<?php
/* For licensing terms, see /license.txt */

/**
 * Class Answer
 * Allows to instantiate an object of type Answer
 * 5 arrays are created to receive the attributes of each answer belonging to a specified question
 * @package chamilo.exercise
 * @author Olivier Brouckaert
 * @package chamilo.exercise
 */
class Answer
{
    public $questionId;

    // these are arrays
    public $answer;
    public $correct;
    public $comment;
    public $weighting;
    public $position;
    public $hotspot_coordinates;
    public $hotspot_type;
    public $destination;
    // these arrays are used to save temporarily new answers
    // then they are moved into the arrays above or deleted in the event of cancellation
    public $new_answer;
    public $new_correct;
    public $new_comment;
    public $new_weighting;
    public $new_position;
    public $new_hotspot_coordinates;
    public $new_hotspot_type;

    public $nbrAnswers;
    public $new_nbrAnswers;
    public $new_destination; // id of the next question if feedback option is set to Directfeedback
    public $course; //Course information

    /**
     * constructor of the class
     *
     * @author 	Olivier Brouckaert
     * @param 	integer	Question ID that answers belong to
     */
    function Answer($questionId, $course_id = null)
    {
        $this->questionId			= intval($questionId);
        $this->answer				= array();
        $this->correct				= array();
        $this->comment				= array();
        $this->weighting			= array();
        $this->position				= array();
        $this->hotspot_coordinates	= array();
        $this->hotspot_type 		= array();
        $this->destination  		= array();
        // clears $new_* arrays
        $this->cancel();

        if (!empty($course_id)) {
            $course_info = api_get_course_info_by_id($course_id);
        } else {
            $course_info = api_get_course_info();
        }

        $this->course    = $course_info;
        $this->course_id = $course_info['real_id'];

        // fills arrays
        $objExercise = new Exercise($this->course_id);
        $exerciseId = isset($_REQUEST['exerciseId']) ? $_REQUEST['exerciseId'] : null;
        $objExercise->read($exerciseId);
        if ($objExercise->random_answers == '1') {
            $this->readOrderedBy('rand()', '');// randomize answers
        } else {
            $this->read(); // natural order
        }
    }

    /**
     * Clears $new_* arrays
     *
     * @author Olivier Brouckaert
     */
    function cancel() {
        $this->new_answer				= array();
        $this->new_correct				= array();
        $this->new_comment				= array();
        $this->new_weighting			= array();
        $this->new_position				= array();
        $this->new_hotspot_coordinates	= array();
        $this->new_hotspot_type			= array();
        $this->new_nbrAnswers			= 0;
        $this->new_destination			= array();
    }

    /**
     * Reads answer information from the database
     *
     * @author Olivier Brouckaert
     */
    public function read()
    {
        $TBL_ANSWER = Database::get_course_table(TABLE_QUIZ_ANSWER);
        $questionId = $this->questionId;

        $sql = "SELECT * FROM $TBL_ANSWER
                WHERE
                    c_id = {$this->course_id} AND
                    question_id ='".$questionId."'
                ORDER BY position";

        $result = Database::query($sql);
        $i=1;

		// while a record is found
		while ($object = Database::fetch_object($result)) {
			$this->id[$i] = $object->id;
			$this->answer[$i] = $object->answer;
			$this->correct[$i] = $object->correct;
			$this->comment[$i] = $object->comment;
			$this->weighting[$i] = $object->ponderation;
			$this->position[$i] = $object->position;
			$this->hotspot_coordinates[$i] = $object->hotspot_coordinates;
			$this->hotspot_type[$i] = $object->hotspot_type;
			$this->destination[$i] = $object->destination;
			$this->autoId[$i] = $object->id_auto;
			$i++;
		}
		$this->nbrAnswers = $i-1;
	}

     /**
     * returns all answer ids from this question Id
     *
     * @author Yoselyn Castillo
     * @return array - $id (answer ids)
     */
    public function selectAnswerId()
    {
        $TBL_ANSWER = Database::get_course_table(TABLE_QUIZ_ANSWER);
        $questionId = $this->questionId;

        $sql="SELECT id FROM
              $TBL_ANSWER WHERE c_id = {$this->course_id} AND question_id ='".$questionId."'";

        $result = Database::query($sql);
        $id = array();
        // while a record is found
        if (Database::num_rows($result) > 0) {
            while ($object = Database::fetch_array($result)) {
                  $id[] = $object['id'];
            }
        }
        return $id;
	}

