<?php
/**
 * ownCloud
 *
 * @author Bjoern Schiessle, Michael Gapczynski
 * @copyright 2011 Michael Gapczynski <mtgap@owncloud.com>
 *            2014 Bjoern Schiessle <schiessle@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\Storage;

/**
 * Convert target path to source path and pass the function call to the correct storage provider
 */
class Shared extends \OC\Files\Storage\Common {

	private $share;   // the shared resource
	private $files = array();

	public function __construct($arguments) {
		$this->share = $arguments['share'];
	}

	/**
	 * get id of the mount point
	 * @return string
	 */
	public function getId() {
		return 'shared::' . $this->getMountPoint();
	}

	/**
	 * get file cache of the shared item source
	 * @return string
	 */
	public function getSourceId() {
		return $this->share['file_source'];
	}

	/**
	 * Get the source file path, permissions, and owner for a shared file
	 * @param string $target Shared target file path
	 * @return Returns array with the keys path, permissions, and owner or false if not found
	 */
	public function getFile($target) {
		if (!isset($this->files[$target])) {
			// Check for partial files
			if (pathinfo($target, PATHINFO_EXTENSION) === 'part') {
				$source = \OC_Share_Backend_File::getSource(substr($target, 0, -5), $this->getMountPoint(), $this->getItemType());
				if ($source) {
					$source['path'] .= '.part';
					// All partial files have delete permission
					$source['permissions'] |= \OCP\PERMISSION_DELETE;
				}
			} else {
				$source = \OC_Share_Backend_File::getSource($target, $this->getMountPoint(), $this->getItemType());
			}
			$this->files[$target] = $source;
		}
		return $this->files[$target];
	}

	/**
	 * Get the source file path for a shared file
	 * @param string $target Shared target file path
	 * @return string source file path or false if not found
	 */
	public function getSourcePath($target) {
		$source = $this->getFile($target);
		if ($source) {
			if (!isset($source['fullPath'])) {
				\OC\Files\Filesystem::initMountPoints($source['fileOwner']);
				$mount = \OC\Files\Filesystem::getMountByNumericId($source['storage']);
				if (is_array($mount) && !empty($mount)) {
					$this->files[$target]['fullPath'] = $mount[key($mount)]->getMountPoint() . $source['path'];
				} else {
					$this->files[$target]['fullPath'] = false;
					\OCP\Util::writeLog('files_sharing', "Unable to get mount for shared storage '" . $source['storage'] . "' user '" . $source['fileOwner'] . "'", \OCP\Util::ERROR);
				}
			}
			return $this->files[$target]['fullPath'];
		}
		return false;
	}

	/**
	 * Get the permissions granted for a shared file
	 * @param string $target Shared target file path
	 * @return int CRUDS permissions granted
	 */
	public function getPermissions($target) {
		$permissions = $this->share['permissions'];
		// part file are always have delete permissions
		if (pathinfo($target, PATHINFO_EXTENSION) === 'part') {
			$permissions |= \OCP\PERMISSION_DELETE;
		}

		if (\OC_Util::isSharingDisabledForUser()) {
			$permissions &= ~\OCP\PERMISSION_SHARE;
		}

		return $permissions;
	}

	public function mkdir($path) {
		if ($path == '' || $path == '/' || !$this->isCreatable(dirname($path))) {
			return false;
		} else if ($source = $this->getSourcePath($path)) {
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			return $storage->mkdir($internalPath);
		}
		return false;
	}

	public function rmdir($path) {
		if (($source = $this->getSourcePath($path)) && $this->isDeletable($path)) {
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			return $storage->rmdir($internalPath);
		}
		return false;
	}

	public function opendir($path) {
		$source = $this->getSourcePath($path);
		list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
		return $storage->opendir($internalPath);
	}

	public function is_dir($path) {
		$source = $this->getSourcePath($path);
		list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
		return $storage->is_dir($internalPath);
	}

