<?php // $Id: question_pool.php 20451 2009-05-10 12:02:22Z ivantcholakov $
 
/*
==============================================================================
	Dokeos - elearning and course management software

	Copyright (c) 2004-2009 Dokeos SPRL
	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 address: Dokeos, rue du Corbeau, 108, B-1030 Brussels, Belgium
	Mail: info@dokeos.com
==============================================================================
*/

/**
*	Question Pool
* 	This script allows administrators to manage questions and add them into their exercises.
* 	One question can be in several exercises
*	@package dokeos.exercise
* 	@author Olivier Brouckaert
* 	@version $Id: question_pool.php 20451 2009-05-10 12:02:22Z ivantcholakov $
*/

// name of the language file that needs to be included
$language_file='exercice';

include('exercise.class.php');
include('question.class.php');
include('answer.class.php');
include('../inc/global.inc.php');

$this_section=SECTION_COURSES;

$is_allowedToEdit=api_is_allowed_to_edit();

$TBL_EXERCICE_QUESTION = Database::get_course_table(TABLE_QUIZ_TEST_QUESTION);
$TBL_EXERCICES         = Database::get_course_table(TABLE_QUIZ_TEST);
$TBL_QUESTIONS         = Database::get_course_table(TABLE_QUIZ_QUESTION);
$TBL_REPONSES          = Database::get_course_table(TABLE_QUIZ_ANSWER);

if ( empty ( $delete ) ) {
    $delete = intval($_GET['delete']);
}
if ( empty ( $recup ) ) {
    $recup = intval($_GET['recup']);
}
if ( empty ( $fromExercise ) ) {
    $fromExercise = intval($_GET['fromExercise']);
}
if(isset($_GET['exerciseId'])){
	$exerciseId = intval($_GET['exerciseId']);
}
if(isset($_GET['exerciseLevel'])){
	$exerciseLevel = intval($_GET['exerciseLevel']);
}
if(!empty($_GET['page'])){
	$page = intval($_GET['page']);
}

//only that type of question
if(!empty($_GET['type'])){
	$type = intval($_GET['type']);
}

// maximum number of questions on a same page
$limitQuestPage=50;

// document path
$documentPath=api_get_path(SYS_COURSE_PATH).$_course['path'].'/document';

// picture path
$picturePath=$documentPath.'/images';


if(!($objExcercise instanceOf Exercise) && !empty($fromExercise))
{
    $objExercise = new Exercise();
    $objExercise->read($fromExercise);
}
if(!($objExcercise instanceOf Exercise) && !empty($exerciseId))
{
    $objExercise = new Exercise();
    $objExercise->read($exerciseId);
}

if($is_allowedToEdit)
{
	// deletes a question from the data base and all exercises
	if($delete)
	{
		// construction of the Question object
		// if the question exists
		if($objQuestionTmp = Question::read($delete))
		{
			// deletes the question from all exercises
			$objQuestionTmp->delete();
		}

		// destruction of the Question object
		unset($objQuestionTmp);
	}
	// gets an existing question and copies it into a new exercise
	elseif($recup && $fromExercise)
	{
		// if the question exists
		if($objQuestionTmp = Question :: read($recup))
		{
			// adds the exercise ID represented by $fromExercise into the list of exercises for the current question
			$objQuestionTmp->addToList($fromExercise);
		}

		// destruction of the Question object
		unset($objQuestionTmp);

        if(!$objExcercise instanceOf Exercise)
        {
        	$objExercise = new Exercise();
            $objExercise->read($fromExercise);
        }
		// adds the question ID represented by $recup into the list of questions for the current exercise
		$objExercise->addToList($recup);
		api_session_register('objExercise');
		header("Location: admin.php?exerciseId=$fromExercise");
		exit();
	}
}

if (isset($_SESSION['gradebook'])){
	$gradebook=	$_SESSION['gradebook'];
}

if (!empty($gradebook) && $gradebook=='view') {	
	$interbreadcrumb[]= array (
			'url' => '../gradebook/'.$_SESSION['gradebook_dest'],
			'name' => get_lang('Gradebook')
		);
}

$nameTools=get_lang('QuestionPool');

$interbreadcrumb[]=array("url" => "exercice.php","name" => get_lang('Exercices'));

// if admin of course
if($is_allowedToEdit)
{
	Display::display_header($nameTools,"Exercise");
?>