    /**
     * Reads answer information from the data base ordered by parameter
     * @param	string	Field we want to order by
     * @param	string	DESC or ASC
     * @author 	Frederic Vauthier
     */
    function readOrderedBy($field, $order='ASC')
    {
		$field = Database::escape_string($field);
		if (empty($field)) {
			$field = 'position';
		}

		if ($order != 'ASC' && $order!='DESC') {
			$order = 'ASC';
		}

		$TBL_ANSWER   = Database::get_course_table(TABLE_QUIZ_ANSWER);
		$TBL_QUIZ     = Database::get_course_table(TABLE_QUIZ_QUESTION);
		$questionId=intval($this->questionId);

		$sql = "SELECT type FROM $TBL_QUIZ WHERE c_id = {$this->course_id} AND id = $questionId";
		$result_question = Database::query($sql);
		$question_type = Database::fetch_array($result_question);

		$sql = "SELECT answer,correct,comment,ponderation,position, hotspot_coordinates, hotspot_type, destination, id_auto " .
               "FROM $TBL_ANSWER WHERE c_id = {$this->course_id} AND question_id='".$questionId."'   " .
               "ORDER BY $field $order";
		$result=Database::query($sql);

		$i = 1;
		// while a record is found
		$doubt_data = null;
		while($object = Database::fetch_object($result)) {
		    if ($question_type['type'] == UNIQUE_ANSWER_NO_OPTION && $object->position == 666) {
		        $doubt_data = $object;
                continue;
		    }
			$this->answer[$i]		= $object->answer;
			$this->correct[$i]		= $object->correct;
			$this->comment[$i]		= $object->comment;
			$this->weighting[$i]	= $object->ponderation;
			$this->position[$i]		= $object->position;
			$this->destination[$i]	= $object->destination;
			$this->autoId[$i]		= $object->id_auto;
			$i++;
		}

		if ($question_type['type'] == UNIQUE_ANSWER_NO_OPTION && !empty($doubt_data)) {
		    $this->answer[$i]       = $doubt_data->answer;
			$this->correct[$i]		= $doubt_data->correct;
			$this->comment[$i]		= $doubt_data->comment;
			$this->weighting[$i]	= $doubt_data->ponderation;
			$this->position[$i]		= $doubt_data->position;
			$this->destination[$i]	= $doubt_data->destination;
			$this->autoId[$i]		= $doubt_data->id_auto;
			$i++;
	    }
        $this->nbrAnswers = $i-1;
	}

	/**
	 * returns the autoincrement id identificator
	 *
	 * @author Juan Carlos Ra�a
	 * @return integer - answer num
	 */
	function selectAutoId($id)
    {
		return isset($this->autoId[$id]) ? $this->autoId[$id] : null;
	}

	/**
	 * returns the number of answers in this question
	 *
	 * @author Olivier Brouckaert
	 * @return integer - number of answers
	 */
	function selectNbrAnswers()
    {
		return $this->nbrAnswers;
	}

	/**
	 * returns the question ID which the answers belong to
	 *
	 * @author Olivier Brouckaert
	 * @return integer - the question ID
	 */
	function selectQuestionId()
    {
		return $this->questionId;
	}

	/**
	 * returns the question ID of the destination question
	 *
	 * @author Julio Montoya
	 * @return integer - the question ID
	 */
	function selectDestination($id)
    {
		return isset($this->destination[$id]) ? $this->destination[$id] : null;
	}

    /**
	 * returns the answer title
	 *
	 * @author Olivier Brouckaert
	 * @param - integer $id - answer ID
	 * @return string - answer title
	 */
	function selectAnswer($id)
        {
            return isset($this->answer[$id]) ? $this->answer[$id] : null;
	}

	/**
	 * return array answer by id else return a bool
	 */
	function selectAnswerByAutoId($auto_id) {
		$TBL_ANSWER = Database::get_course_table(TABLE_QUIZ_ANSWER);

		$auto_id = intval($auto_id);
		$sql="SELECT id, answer, id_auto FROM $TBL_ANSWER WHERE c_id = {$this->course_id} AND id_auto='$auto_id'";
		$rs = Database::query($sql);

		if (Database::num_rows($rs) > 0) {
			$row = Database::fetch_array($rs);
			return $row;
		}
		return false;
	}

