array($rs_thematic);
    				$thematic_id = $row_thematic['thematic_id'];

    				$query = "SELECT session.id, session.name, user.username FROM $tbl_thematic t, $table_session session, $table_user user" .
                            " WHERE t.c_id = $course_id AND t.session_id = session.id AND session.id_coach = user.user_id AND t.id = $thematic_id";
    				$recorset = Database::query($query);
    			}
    		} else {
    			$query = "SELECT session.id, session.name, user.username FROM $table_tool tool, $table_session session, $table_user user
    			          WHERE tool.c_id = $course_id AND tool.session_id = session.id AND session.id_coach = user.user_id AND tool.$id = $ref";
    			$recorset = Database::query($query);
    		}

    		if (!empty($recorset)) {
    			$obj = Database::fetch_object($recorset);

    			$name_session = '';
    			$coach_name = '';
    			if (!empty($obj)) {
    				$name_session = $obj->name;
    				$coach_name   = $obj->username;
    			}

    			$url_tool = api_get_path(WEB_CODE_PATH).$table_name['link_tool'];
    			$row[0] = '';
    			if ($row['col6'] != 2) {
    				if (in_array($row['col0'], $thematic_tools)) {

    					$exp_thematic_tool = explode('_', $row['col0']);
    					$thematic_tool_title = '';
    					if (is_array($exp_thematic_tool)) {
    						foreach ($exp_thematic_tool as $exp) {
    							$thematic_tool_title .= api_ucfirst($exp);
    						}
    					} else {
    						$thematic_tool_title = api_ucfirst($row['col0']);
    					}

    					$row[0] = '<a href="'.$url_tool.'?'.api_get_cidreq().'&action=thematic_details">'.get_lang($thematic_tool_title).'</a>';
    				} else {
    					$row[0] = '<a href="'.$url_tool.'?'.api_get_cidreq().'">'.get_lang('Tool'.api_ucfirst($row['col0'])).'</a>';
    				}
    			} else {
    				$row[0] = api_ucfirst($row['col0']);
    			}
    			$row[1] = get_lang($row[1]);
    			$row[6] = api_convert_and_format_date($row['col5'], null, date_default_timezone_get());
    			$row[5] = '';
    			//@todo Improve this code please
    			switch ($table_name['table_name']) {
    				case 'document' :
    					$query_document = "SELECT tool.title as title FROM $table_tool tool WHERE c_id = $course_id AND id = $ref";
    					$rs_document = Database::query($query_document);
    					$obj_document = Database::fetch_object($rs_document);
    					$row[5] = $obj_document->title;

    					break;
    				case 'announcement':
    					$query_document = "SELECT title FROM $table_tool WHERE c_id = $course_id AND id = $ref";
    					$rs_document = Database::query($query_document);
    					$obj_document = Database::fetch_object($rs_document);
    					$row[5] = $obj_document->title;
    					break;
    				case 'glossary':
    					$query_document = "SELECT name FROM $table_tool WHERE c_id = $course_id AND glossary_id = $ref";
    					$rs_document = Database::query($query_document);
    					$obj_document = Database::fetch_object($rs_document);
    					$row[5] = $obj_document->name;
    					break;
    				case 'lp':
    					$query_document = "SELECT name FROM $table_tool WHERE c_id = $course_id AND id = $ref";
    					$rs_document = Database::query($query_document);
    					$obj_document = Database::fetch_object($rs_document);
    					$row[5] = $obj_document->name;
    					break;
    				case 'quiz':
    					$query_document = "SELECT title FROM $table_tool WHERE c_id = $course_id AND id = $ref";
    					$rs_document = Database::query($query_document);
    					$obj_document = Database::fetch_object($rs_document);
    					$row[5] = $obj_document->title;
    					break;

    				case 'course_description':
    					$query_document = "SELECT title FROM $table_tool WHERE c_id = $course_id AND id = $ref";
    					$rs_document = Database::query($query_document);
    					$obj_document = Database::fetch_object($rs_document);
    					$row[5] = $obj_document->title;
    					break;

    				case 'thematic':
    					$rs = Database::query("SELECT title FROM $table_tool WHERE c_id = $course_id AND id = $ref");
    					if (Database::num_rows($rs) > 0) {
    						$obj = Database::fetch_object($rs);
    						$row[5] = $obj->title;
    					}
    					break;
    				case 'thematic_advance':
    					$rs = Database::query("SELECT content FROM $table_tool WHERE c_id = $course_id AND id = $ref");
    					if (Database::num_rows($rs) > 0) {
    						$obj = Database::fetch_object($rs);
    						$row[5] = $obj->content;
    					}
    					break;
    				case 'thematic_plan':
    					$rs = Database::query("SELECT title FROM $table_tool WHERE c_id = $course_id AND id = $ref");
    					if (Database::num_rows($rs) > 0) {
    						$obj = Database::fetch_object($rs);
    						$row[5] = $obj->title;
    					}
    					break;

    				default:
    					break;
    			}

    			$row2 = $name_session;
    			if (!empty($coach_name)) {
    				$row2 .= '<br />'.get_lang('Coach').': '.$coach_name;
    			}
    			$row[2] = $row2;
                        if (!empty($row['col3'])) {
                            $row['col3'] = Display::url($row['col3'],api_get_path(WEB_CODE_PATH).'user/userInfo.php?'.api_get_cidreq().'&origin=tracking&uInfo='.$row['user_id']);
                            $row[3] = $row['col3'];

                            $ip = TrackingUserLog::get_ip_from_user_event($row['user_id'], $row['col5'], true);
                            if (empty($ip)) {
                                $ip = get_lang('Unknown');
                            }
                            $row[4] = $ip;
                        }

