<?php
  /**
   * @author Jörn Friedrich Dreyer
   * @copyright (c) 2014 Jörn Friedrich Dreyer <jfd@owncloud.com>
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
   * License as published by the Free Software Foundation; either
   * version 3 of the License, or any later version.
   *
   * This library 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 AFFERO GENERAL PUBLIC LICENSE for more details.
   *
   * You should have received a copy of the GNU Affero General Public
   * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
   *
   */
  
  namespace OC\Files\ObjectStore;
  
  use Guzzle\Http\Exception\ClientErrorResponseException;
  use OCP\Files\ObjectStore\IObjectStore;
  use OpenCloud\OpenStack;
  use OpenCloud\Rackspace;
  
  class Swift implements IObjectStore {
  	/**
  	 * @var \OpenCloud\OpenStack
  	 */
  	private $client;
  
  	/**
  	 * @var array
  	 */
  	private $params;
  
  	/**
  	 * @var \OpenCloud\ObjectStore\Service
  	 */
  	private $objectStoreService;
  
  	/**
  	 * @var \OpenCloud\ObjectStore\Resource\Container
  	 */
  	private $container;
  
  	public function __construct($params) {
  		if (!isset($params['container'])) {
  			$params['container'] = 'owncloud';
  		}
  		if (!isset($params['autocreate'])) {
  			// should only be true for tests
  			$params['autocreate'] = false;
  		}
  
  		if (isset($params['apiKey'])) {
  			$this->client = new Rackspace($params['url'], $params);
  		} else {
  			$this->client = new OpenStack($params['url'], $params);
  		}
  		$this->params = $params;
  	}
  
  	protected function init() {
  		if ($this->container) {
  			return;
  		}
  
  		// the OpenCloud client library will default to 'cloudFiles' if $serviceName is null
  		$serviceName = null;
  		if ($this->params['serviceName']) {
  			$serviceName = $this->params['serviceName'];
  		}
  
  		$this->objectStoreService = $this->client->objectStoreService($serviceName, $this->params['region']);
  
  		try {
  			$this->container = $this->objectStoreService->getContainer($this->params['container']);
  		} catch (ClientErrorResponseException $ex) {
  			// if the container does not exist and autocreate is true try to create the container on the fly
  			if (isset($this->params['autocreate']) && $this->params['autocreate'] === true) {
  				$this->container = $this->objectStoreService->createContainer($this->params['container']);
  			} else {
  				throw $ex;
  			}
  		}
  	}
  
  	/**
  	 * @return string the container name where objects are stored
  	 */
  	public function getStorageId() {
  		return $this->params['container'];
  	}
  
  	/**
  	 * @param string $urn the unified resource name used to identify the object
  	 * @param resource $stream stream with the data to write
  	 * @throws Exception from openstack lib when something goes wrong
  	 */
  	public function writeObject($urn, $stream) {
  		$this->init();
  		$this->container->uploadObject($urn, $stream);
  	}
  
  	/**
  	 * @param string $urn the unified resource name used to identify the object
  	 * @return resource stream with the read data
  	 * @throws Exception from openstack lib when something goes wrong
  	 */
  	public function readObject($urn) {
  		$this->init();
  		$object = $this->container->getObject($urn);
  
  		// we need to keep a reference to objectContent or
  		// the stream will be closed before we can do anything with it
  		/** @var $objectContent \Guzzle\Http\EntityBody * */
  		$objectContent = $object->getContent();
  		$objectContent->rewind();

  		$stream = $objectContent->getStream();
  		// save the object content in the context of the stream to prevent it being gc'd until the stream is closed
  		stream_context_set_option($stream, 'swift','content', $objectContent);

  		return $stream;

  	}
  
  	/**
  	 * @param string $urn Unified Resource Name
  	 * @return void
  	 * @throws Exception from openstack lib when something goes wrong
  	 */
  	public function deleteObject($urn) {
  		$this->init();
  		// see https://github.com/rackspace/php-opencloud/issues/243#issuecomment-30032242
  		$this->container->dataObject()->setName($urn)->delete();
  	}
  
  	public function deleteContainer($recursive = false) {
  		$this->init();
  		$this->container->delete($recursive);
  	}
  
  }