    /**
     * returns the answer title from an answer's position
     *
     * @author Yannick Warnier
     * @param - integer $id - answer ID
     * @return bool - answer title
     */
	function selectAnswerIdByPosition($pos) {
		foreach ($this->position as $k => $v) {
			if ($v != $pos) { continue; }
			return $k;
		}
		return false;
	}

    /**
     * Returns a list of answers
     * @author Yannick Warnier <ywarnier@beeznest.org>
     * @return array	List of answers where each answer is an array of (id, answer, comment, grade) and grade=weighting
     */
	 function getAnswersList($decode = false)
     {
	 	$list = array();
	 	for($i = 1; $i<=$this->nbrAnswers;$i++){
	 		if(!empty($this->answer[$i])){

	 			//Avoid problems when parsing elements with accents
	 			if ($decode) {
	        		$this->answer[$i] 	= api_html_entity_decode($this->answer[$i], ENT_QUOTES, api_get_system_encoding());
	        		$this->comment[$i]	= api_html_entity_decode($this->comment[$i], ENT_QUOTES, api_get_system_encoding());
	 			}

	 			$list[] = array(
                    'id'            => $i,
                    'answer'        => $this->answer[$i],
                    'comment'       => $this->comment[$i],
                    'grade'         => $this->weighting[$i],
                    'hotspot_coord' => $this->hotspot_coordinates[$i],
                    'hotspot_type'	=> $this->hotspot_type[$i],
                    'correct'		=> $this->correct[$i],
                    'destination'	=> $this->destination[$i]
				);
	 		}
	 	}
	 	return $list;
	 }
	/**
	 * Returns a list of grades
	 * @author Yannick Warnier <ywarnier@beeznest.org>
	 * @return array	List of grades where grade=weighting (?)
	 */
	 function getGradesList() {
	 	$list = array();
	 	for($i = 0; $i<$this->nbrAnswers;$i++){
	 		if(!empty($this->answer[$i])){
	 			$list[$i] = $this->weighting[$i];
	 		}
	 	}
	 	return $list;
	 }

	 /**
	  * Returns the question type
	  * @author	Yannick Warnier <ywarnier@beeznest.org>
	  * @return	integer	The type of the question this answer is bound to
	  */
	 function getQuestionType() {
	 	$TBL_QUESTIONS = Database::get_course_table(TABLE_QUIZ_QUESTION);
	 	$sql = "SELECT type FROM $TBL_QUESTIONS WHERE c_id = {$this->course_id} AND id = '".$this->questionId."'";
	 	$res = Database::query($sql);
	 	if(Database::num_rows($res)<=0){
	 		return null;
	 	}
	 	$row = Database::fetch_array($res);
	 	return $row['type'];
	 }


	/**
	 * tells if answer is correct or not
	 *
	 * @author Olivier Brouckaert
	 * @param - integer $id - answer ID
	 * @return integer - 0 if bad answer, not 0 if good answer
	 */
	function isCorrect($id)
	{
		return isset($this->correct[$id]) ? $this->correct[$id] : null;
	}

	/**
	 * returns answer comment
	 *
	 * @author Olivier Brouckaert
	 * @param - integer $id - answer ID
	 * @return string - answer comment
	 */
	function selectComment($id)
	{
        return isset($this->comment[$id]) ? $this->comment[$id] : null;
	}

	/**
	 * returns answer weighting
	 *
	 * @author Olivier Brouckaert
	 * @param - integer $id - answer ID
	 * @return integer - answer weighting
	 */
	function selectWeighting($id)
	{
		return isset($this->weighting[$id]) ? $this->weighting[$id] : null;
	}

	/**
	 * returns answer position
	 *
	 * @author Olivier Brouckaert
	 * @param - integer $id - answer ID
	 * @return integer - answer position
	 */
	function selectPosition($id)
	{
		return isset($this->position[$id]) ? $this->position[$id] : null;
	}

	/**
	 * returns answer hotspot coordinates
	 *
	 * @author	Olivier Brouckaert
	 * @param	integer	Answer ID
	 * @return	integer	Answer position
	 */
	function selectHotspotCoordinates($id)
	{
		return isset($this->hotspot_coordinates[$id]) ? $this->hotspot_coordinates[$id] : null;
	}

	/**
	 * returns answer hotspot type
	 *
	 * @author	Toon Keppens
	 * @param	integer		Answer ID
	 * @return	integer		Answer position
	 */
	function selectHotspotType($id)
	{
		return isset($this->hotspot_type[$id]) ? $this->hotspot_type[$id] : null;
	}

