<?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
  	 * @throws OC_Connector_Sabre_Exception_UnsupportedMediaType
  	 * @throws \Sabre\DAV\Exception\BadRequest
  	 * @throws \Sabre\DAV\Exception
  	 * @throws OC_Connector_Sabre_Exception_EntityTooLarge
  	 * @throws \Sabre\DAV\Exception\ServiceUnavailable

  	 * @return string|null
  	 */
  	public function put($data) {

  		if ($this->info && $this->fileView->file_exists($this->path) &&
  			!$this->info->isUpdateable()) {
  			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();
  		}
  
  		$fileName = basename($this->path);
  		if (!\OCP\Util::isValidFileName($fileName)) {
  			throw new \Sabre\DAV\Exception\BadRequest();

  		}
  
  		// chunked handling
  		if (isset($_SERVER['HTTP_OC_CHUNKED'])) {
  			return $this->createFileChunked($data);
  		}

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

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

  		try {

  			$putOkay = $this->fileView->file_put_contents($partFilePath, $data);

  			if ($putOkay === false) {
  				\OC_Log::write('webdav', '\OC\Files\Filesystem::file_put_contents() failed', \OC_Log::ERROR);

  				$this->fileView->unlink($partFilePath);

  				// 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());
  		} catch (\OCP\Files\LockNotAcquiredException $e) {
  			// the file is currently being written to by another process
  			throw new OC_Connector_Sabre_Exception_FileLocked($e->getMessage(), $e->getCode(), $e);
  		}
  
  		// double check if the file was fully received
  		// compare expected and actual size
  		$expected = $_SERVER['CONTENT_LENGTH'];
  		$actual = $this->fileView->filesize($partFilePath);
  		if ($actual != $expected) {
  			$this->fileView->unlink($partFilePath);
  			throw new \Sabre\DAV\Exception\BadRequest('expected filesize ' . $expected . ' got ' . $actual);

  		}
  
  		// rename to correct path

  		try {
  			$renameOkay = $this->fileView->rename($partFilePath, $this->path);
  			$fileExists = $this->fileView->file_exists($this->path);
  			if ($renameOkay === false || $fileExists === false) {
  				\OC_Log::write('webdav', '\OC\Files\Filesystem::rename() failed', \OC_Log::ERROR);
  				$this->fileView->unlink($partFilePath);
  				throw new \Sabre\DAV\Exception('Could not rename part file to final file');
  			}
  		}
  		catch (\OCP\Files\LockNotAcquiredException $e) {
  			// the file is currently being written to by another process
  			throw new OC_Connector_Sabre_Exception_FileLocked($e->getMessage(), $e->getCode(), $e);

  		}

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

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

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

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

  		$this->refreshInfo();

  		return '"' . $this->info->getEtag() . '"';

  	}
  
  	/**
  	 * Returns the data
  	 *

  	 * @return string|resource

  	 */
  	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 $this->fileView->fopen(ltrim($this->path, '/'), 'rb');

  		}

  
  	}
  
  	/**
  	 * Delete the current file
  	 *
  	 * @return void

  	 * @throws \Sabre\DAV\Exception\Forbidden

  	 */
  	public function delete() {

  		if (!$this->info->isDeletable()) {
  			throw new \Sabre\DAV\Exception\Forbidden();

  		}

  		$this->fileView->unlink($this->path);

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

  	}
  
  	/**
  	 * Returns the size of the node, in bytes
  	 *

  	 * @return int|float

  	 */
  	public function getSize() {

  		return $this->info->getSize();

  	}
  
  	/**
  	 * 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() {

  		return '"' . $this->info->getEtag() . '"';

  	}
  
  	/**
  	 * Returns the mime-type for a file
  	 *
  	 * If null is returned, we'll assume application/octet-stream
  	 *
  	 * @return mixed
  	 */
  	public function getContentType() {

  		$mimeType = $this->info->getMimetype();

  		return \OC_Helper::getSecureMimeType($mimeType);

  	}

  	/**
  	 * @param resource $data
  	 * @return null|string
  	 */

  	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

  			$targetPath = $path . '/' . $info['name'];

  			$renameOkay = $this->fileView->rename($partFile, $targetPath);
  			$fileExists = $this->fileView->file_exists($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) {

  					$this->fileView->unlink($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($this->fileView->touch($targetPath, $mtime)) {

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

  			$info = $this->fileView->getFileInfo($targetPath);
  			return $info->getEtag();

  		}
  
  		return null;
  	}

  }