<?php // $Id: answer_matching.class.php 12639 2010-09-28 12:32:46Z ffervaille $
if ( count( get_included_files() ) == 1 ) die( '---' );
/**
 * CLAROLINE
 *
 * @version 1.8 $Revision: 12639 $
 *
 * @copyright (c) 2001-2006 Universite catholique de Louvain (UCL)
 *
 * @license http://www.gnu.org/copyleft/gpl.html (GPL) GENERAL PUBLIC LICENSE
 *
 * @author Claro Team <cvs@claroline.net>
 *
 */

/*
 * "match" contains the value of "code" of the answer
 *
 */
class answerMatching
{
    /**
     * @var $id id of question, -1 if answer doesn't exist already
     */
    var $questionId;

    /**
     * @var $leftList array with list of proposal
     *         $leftList[]['answer'] // text
     *         $leftList[]['match'] // code of matching answer
     *         $leftList[]['grade'] // float
     *         $leftList[]['code'] // string,  see getUniqueCode
     *         $leftlist[]['response'] // choice of user needs to be compared with rightList['code']
     */
    var $leftList;

    /**
     * @var $rightList array with list of proposal
     *         $rightList[$code]['answer'] // text
     *         $rightList[$code]['code'] // integer
     */
    var $rightList;

    /**
     * @var $errorList is used to store error that comes on form post
     */
    var $errorList;

    /**
     * @var $tblAnswer
     */
    var $tblAnswer;

    /**
     * constructor
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @param $questionId integer question that use this answer
     * @param $course_id to use the class when not in course context
     * @return string
     */
    function answerMatching($questionId, $course_id = null)
    {
        $this->questionId = $questionId;

        $this->leftList = array();
        $this->rightList = array();

        $this->errorList = array();

        $tbl_cdb_names = get_module_course_tbl( array( 'qwz_answer_matching' ), $course_id );
        $this->tblAnswer = $tbl_cdb_names['qwz_answer_matching'];
    }

    /**
     * load answers in object
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean result of operation
     */
    function load()
    {
        $sql = "SELECT
                    `answer`,
                    `match`,
                    `grade`,
                    `code`
            FROM `".$this->tblAnswer."`
            WHERE `questionId` = ".(int) $this->questionId."
            ORDER BY `id` ASC";

        $answerList = claro_sql_query_fetch_all($sql);

        if( !empty($answerList) )
        {
            $this->leftList = array();
            $this->rightList = array();
            foreach( $answerList as $answer )
            {
                if( !is_null($answer['match']) )
                {
                    $this->addLeft($answer['answer'],$answer['match'],$answer['grade'],$answer['code']);
                }
                else // match is null -> right option
                {
                    $this->addRight($answer['answer'], $answer['code']);
                }
            }

            // ensure we have minimum requirements
            while( count($this->leftList) < 2 )
            {
                // we need at least 2 answers !
                $this->addLeft();
            }

            while( count($this->rightList) < 2 )
            {
                // we need at least 2 answers !
                $this->addRight();
            }
            
            shuffle( $this->leftList );
            
            return true;
        }
        else
        {
            return false;
        }
    }

    /**
     * save object in db
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean result of operation
     */
    function save()
    {
        $sql = "DELETE FROM `".$this->tblAnswer."`
                WHERE `questionId` = ".(int) $this->questionId;

        if( claro_sql_query($sql) == false ) return false;

           // inserts new answers into data base
        $sql = "INSERT INTO `".$this->tblAnswer."`(`questionId`,`answer`,`match`,`grade`,`code`)
                VALUES ";

        foreach( $this->leftList as $leftElt )
        {
            $sql .= "(".(int) $this->questionId.","
                    ."'".claro_sql_escape($leftElt['answer'])."',"
                    ."'".claro_sql_escape($leftElt['match'])."',"
                    ."'".claro_sql_escape($leftElt['grade'])."',"
                    ."'".claro_sql_escape($leftElt['code'])."'),";
        }

        foreach( $this->rightList as $rightElt )
        {
            $sql .= "(".(int) $this->questionId.","
                    ."'".claro_sql_escape($rightElt['answer'])."',"
                    ."NULL,"
                    ."'0',"
                    ."'".claro_sql_escape($rightElt['code'])."'),";
        }