	/**
	 * Creates a new answer
	 *
	 * @author Olivier Brouckaert
	 * @param string 	answer title
	 * @param integer 	0 if bad answer, not 0 if good answer
	 * @param string 	answer comment
	 * @param integer 	answer weighting
	 * @param integer 	answer position
	 * @param coordinates 	Coordinates for hotspot exercises (optional)
	 * @param integer		Type for hotspot exercises (optional)
	 */
	function createAnswer($answer,$correct,$comment,$weighting, $position, $new_hotspot_coordinates = null, $new_hotspot_type = null, $destination='')
    {
		$this->new_nbrAnswers++;
		$id=$this->new_nbrAnswers;
		$this->new_answer[$id]=$answer;
		$this->new_correct[$id]=$correct;
		$this->new_comment[$id]=$comment;
		$this->new_weighting[$id]=$weighting;
		$this->new_position[$id]=$position;
		$this->new_hotspot_coordinates[$id]=$new_hotspot_coordinates;
		$this->new_hotspot_type[$id]=$new_hotspot_type;
		$this->new_destination[$id] = $destination;
	}

    /**
     * Updates an answer
     *
     * @author Toon Keppens
     *
     * @param string $answer
     * @param string $comment
     * @param string $correct
     * @param string $weighting
     * @param string $position
     * @param string $destination
     * @param string $hotspot_coordinates
     * @param string $hotspot_type
     */
    function updateAnswers($answer, $comment, $correct, $weighting, $position, $destination, $hotspot_coordinates, $hotspot_type)
    {
		    $TBL_REPONSES = Database :: get_course_table(TABLE_QUIZ_ANSWER);
        $idAnswer = $this->selectAnswerId();
        $id = $this->getQuestionType() == 3 ? $idAnswer[0] : Database::escape_string($position);
		    $questionId=$this->questionId;
		    $sql = "UPDATE $TBL_REPONSES SET
        answer = '".Database::escape_string($answer)."',
				comment = '".Database::escape_string($comment)."',
        correct = '".Database::escape_string($correct)."',
				ponderation = '".Database::escape_string($weighting)."',
				position = '".Database::escape_string($position)."',
				destination = '".Database::escape_string($destination)."',
				hotspot_coordinates = '".Database::escape_string($hotspot_coordinates)."',
        hotspot_type = '".Database::escape_string($hotspot_type)."'
				WHERE c_id = {$this->course_id} AND id = '$id'
				AND question_id = ".intval($questionId)."";
        Database::query($sql);
	}

	/**
	 * Records answers into the data base
	 *
	 * @author Olivier Brouckaert
	 */
	function save()
    {
		$TBL_REPONSES = Database::get_course_table(TABLE_QUIZ_ANSWER);
		$questionId   = intval($this->questionId);

		$c_id = $this->course['real_id'];
		// inserts new answers into data base
        $flag = 0;
		$sql = "INSERT INTO $TBL_REPONSES (c_id, id, question_id, answer, correct, comment, ponderation, position, hotspot_coordinates, hotspot_type, destination) VALUES ";
		for ($i=1;$i <= $this->new_nbrAnswers; $i++) {

			$answer					= Database::escape_string($this->new_answer[$i]);
            $correct				= Database::escape_string($this->new_correct[$i]);
			$comment				= Database::escape_string($this->new_comment[$i]);
			$weighting				= Database::escape_string($this->new_weighting[$i]);
			$position				= Database::escape_string($this->new_position[$i]);
			$hotspot_coordinates	= Database::escape_string($this->new_hotspot_coordinates[$i]);
			$hotspot_type			= Database::escape_string($this->new_hotspot_type[$i]);
			$destination			= Database::escape_string($this->new_destination[$i]);

            if (!(isset($this->position[$i]))) {
                $flag = 1;
			    $sql.="($c_id, '$i','$questionId','$answer','$correct','$comment','$weighting','$position','$hotspot_coordinates','$hotspot_type','$destination'),";
            } else {
                // https://support.chamilo.org/issues/6558
                // function updateAnswers already escape_string, error if we do it twice.
                // Feed function updateAnswers with none escaped strings
                $this->updateAnswers(
                    $this->new_answer[$i],
                    $this->new_comment[$i],
                    $this->new_correct[$i],
                    $this->new_weighting[$i],
                    $this->new_position[$i],
                    $this->new_destination[$i],
                    $this->new_hotspot_coordinates[$i],
                    $this->new_hotspot_type[$i]
                );
            }
        }

