<?php // $Id: exercise.class.php,v 1.19 2005/05/20 13:51:58 bvanderkimpen Exp $
/*
============================================================================== 
	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) Olivier Brouckaert
	
	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
============================================================================== 
*/

if(!class_exists('Exercise')):
 
/**
============================================================================== 
	CLASS EXERCISE
*
*	This class allows to instantiate an object of type Exercise
*
*	@author Olivier Brouckaert
*	@package dokeos.exercise
============================================================================== 
*/
class Exercise
{
	var $id;
	var $exercise;
	var $description;
	var $sound;
	var $type;
	var $random;
	var $active;

	var $questionList;  // array with the list of this exercise's questions

	/**
	 * constructor of the class
	 *
	 * @author - Olivier Brouckaert
	 */
	function Exercise()
	{
		$this->id=0;
		$this->exercise='';
		$this->description='';
		$this->sound='';
		$this->type=1;
		$this->random=0;
		$this->active=1;

		$this->questionList=array();
	}

	/**
	 * reads exercise informations from the data base
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $id - exercise ID
	 * @return - boolean - true if exercise exists, otherwise false
	 */
	function read($id)
	{
		global $_course;
		#$TBL_EXERCICE_QUESTION = $_course['dbNameGlu'].'quiz_rel_question';
		#$TBL_EXERCICES         = $_course['dbNameGlu'].'quiz';
		#$TBL_QUESTIONS         = $_course['dbNameGlu'].'quiz_question';
		#$TBL_REPONSES          = $_course['dbNameGlu'].'quiz_answer';
    $TBL_EXERCICE_QUESTION  = Database::get_course_table(QUIZ_TEST_QUESTION_TABLE);
    $TBL_EXERCICES          = Database::get_course_table(QUIZ_TEST_TABLE);
    $TBL_QUESTIONS          = Database::get_course_table(QUIZ_QUESTION_TABLE);
    #$TBL_REPONSES           = Database::get_course_table(QUIZ_ANSWER_TABLE);

		$sql="SELECT title,description,sound,type,random,active FROM $TBL_EXERCICES WHERE id='$id'";
		$result=api_sql_query($sql,__FILE__,__LINE__);

		// if the exercise has been found
		if($object=mysql_fetch_object($result))
		{
			$this->id=$id;
			$this->exercise=$object->title;
			$this->description=$object->description;
			$this->sound=$object->sound;
			$this->type=$object->type;
			$this->random=$object->random;
			$this->active=$object->active;

			$sql="SELECT question_id,position FROM $TBL_EXERCICE_QUESTION,$TBL_QUESTIONS WHERE question_id=id AND exercice_id='$id' ORDER BY position";
			$result=api_sql_query($sql,__FILE__,__LINE__);

			// fills the array with the question ID for this exercise
			// the key of the array is the question position
			while($object=mysql_fetch_object($result))
			{
				// makes sure that the question position is unique
				while(isset($this->questionList[$object->position]))
				{
					$object->position++;
				}

				$this->questionList[$object->position]=$object->question_id;
			}
			return true;
		}

		// exercise not found
		return false;
	}

	/**
	 * returns the exercise ID
	 *
	 * @author - Olivier Brouckaert
	 * @return - integer - exercise ID
	 */
	function selectId()
	{
		return $this->id;
	}

	/**
	 * returns the exercise title
	 *
	 * @author - Olivier Brouckaert
	 * @return - string - exercise title
	 */
	function selectTitle()
	{
		return $this->exercise;
	}

	/**
	 * returns the exercise description
	 *
	 * @author - Olivier Brouckaert
	 * @return - string - exercise description
	 */
	function selectDescription()
	{
		return $this->description;
	}

	/**
	 * returns the exercise sound file
	 *
	 * @author - Olivier Brouckaert
	 * @return - string - exercise description
	 */
	function selectSound()
	{
		return $this->sound;
	}

	/**
	 * returns the exercise type
	 *
	 * @author - Olivier Brouckaert
	 * @return - integer - exercise type
	 */
	function selectType()
	{
		return $this->type;
	}

	/**
	 * tells if questions are selected randomly, and if so returns the draws
	 *
	 * @author - Olivier Brouckaert
	 * @return - integer - 0 if not random, otherwise the draws
	 */
	function isRandom()
	{
		return $this->random;
	}

	/**
	 * returns the exercise status (1 = enabled ; 0 = disabled)
	 *
	 * @author - Olivier Brouckaert
	 * @return - boolean - true if enabled, otherwise false
	 */
	function selectStatus()
	{
		return $this->active;
	}

	/**
	 * returns the array with the question ID list
	 *
	 * @author - Olivier Brouckaert
	 * @return - array - question ID list
	 */
	function selectQuestionList()
	{
		return $this->questionList;
	}

	/**
	 * returns the number of questions in this exercise
	 *
	 * @author - Olivier Brouckaert
	 * @return - integer - number of questions
	 */
	function selectNbrQuestions()
	{
		return sizeof($this->questionList);
	}