        $sql = substr($sql,0,-1); // remove trailing ,

        return claro_sql_query($sql);
    }

    /**
     * delete answers from db
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean result of operation
     */
    function delete()
    {
        $sql = "DELETE FROM `".$this->tblAnswer."`
                WHERE `questionId` = ".(int) $this->questionId;

        return claro_sql_query($sql);
    }

    /**
     * clone the object
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean result of operation
     */
    function duplicate($duplicatedQuestionId)
    {
        $duplicated = new answerMatching($duplicatedQuestionId);

        $duplicated->leftList = $this->leftList;
        $duplicated->rightList = $this->rightList;

        $duplicated->save();

        return $duplicated;
    }

    /**
     * check if the object content is valide (use before using save method)
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean result of operation
     */
    function validate()
    {
        $rightCodeList = array();

        // check that all right values are filled
        foreach( $this->rightList as $rightElt )
        {
            if( $rightElt['answer'] == '' )
            {
                $this->errorList[] = get_lang('Please fill the two lists below');
                return false;
            }
            $rightCodeList[] = $rightElt['code'];
        }

        foreach( $this->leftList as $leftElt )
        {
            // check that all left values are filled
            if( $leftElt['answer'] == '' )
            {
                $this->errorList[] = get_lang('Please fill the two lists below');
                return false;
            }

            // find matching code in right proposals
            if( ! in_array($leftElt['match'], $rightCodeList) )
            {
                $this->errorList[] = get_lang('Invalid matching choice');
                return false;
            }
        }

        return true;
    }

    /**
     * handle the form, get data of request and put in the object, handle commands if required
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean true if form can be checked and saved, false
     */
    function handleForm()
    {
        // reinit array
        $this->leftList = array();
        $this->rightList = array();

        //-- set form value in object
        for( $i = 0; $i < $_REQUEST['rightCount']; $i++ )
        {
            $answerNumber = $i + 1;

            //-- answer text
            $right = 'right_'.$this->questionId.'_'.$answerNumber;
            if( isset($_REQUEST[$right]) )         $answer = trim($_REQUEST[$right]);
            else                                $answer = '';

            $this->addRight($answer);
        }

        // we need to have a correspondance between number of the answer in the form and code of corresponding proposal
        $righCodeList = array_keys($this->rightList);

        for( $i = 0; $i < $_REQUEST['leftCount']; $i++ )
        {
            $answerNumber = $i + 1;

            //-- answer text
            $answerFieldName = 'answer_'.$this->questionId.'_'.$answerNumber;
            if( isset($_REQUEST[$answerFieldName]) )     $answer = trim($_REQUEST[$answerFieldName]);
            else                                        $answer = '';

            //-- matching choice
            $matchFieldName = 'match_'.$this->questionId.'_'.$answerNumber;
            if( isset($_REQUEST[$matchFieldName]) )
            {
                // 'match' value is the code of the matching right answer
                if( isset($righCodeList[$_REQUEST[$matchFieldName]]) )
                {
                    $match = $righCodeList[$_REQUEST[$matchFieldName]];
                }
                else
                {
                    $match = '';
                }
            }
            else
            {
                $match = '';
            }

            //-- grade
            $gradeFieldName = 'grade_'.$this->questionId.'_'.$answerNumber;
            if( isset($_REQUEST[$gradeFieldName]) ) $grade = castToFloat($_REQUEST[$gradeFieldName]);
            else                                    $grade = '';

            $this->addLeft($answer, $match, $grade);
        }

        //-- cmd
        if( isset($_REQUEST['cmdRemLeft']) )
        {
            $this->remLeft();
            return false;
        }

        if( isset($_REQUEST['cmdAddLeft']) )
        {
            $this->addLeft();
            return false;
        }

        if( isset($_REQUEST['cmdRemRight']) )
        {
            $this->remRight();
            return false;
        }

        if( isset($_REQUEST['cmdAddRight']) )
        {
            $this->addRight();
            return false;
        }

        // no special command
        return true;

    }

    /**
     * provide the list of error that validate found
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return array list of errors
     */
    function getErrorList()
    {
        return $this->errorList;
    }

    /**
     * display the answers as a form part for display in quizz submission page
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return string html code for display of answer
     */
    function getAnswerHtml()
    {
        if( empty($this->leftList) || empty($this->rightList) )
        {
            $html = "\n" . '<p>' . get_lang('There is no answer for the moment') . '</p>' . "\n\n";
        }
        else
        {

