<?php

class MathAnswer extends BaseAnswer {
    public $table = "math_answers";
    protected $correct;
    protected $answer;

    public function getCorrect() {
        return $this->correct;
    }

    public function setCorrect($val) {
        $this->correct = $val;
    }
    
    public function getAnswer() {
        return $this->answer;
    }

    public function setAnswer($val) {
        $this->answer = $val;
    }

    public function getAnswerById($aid) {
        foreach (split(";", $this->getAnswer()) as $answer_element){
            $a = split(":", $answer_element);
            if (is_array($a)){
                if ($a[0]==$aid){
                    if ($a[1]==""){return "_";}
                    return $a[1];
                }
            }
        }
        return false;
    }
    
    public function getResult() {
        $score = 0;
        $tot = 0;
        foreach (unserialize($this->getCorrect()) as $correct_element) {
            if ($correct_element) {
                $score++;
            }
            $tot++;
        }
        $percent = round(100*$score/$tot);
        return $score." punkti ".$tot."-st, ".$percent."%";
    }
    
    public function getCorrectById($cid) {
        $correct_elements = unserialize($this->getCorrect());
        if (array_key_exists($cid, $correct_elements)){
            return $correct_elements[$cid];
        }
        return false;
    }

    public function save() {
        global $kdb;
        $aid = $this->getAnswerID();
        parent::save();
        if ( $aid == null ) {
            $sql = "INSERT INTO ".$this->table." (answerID, answer, correct) values(".$this->getAnswerID().", '".$this->getAnswer()."', '".$this->getCorrect()."')";
            $kdb->query($sql);
        } else {
            // update answer
        }
    }
}
?>