	/**
     * selects questions randomly in the question list
	 *
	 * @author - Olivier Brouckaert
	 * @return - array - if the exercise is not set to take questions randomly, returns the question list
	 *					 without randomizing, otherwise, returns the list with questions selected randomly
     */
	function selectRandomList()
	{
		// if the exercise is not a random exercise, or if there are not at least 2 questions
		if(!$this->random || $this->selectNbrQuestions() < 2)
		{
			return $this->questionList;
		}

		// takes all questions
		if($this->random == -1 || $this->random > $this->selectNbrQuestions())
		{
			$draws=$this->selectNbrQuestions();
		}
		else
		{
			$draws=$this->random;
		}

		srand((double)microtime()*1000000);

		$randQuestionList=array();
		$alreadyChosed=array();

		// loop for the number of draws
		for($i=0;$i < $draws;$i++)
		{
			// selects a question randomly
			do
			{
				$rand=rand(0,$this->selectNbrQuestions()-1);
			}
			// if the question has already been selected, continues in the loop
			while(in_array($rand,$alreadyChosed));

			$alreadyChosed[]=$rand;

			$j=0;

			foreach($this->questionList as $key=>$val)
			{
				// if we have found the question chosed above
				if($j == $rand)
				{
					$randQuestionList[$key]=$val;
					break;
				}

				$j++;
			}
		}

		return $randQuestionList;
	}

	/**
	 * returns 'true' if the question ID is in the question list
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $questionId - question ID
	 * @return - boolean - true if in the list, otherwise false
	 */
	function isInList($questionId)
	{
		return in_array($questionId,$this->questionList);
	}

	/**
	 * changes the exercise title
	 *
	 * @author - Olivier Brouckaert
	 * @param - string $title - exercise title
	 */
	function updateTitle($title)
	{
		$this->exercise=$title;
	}

	/**
	 * changes the exercise description
	 *
	 * @author - Olivier Brouckaert
	 * @param - string $description - exercise description
	 */
	function updateDescription($description)
	{
		$this->description=$description;
	}

	/**
	 * changes the exercise sound file
	 *
	 * @author - Olivier Brouckaert
	 * @param - string $sound - exercise sound file
	 * @param - string $delete - ask to delete the file
	 */
	function updateSound($sound,$delete)
	{
		global $audioPath, $documentPath,$_course,$_uid;
        $TBL_DOCUMENT = Database::get_course_document_table();
        $TBL_ITEM_PROPERTY = Database::get_course_last_tool_edit_table();

		if($sound['size'] && (strstr($sound['type'],'audio') || strstr($sound['type'],'video')))
		{
			$this->sound=$sound['name'];

			if(@move_uploaded_file($sound['tmp_name'],$audioPath.'/'.$this->sound))
			{
				$query="SELECT 1 FROM $TBL_DOCUMENT "
            ." WHERE path='".str_replace($documentPath,'',$audioPath).'/'.$this->sound."'";
				$result=api_sql_query($query,__FILE__,__LINE__);

				if(!mysql_num_rows($result))
				{
        /*$query="INSERT INTO $TBL_DOCUMENT(path,filetype) VALUES "
            ." ('".str_replace($documentPath,'',$audioPath).'/'.$this->sound."','file')";
        api_sql_query($query,__FILE__,__LINE__);*/
        $id = add_document($_course,str_replace($documentPath,'',$audioPath).'/'.$this->sound,'file',$sound['size'],$sound['name']);

        //$id = Database::get_last_insert_id();
        //$time = time();
        //$time = date("Y-m-d H:i:s", $time);
        // insert into the item_property table, using default visibility of "visible"
        /*$query = "INSERT INTO $TBL_ITEM_PROPERTY "
                ."(tool, ref, insert_user_id,to_group_id, insert_date, lastedit_date, lastedit_type) "
                ." VALUES "
                ."('".TOOL_DOCUMENT."', $id, $_uid, 0, '$time', '$time', 'DocumentAdded' )";
        api_sql_query($query,__FILE__,__LINE__);*/
        item_property_update($_course, TOOL_DOCUMENT, $id, 'DocumentAdded',$_uid);
        item_property_update_on_folder($_course,str_replace($documentPath,'',$audioPath),$_uid);
				}
			}
		}
		elseif($delete && is_file($audioPath.'/'.$this->sound))
		{
			$this->sound='';
		}
	}

	/**
	 * changes the exercise type
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $type - exercise type
	 */
	function updateType($type)
	{
		$this->type=$type;
	}

	/**
	 * sets to 0 if questions are not selected randomly
	 * if questions are selected randomly, sets the draws
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $random - 0 if not random, otherwise the draws
	 */
	function setRandom($random)
	{
		$this->random=$random;
	}

	/**
	 * enables the exercise
	 *
	 * @author - Olivier Brouckaert
	 */
	function enable()
	{
		$this->active=1;
	}