    			$resources[] = $row;
    		}
    	}

    	return $resources;
    }

    function get_tool_name_table($tool) {
    	switch ($tool) {
    		case 'document':
    			$table_name = TABLE_DOCUMENT;
    			$link_tool = 'document/document.php';
    			$id_tool = 'id';
    			break;
    		case 'learnpath':
    			$table_name = TABLE_LP_MAIN;
    			$link_tool = 'newscorm/lp_controller.php';
    			$id_tool = 'id';
    			break;
    		case 'quiz':
    			$table_name = TABLE_QUIZ_TEST;
    			$link_tool = 'exercice/exercice.php';
    			$id_tool = 'id';
    			break;
    		case 'glossary':
    			$table_name = TABLE_GLOSSARY;
    			$link_tool = 'glossary/index.php';
    			$id_tool = 'glossary_id';
    			break;
    		case 'link':
    			$table_name = TABLE_LINK;
    			$link_tool = 'link/link.php';
    			$id_tool = 'id';
    			break;
    		case 'course_description':
    			$table_name = TABLE_COURSE_DESCRIPTION;
    			$link_tool = 'course_description/';
    			$id_tool = 'id';
    			break;
    		case 'announcement':
    			$table_name = TABLE_ANNOUNCEMENT;
    			$link_tool = 'announcements/announcements.php';
    			$id_tool = 'id';
    			break;
    		case 'thematic':
    			$table_name = TABLE_THEMATIC;
    			$link_tool = 'course_progress/index.php';
    			$id_tool = 'id';
    			break;
    		case 'thematic_advance':
    			$table_name = TABLE_THEMATIC_ADVANCE;
    			$link_tool = 'course_progress/index.php';
    			$id_tool = 'id';
    			break;
    		case 'thematic_plan':
    			$table_name = TABLE_THEMATIC_PLAN;
    			$link_tool = 'course_progress/index.php';
    			$id_tool = 'id';
    			break;
    		default:
    			$table_name = $tool;
    		break;
    	}
    	return array('table_name' => $table_name,'link_tool' => $link_tool,'id_tool' => $id_tool);
    }

    static function display_additional_profile_fields()
    {
    	// getting all the extra profile fields that are defined by the platform administrator
    	$extra_fields = UserManager :: get_extra_fields(0,50,5,'ASC');


    	// creating the form
    	$return = '<form action="courseLog.php" method="get" name="additional_profile_field_form" id="additional_profile_field_form">';

    	// the select field with the additional user profile fields (= this is where we select the field of which we want to see
    	// the information the users have entered or selected.
    	$return .= '<select name="additional_profile_field">';
    	$return .= '<option value="-">'.get_lang('SelectFieldToAdd').'</option>';
    	$extra_fields_to_show = 0;
    	foreach ($extra_fields as $key=>$field) {
    		// show only extra fields that are visible + and can be filtered, added by J.Montoya
    		if ($field[6]==1 && $field[8] == 1) {
    			if (isset($_GET['additional_profile_field']) && $field[0] == $_GET['additional_profile_field'] ) {
    				$selected = 'selected="selected"';
    			} else {
    				$selected = '';
    			}
    			$extra_fields_to_show++;
    			$return .= '<option value="'.$field[0].'" '.$selected.'>'.$field[3].'</option>';
    		}
    	}
    	$return .= '</select>';

    	// the form elements for the $_GET parameters (because the form is passed through GET
    	foreach ($_GET as $key=>$value){
    		if ($key <> 'additional_profile_field')    {
    			$return .= '<input type="hidden" name="'.Security::remove_XSS($key).'" value="'.Security::remove_XSS($value).'" />';
    		}
    	}
    	// the submit button
    	$return .= '<button class="save" type="submit">'.get_lang('AddAdditionalProfileField').'</button>';
    	$return .= '</form>';
    	if ($extra_fields_to_show > 0) {
    		return $return;
    	} else {
    		return '';
    	}
    }

    /**
     * This function gets all the information of a certrain ($field_id) additional profile field.
     * It gets the information of all the users so that it can be displayed in the sortable table or in the csv or xls export
     *
     * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University, Belgium
     * @since October 2009
     * @version 1.8.7
     */
    function get_addtional_profile_information_of_field($field_id)
    {
    	// Database table definition
    	$table_user             = Database::get_main_table(TABLE_MAIN_USER);
    	$table_user_field_values     = Database::get_main_table(TABLE_MAIN_USER_FIELD_VALUES);

    	$sql = "SELECT user.user_id, field.field_value FROM $table_user user, $table_user_field_values field
            WHERE user.user_id = field.user_id
            AND field.field_id='".intval($field_id)."'";
    	$result = Database::query($sql);
    	while($row = Database::fetch_array($result)) {
    		$return[$row['user_id']][] = $row['field_value'];
    	}
    	return $return;
    }

    /**
     * This function gets all the information of a certrain ($field_id)
     * additional profile field for a specific list of users is more efficent
     * than get_addtional_profile_information_of_field() function
     * It gets the information of all the users so that it can be displayed
     * in the sortable table or in the csv or xls export
     *
     * @author    Julio Montoya <gugli100@gmail.com>
     * @param    int field id
     * @param    array list of user ids
     * @return    array
     * @since    Nov 2009
     * @version    1.8.6.2
     */
    function get_addtional_profile_information_of_field_by_user($field_id, $users)
    {
    	// Database table definition
    	$table_user                 = Database::get_main_table(TABLE_MAIN_USER);
    	$table_user_field_values     = Database::get_main_table(TABLE_MAIN_USER_FIELD_VALUES);
    	$result_extra_field         = UserManager::get_extra_field_information($field_id);

    	if (!empty($users)) {
    		if ($result_extra_field['field_type'] == USER_FIELD_TYPE_TAG ) {
    			foreach($users as $user_id) {
    				$user_result = UserManager::get_user_tags($user_id, $field_id);
    				$tag_list = array();
    				foreach($user_result as $item) {
    					$tag_list[] = $item['tag'];
    				}
    				$return[$user_id][] = implode(', ',$tag_list);
    			}
    		} else {
    			$new_user_array = array();
    			foreach($users as $user_id) {
    				$new_user_array[]= "'".$user_id."'";
    			}
    			$users = implode(',',$new_user_array);
    			//selecting only the necessary information NOT ALL the user list
    			$sql = "SELECT user.user_id, field.field_value FROM $table_user user INNER JOIN $table_user_field_values field
                        ON (user.user_id = field.user_id)
                        WHERE field.field_id=".intval($field_id)." AND user.user_id IN ($users)";