<h3><?php echo $nameTools; ?></h3>

<div class="actions">
	<?php
	if(!empty($fromExercise)) {
		echo '<a href="admin.php?',api_get_cidreq(),'&exerciseId=',$fromExercise,'">'.Display::return_icon('quiz.gif', get_lang('GoBackToEx')),get_lang('GoBackToEx'),'</a>';
	} else {
		echo '<a href="admin.php?',api_get_cidreq(),'&newQuestion=yes">'.Display::return_icon('new_test.gif'),get_lang('NewQu'),'</a>';
	}	
	if (isset($type)) {		
		$url = api_get_self().'?type=1';
	} else {
		$url = api_get_self();
	}
	?>
	
	<form method="get" action="<?php echo $url; ?>" style="display:inline;">
	<?php	
	if (isset($type)) { 
		echo '<input type="hidden" name="type" value="1">';
	} 
	?>
	<input type="hidden" name="fromExercise" value="<?php echo $fromExercise; ?>">
	
	<?php echo get_lang('Filter'); ?> : 
	<select name="exerciseId">
	<option value="0">-- <?php echo get_lang('AllExercises'); ?> --</option>
	<option value="-1" <?php if($exerciseId == -1) echo 'selected="selected"'; ?>>-- <?php echo get_lang('OrphanQuestions'); ?> --</option>
	<?php 
	$sql="SELECT id,title FROM $TBL_EXERCICES WHERE id<>'".Database::escape_string($fromExercise)."' AND active<>'-1' ORDER BY id";
	$result=api_sql_query($sql,__FILE__,__LINE__);

	// shows a list-box allowing to filter questions
	while($row=Database::fetch_array($result)) {
		?>
		<option value="<?php echo $row['id']; ?>" <?php if($exerciseId == $row['id']) echo 'selected="selected"'; ?>><?php echo $row['title']; ?></option>
		<?php
	}
	?> 
    </select>
    &nbsp;
    <?php 
    	echo get_lang('Difficulty');
    	echo ' : <select name="exerciseLevel">';    	
		//echo '<option value="-1">-- '.get_lang('AllExercises').' --</option>';
		//level difficulty only from 1 to 5
		if (!isset($exerciseLevel)) $exerciseLevel = -1;
		
		for ($level = -1; $level <=5; $level++) {
			$selected ='';
			if ($level!=0) {	
				if ($exerciseLevel == $level) 
					$selected = ' selected="selected" ';								 
				if ($level==-1) {
					echo '<option value="'.$level.'" '.$selected.'>-- '.get_lang('AllExercises').' --</option>';	
				} else   {
					echo '<option value="'.$level.'" '.$selected.'>'.$level.'</option>';
				}
			}
		}
		echo '</select> ';
	?>
	<button class="save" type="submit" name="name" value="<?php echo get_lang('Ok') ?>"><?php echo get_lang('Ok') ?></button>
    </form>
</div>

<table class="data_table">
<?php
	$from=$page*$limitQuestPage;
	// if we have selected an exercise in the list-box 'Filter'
	if ($exerciseId > 0) {
		//$sql="SELECT id,question,type FROM $TBL_EXERCICE_QUESTION,$TBL_QUESTIONS WHERE question_id=id AND exercice_id='".Database::escape_string($exerciseId)."' ORDER BY question_order LIMIT $from, ".($limitQuestPage + 1);
		$where = '';
		if (isset($type) && $type==1) {
			$where = ' type = 1 AND ';	
		}		

		if (isset($exerciseLevel) && $exerciseLevel != -1) {
			$where .= ' level='.$exerciseLevel.' AND ';
		}
		
		$sql="SELECT id,question,type,level 
				FROM $TBL_EXERCICE_QUESTION,$TBL_QUESTIONS 
			  	WHERE $where question_id=id AND exercice_id='".Database::escape_string($exerciseId)."'			 	
				ORDER BY question_order";
	} elseif($exerciseId == -1) {
		// if we have selected the option 'Orphan questions' in the list-box 'Filter'
		
		// 1. Old logic: When a test is deleted, the correspondent records in 'quiz' and 'quiz_rel_question' tables are deleted.
		//$sql='SELECT id, question, type, exercice_id FROM '.$TBL_QUESTIONS.' as questions LEFT JOIN '.$TBL_EXERCICE_QUESTION.' as quizz_questions ON questions.id=quizz_questions.question_id WHERE exercice_id IS NULL LIMIT $from, '.($limitQuestPage + 1);

		// 2. New logic: When a test is deleted, the field 'active' takes value -1 (it is in the correspondent record in 'quiz' table).
		//$sql='SELECT questions.id, questions.question, questions.type, quizz_questions.exercice_id FROM '.$TBL_QUESTIONS.
		//	' as questions LEFT JOIN '.$TBL_EXERCICE_QUESTION.' as quizz_questions ON questions.id=quizz_questions.question_id LEFT JOIN '.$TBL_EXERCICES.
		//	' as exercices ON exercice_id=exercices.id WHERE exercices.active = -1 LIMIT $from, '.($limitQuestPage + 1);

		// 3. This is more safe to changes, it is a mix between old and new logic.
		