	/**
	 * disables the exercise
	 *
	 * @author - Olivier Brouckaert
	 */
	function disable()
	{
		$this->active=0;
	}

	/**
	 * updates the exercise in the data base
	 *
	 * @author - Olivier Brouckaert
	 */
	function save()
	{
		$TBL_EXERCICES = Database::get_course_table(QUIZ_TEST_TABLE);
        $TBL_QUESTIONS = Database::get_course_table(QUIZ_QUESTION_TABLE);

		$id=$this->id;
		$exercise=addslashes($this->exercise);
		$description=addslashes($this->description);
		$sound=addslashes($this->sound);
		$type=$this->type;
		$random=$this->random;
		$active=$this->active;

		// exercise already exists
		if($id)
		{
			$sql="UPDATE $TBL_EXERCICES SET title='$exercise',description='$description',sound='$sound',type='$type',random='$random',active='$active' WHERE id='$id'";
			api_sql_query($sql,__FILE__,__LINE__);
		}
		// creates a new exercise
		else
		{
			$sql="INSERT INTO $TBL_EXERCICES(title,description,sound,type,random,active) VALUES('$exercise','$description','$sound','$type','$random','$active')";
			api_sql_query($sql,__FILE__,__LINE__);

			$this->id=mysql_insert_id();
		}

		// updates the question position
		foreach($this->questionList as $position=>$questionId)
		{
			$sql="UPDATE $TBL_QUESTIONS SET position='$position' WHERE id='$questionId'";
			api_sql_query($sql,__FILE__,__LINE__);
		}
	}

	/**
	 * moves a question up in the list
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $id - question ID to move up
	 */
	function moveUp($id)
	{
		foreach($this->questionList as $position=>$questionId)
		{
			// if question ID found
			if($questionId == $id)
			{
				// position of question in the array
				$pos1=$position;

				prev($this->questionList);

				// position of previous question in the array
				$pos2=key($this->questionList);

				// error, can't move question
				if(!$pos2)
				{
					return;
				}

				$id2=$this->questionList[$pos2];

				// exits foreach()
				break;
			}

			// goes to next question
			next($this->questionList);
		}

		// permutes questions in the array
		$temp=$this->questionList[$pos2];
		$this->questionList[$pos2]=$this->questionList[$pos1];
		$this->questionList[$pos1]=$temp;
	}

	/**
	 * moves a question down in the list
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $id - question ID to move down
	 */
	function moveDown($id)
	{
		foreach($this->questionList as $position=>$questionId)
		{
			// if question ID found
			if($questionId == $id)
			{
				// position of question in the array
				$pos1=$position;

				next($this->questionList);

				// position of next question in the array
				$pos2=key($this->questionList);

				// error, can't move question
				if(!$pos2)
				{
					return;
				}

				$id2=$this->questionList[$pos2];

				// exits foreach()
				break;
			}

			// goes to next question
			next($this->questionList);
		}

		// permutes questions in the array
		$temp=$this->questionList[$pos2];
		$this->questionList[$pos2]=$this->questionList[$pos1];
		$this->questionList[$pos1]=$temp;
	}

	/**
	 * adds a question into the question list
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $questionId - question ID
	 * @return - boolean - true if the question has been added, otherwise false
	 */
	function addToList($questionId)
	{
		// checks if the question ID is not in the list
		if(!$this->isInList($questionId))
		{
			// selects the max position
			if(!$this->selectNbrQuestions())
			{
				$pos=1;
			}
			else
			{
				$pos=max(array_keys($this->questionList))+1;
			}

			$this->questionList[$pos]=$questionId;

			return true;
		}

		return false;
	}

	/**
	 * removes a question from the question list
	 *
	 * @author - Olivier Brouckaert
	 * @param - integer $questionId - question ID
	 * @return - boolean - true if the question has been removed, otherwise false
	 */
	function removeFromList($questionId)
	{
		// searches the position of the question ID in the list
		$pos=array_search($questionId,$this->questionList);

		// question not found
		if($pos === false)
		{
			return false;
		}
		else
		{
			// deletes the position from the array containing the wanted question ID
			unset($this->questionList[$pos]);

			return true;
		}
	}

	/**
	 * deletes the exercise from the database
	 * Notice : leaves the question in the data base
	 *
	 * @author - Olivier Brouckaert
	 */
	function delete()
	{
		$TBL_EXERCICE_QUESTION = Database::get_course_table(QUIZ_TEST_QUESTION_TABLE);
		$TBL_EXERCICES = Database::get_course_table(QUIZ_TEST_TABLE);

		$id=$this->id;

		$sql="DELETE FROM $TBL_EXERCICE_QUESTION WHERE exercice_id='$id'";
		api_sql_query($sql,__FILE__,__LINE__);

		$sql="DELETE FROM $TBL_EXERCICES WHERE id='$id'";
		api_sql_query($sql,__FILE__,__LINE__);
	}
}

endif;
?>