    			$result = Database::query($sql);
    			while($row = Database::fetch_array($result)) {
    				// get option value for field type double select by id
    				if (!empty($row['field_value'])) {
    					if ($result_extra_field['field_type'] == USER_FIELD_TYPE_DOUBLE_SELECT) {
    						$id_double_select = explode(';',$row['field_value']);
    						if (is_array($id_double_select)) {
    							$value1 = $result_extra_field['options'][$id_double_select[0]]['option_value'];
    							$value2 = $result_extra_field['options'][$id_double_select[1]]['option_value'];
    							$row['field_value'] = ($value1.';'.$value2);
    						}
    					}
    				}
    				// get other value from extra field
    				$return[$row['user_id']][] = $row['field_value'];
    			}
    		}
    	}
    	return $return;
    }

    /**
     * count the number of students in this course (used for SortableTable)
     * Deprecated
     */
    function count_student_in_course()
    {
    	global $nbStudents;
    	return $nbStudents;
    }

    function sort_users($a, $b)
    {
    	return strcmp(trim(api_strtolower($a[$_SESSION['tracking_column']])), trim(api_strtolower($b[$_SESSION['tracking_column']])));
    }

    function sort_users_desc($a, $b)
    {
    	return strcmp( trim(api_strtolower($b[$_SESSION['tracking_column']])), trim(api_strtolower($a[$_SESSION['tracking_column']])));
    }

    /**
     * Get number of users for sortable with pagination
     * @return int
     */
    static function get_number_of_users()
    {
    	global $user_ids;
    	return count($user_ids);
    }

    /**
     * Get data for users list in sortable with pagination
     * @param $from
     * @param $number_of_items
     * @param $column
     * @param $direction
     * @return array
     */
    static function get_user_data($from, $number_of_items, $column, $direction)
    {
    	global $user_ids, $course_code, $additional_user_profile_info, $export_csv, $is_western_name_order, $csv_content, $session_id, $_configuration;

    	$course_code        = Database::escape_string($course_code);
    	$tbl_user           = Database::get_main_table(TABLE_MAIN_USER);
    	$tbl_url_rel_user   = Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);

    	$access_url_id      = api_get_current_access_url_id();

    	// get all users data from a course for sortable with limit
    	$condition_user = "";
    	if (is_array($user_ids)) {
    		$user_ids = array_map('intval', $user_ids);
    		$condition_user = " WHERE user.user_id IN (".implode(',',$user_ids).") ";
    	} else {
    		$user_ids = intval($user_ids);
    		$condition_user = " WHERE user.user_id = $user_ids ";
    	}

    	if (!empty($_GET['user_keyword'])) {
    		$keyword = trim(Database::escape_string($_GET['user_keyword']));
    		$condition_user .=  " AND (user.firstname LIKE '%".$keyword."%' OR user.lastname LIKE '%".$keyword."%'  OR user.username LIKE '%".$keyword."%'  OR user.email LIKE '%".$keyword."%' ) ";
    	}

    	if (api_is_multiple_url_enabled()) {
    		$url_table = ", ".$tbl_url_rel_user."as url_users";
    		$url_condition = " AND user.user_id = url_users.user_id AND access_url_id='$access_url_id'";
    	}

    	$sql = "SELECT  user.user_id as user_id,
                        user.official_code  as col0,
                        user.lastname       as col1,
                        user.firstname      as col2,
                        user.username       as col3
                FROM $tbl_user as user $url_table
    	        $condition_user $url_condition";

    	if (!in_array($direction, array('ASC','DESC'))) {
    		$direction = 'ASC';
    	}

    	$column = intval($column);

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

    	$sql .= " ORDER BY col$column $direction ";
    	$sql .= " LIMIT $from,$number_of_items";

    	$res      = Database::query($sql);
    	$users    = array();
    	$t        = time();

        $course_info = api_get_course_info($course_code);
        $total_surveys = 0;
        $total_exercises = get_all_exercises($course_info, $session_id);

        if (empty($session_id)) {
            $survey_user_list = array();
            $survey_list = survey_manager::get_surveys($course_code, $session_id);

            $total_surveys = count($survey_list);
            $survey_data = array();
            foreach ($survey_list as $survey) {
                $user_list = survey_manager::get_people_who_filled_survey($survey['survey_id'], false, $course_info['real_id']);

                foreach ($user_list as $user_id) {
                    isset($survey_user_list[$user_id]) ? $survey_user_list[$user_id]++ : $survey_user_list[$user_id] = 1;
                }
            }
        }

    	while ($user = Database::fetch_array($res, 'ASSOC')) {
    		$user['official_code']  = $user['col0'];
            $user['lastname']       = $user['col1'];
            $user['firstname']      = $user['col2'];
    		$user['username']       = $user['col3'];
    		$user['time'] = api_time_to_hms(Tracking::get_time_spent_on_the_course($user['user_id'], $course_code, $session_id));

    		$avg_student_score = Tracking::get_avg_student_score($user['user_id'], $course_code, array(), $session_id);

    		$avg_student_progress = Tracking::get_avg_student_progress($user['user_id'], $course_code, array(), $session_id);
    		if (empty($avg_student_progress)) {
    			$avg_student_progress=0;
    		}
    		$user['average_progress']   = $avg_student_progress.'%';

            $total_user_exercise = Tracking::get_exercise_student_progress($total_exercises, $user['user_id'], $course_code, $session_id);
            $user['exercise_progress']  = $total_user_exercise;

            $total_user_exercise = Tracking::get_exercise_student_average_best_attempt($total_exercises, $user['user_id'], $course_code, $session_id);
            $user['exercise_average_best_attempt']  = $total_user_exercise;

    		if (is_numeric($avg_student_score)) {
    			$user['student_score']  = $avg_student_score.'%';
    		} else {
    			$user['student_score']  = $avg_student_score;
    		}

    		$user['count_assignments']  = Tracking::count_student_assignments($user['user_id'], $course_code, $session_id);
    		$user['count_messages']     = Tracking::count_student_messages($user['user_id'], $course_code, $session_id);
    		$user['first_connection']   = Tracking::get_first_connection_date_on_the_course($user['user_id'], $course_code, $session_id);
    		$user['last_connection']    = Tracking::get_last_connection_date_on_the_course($user['user_id'], $course_code, $session_id);

