<?php
/**
 * DigiMinaItemMultipleChoice class
 *
 * @package Digimina 
 */
class DigiMinaItemMultipleChoice extends DigiMinaItem {

    /**
     * Initialize
     *
     * @return void
     */
    protected function initializeAttributes() {
		parent::initializeAttributes();
		$this->itemtype = "multipleChoice";
    }

    /**
     * Build From XML
     *
     * @param DOMNode $resource_dom Item resource tag from manifest xml
     * @param DOMDocument $item_dom Item DOM document
     *
     * @return void
     */
    function buildFromXML($resource_dom, $item_dom) {
        parent::buildFromXML($resource_dom);
        $title = $this->getTitleFromXML($item_dom);
        $this->title = $title;
        $this->itembody = $this->getItemBodyFromXML($item_dom);
        $choices = $this->getChoicesFromXML($item_dom);
        $this->choices = serialize($choices);
        $correct_choice = $this->getCorrectChoice($item_dom);
        $this->correct = $correct_choice;
    }

    /**
     * Return choices from xml
     *
     * @param DOMDocument $dom Item DOM document
     *
     * @return array Choices array
     */
    function getChoicesFromXML($dom) {
        $choice_interaction = $dom->getElementsByTagName("choiceInteraction")->item(0);
        $choices = $choice_interaction->getElementsByTagName("simpleChoice");
        $new_choices = array();
        //$correct_choice = $this->getCorrectChoice($dom);
        for ($i=0; $i<$choices->length; $i++) {
            $choice = $choices->item($i);
            $identifier = $choice->getAttribute("identifier");
            $choice_text = $this->findNodeText($choice);
            $new_choices[$identifier]["choice_text"] = $choice_text;
            /*if ($correct_choice == $identifier) {
                $new_choices[$identifier]["correct"] = true;
            } else {
                $new_choices[$identifier]["correct"] = false;
            }*/
        }
        return $new_choices;
    }

    /**
     * Return correct choice from xml
     *
     * @param DOMDocument $dom Item DOM document
     *
     * @return string Correct choice
     */
    function getCorrectChoice($dom) {
        $correct_response = $dom->getElementsByTagName("correctResponse")->item(0);
        $value = $correct_response->getElementsByTagName("value")->item(0);
        $correct = $this->findNodeText($value);
        return $correct;
    }

    /**
     * Returns true or false based on given answer
     *
     * @param string chosen User answer
     * @return bool
     *
     */
    function answer($chosen) {
        if ($chosen == $this->correct) {
            return true;
        }
        return false;
    }

}