<?php

// (c) Copyright by authors of the Tiki Wiki CMS Groupware Project
//
// All Rights Reserved. See copyright.txt for details and a complete list of authors.
// Licensed under the GNU LESSER GENERAL PUBLIC LICENSE. See license.txt for details.
// $Id$

class ScormLib
{
    public function handle_file_creation($args)
    {
        if ($metadata = $this->getRequestMetadata($args)) {
            $this->createItem(
                $metadata,
                [
                    'scormPackage' => $args['object'],
                ]
            );
        }
    }

    public function handle_file_update($args)
    {
        if (isset($args['initialFileId']) && $metadata = $this->getRequestMetadata($args)) {
            $relationlib = TikiLib::lib('relation');
            $items = $relationlib->get_relations_to('file', $args['initialFileId'], 'tiki.file.attach');

            $transaction = TikiDb::get()->begin();

            foreach ($items as $item) {
                if ($item['type'] == 'trackeritem') {
                    $this->updateItem(
                        $item['itemId'],
                        $metadata,
                        [
                            'scormPackage' => $args['object'],
                        ]
                    );
                }
            }

            $transaction->commit();
        }
    }

    private function getRequestMetadata($args)
    {
        $metadata = null;

        $file = \Tiki\FileGallery\File::id($args['object']);

        if (
            $this->isZipFile($args)
            && $zip = $this->getZipFile($file)
        ) {
            if ($manifest = $this->getScormManifest($zip)) {
                $metadata = $this->getMetadata($manifest);
            }

            $zip->close();
        }

        return $metadata;
    }

    private function isZipFile($args)
    {
        if (! isset($args['filetype'])) {
            return false;
        }

        return in_array($args['filetype'], ['application/zip', 'application/x-zip', 'application/x-zip-compressed']);
    }

    private function getZipFile($file)
    {
        global $prefs;

        if (! class_exists('ZipArchive')) {
            return null;
        }

        $zip = new ZipArchive();

        $filepath = $file->getWrapper()->getReadableFile();

        if ($zip->open($filepath) === true) {
            return $zip;
        }
    }

    private function getScormManifest($zip)
    {
        return $zip->getFromName('imsmanifest.xml');
    }

    private function getMetadata($manifest)
    {
        $dom = new DOMDocument();
        $dom->loadXML($manifest);

        $metadata = [];
        foreach ($dom->getElementsByTagName('general')->item(0)->childNodes as $node) {
            if ($node instanceof DOMElement) {
                $metadata[$this->getKey($node)][] = $this->getData($node);
            }
        }

        return $metadata;
    }

    private function getKey($node)
    {
        $raw = $node->tagName;
        return substr($raw, strpos($raw, ':') + 1);
    }

    private function getData($node)
    {
        $data = [];
        foreach ($node->getElementsByTagName('langstring') as $text) {
            $data[$text->getAttribute('xml:lang')] = trim($text->textContent);
        }

        return $data;
    }

    private function createItem($metadata, $additional)
    {
        $definition = $this->getScormTracker();
        $fields = $this->buildFields($definition, $metadata, $additional);

        $utilities = new Services_Tracker_Utilities();
        $utilities->insertItem(
            $definition,
            [
                'status' => 'o',
                'fields' => $fields,
            ]
        );
    }

    private function updateItem($itemId, $metadata, $additional)
    {
        $definition = $this->getScormTracker();
        $fields = $this->buildFields($definition, $metadata, $additional);

        $utilities = new Services_Tracker_Utilities();
        $utilities->updateItem(
            $definition,
            [
                'itemId' => (int) $itemId,
                'status' => 'o',
                'fields' => $fields,
            ]
        );
    }

    private function getScormTracker()
    {
        global $prefs;

        return Tracker_Definition::get($prefs['scorm_tracker']);
    }

    private function buildFields($definition, $metadata, $additional)
    {
        $fields = [];

        foreach ($metadata as $key => $values) {
            if ($field = $definition->getFieldFromPermName($key)) {
                if ($field['type'] === 'F') {
                    $fields[$key] = $this->getTagString($values);
                } elseif ($field['isMultilingual'] == 'y') {
                    $fields[$key] = reset($values);
                } else {
                    $fields[$key] = $this->getForDefaultLanguage($values);
                }
            }
        }

        return array_merge($fields, $additional);
    }

    private function getTagString($values)
    {
        $completeSet = [];
        foreach ($values as $val) {
            $completeSet = array_merge($completeSet, array_values($val));
        }

        return implode(' ', array_unique($completeSet));
    }

    private function getForDefaultLanguage($values)
    {
        global $prefs;

        $defaultLanguage = $prefs['language'];
        foreach ($values as $valueSet) {
            if (isset($valueSet[$defaultLanguage])) {
                return $valueSet[$defaultLanguage];
            }
        }

        // If nothing matching the language found, return the first value
        return reset(reset($values));
    }
}