            // prepare list of right proposition to allow
            // - easiest display
            // - easiest randomisation if needed one day
            // (here I use array_values to change array keys from $code1 $code2 ... to 0 1 ...)
            $displayedRightList = array_values($this->rightList);

            // get max length of displayed array
            $arrayLength = max( count($this->leftList), count($this->rightList) );

            $html = '<table width="100%">' . "\n\n";

            $leftCpt = 1;
            $rightCpt = 'A';
            for( $i = 0; $i < $arrayLength; $i++ )
            {
                if( isset($this->leftList[$i]['answer']) )
                {
                    // build html option list - we have to do this here for "selected" attribute
                    $optionList = array();
                    $optionCpt = 'A';
                    $selected = '';
                    $optionList['--'] = '';

                    foreach( $this->rightList as $rightElt )
                    {
                        $optionList[$optionCpt] = $rightElt['code'];

                        if( $this->leftList[$i]['response'] == $rightElt['code'] ) $selected = $rightElt['code'];

                        $optionCpt++;
                    }

                    $leftHtml = $leftCpt . '. ' . $this->leftList[$i]['answer'];
                    $centerHtml = claro_html_form_select('a_'.$this->questionId.'_'.$this->leftList[$i]['code'], $optionList, $selected);
                }
                else
                {
                    $leftHtml = '&nbsp;';
                    $centerHtml = '&nbsp;';
                }

                if( isset($displayedRightList[$i]['answer']) )
                {
                    $rightHtml = $rightCpt . '. ' . $displayedRightList[$i]['answer'];
                }
                else
                {
                    $rightHtml = '&nbsp;';
                }

                $html .=
                    '<tr>' . "\n"
                .     '<td valign="top" width="40%">' . "\n" . $leftHtml . "\n" . '</td>' . "\n"
                .     '<td valign="top" width="20%">' . "\n" . $centerHtml . "\n" . '</td>' . "\n"
                .     '<td valign="top" width="40%">' . "\n" . $rightHtml . "\n" . '</td>' . "\n"
                .    '</tr>' . "\n\n";

                $leftCpt++;
                $rightCpt++;
            }


            $html .=
                '</table>' . "\n"
            .    '<p><small>' . get_lang('Matching') . '</small></p>' . "\n";
        }

        return $html;
    }

    /**
     * display the input hidden field depending on what was submitted in exercise submit form
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return string html code for display of hidden sent data
     */
    function getHiddenAnswerHtml()
    {
        $html = "\n" . '<!-- ' . $this->questionId . ' -->' . "\n";

        foreach( $this->leftList as $leftElt )
        {
            if( !empty($leftElt['response']) )
            {
                $html .= '<input type="hidden" name="a_'.$this->questionId.'_'.$leftElt['code'].'" value="'.$leftElt['response'].'" />' . "\n";
            }
        }
        $html .= "\n" . '<!-- ' . $this->questionId . '(end) -->' . "\n";
        return $html;
    }

    /**
     * display the input hidden field depending on what was submitted in exercise submit form
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return string html code for display of feedback for this answer
     */
    function getAnswerFeedbackHtml()
    {
        $html =
            '<table width="100%">' . "\n\n"

        .    '<tr style="font-style:italic;font-size:small;">' . "\n"
        .    '<td valign="top" width="50%">'.get_lang('Element list').'</td>' . "\n"
        .    '<td valign="top" width="50%">'.get_lang('Corresponds to').'</td>' . "\n"
        .    '</tr>' . "\n\n";


        foreach( $this->leftList as $leftElt )
        {
            $html .=
                '<tr>' . "\n"
            .    '<td>'.$leftElt['answer'].'</td>' . "\n"
            .    '<td>';

            if( $leftElt['match'] == $leftElt['response'] )
            {
                   $html .= $this->rightList[$leftElt['response']]['answer'] . ' / <span class="correct"><b>'.$this->rightList[$leftElt['match']]['answer'].'</b></span>';
               }
               elseif( empty($leftElt['response']) )
               {
                      $html .= '&nbsp;&nbsp;&nbsp; / <span class="correct"><b>'.$this->rightList[$leftElt['match']]['answer'].'</b></span>';
               }
               else
               {
                   $html .= '<span class="error">' . $this->rightList[$leftElt['response']]['answer'] . '</span> / <span class="correct"><b>'.$this->rightList[$leftElt['match']]['answer'].'</b></span>';
               }

            $html .=
                '</td>' . "\n"
            .    '</tr>' . "\n\n";
        }

