<?php

/*
 * 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; under version 2
 * of the License (non-upgradable).
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright (c) 2013 (original work) Open Assessment Technologies SA (under the project TAO-PRODUCT);
 *
 *
 */

namespace oat\taoQtiItem\model\qti;

use oat\taoQtiItem\model\qti\exception\ParsingException;
use \SimpleXMLElement;

/**
 * The ParserFactory provides some methods to build the QTI_Data objects from an
 * element.
 * SimpleXML is used as source to build the model.
 *
 * @access public
 * @author Joel Bout, <joel.bout@tudor.lu>
 * @package taoQTI

 */
class ManifestParserFactory
{
    
    /**
     * Enables you to build the QTI_Resources from a manifest xml data node
     * Content Packaging 1.1)
     *
     * @access public
     * @author Joel Bout, <joel.bout@tudor.lu>
     * @param  SimpleXMLElement source
     * @return array
     * @see http://www.imsglobal.org/question/qti_v2p0/imsqti_intgv2p0.html#section10003
     */
    public static function getResourcesFromManifest(SimpleXMLElement $source)
    {
        $returnValue = [];

        //check of the root tag
        if ($source->getName() != 'manifest') {
            throw new ParsingException("incorrect manifest root tag");
        }
            
        $resourceNodes = $source->xpath("//*[name(.)='resource']");
        foreach ($resourceNodes as $resourceNode) {
            $type = (string) $resourceNode['type'];
            if (Resource::isAssessmentItem($type)) {
                $id = (string) $resourceNode['identifier'];
                $href = (isset($resourceNode['href'])) ? (string) $resourceNode['href'] : '';
                    
                $auxFiles = [];
                
                //parse for auxiliary files
                foreach ($resourceNode->file as $fileNode) {
                    $fileHref = (string) $fileNode['href'];
                    if ($href != $fileHref) {
                        $auxFiles[] = $fileHref;
                    }
                }
                
                //include dependency files in item
                foreach ($resourceNode->dependency as $dependencyNode) {
                    $ref = (string) $dependencyNode['identifierref'];
                    //find referenced files within the current manifest:
                    $refResourceNodes = $source->xpath("//*[name(.)='resource' and @identifier='" . $ref . "']");
                    foreach ($refResourceNodes as $refResourceNode) {
                        if (isset($refResourceNode['href'])) {
                            $auxFiles[] = (string) $refResourceNode['href'];
                        }
                    }
                }
                
                $resource = new Resource($id, $type, $href);
                $resource->setAuxiliaryFiles($auxFiles);
                    
                $returnValue[] = $resource;
            }
        }

        return (array) $returnValue;
    }
}