		/*$sql='SELECT questions.id, questions.question, questions.type, quizz_questions.exercice_id FROM '.$TBL_QUESTIONS.
			' as questions LEFT JOIN '.$TBL_EXERCICE_QUESTION.' as quizz_questions ON questions.id=quizz_questions.question_id LEFT JOIN '.$TBL_EXERCICES.
			' as exercices ON exercice_id=exercices.id WHERE quizz_questions.exercice_id IS NULL OR exercices.active = -1 LIMIT '.$from.', '.($limitQuestPage + 1);	
		*/
		
		/*	4. Query changed because of the Level feature implemented
		$sql='SELECT id, question, type, exercice_id,level FROM '.$TBL_QUESTIONS.' as questions LEFT JOIN '.$TBL_EXERCICE_QUESTION.' as quizz_questions
			ON questions.id=quizz_questions.question_id AND exercice_id IS NULL '.
			(!is_null($exerciseLevel) && $exerciseLevel >= 0 ? 'WHERE level=\''.$exerciseLevel.'\' ' : '');
		*/
		// 5. this is the combination of the 3 and 4 query because of the level feature implementation
		
		// we filter the type of question, because in the DirectFeedback we can only add questions with type=1 = UNIQUE_ANSWER
		$type_where= '';
		if (isset($type) && $type==1) {
			$type_where = ' AND questions.type = 1 ';	
		}
				
		$level_where = '';		
		if (isset($exerciseLevel) && $exerciseLevel!= -1 ) {			
			$level_where = ' level='.$exerciseLevel.' AND ';
		}			
		$sql='SELECT questions.id, questions.question, questions.type, quizz_questions.exercice_id , level
				FROM '.$TBL_QUESTIONS.' as questions LEFT JOIN '.$TBL_EXERCICE_QUESTION.' as quizz_questions 
				ON questions.id=quizz_questions.question_id LEFT JOIN '.$TBL_EXERCICES.' as exercices 
				ON exercice_id=exercices.id 
				WHERE '.$level_where.' (quizz_questions.exercice_id IS NULL OR exercices.active = -1 )  '.$type_where.'
				LIMIT '.$from.', '.($limitQuestPage + 1);		
			
	} else {
		// if we have not selected any option in the list-box 'Filter'
		
		//$sql="SELECT id,question,type FROM $TBL_QUESTIONS LIMIT $from, ".($limitQuestPage + 1);
		$where = '';
		
		if (isset($type)&& $type==1){
			$where = ' WHERE type = 1 ';				
		}
		
		if (isset($exerciseLevel) && $exerciseLevel != -1) {			
			if (strlen($where)>0)
				$where .= ' AND level='.$exerciseLevel.' ';
			else 
				$where = ' WHERE level='.$exerciseLevel.' ';			
		}
		$sql="SELECT id,question,type,level FROM $TBL_QUESTIONS $where ";
			
		// forces the value to 0
		//echo $sql;
		$exerciseId=0;
	}
	
	$result=api_sql_query($sql,__FILE__,__LINE__);
	$nbrQuestions=Database::num_rows($result);
	
    echo '<tr>',
      '<td colspan="',($fromExercise?3:3),'">',
    	'<table border="0" cellpadding="0" cellspacing="0" width="100%">',
    	'<tr>',
    	  '<td>';
	echo '</td>',
	 '<td align="right">';
	 
	if(!empty($page)) {
	   echo '<a href="',api_get_self(),'?',api_get_cidreq(),'&exerciseId=',$exerciseId,'&fromExercise=',$fromExercise,'&page=',($page-1),'">&lt;&lt; ',get_lang('PreviousPage'),'</a> |';
	} elseif($nbrQuestions > $limitQuestPage) {
	   echo '&lt;&lt; ',get_lang('PreviousPage'),' |';
	}

