<?php
  
  /**
   * ownCloud
   *
   * @author Jakob Sack
   * @copyright 2011 Jakob Sack kde@jakobsack.de
   *
   * 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/>.
   *
   */
  
  class OC_Connector_Sabre_File extends OC_Connector_Sabre_Node implements Sabre_DAV_IFile {
  
  	/**
  	 * Updates the data
  	 *
  	 * The data argument is a readable stream resource.
  	 *

  	 * After a successful put operation, you may choose to return an ETag. The

  	 * etag must always be surrounded by double-quotes. These quotes must
  	 * appear in the actual string you're returning.
  	 *
  	 * Clients may use the ETag from a PUT request to later on make sure that
  	 * when they update the file, the contents haven't changed in the mean
  	 * time.
  	 *
  	 * If you don't plan to store the file byte-by-byte, and you return a
  	 * different object on a subsequent GET you are strongly recommended to not
  	 * return an ETag, and just return null.
  	 *
  	 * @param resource $data
  	 * @throws Sabre_DAV_Exception_Forbidden
  	 * @return string|null
  	 */
  	public function put($data) {

  		$fs = $this->getFS();
  
  		if ($fs->file_exists($this->path) &&
  			!$fs->isUpdatable($this->path)) {

  			throw new \Sabre_DAV_Exception_Forbidden();
  		}

  		// throw an exception if encryption was disabled but the files are still encrypted
  		if (\OC_Util::encryptedFiles()) {
  			throw new \Sabre_DAV_Exception_ServiceUnavailable();
  		}
  
  		// chunked handling
  		if (isset($_SERVER['HTTP_OC_CHUNKED'])) {
  			return $this->createFileChunked($data);
  		}

  		// mark file as partial while uploading (ignored by the scanner)

  		$partpath = $this->path . '.ocTransferId' . rand() . '.part';

  
  		// if file is located in /Shared we write the part file to the users
  		// root folder because we can't create new files in /shared
  		// we extend the name with a random number to avoid overwriting a existing file

  		if (dirname($partpath) === 'Shared') {

  			$partpath = pathinfo($partpath, PATHINFO_FILENAME) . rand() . '.part';
  		}

  		try {
  			$putOkay = $fs->file_put_contents($partpath, $data);
  			if ($putOkay === false) {
  				\OC_Log::write('webdav', '\OC\Files\Filesystem::file_put_contents() failed', \OC_Log::ERROR);
  				$fs->unlink($partpath);
  				// because we have no clue about the cause we can only throw back a 500/Internal Server Error

  				throw new Sabre_DAV_Exception('Could not write file contents');

  			}

  		} catch (\OCP\Files\NotPermittedException $e) {
  			// a more general case - due to whatever reason the content could not be written
  			throw new Sabre_DAV_Exception_Forbidden($e->getMessage());
  
  		} catch (\OCP\Files\EntityTooLargeException $e) {
  			// the file is too big to be stored
  			throw new OC_Connector_Sabre_Exception_EntityTooLarge($e->getMessage());
  
  		} catch (\OCP\Files\InvalidContentException $e) {
  			// the file content is not permitted
  			throw new OC_Connector_Sabre_Exception_UnsupportedMediaType($e->getMessage());
  
  		} catch (\OCP\Files\InvalidPathException $e) {
  			// the path for the file was not valid
  			// TODO: find proper http status code for this case
  			throw new Sabre_DAV_Exception_Forbidden($e->getMessage());

  		}
  
  		// rename to correct path

  		$renameOkay = $fs->rename($partpath, $this->path);
  		$fileExists = $fs->file_exists($this->path);

  		if ($renameOkay === false || $fileExists === false) {
  			\OC_Log::write('webdav', '\OC\Files\Filesystem::rename() failed', \OC_Log::ERROR);

  			$fs->unlink($partpath);

  			throw new Sabre_DAV_Exception('Could not rename part file to final file');

  		}

  		// allow sync clients to send the mtime along in a header

  		$mtime = OC_Request::hasModificationTime();
  		if ($mtime !== false) {

  			if($fs->touch($this->path, $mtime)) {

  				header('X-OC-MTime: accepted');
  			}
  		}

  		return $this->getETagPropertyForPath($this->path);

  	}
  
  	/**
  	 * Returns the data
  	 *
  	 * @return string
  	 */
  	public function get() {

  		//throw exception if encryption is disabled but files are still encrypted
  		if (\OC_Util::encryptedFiles()) {
  			throw new \Sabre_DAV_Exception_ServiceUnavailable();
  		} else {
  			return \OC\Files\Filesystem::fopen($this->path, 'rb');
  		}