        $html .=
            '</table>' . "\n"
        .    '<p><small>' . get_lang('Matching') . '</small></p>' . "\n";

        return $html;

    }

    /**
     * display the form to edit answers
     *
     * @param $exId exercise id, required to get stay in the exercise context if required after posting the form
     * @param $askDuplicate display or not the form elements allowing to choose if the question must be duplicated or modified in all exercises
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return string html code for display of answer edition form
     */
    function getFormHtml($exId = null, $askDuplicate)
    {
        $html =
            '<form method="post" action="./edit_answers.php?exId='.$exId.'&amp;quId='.$this->questionId.'">' . "\n"
        .    '<input type="hidden" name="cmd" value="exEdit" />' . "\n"
        .    '<input type="hidden" name="leftCount" value="'.count($this->leftList).'" />' . "\n"
        .    '<input type="hidden" name="rightCount" value="'.count($this->rightList).'" />' . "\n"
        .    '<input type="hidden" name="claroFormId" value="' . uniqid('') . '" />' . "\n";

        if( !empty($exId) && $askDuplicate )
        {
            $html .= '<p>' . html_ask_duplicate() . '</p>' . "\n";
        }

        $html .= '<table border="0" cellpadding="5">' . "\n\n"
        .     '<tr>' . "\n"
        .    '<td colspan="3">' . get_lang('Make correspond') . '&nbsp;:</td>' . "\n"
        .    '<td>' . get_lang('Weighting') . '&nbsp;:</td>' . "\n"
        .    '</tr>' . "\n\n";

        $leftCpt = 1;
        $i = 1;
        foreach( $this->leftList as $leftElt )
        {
            // build html option list - we have to do this here for "selected" attribute
            $optionList = '';
            $rightCpt = 'A';
            $j = 0;
            foreach( $this->rightList as $rightElt )
            {
                $optionList .= '<option value="'.$j.'"';
                if( $leftElt['match'] == $rightElt['code'] ) $optionList .= ' selected="selected"';
                $optionList .= '>'.$rightCpt.'</option>' . "\n";

                $rightCpt++;
                $j++;
            }

            $html .=
                 '<tr>' . "\n"
            .    '<td>' . $leftCpt . '.</td>' . "\n"
            .    '<td><input type="text" name="answer_'.$this->questionId.'_'.$i.'" size="58" value="'.htmlspecialchars($leftElt['answer']).'" /></td>' . "\n"
            .    '<td>'
            .    '<select name="match_'.$this->questionId.'_'.$i.'" />' . "\n" . $optionList . "\n" . '</select>' . "\n"
            .    '</td>' . "\n"
            .    '<td><input type="text" name="grade_'.$this->questionId.'_'.$i.'" size="8" value="'.htmlspecialchars($leftElt['grade']).'" /></td>' . "\n"
            .    '</tr>' . "\n\n";

            ;

            $leftCpt++;
            $i++;
        }

        $html .=
            '<tr>' . "\n"
        .    '<td colspan="4">'
        .     '<input type="submit" name="cmdRemLeft" value="' . get_lang('Rem. elem.') . '" />&nbsp;&nbsp;'
        .     '<input type="submit" name="cmdAddLeft" value="' . get_lang('Add elem.') . '" />'
        .     '</td>' . "\n"
        .     '</tr>' . "\n\n";

        $html .=
             '<tr>' . "\n"
        .    '<td colspan="4">' . get_lang('Please define the options') . '&nbsp;:</td>' . "\n"
        .    '</tr>' . "\n\n";


        $rightCpt = 'A';
        $i = 1;
        foreach( $this->rightList as $rightElt )
        {
            $html .=
                 '<tr>' . "\n"
            .    '<td>' . $rightCpt . '.</td>' . "\n"
            .    '<td colspan="3"><input type="text" name="right_'.$this->questionId.'_'.$i.'" size="58" value="'.htmlspecialchars($rightElt['answer']).'" /></td>' . "\n"
            .    '</tr>' . "\n\n";

            ;

            $rightCpt++;
            $i++;
        }

        $html .=
            '<tr>' . "\n"
        .     '<td colspan="4">'
        .     '<input type="submit" name="cmdRemRight" value="' . get_lang('Rem. elem.') . '" />&nbsp;&nbsp;'
        .     '<input type="submit" name="cmdAddRight" value="' . get_lang('Add elem.') . '" />'
        .     '</td>' . "\n"
        .     '</tr>' . "\n\n";

