<?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) 2016 (original work) Open Assessment Technologies SA;
 *
 */

namespace oat\tao\model\websource;

use common_ext_ExtensionsManager;

/**
 * @access public
 * @package tao
 * @license GPLv2  http://www.opensource.org/licenses/gpl-2.0.php
 */
class FlyTokenWebSource extends TokenWebSource
{
    const ENTRY_POINT = '/getFileFlysystem.php/';

    /**
     * @param $fileSystem
     */
    public function setFileSystem($fileSystem)
    {
        $this->fileSystem = $fileSystem;
    }

    /**
     * Get file path from url.
     * @param null $url
     * @return string
     * @throws \tao_models_classes_FileNotFoundException
     */
    public function getFilePathFromUrl($url)
    {
        $url = parse_url($url)['path']; //remove query part from url.
        $rel = substr($url, strpos($url, self::ENTRY_POINT) + strlen(self::ENTRY_POINT));
        $parts = explode('/', $rel, 4);
        list ($webSourceId, $timestamp, $token, $subPath) = $parts;

        $parts = explode('*/', $subPath, 2);
        if (count($parts) < 2) {
            throw new \tao_models_classes_FileNotFoundException('`' . $subPath . '` - (wrong number of path parts)');
        }
        list ($subPath, $file) = $parts;

        $secret = $this->getOption('secret');
        $ttl = $this->getOption('ttl');

        $correctToken = md5($timestamp . $subPath . $secret);

        if (time() - $timestamp > $ttl) {
            throw new \tao_models_classes_FileNotFoundException('`' . $subPath . $file . '` - (file link expired)');
        }
        if ($token != $correctToken) {
            throw new \tao_models_classes_FileNotFoundException('`' . $subPath . $file . '` - (wrong token)');
        }


        $path = [];
        foreach (explode('/', $subPath . $file) as $ele) {
            $path[] = rawurldecode($ele);
        }
        $filename = implode('/', $path);

        return $filename;
    }

    /**
     * @param string $relativePath
     * @return string
     * @throws \common_exception_Error
     * @throws \common_ext_ExtensionException
     */
    public function getAccessUrl($relativePath)
    {
        $path = [];
        foreach (preg_split('/[\/\\\]/', ltrim($relativePath, '/\\')) as $ele) {
            $path[] = rawurlencode($ele);
        }
        $relUrl = implode('/', $path);
        $token = $this->generateToken($relUrl);
        $taoExtension = common_ext_ExtensionsManager::singleton()->getExtensionById('tao');
        return $taoExtension->getConstant('BASE_URL') . 'getFileFlysystem.php/' . $this->getId() . '/' . $token . '/' . $relUrl . '*/';
    }
}