    		// we need to display an additional profile field
    		$user['additional'] = '';

    		if (isset($_GET['additional_profile_field']) AND is_numeric($_GET['additional_profile_field'])) {
    			if (isset($additional_user_profile_info[$user['user_id']]) && is_array($additional_user_profile_info[$user['user_id']])) {
    				$user['additional'] = implode(', ', $additional_user_profile_info[$user['user_id']]);
    			}
    		}

            if (empty($session_id)) {
                $user['survey'] = (isset($survey_user_list[$user['user_id']]) ? $survey_user_list[$user['user_id']] : 0) .' / '.$total_surveys;
            }

    		$user['link'] = '<center><a href="../mySpace/myStudents.php?student='.$user['user_id'].'&details=true&course='.$course_code.'&origin=tracking_course&id_session='.$session_id.'"><img src="'.api_get_path(WEB_IMG_PATH).'2rightarrow.gif" border="0" /></a></center>';

    		// store columns in array $users

    		$is_western_name_order = api_is_western_name_order();
            $user_row = array();

            $user_row[]= $user['official_code']; //0

            if ($is_western_name_order) {
                $user_row[]= $user['firstname'];
                $user_row[]= $user['lastname'];
            } else {
                $user_row[]= $user['lastname'];
                $user_row[]= $user['firstname'];
            }
            $user_row[]= $user['username'];
            $user_row[]= $user['time'];
            $user_row[]= $user['average_progress'];
            $user_row[]= $user['exercise_progress'];
            $user_row[]= $user['exercise_average_best_attempt'];
            $user_row[]= $user['student_score'];
            $user_row[]= $user['count_assignments'];
            $user_row[]= $user['count_messages'];

            if (empty($session_id)) {
                $user_row[]= $user['survey'];
            }

            $user_row[]= $user['first_connection'];
            $user_row[]= $user['last_connection'];
            if (isset($_GET['additional_profile_field']) AND is_numeric($_GET['additional_profile_field'])) {
                $user_row[]= $user['additional'];
            }

            $user_row[]= $user['link'];

            $users[] = $user_row;

    		if ($export_csv) {
    		    if (empty($session_id)) {
                    $user_row = array_map('strip_tags', $user_row);
    			    unset($user_row[14]);
    			    unset($user_row[15]);
                } else {
                    $user_row = array_map('strip_tags', $user_row);
                    unset($user_row[13]);
                    unset($user_row[14]);
                }

    			$csv_content[] = $user_row;
    		}
    	}
    	return $users;
    }
}

/**
 * @package chamilo.tracking
 */
class TrackingUserLog
{

    /**
     * Displays the number of logins every month for a specific user in a specific course.
     */
    function display_login_tracking_info($view, $user_id, $course_id, $session_id = 0)
    {
    	$MonthsLong = $GLOBALS['MonthsLong'];

    	// protected data
    	$user_id = intval($user_id);
    	$session_id = intval($session_id);
    	$course_id = Database::escape_string($course_id);

    	$track_access_table = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ACCESS);
    	$tempView = $view;
    	if(substr($view,0,1) == '1') {
    		$new_view = substr_replace($view,'0',0,1);
    		echo "
                <tr>
                    <td valign='top'>
                    <font color='#0000FF'>-&nbsp;&nbsp;&nbsp;</font>" .
                    "<b>".get_lang('LoginsAndAccessTools')."</b>&nbsp;&nbsp;&nbsp;[<a href='".api_get_self()."?uInfo=".$user_id."&view=".Security::remove_XSS($new_view)."'>".get_lang('Close')."</a>]&nbsp;&nbsp;&nbsp;[<a href='userLogCSV.php?".api_get_cidreq()."&uInfo=".Security::remove_XSS($_GET['uInfo'])."&view=10000'>".get_lang('ExportAsCSV')."</a>]
                    </td>
                </tr>
                ";
    		echo "<tr><td style='padding-left : 40px;' valign='top'>".get_lang('LoginsDetails')."<br>";

    		$sql = "SELECT UNIX_TIMESTAMP(access_date), count(access_date)
                        FROM $track_access_table
                        WHERE access_user_id = '$user_id'
                        AND access_cours_code = '$course_id'
                        AND access_session_id = '$session_id'
                        GROUP BY YEAR(access_date),MONTH(access_date)
                        ORDER BY YEAR(access_date),MONTH(access_date) ASC";

    		echo "<tr><td style='padding-left : 40px;padding-right : 40px;'>";
    		//$results = getManyResults2Col($sql);
    		$results = getManyResults3Col($sql);

    		echo "<table cellpadding='2' cellspacing='1' border='0' align=center>";
    		echo "<tr>
                    <td class='secLine'>
                    ".get_lang('LoginsTitleMonthColumn')."
                    </td>
                    <td class='secLine'>
                    ".get_lang('LoginsTitleCountColumn')."
                    </td>
                </tr>";
    		$total = 0;
    		if (is_array($results)) {
    			for($j = 0 ; $j < count($results) ; $j++) {
    				echo "<tr>";
    				echo "<td class='content'><a href='logins_details.php?uInfo=".$user_id."&reqdate=".$results[$j][0]."&view=".Security::remove_XSS($view)."'>".$MonthsLong[date('n', $results[$j][0])-1].' '.date('Y', $results[$j][0])."</a></td>";
    				echo "<td valign='top' align='right' class='content'>".$results[$j][1]."</td>";
    				echo"</tr>";
    				$total = $total + $results[$j][1];
    			}
    			echo "<tr>";
    			echo "<td>".get_lang('Total')."</td>";
    			echo "<td align='right' class='content'>".$total."</td>";
    			echo"</tr>";
    		} else {
    			echo "<tr>";
    			echo "<td colspan='2'><center>".get_lang('NoResult')."</center></td>";
    			echo"</tr>";
    		}
    		echo "</table>";
    		echo "</td></tr>";
    	} else {
    		$new_view = substr_replace($view,'1',0,1);
    		echo "
                <tr>
                    <td valign='top'>
                    +<font color='#0000FF'>&nbsp;&nbsp;</font><a href='".api_get_self()."?uInfo=".$user_id."&view=".Security::remove_XSS($new_view)."' class='specialLink'>".get_lang('LoginsAndAccessTools')."</a>
                    </td>
                </tr>
            ";
    	}
    }