        $html .=
            '<tr>' . "\n"
        .     '<td colspan="4" align="center">'
        .     '<input type="submit" name="cmdOk" value="' . get_lang('Ok') . '" />&nbsp;&nbsp;'
        .     claro_html_button('./edit_question.php?exId='.$exId.'&amp;quId='.$this->questionId, get_lang("Cancel") )
        .     '</td>' . "\n"
        .     '</tr>' . "\n\n"
        .    '</table>';

        return $html;
    }

    function getUniqueCode()
    {
        return md5(uniqid(''));
    }

    /**
     * add example content
     *
     * @return boolean result of operation
     */
    function addExample()
    {
        $code = $this->addRight( get_lang('rich') );
        $this->addLeft( get_lang('Your daddy is'), $code, 5 );

        $code = $this->addRight( get_lang('good looking') );
        $this->addLeft( get_lang('Your mother is'), $code, 5 );

        return true;
    }

    /**
     * add empty answer at end of answerList
     *
     * @return true
     */
    function addLeft($answer = '', $match = 0, $grade = 0, $code = '', $response = '')
    {
        if( empty($code) ) $code = $this->getUniqueCode();

        $addedAnswer = array(
                            'answer' => $answer,
                            'match' => $match,
                            'grade' => $grade,
                            'code' => $code,
                            'response' => $response
                            );

        $this->leftList[] = $addedAnswer;
        return true;
    }

    /**
     * remove empty answer at end of answerList
     *
     * @return boolean result of operation
     */
    function remLeft()
    {
        if( count($this->leftList) > 2 )
        {
            $removedAnswer = array_pop($this->leftList);

            if( !is_null($removedAnswer) )
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        else
        {
            return false;
        }
    }

    /**
     * add empty option at the end of optionList
     *
     * @return 'code' of inserted row
     */
    function addRight($answer = '', $code = '')
    {
        if( empty($code) ) $code = $this->getUniqueCode();

        $addedAnswer = array(
                            'answer' => $answer,
                            'code' => $code
                            );

        $this->rightList[$code] = $addedAnswer;

        return $code;
    }

    /**
     * remove last right answer
     *
     * @return boolean result of operation
     */
    function remRight()
    {
        if( count($this->rightList) > 2 )
        {
            $removedAnswer = array_pop($this->rightList);

            if( !is_null($removedAnswer) )
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        else
        {
            return false;
        }
    }

    /**
     * read response from request grade it, write grade in object, return grade
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return float question grade
     * @desc return score of checked answer or 0 if nothing was checked
     */
    function gradeResponse()
    {
        $grade = 0;

        foreach( $this->leftList as $leftElt )
        {
            if( $leftElt['match'] == $leftElt['response'] )
            {
                   $grade += $leftElt['grade'];
               }
        }
        return $grade;
    }

    /**
     * get response of user via $_REQUEST and store it in object
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return boolean result of operation
     */
    function extractResponseFromRequest()
    {
        $answerCount = count($this->leftList);

        for( $i = 0; $i < $answerCount ; $i++ )
        {
            if( isset($_REQUEST['a_'.$this->questionId.'_'.$this->leftList[$i]['code']]) )
            {
                $this->leftList[$i]['response'] = $_REQUEST['a_'.$this->questionId.'_'.$this->leftList[$i]['code']];
            }
            else
            {
                $this->leftList[$i]['response'] = '';
            }
        }
        return true;
    }

    /**
     * compute grade of question from answer
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return float question grade
     */
    function getGrade()
    {
        $grade = 0;

        foreach( $this->leftList as $answer )
        {
            $grade += $answer['grade'];
        }

           return $grade;
    }

    /**
     * return a array with values needed for tracking
     * we cannot rely on the code for tracking has the code
     * change when answers are edited
     *
     * @author Sebastien Piraux <pir@cerdecam.be>
     * @return array
     */
    function getTrackingValues()
    {
        $values = array();

        foreach( $this->leftList as $leftElt )
        {
            if( !empty($leftElt['response']) && isset($this->rightList[$leftElt['response']]['answer'])  )
            {
                $values[] = $leftElt['answer']. ' -> ' . $this->rightList[$leftElt['response']]['answer'];
            }
            else
            {
                $values[] = $leftElt['answer'].' -> ';
            }
        }

        return $values;
    }

}
?>