		if ($flag == 1) {
            $sql = api_substr($sql,0,-1);
            Database::query($sql);
        }
        if (count($this->position) > $this->new_nbrAnswers) {
            $i = $this->new_nbrAnswers+1;
            while ($this->position[$i]) {
                $position = $this->position[$i];
                $sql = "DELETE FROM $TBL_REPONSES WHERE c_id = {$this->course_id} AND question_id = '".($questionId)."' AND position ='$position'";
                Database::query($sql);
                $i++;
            }

        }

		// moves $new_* arrays
		$this->answer=$this->new_answer;
		$this->correct=$this->new_correct;
		$this->comment=$this->new_comment;
		$this->weighting=$this->new_weighting;
		$this->position=$this->new_position;
		$this->hotspot_coordinates=$this->new_hotspot_coordinates;
		$this->hotspot_type=$this->new_hotspot_type;

		$this->nbrAnswers=$this->new_nbrAnswers;
		$this->destination=$this->new_destination;
		// clears $new_* arrays

		$this->cancel();
	}

	/**
	 * Duplicates answers by copying them into another question
	 *
	 * @author Olivier Brouckaert
	 * @param  int question id
     * @param  array destination course info (result of the function api_get_course_info() )
	 */
	function duplicate($newQuestionId, $course_info = null) {
        if (empty($course_info)) {
            $course_info = $this->course;
        } else {
            $course_info = $course_info;
        }

		$TBL_REPONSES = Database :: get_course_table(TABLE_QUIZ_ANSWER);

        if (self::getQuestionType() == MULTIPLE_ANSWER_TRUE_FALSE || self::getQuestionType() == MULTIPLE_ANSWER_TRUE_FALSE) {

            //Selecting origin options
            $origin_options = Question::readQuestionOption($this->selectQuestionId(), $this->course['real_id']);


            if (!empty($origin_options)) {
                foreach($origin_options as $item) {
            	   $new_option_list[]=$item['id'];
                }
            }

            $destination_options = Question::readQuestionOption($newQuestionId, $course_info['real_id']);
            $i=0;
            $fixed_list = array();
            if (!empty($destination_options)) {
                foreach($destination_options as $item) {
                    $fixed_list[$new_option_list[$i]] = $item['id'];
                    $i++;
                }
            }
        }

		// if at least one answer
		if ($this->nbrAnswers) {
			// inserts new answers into data base
			$sql = "INSERT INTO $TBL_REPONSES (c_id, id,question_id,answer,correct,comment, ponderation,position,hotspot_coordinates,hotspot_type,destination) VALUES";
			$c_id = $course_info['real_id'];

			for ($i=1;$i <= $this->nbrAnswers;$i++) {
                if ($this->course['id'] != $course_info['id']) {
                	$this->answer[$i]  = DocumentManager::replace_urls_inside_content_html_from_copy_course($this->answer[$i],$this->course['id'], $course_info['id']) ;
                    $this->comment[$i] = DocumentManager::replace_urls_inside_content_html_from_copy_course($this->comment[$i],$this->course['id'], $course_info['id']) ;
                }

				$answer					= Database::escape_string($this->answer[$i]);
				$correct				= Database::escape_string($this->correct[$i]);

                if (self::getQuestionType() == MULTIPLE_ANSWER_TRUE_FALSE || self::getQuestionType() == MULTIPLE_ANSWER_TRUE_FALSE ) {
                    $correct = $fixed_list[intval($correct)];
                }

				$comment				= Database::escape_string($this->comment[$i]);
				$weighting				= Database::escape_string($this->weighting[$i]);
				$position				= Database::escape_string($this->position[$i]);
				$hotspot_coordinates	= Database::escape_string($this->hotspot_coordinates[$i]);
				$hotspot_type			= Database::escape_string($this->hotspot_type[$i]);
				$destination			= Database::escape_string($this->destination[$i]);
				$sql.="($c_id, '$i','$newQuestionId','$answer','$correct','$comment'," .
						"'$weighting','$position','$hotspot_coordinates','$hotspot_type','$destination'),";
			}
			$sql = api_substr($sql,0,-1);
			Database::query($sql);
		}
	}
}