    /**
     * Displays the exercise results for a specific user in a specific course.
     * @todo remove globals
     */
    function display_exercise_tracking_info($view, $user_id, $course_id)
    {
    	global $TABLECOURSE_EXERCICES, $TABLETRACK_EXERCICES, $dateTimeFormatLong;
    	if(substr($view,1,1) == '1')
    	{
    		$new_view = substr_replace($view,'0',1,1);
    		echo "<tr>
                    <td valign='top'>
                        <font color='#0000FF'>-&nbsp;&nbsp;&nbsp;</font><b>".get_lang('ExercicesResults')."</b>&nbsp;&nbsp;&nbsp;[<a href='".api_get_self()."?uInfo=".Security::remove_XSS($user_id)."&view=".Security::remove_XSS($new_view)."'>".get_lang('Close')."</a>]&nbsp;&nbsp;&nbsp;[<a href='userLogCSV.php?".api_get_cidreq()."&uInfo=".Security::remove_XSS($_GET['uInfo'])."&view=01000'>".get_lang('ExportAsCSV')."</a>]
                    </td>
                </tr>";
    		echo "<tr><td style='padding-left : 40px;' valign='top'>".get_lang('ExercicesDetails')."<br />";

    		$sql = "SELECT ce.title, te.exe_result , te.exe_weighting, UNIX_TIMESTAMP(te.exe_date)
                FROM $TABLECOURSE_EXERCICES AS ce , $TABLETRACK_EXERCICES AS te
                WHERE te.exe_cours_id = '".Database::escape_string($course_id)."'
                    AND te.exe_user_id = '".Database::escape_string($user_id)."'
                    AND te.exe_exo_id = ce.id
                ORDER BY ce.title ASC, te.exe_date ASC";

    		$hpsql = "SELECT te.exe_name, te.exe_result , te.exe_weighting, UNIX_TIMESTAMP(te.exe_date)
                FROM $TBL_TRACK_HOTPOTATOES AS te
                WHERE te.exe_user_id = '".Database::escape_string($user_id)."' AND te.exe_cours_id = '".Database::escape_string($course_id)."'
                ORDER BY te.exe_cours_id ASC, te.exe_date ASC";

    		$hpresults = getManyResultsXCol($hpsql, 4);

    		$NoTestRes = 0;
    		$NoHPTestRes = 0;

    		echo "<tr>\n<td style='padding-left : 40px;padding-right : 40px;'>\n";
    		$results = getManyResultsXCol($sql, 4);
    		echo "<table cellpadding='2' cellspacing='1' border='0' align='center'>\n";
    		echo "
                <tr bgcolor='#E6E6E6'>
                    <td>
                    ".get_lang('ExercicesTitleExerciceColumn')."
                    </td>
                    <td>
                    ".get_lang('Date')."
                    </td>
                    <td>
                    ".get_lang('ExercicesTitleScoreColumn')."
                    </td>
                </tr>";

    		if (is_array($results)) {
    			for($i = 0; $i < sizeof($results); $i++) {
    				$display_date = api_convert_and_format_date($results[$i][3], null, date_default_timezone_get());
    				echo "<tr>\n";
    				echo "<td class='content'>".$results[$i][0]."</td>\n";
    				echo "<td class='content'>".$display_date."</td>\n";
    				echo "<td valign='top' align='right' class='content'>".$results[$i][1]." / ".$results[$i][2]."</td>\n";
    				echo "</tr>\n";
    			}
    		} else {
    			// istvan begin
    			$NoTestRes = 1;
    		}

    		// The Result of Tests
    		if(is_array($hpresults)) {
    			for($i = 0; $i < sizeof($hpresults); $i++) {
    				$title = GetQuizName($hpresults[$i][0],'');
    				if ($title == '')
    				$title = basename($hpresults[$i][0]);
    				$display_date = api_convert_and_format_date($hpresults[$i][3], null, date_default_timezone_get());
    				?>
<tr>
    <td class="content"><?php echo $title; ?></td>
    <td class="content" align="center"><?php echo $display_date; ?></td>
    <td class="content" align="center"><?php echo $hpresults[$i][1]; ?> / <?php echo $hpresults[$i][2]; ?>
    </td>
</tr>

<?php        }
    		} else {
    			$NoHPTestRes = 1;
    		}

    		if ($NoTestRes == 1 && $NoHPTestRes == 1) {
    			echo "<tr>\n";
    			echo "<td colspan='3'><center>".get_lang('NoResult')."</center></td>\n";
    			echo "</tr>\n";
    		}
    		echo "</table>";
    		echo "</td>\n</tr>\n";
    	} else {
    		$new_view = substr_replace($view,'1',1,1);
    		echo "
                <tr>
                    <td valign='top'>
                        +<font color='#0000FF'>&nbsp;&nbsp;</font><a href='".api_get_self()."?uInfo=$user_id&view=".$new_view."' class='specialLink'>".get_lang('ExercicesResults')."</a>
                    </td>
                </tr>";
    	}
    }