	if($nbrQuestions > $limitQuestPage) {
    	echo '<a href="',api_get_self(),'?',api_get_cidreq(),'&exerciseId=',$exerciseId,'&fromExercise=',$fromExercise,'&page=',($page+1),'">',get_lang('NextPage'),' &gt;&gt;</a>';
	} elseif($page) {
	   echo '  ',get_lang('NextPage'),' &gt;&gt;';
	}
    echo '</td>
	</tr>
	</table>
  </td>
</tr>
<tr bgcolor="#e6e6e6">';

	if(!empty($fromExercise)) {
        echo '<th>',get_lang('Question'),'</th>',
            '<th>',get_lang('Level'),'</th>',
            '<th>',get_lang('Reuse'),'</th>';
	} else {
        echo '<td width="60%" align="center">',get_lang('Question'),'</td>',
            '<td width="20%" align="center">',get_lang('Modify'),'</td>',
            '<td width="20%" align="center">',get_lang('Delete'),'</td>';
	}
    echo '</tr>';
	$i=1;
	echo '<pre>';
	
	echo '</pre>';
	while ($row = Database::fetch_array($result)) {		
		// if we come from the exercise administration to get a question, 
        // don't show the questions already used by that exercise
        
        /*if (!$fromExercise) {echo '1'; }   
        if (!isset($objExercise)){echo '2';}    
        if (!($objExercise instanceOf Exercise)){echo '3';}    
        if (!$objExercise->isInList($row['id'])) {echo '4';}        
        */
        
        // original recipe - 
      //if (!$fromExercise || !isset($objExercise) || !($objExercise instanceOf Exercise) || (!$objExercise->isInList($row['id'])))
		if (!$fromExercise || !isset($objExercise) || !($objExercise instanceOf Exercise) || (is_array($objExercise->questionList)) ) {	
            echo '<tr ',($i%2==0?'class="row_odd"':'class="row_even"'),'>';
            echo '  <td><a href="admin.php?',api_get_cidreq(),'&editQuestion=',$row['id'],'&fromExercise=',$fromExercise,'">',$row['question'],'</a></td>';
            echo '  <td align="center" >';
			if (empty($fromExercise)) {
                echo '<a href="admin.php?'.api_get_cidreq().'&amp;editQuestion=',$row['id'],'"><img src="../img/edit.gif" border="0" alt="',get_lang('Modify'),'"></a>',
                    '</td>',
                    '<td align="center">',
                    '<a href="',api_get_self(),'?',api_get_cidreq(),'&exerciseId=',$exerciseId,'&delete=',$row['id'],'" onclick="javascript:if(!confirm(\'',addslashes(api_htmlentities(get_lang('ConfirmYourChoice'),ENT_QUOTES,$charset)),'\')) return false;"><img src="../img/delete.gif" border="0" alt="',get_lang('Delete'),'"></a>';
                    //'<a href="',api_get_self(),'?',api_get_cidreq(),'&exerciseId=',$exerciseId,'&delete=',$row['id'],'" onclick="javascript:if(!confirm(\'',addslashes(api_htmlentities(get_lang('ConfirmYourChoice'),ENT_QUOTES,$charset)),'\')) return false;"><img src="../img/delete.gif" border="0" alt="',get_lang('Delete'),'"></a>';
			} else {
                //echo $row['level'],'</td>',
//					'<td><a href="',api_get_self(),'?',api_get_cidreq(),'&recup=',$row['id'],'&fromExercise=',$fromExercise,'"><img src="../img/view_more_stats.gif" border="0" alt="',get_lang('Reuse'),'"></a>';
				echo $row['level'],'</td>',
					'<td align="center" ><a href="',api_get_self(),'?',api_get_cidreq(),'&recup=',$row['id'],'&fromExercise=',$fromExercise,'">' .
							'<img src="../img/view_more_stats.gif" border="0" alt="',get_lang('Reuse'),'"></a>';
			}
            echo '</td>';
            echo '</tr>';

			// skips the last question, that is only used to know if we have or not to create a link "Next page"
			if($i == $limitQuestPage) {
				break;
			}

			$i++;
		}
	}

	if (!$nbrQuestions) {
        echo '<tr>',
            '<td colspan="',($fromExercise?3:3),'">',get_lang('NoQuestion'),'</td>',
            '</tr>';
	}
    echo '</table>';
	Display::display_footer();
} else {
	// if not admin of course
	api_not_allowed(true);
}

?>
