<?php // $Id: tracking.lib.php 2007-28-02 15:51:53
/*
==============================================================================
	Dokeos - elearning and course management software

	Copyright (c) 2004 Dokeos S.A.
	Copyright (c) 2003 Ghent University (UGent)
	Copyright (c) 2001 Universite catholique de Louvain (UCL)
	Copyright (c) various contributors

	For a full list of contributors, see "credits.txt".
	The full license can be read in "license.txt".

	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.

	See the GNU General Public License for more details.

	Contact: Dokeos, 181 rue Royale, B-1000 Brussels, Belgium, info@dokeos.com
==============================================================================
*/
/**
==============================================================================
*	This is the tracking library for Dokeos.
*	Include/require it in your code to use its functionality.
*
*	@package dokeos.library
==============================================================================
*/


class Tracking {
	
	/**
	 * Calculates the time spent on the platform by a user
	 * @param integer $user_id the user id
	 * @return timestamp $nb_seconds
	 */
	function get_time_spent_on_the_platform ($user_id) 
	{
		
		$tbl_track_login = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_LOGIN);
					
		$sql = 'SELECT login_date, logout_date FROM '.$tbl_track_login.' 
				WHERE login_user_id = '.intval($user_id);
		
		$rs = api_sql_query($sql);
		
		$nb_seconds=0;
		
		while($a_connections=mysql_fetch_array($rs))
		{
			
			$s_login_date = $a_connections["login_date"];
			$s_logout_date = $a_connections["logout_date"];
			
			$i_timestamp_login_date = strtotime($s_login_date);
			$i_timestamp_logout_date = strtotime($s_logout_date);
			
			$nb_seconds += ($i_timestamp_logout_date-$i_timestamp_login_date);
			
		}
		
		return $nb_seconds;
	}
	
	/**
	 * Calculates the time spent on the course
	 * @param integer $user_id the user id
	 * @param string $course_code the course code
	 * @return timestamp $nb_seconds
	 */
	function get_time_spent_on_the_course ($user_id, $course_code) 
	{
		// protect datas
		$student_id = intval($student_id);
		$course_code = addslashes($course_code);
		
		$tbl_track_course = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_COURSE_ACCESS);
					
		$sql = 'SELECT login_course_date, logout_course_date FROM '.$tbl_track_course.' 
				WHERE user_id = '.intval($user_id).'
				AND course_code="'.$course_code.'"';
		
		$rs = api_sql_query($sql);
		
		$nb_seconds=0;
		
		while($a_connections=mysql_fetch_array($rs))
		{
			
			$s_login_date = $a_connections["login_course_date"];
			$s_logout_date = $a_connections["logout_course_date"];
			
			$i_timestamp_login_date = strtotime($s_login_date);
			$i_timestamp_logout_date = strtotime($s_logout_date);
			
			$nb_seconds += ($i_timestamp_logout_date-$i_timestamp_login_date);
			
		}
		
		return $nb_seconds;
	}
	
	function get_last_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 DESC LIMIT 0,1';
		
		$rs = api_sql_query($sql);
		if($last_login_date = mysql_result($rs,0,0))
		{
			return $last_login_date;
		}
		else
		{
			return false;
		}
	}
	
	function count_course_per_student ($user_id)
	{
		
		$user_id = intval($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;
		$rs = api_sql_query($sql , __FILE__ , __LINE__);
		$nb_courses = mysql_num_rows($rs);
		
		$sql = 'SELECT DISTINCT course_code
				FROM '.$tbl_session_course_rel_user.'
				WHERE id_user = '.$user_id;
		$rs = api_sql_query($sql , __FILE__ , __LINE__);
		$nb_courses += mysql_num_rows($rs);
		
		return $nb_courses;
	}
	
	function get_avg_student_progress($student_id, $course_code)
	{
		require_once(api_get_path(LIBRARY_PATH).'course.lib.php');
		
		// protect datas
		$student_id = intval($student_id);
		$course_code = addslashes($course_code);
		