    /**
     * Displays the student publications for a specific user in a specific course.
     * @todo remove globals
     */
    function display_student_publications_tracking_info($view, $user_id, $course_id)
    {
    	global $TABLETRACK_UPLOADS, $TABLECOURSE_WORK, $dateTimeFormatLong, $_course;
    	if (substr($view,2,1) == '1') {
    		$new_view = substr_replace($view,'0',2,1);
    		echo "<tr>
                        <td valign='top'>
                        <font color='#0000FF'>-&nbsp;&nbsp;&nbsp;</font><b>".get_lang('WorkUploads')."</b>&nbsp;&nbsp;&nbsp;[<a href='".api_get_self()."?uInfo=".Security::remove_XSS($user_id)."&view=".Security::remove_XSS($new_view)."'>".get_lang('Close')."</a>]&nbsp;&nbsp;&nbsp;[<a href='userLogCSV.php?".api_get_cidreq()."&uInfo=".Security::remove_XSS($_GET['uInfo'])."&view=00100'>".get_lang('ExportAsCSV')."</a>]
                        </td>
                </tr>";
    		echo "<tr><td style='padding-left : 40px;' valign='top'>".get_lang('WorksDetails')."<br>";
    		$sql = "SELECT u.upload_date, w.title, w.author,w.url
                                FROM $TABLETRACK_UPLOADS u , $TABLECOURSE_WORK w
                                WHERE u.upload_work_id = w.id
                                    AND u.upload_user_id = '".Database::escape_string($user_id)."'
                                    AND u.upload_cours_id = '".Database::escape_string($course_id)."'
                                ORDER BY u.upload_date DESC";
    		echo "<tr><td style='padding-left : 40px;padding-right : 40px;'>";
    		$results = getManyResultsXCol($sql,4);
    		echo "<table cellpadding='2' cellspacing='1' border='0' align=center>";
    		echo "<tr>
                    <td class='secLine' width='40%'>
                    ".get_lang('WorkTitle')."
                    </td>
                    <td class='secLine' width='30%'>
                    ".get_lang('WorkAuthors')."
                    </td>
                    <td class='secLine' width='30%'>
                    ".get_lang('Date')."
                    </td>
                </tr>";
    		if (is_array($results)) {
    			for($j = 0 ; $j < count($results) ; $j++) {
    				$pathToFile = api_get_path(WEB_COURSE_PATH).$_course['path']."/".$results[$j][3];
    				$beautifulDate = api_convert_and_format_date($results[$j][0], null, date_default_timezone_get());
    				echo "<tr>";
    				echo "<td class='content'>"
    				."<a href ='".$pathToFile."'>".$results[$j][1]."</a>"
    				."</td>";
    				echo "<td class='content'>".$results[$j][2]."</td>";
    				echo "<td class='content'>".$beautifulDate."</td>";
    				echo"</tr>";
    			}
    		} else {
    			echo "<tr>";
    			echo "<td colspan='3'><center>".get_lang('NoResult')."</center></td>";
    			echo"</tr>";
    		}
    		echo "</table>";
    		echo "</td></tr>";
    	} else {
    		$new_view = substr_replace($view,'1',2,1);
    		echo "
                <tr>
                        <td valign='top'>
                        +<font color='#0000FF'>&nbsp;&nbsp;</font><a href='".api_get_self()."?uInfo=".Security::remove_XSS($user_id)."&view=".Security::remove_XSS($new_view)."' class='specialLink'>".get_lang('WorkUploads')."</a>
                        </td>
                </tr>
            ";
    	}
    }

    /**
     * Displays the links followed for a specific user in a specific course.
     * @todo remove globals
     */
    function display_links_tracking_info($view, $user_id, $course_id)
    {
    	global $TABLETRACK_LINKS, $TABLECOURSE_LINKS;
    	if(substr($view,3,1) == '1') {
    		$new_view = substr_replace($view,'0',3,1);
    		echo "
                <tr>
                        <td valign='top'>
                        <font color='#0000FF'>-&nbsp;&nbsp;&nbsp;</font><b>".get_lang('LinksAccess')."</b>&nbsp;&nbsp;&nbsp;[<a href='".api_get_self()."?uInfo=".Security::remove_XSS($user_id)."&view=".Security::remove_XSS($new_view)."'>".get_lang('Close')."</a>]&nbsp;&nbsp;&nbsp;[<a href='userLogCSV.php?".api_get_cidreq()."&uInfo=".Security::remove_XSS($_GET['uInfo'])."&view=00010'>".get_lang('ExportAsCSV')."</a>]
                        </td>
                </tr>
            ";
    		echo "<tr><td style='padding-left : 40px;' valign='top'>".get_lang('LinksDetails')."<br>";
    		$sql = "SELECT cl.title, cl.url
                        FROM $TABLETRACK_LINKS AS sl, $TABLECOURSE_LINKS AS cl
                        WHERE sl.links_link_id = cl.id
                            AND sl.links_cours_id = '".Database::escape_string($course_id)."'
                            AND sl.links_user_id = '".Database::escape_string($user_id)."'
                        GROUP BY cl.title, cl.url";
    		echo "<tr><td style='padding-left : 40px;padding-right : 40px;'>";
    		$results = getManyResults2Col($sql);
    		echo "<table cellpadding='2' cellspacing='1' border='0' align=center>";
    		echo "<tr>
                    <td class='secLine'>
                    ".get_lang('LinksTitleLinkColumn')."
                    </td>
                </tr>";
    		if (is_array($results)) {
    			for($j = 0 ; $j < count($results) ; $j++) {
    				echo "<tr>";
    				echo "<td class='content'><a href='".$results[$j][1]."'>".$results[$j][0]."</a></td>";
    				echo"</tr>";
    			}
    		} else {
    			echo "<tr>";
    			echo "<td ><center>".get_lang('NoResult')."</center></td>";
    			echo"</tr>";
    		}
    		echo "</table>";
    		echo "</td></tr>";
    	} else {
    		$new_view = substr_replace($view,'1',3,1);
    		echo "
                <tr>
                        <td valign='top'>
                        +<font color='#0000FF'>&nbsp;&nbsp;</font><a href='".api_get_self()."?uInfo=".Security::remove_XSS($user_id)."&view=".Security::remove_XSS($new_view)."' class='specialLink'>".get_lang('LinksAccess')."</a>
                        </td>
                </tr>
            ";
    	}
    }

    /**
     * Displays the documents downloaded for a specific user in a specific course.
     * @param     string    kind of view inside tracking info
     * @param    int        User id
     * @param    string    Course code
     * @param    int        Session id (optional, default = 0)
     * @return     void
     */
    static function display_document_tracking_info($view, $user_id, $course_id, $session_id = 0) {

    	// protect data
    	$user_id     = intval($user_id);
    	$course_id     = Database::escape_string($course_id);
    	$session_id = intval($session_id);

    	$downloads_table = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_DOWNLOADS);
    	if(substr($view,4,1) == '1')
    	{
    		$new_view = substr_replace($view,'0',4,1);
    		echo "
                <tr>
                        <td valign='top'>
                        <font color='#0000FF'>-&nbsp;&nbsp;&nbsp;</font><b>".get_lang('DocumentsAccess')."</b>&nbsp;&nbsp;&nbsp;[<a href='".api_get_self()."?uInfo=".Security::remove_XSS($user_id)."&view=".Security::remove_XSS($new_view)."'>".get_lang('Close')."</a>]&nbsp;&nbsp;&nbsp;[<a href='userLogCSV.php?".api_get_cidreq()."&uInfo=".Security::remove_XSS($_GET['uInfo'])."&view=00001'>".get_lang('ExportAsCSV')."</a>]
                        </td>
                </tr>
            ";
    		echo "<tr><td style='padding-left : 40px;' valign='top'>".get_lang('DocumentsDetails')."<br>";