  
  	}
  
  	/**
  	 * Delete the current file
  	 *
  	 * @return void
  	 * @throws Sabre_DAV_Exception_Forbidden
  	 */
  	public function delete() {

  		if ($this->path === 'Shared') {
  			throw new \Sabre_DAV_Exception_Forbidden();
  		}

  		if (!\OC\Files\Filesystem::isDeletable($this->path)) {
  			throw new \Sabre_DAV_Exception_Forbidden();
  		}
  		\OC\Files\Filesystem::unlink($this->path);

  		// remove properties
  		$this->removeProperties();

  	}
  
  	/**
  	 * Returns the size of the node, in bytes
  	 *
  	 * @return int
  	 */
  	public function getSize() {
  		$this->getFileinfoCache();
  		if ($this->fileinfo_cache['size'] > -1) {
  			return $this->fileinfo_cache['size'];
  		} else {
  			return null;
  		}
  	}
  
  	/**
  	 * Returns the ETag for a file
  	 *
  	 * An ETag is a unique identifier representing the current version of the
  	 * file. If the file changes, the ETag MUST change.  The ETag is an

  	 * arbitrary string, but MUST be surrounded by double-quotes.

  	 *
  	 * Return null if the ETag can not effectively be determined
  	 *
  	 * @return mixed
  	 */
  	public function getETag() {
  		$properties = $this->getProperties(array(self::GETETAG_PROPERTYNAME));
  		if (isset($properties[self::GETETAG_PROPERTYNAME])) {
  			return $properties[self::GETETAG_PROPERTYNAME];
  		}
  		return null;
  	}
  
  	/**
  	 * Returns the mime-type for a file
  	 *
  	 * If null is returned, we'll assume application/octet-stream
  	 *
  	 * @return mixed
  	 */
  	public function getContentType() {
  		if (isset($this->fileinfo_cache['mimetype'])) {

  			$mimeType = $this->fileinfo_cache['mimetype'];
  		} else {
  			$mimeType = \OC\Files\Filesystem::getMimeType($this->path);

  		}

  		return \OC_Helper::getSecureMimeType($mimeType);

  	}

  
  	private function createFileChunked($data)
  	{
  		list($path, $name) = \Sabre_DAV_URLUtil::splitPath($this->path);
  
  		$info = OC_FileChunking::decodeName($name);
  		if (empty($info)) {
  			throw new Sabre_DAV_Exception_NotImplemented();
  		}
  		$chunk_handler = new OC_FileChunking($info);
  		$bytesWritten = $chunk_handler->store($info['index'], $data);
  
  		//detect aborted upload
  		if (isset ($_SERVER['REQUEST_METHOD']) && $_SERVER['REQUEST_METHOD'] === 'PUT' ) {
  			if (isset($_SERVER['CONTENT_LENGTH'])) {
  				$expected = $_SERVER['CONTENT_LENGTH'];
  				if ($bytesWritten != $expected) {
  					$chunk_handler->remove($info['index']);
  					throw new Sabre_DAV_Exception_BadRequest(
  						'expected filesize ' . $expected . ' got ' . $bytesWritten);
  				}
  			}
  		}
  
  		if ($chunk_handler->isComplete()) {
  
  			// we first assembly the target file as a part file
  			$partFile = $path . '/' . $info['name'] . '.ocTransferId' . $info['transferid'] . '.part';
  			$chunk_handler->file_assemble($partFile);
  
  			// here is the final atomic rename
  			$fs = $this->getFS();
  			$targetPath = $path . '/' . $info['name'];
  			$renameOkay = $fs->rename($partFile, $targetPath);
  			$fileExists = $fs->file_exists($targetPath);
  			if ($renameOkay === false || $fileExists === false) {
  				\OC_Log::write('webdav', '\OC\Files\Filesystem::rename() failed', \OC_Log::ERROR);

  				// only delete if an error occurred and the target file was already created
  				if ($fileExists) {
  					$fs->unlink($targetPath);
  				}
  				throw new Sabre_DAV_Exception('Could not rename part file assembled from chunks');

  			}
  
  			// allow sync clients to send the mtime along in a header
  			$mtime = OC_Request::hasModificationTime();
  			if ($mtime !== false) {
  				if($fs->touch($targetPath, $mtime)) {
  					header('X-OC-MTime: accepted');
  				}
  			}
  
  			return OC_Connector_Sabre_Node::getETagPropertyForPath($targetPath);
  		}
  
  		return null;
  	}

  }