		// get the informations of the course 
		$a_course = CourseManager :: get_course_information($course_code);
		
		// table definition
		$tbl_course_lp_view = Database :: get_course_table(TABLE_LP_VIEW , $a_course['db_name']);
		$tbl_course_lp_view_item = Database :: get_course_table(TABLE_LP_ITEM_VIEW , $a_course['db_name']);
		$tbl_course_lp_item = Database :: get_course_table(TABLE_LP_ITEM , $a_course['db_name']);
		$tbl_course_lp = Database :: get_course_table(TABLE_LP , $a_course['db_name']);
		
		// get the progress in learning pathes	
		$sqlProgress = "SELECT COUNT( DISTINCT item_view.lp_item_id ) AS nbItem 
						FROM ".$tbl_course_lp_view_item." AS item_view 
						INNER JOIN ".$tbl_course_lp_view." AS lpview 
							ON lpview.user_id = ".$student_id." 
						WHERE item_view.status = 'completed' 
					   ";
		
		$resultProgress = api_sql_query($sqlProgress);
		$a_nbItem = mysql_fetch_array($resultProgress);
		
		$nbTotalItem = Database::count_rows($tbl_course_lp_item);

		$totalItem = $totalItem + $nbTotalItem;
		
		$totalProgress = $totalProgress + $a_nbItem['nbItem'];
		
		$progress = round(($a_nbItem['nbItem'] * 100) / $nbTotalItem);
		
		return $progress;
	}
	
	function get_avg_student_score($student_id, $course_code)
	{
		
		// protect datas
		$student_id = intval($student_id);
		$course_code = addslashes($course_code);
		
		
		$sqlScore = "	SELECT  exe_result,
								exe_weighting
		 				FROM ".Database::get_statistic_table(TABLE_STATISTIC_TRACK_E_EXERCICES)."
						WHERE exe_user_id = ".$student_id."
		 				AND exe_cours_id = '".$course_code."'
					";
		$resultScore = api_sql_query($sqlScore);
		$i = 0;
		$score = 0;
		while($a_score = mysql_fetch_array($resultScore))
		{
			$score = $score + $a_score['exe_result'];
			$weighting = $weighting + $a_score['exe_weighting'];
			$i++;
		}
		
		$totalScore = $totalScore + $score;
		$totalWeighting = $totalWeighting + $weighting;
		
		$pourcentageScore = round(($score*100)/$weighting);
		
		return $pourcentageScore;
	}
	
	/**
	 * gets the list of students followed by coach
	 * @param integer $coach_id the id of the coach
	 * @return Array the list of students
	 */
	function get_student_followed_by_coach ($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 		= 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.' WHERE id_coach='.$coach_id;
		$result=api_sql_query($sql);
		
		while($a_courses=mysql_fetch_array($result))
		{
	    	$course_code=$a_courses["course_code"];
	    	$id_session=$a_courses["id_session"];
	    	
	    	$sql = "SELECT distinct	srcru.id_user  
					FROM $tbl_session_course_user AS srcru 
					WHERE course_code='$course_code' AND id_session='$id_session'";

			$rs=api_sql_query($sql);
			
			while($row=mysql_fetch_array($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 '.$tbl_session_course.' as session_course
					ON session_course.course_code = session_course_user.course_code
				INNER JOIN '.$tbl_session.' as session
					ON session.id = session_course.id_session
					AND session.id_coach = '.$coach_id;
		$result=api_sql_query($sql);
		
		while($row=mysql_fetch_array($result))
		{
			$a_students[$row['id_user']]=$row['id_user'];
		}
		
		return $a_students;
	}
	
	function get_courses_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 				= 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.' WHERE id_coach='.$coach_id;
		$result=api_sql_query($sql);
		while($row = mysql_fetch_array($result))
		{
			$a_courses[$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';
		$result=api_sql_query($sql);
		
		while($row=mysql_fetch_array($result))
		{
			$a_courses[$row['course_code']] = $row['course_code'];
		}
		
		return $a_courses;
	}
	
	function get_sessions_coached_by_user($coach_id)
	{
		// table definition
		$tbl_session = Database :: get_main_table(TABLE_MAIN_SESSION);
		$tbl_session_course = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE);
		