    		$sql = "SELECT down_doc_path
                        FROM $downloads_table
                        WHERE down_cours_id = '".$course_id."'
                            AND down_user_id = '$user_id'
                            AND down_session_id = '$session_id'
                        GROUP BY down_doc_path";

    		echo "<tr><td style='padding-left : 40px;padding-right : 40px;'>";
    		$results = getManyResults1Col($sql);
    		echo "<table cellpadding='2' cellspacing='1' border='0' align='center'>";
    		echo "<tr>
                    <td class='secLine'>
                    ".get_lang('DocumentsTitleDocumentColumn')."
                    </td>
                </tr>";
    		if (is_array($results)) {
    			for($j = 0 ; $j < count($results) ; $j++) {
    				echo "<tr>";
    				echo "<td class='content'>".$results[$j]."</td>";
    				echo"</tr>";
    			}
    		} else {
    			echo "<tr>";
    			echo "<td><center>".get_lang('NoResult')."</center></td>";
    			echo"</tr>";
    		}
    		echo "</table>";
    		echo "</td></tr>";
    	} else {
    		$new_view = substr_replace($view,'1',4,1);
    		echo "
                <tr>
                        <td valign='top'>
                        +<font color='#0000FF'>&nbsp;&nbsp;</font><a href='".api_get_self()."?uInfo=".Security::remove_XSS($user_id)."&view=".Security::remove_XSS($new_view)."' class='specialLink'>".get_lang('DocumentsAccess')."</a>
                        </td>
                </tr>
            ";
    	}
    }

    /**
     * Gets the IP of a given user, using the last login before the given date
     * @param int User ID
     * @param string Datetime
     * @param bool Whether to return the IP as a link or just as an IP
     * @param string If defined and return_as_link if true, will be used as the text to be shown as the link
     * @return string IP address (or false on error)
     * @assert (0,0) === false
     */
    static function get_ip_from_user_event($user_id, $event_date, $return_as_link = false, $body_replace = null) {
        if (empty($user_id) or empty($event_date)) {
            return false;
        }
        $table_login = Database :: get_main_table(TABLE_STATISTIC_TRACK_E_LOGIN);
        $sql_ip = "SELECT login_date, login_ip FROM $table_login WHERE login_user_id = $user_id AND login_date < '$event_date' ORDER BY login_date DESC LIMIT 1";
        $ip = '';
        $res_ip = Database::query($sql_ip);
        if ($res_ip !== false && Database::num_rows($res_ip)>0) {
            $row_ip = Database::fetch_row($res_ip);
            if ($return_as_link) {
                $ip = Display::url((empty($body_replace)?$row_ip[1]:$body_replace), 'http://www.whatsmyip.org/ip-geo-location/?ip='.$row_ip[1], array('title'=>get_lang('TraceIP'), 'target'=>'_blank'));
            } else {
                $ip = $row_ip[1];
            }
        }
        return $ip;
    }
}

/**
 * @package chamilo.tracking
 */
class TrackingUserLogCSV
{

    /**
     * Displays the number of logins every month for a specific user in a specific course.
     */
    function display_login_tracking_info($view, $user_id, $course_id, $session_id = 0)
    {
    	$MonthsLong = $GLOBALS['MonthsLong'];
    	$track_access_table = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_ACCESS);

    	// protected data
    	$user_id    = intval($user_id);
    	$session_id = intval($session_id);
    	$course_id  = Database::escape_string($course_id);

    	$tempView = $view;
    	if(substr($view,0,1) == '1')
    	{
    		$new_view = substr_replace($view,'0',0,1);
    		$title[1]= get_lang('LoginsAndAccessTools').get_lang('LoginsDetails');
    		$sql = "SELECT UNIX_TIMESTAMP(access_date), count(access_date)
                        FROM $track_access_table
                        WHERE access_user_id = '$user_id'
                        AND access_cours_code = '".$course_id."'
                        AND access_session_id = '$session_id'
                        GROUP BY YEAR(access_date),MONTH(access_date)
                        ORDER BY YEAR(access_date),MONTH(access_date) ASC";
    		//$results = getManyResults2Col($sql);
    		$results = getManyResults3Col($sql);
    		$title_line= get_lang('LoginsTitleMonthColumn').';'.get_lang('LoginsTitleCountColumn')."\n";
    		$line='';
    		$total = 0;
    		if (is_array($results)) {
    			for($j = 0 ; $j < count($results) ; $j++) {
    				$line .= $results[$j][0].';'.$results[$j][1]."\n";
    				$total = $total + $results[$j][1];
    			}
    			$line .= get_lang('Total').";".$total."\n";
    		} else {
    			$line= get_lang('NoResult')."</center></td>";
    		}
    	} else {
    		$new_view = substr_replace($view,'1',0,1);
    	}
    	return array($title_line, $line);
    }

    /**
     * Displays the exercise results for a specific user in a specific course.
     * @todo remove globals
     */
    function display_exercise_tracking_info($view, $user_id, $course_id)
    {
    	global $TABLECOURSE_EXERCICES, $TABLETRACK_EXERCICES, $TABLETRACK_HOTPOTATOES, $dateTimeFormatLong;
    	if (substr($view,1,1) == '1') {
    		$new_view = substr_replace($view,'0',1,1);
    		$title[1]= get_lang('ExercicesDetails');
    		$line='';
    		$sql = "SELECT ce.title, te.exe_result , te.exe_weighting, UNIX_TIMESTAMP(te.exe_date)
                FROM $TABLECOURSE_EXERCICES AS ce , $TABLETRACK_EXERCICES AS te
                WHERE te.exe_cours_id = '$course_id'
                    AND te.exe_user_id = '$user_id'
                    AND te.exe_exo_id = ce.id
                ORDER BY ce.title ASC, te.exe_date ASC";

    		$hpsql = "SELECT te.exe_name, te.exe_result , te.exe_weighting, UNIX_TIMESTAMP(te.exe_date)
                FROM $TABLETRACK_HOTPOTATOES AS te
                WHERE te.exe_user_id = '$user_id' AND te.exe_cours_id = '$course_id'
                ORDER BY te.exe_cours_id ASC, te.exe_date ASC";

    		$hpresults = getManyResultsXCol($hpsql, 4);

    		$NoTestRes = 0;
    		$NoHPTestRes = 0;

    		$results = getManyResultsXCol($sql, 4);
    		$title_line=get_lang('ExercicesTitleExerciceColumn').";".get_lang('Date').';'.get_lang('ExercicesTitleScoreColumn')."\n";

    		if (is_array($results)) {
    			for($i = 0; $i < sizeof($results); $i++)
    			{
    				$display_date = api_convert_and_format_date($results[$i][3], null, date_default_timezone_get());
    				$line .= $results[$i][0].";".$display_date.";".$results[$i][1]." / ".$results[$i][2]."\n";
    			}
    		} else {
                // istvan begin
    			$NoTestRes = 1;
    		}

    		// The Result of Tests
    		if (is_array($hpresults)) {
    			for($i = 0; $i < sizeof($hpresults); $i++) {
    				$title = GetQuizName($hpresults[$i][0],'');

    				if ($title == '')
    				$title = basename($hpresults[$i][0]);

    				$display_date = api_convert_and_format_date($hpresults[$i][3], null, date_default_timezone_get());

    				$line .= $title.';'.$display_date.';'.$hpresults[$i][1].'/'.$hpresults[$i][2]."\n";
    			}
    		} else {
    			$NoHPTestRes = 1;
    		}

    		if ($NoTestRes == 1 && $NoHPTestRes == 1) {
    			$line=get_lang('NoResult');
    		}
    	} else {
    		$new_view = substr_replace($view,'1',1,1);
    	}
    	return array($title_line, $line);
    }

    /**
     * Displays the student publications for a specific user in a specific course.
     * @todo remove globals
     */
    function display_student_publications_tracking_info($view, $user_id, $course_id)
    {
    	global $TABLETRACK_UPLOADS, $TABLECOURSE_WORK, $dateTimeFormatLong, $_course;
    	if (substr($view,2,1) == '1') {
    		$new_view = substr_replace($view,'0',2,1);
    		$sql = "SELECT u.upload_date, w.title, w.author, w.url
                    FROM $TABLETRACK_UPLOADS u , $TABLECOURSE_WORK w
                    WHERE u.upload_work_id = w.id
                        AND u.upload_user_id = '$user_id'
                        AND u.upload_cours_id = '$course_id'
                    ORDER BY u.upload_date DESC";
    		$results = getManyResultsXCol($sql,4);

    		$title[1]=get_lang('WorksDetails');
    		$line='';
    		$title_line=get_lang('WorkTitle').";".get_lang('WorkAuthors').";".get_lang('Date')."\n";

    		if (is_array($results)) {
    			for($j = 0 ; $j < count($results) ; $j++) {
    				$pathToFile = api_get_path(WEB_COURSE_PATH).$_course['path']."/".$results[$j][3];
    				$beautifulDate = api_convert_and_format_date($results[$j][0], null, date_default_timezone_get());
    				$line .= $results[$j][1].";".$results[$j][2].";".$beautifulDate."\n";
    			}

    		} else {
    			$line= get_lang('NoResult');
    		}
    	} else {
    		$new_view = substr_replace($view,'1',2,1);
    	}
    	return array($title_line, $line);
    }

    /**
     * Displays the links followed for a specific user in a specific course.
     * @todo remove globals
     */
    function display_links_tracking_info($view, $user_id, $course_id)
    {
    	global $TABLETRACK_LINKS, $TABLECOURSE_LINKS;
    	if (substr($view,3,1) == '1') {
    		$new_view = substr_replace($view,'0',3,1);
    		$title[1]=get_lang('LinksDetails');
    		$sql = "SELECT cl.title, cl.url
                        FROM $TABLETRACK_LINKS AS sl, $TABLECOURSE_LINKS AS cl
                        WHERE sl.links_link_id = cl.id
                            AND sl.links_cours_id = '$course_id'
                            AND sl.links_user_id = '$user_id'
                        GROUP BY cl.title, cl.url";
    		$results = getManyResults2Col($sql);
    		$title_line= get_lang('LinksTitleLinkColumn')."\n";
    		if (is_array($results)) {
    			for ($j = 0 ; $j < count($results) ; $j++) {
    				$line .= $results[$j][0]."\n";
    			}
    		} else {
    			$line=get_lang('NoResult');
    		}
    	} else {
    		$new_view = substr_replace($view,'1',3,1);
    	}
    	return array($title_line, $line);
    }

    /**
     * Displays the documents downloaded for a specific user in a specific course.
     * @param     string    kind of view inside tracking info
     * @param    int        User id
     * @param    string    Course code
     * @param    int        Session id (optional, default = 0)
     * @return     void
     */
    function display_document_tracking_info($view, $user_id, $course_id, $session_id = 0)
    {
    	// protect data
    	$user_id     = intval($user_id);
    	$course_id     = Database::escape_string($course_id);
    	$session_id = intval($session_id);

    	$downloads_table = Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_DOWNLOADS);

    	if (substr($view,4,1) == '1') {
    		$new_view = substr_replace($view,'0',4,1);
    		$title[1]= get_lang('DocumentsDetails');

    		$sql = "SELECT down_doc_path
                        FROM $downloads_table
                        WHERE down_cours_id = '$course_id'
                            AND down_user_id = '$user_id'
                            AND down_session_id = '$session_id'
                        GROUP BY down_doc_path";

    		$results = getManyResults1Col($sql);
    		$title_line = get_lang('DocumentsTitleDocumentColumn')."\n";
            $line = null;
    		if (is_array($results)) {
    			for ($j = 0 ; $j < count($results) ; $j++) {
    				$line .= $results[$j]."\n";
    			}
    		} else {
    			$line = get_lang('NoResult');
    		}
    	} else {
    		$new_view = substr_replace($view,'1',4,1);
    	}
    	return array($title_line, $line);
    }
}