		// protect datas
		$coach_id = intval($coach_id);
		
		// session where we are general coach
		$sql = 'SELECT DISTINCT id, name, date_start, date_end
				FROM '.$tbl_session.' 
				WHERE id_coach='.$coach_id;
		$rs = api_sql_query($sql);
		while($row = mysql_fetch_array($rs))
		{
			$a_sessions[$row["id"]]=$row;
		}
		
		// session where we are coach of a course
		$sql = 'SELECT DISTINCT session.id, session.name, session.date_start, session.date_end
				FROM '.$tbl_session.' as session
				INNER JOIN '.$tbl_session_course.' as session_course
					ON session.id = session_course.id_session
					AND session_course.id_coach='.$coach_id;

		$rs = api_sql_query($sql);
		
		while($row = mysql_fetch_array($rs))
		{
			$a_sessions[$row["id"]]=$row;
		}
		
		
		return $a_sessions;
		
	}
	
	
	function get_courses_list_from_session($session_id)
	{
		//protect datas
		$session_id = intval($session_id);
		
		// table definition
		$tbl_session = Database :: get_main_table(TABLE_MAIN_SESSION);
		$tbl_session_course = Database :: get_main_table(TABLE_MAIN_SESSION_COURSE);
		
		$sql = 'SELECT DISTINCT course_code, id_coach 
				FROM '.$tbl_session_course.'
				WHERE id_session='.$session_id;
		
		$rs = api_sql_query($sql,__FILE__,__LINE__);
		$a_courses = array();
		while($row = mysql_fetch_array($rs))
		{
			$a_courses[$row['course_code']] = $row;
		}
		return $a_courses;
	}
	
	function count_student_assignments ($student_id, $course_code)
	{
		require_once(api_get_path(LIBRARY_PATH).'course.lib.php');
		
		// protect datas
		$student_id = intval($student_id);
		$course_code = addslashes($course_code);
		
		// get the informations of the course 
		$a_course = CourseManager :: get_course_information($course_code);
		
		// table definition
		$tbl_item_property = Database :: get_course_table(TABLE_ITEM_PROPERTY, $a_course['db_name']);
		$sql = 'SELECT 1
				FROM '.$tbl_item_property.' 
				WHERE insert_user_id='.$student_id.'
				AND tool="work"';
		
		$rs = api_sql_query($sql, __LINE__, __FILE__);
		return mysql_num_rows($rs);
	}
	
	function count_student_messages ($student_id, $course_code)
	{
		require_once(api_get_path(LIBRARY_PATH).'course.lib.php');
		
		// protect datas
		$student_id = intval($student_id);
		$course_code = addslashes($course_code);
		
		// get the informations of the course 
		$a_course = CourseManager :: get_course_information($course_code);
		
		// table definition
		$tbl_messages = Database :: get_course_table(TABLE_FORUM_POST, $a_course['db_name']);
		$sql = 'SELECT 1
				FROM '.$tbl_messages.' 
				WHERE poster_id='.$student_id;
		
		$rs = api_sql_query($sql, __LINE__, __FILE__);
		return mysql_num_rows($rs);
	}
	
	function count_student_visited_links ($student_id, $course_code)
	{
		// protect datas
		$student_id = intval($student_id);
		$course_code = addslashes($course_code);
		
		// 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.'"';
		
		$rs = api_sql_query($sql, __LINE__, __FILE__);
		return mysql_num_rows($rs);
	}
	
	function count_student_downloaded_documents ($student_id, $course_code)
	{
		// protect datas
		$student_id = intval($student_id);
		$course_code = addslashes($course_code);
		
		// 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.'"';
		
		$rs = api_sql_query($sql, __LINE__, __FILE__);
		return mysql_num_rows($rs);
	}
	
}


?>