	public function is_file($path) {
		if ($source = $this->getSourcePath($path)) {
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			return $storage->is_file($internalPath);
		}
		return false;
	}

	public function stat($path) {
		if ($path == '' || $path == '/') {
			$stat['size'] = $this->filesize($path);
			$stat['mtime'] = $this->filemtime($path);
			return $stat;
		} else if ($source = $this->getSourcePath($path)) {
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			return $storage->stat($internalPath);
		}
		return false;
	}

	public function filetype($path) {
		if ($path == '' || $path == '/') {
			return 'dir';
		} else if ($source = $this->getSourcePath($path)) {
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			return $storage->filetype($internalPath);
		}
		return false;
	}

	public function filesize($path) {
		$source = $this->getSourcePath($path);
		list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
		return $storage->filesize($internalPath);
	}

	public function isCreatable($path) {
		return ($this->getPermissions($path) & \OCP\PERMISSION_CREATE);
	}

	public function isReadable($path) {
		return $this->file_exists($path);
	}

	public function isUpdatable($path) {
		return ($this->getPermissions($path) & \OCP\PERMISSION_UPDATE);
	}

	public function isDeletable($path) {
		return ($this->getPermissions($path) & \OCP\PERMISSION_DELETE);
	}

	public function isSharable($path) {
		if (\OCP\Util::isSharingDisabledForUser()) {
			return false;
		}
		return ($this->getPermissions($path) & \OCP\PERMISSION_SHARE);
	}

	public function file_exists($path) {
		if ($path == '' || $path == '/') {
			return true;
		} else if ($source = $this->getSourcePath($path)) {
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			return $storage->file_exists($internalPath);
		}
		return false;
	}

	public function filemtime($path) {
		$source = $this->getSourcePath($path);
		list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
		return $storage->filemtime($internalPath);
	}

	public function file_get_contents($path) {
		$source = $this->getSourcePath($path);
		if ($source) {
			$info = array(
				'target' => $this->getMountPoint() . $path,
				'source' => $source,
			);
			\OCP\Util::emitHook('\OC\Files\Storage\Shared', 'file_get_contents', $info);
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			return $storage->file_get_contents($internalPath);
		}
	}

	public function file_put_contents($path, $data) {
		if ($source = $this->getSourcePath($path)) {
			// Check if permission is granted
			if (($this->file_exists($path) && !$this->isUpdatable($path))
				|| ($this->is_dir($path) && !$this->isCreatable($path))
			) {
				return false;
			}
			$info = array(
				'target' => $this->getMountPoint() . '/' . $path,
				'source' => $source,
			);
			\OCP\Util::emitHook('\OC\Files\Storage\Shared', 'file_put_contents', $info);
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			$result = $storage->file_put_contents($internalPath, $data);
			return $result;
		}
		return false;
	}

	public function unlink($path) {
		// Delete the file if DELETE permission is granted
		$path = ($path === false) ? '' : $path;
		if ($source = $this->getSourcePath($path)) {
			if ($this->isDeletable($path)) {
				list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
				return $storage->unlink($internalPath);
			}
		}
		return false;
	}

	/**
	 * Format a path to be relative to the /user/files/ directory
	 * @param string $path the absolute path
	 * @return string e.g. turns '/admin/files/test.txt' into '/test.txt'
	 */
	private static function stripUserFilesPath($path) {
		$trimmed = ltrim($path, '/');
		$split = explode('/', $trimmed);

		// it is not a file relative to data/user/files
		if (count($split) < 3 || $split[1] !== 'files') {
			\OCP\Util::writeLog('file sharing',
					'Can not strip userid and "files/" from path: ' . $path,
					\OCP\Util::DEBUG);
			return false;
		}

		// skip 'user' and 'files'
		$sliced = array_slice($split, 2);
		$relPath = implode('/', $sliced);

		return '/' . $relPath;
	}

	/**
	 * rename a shared folder/file
	 * @param string $sourcePath
	 * @param string $targetPath
	 * @return bool
	 */
	private function renameMountPoint($sourcePath, $targetPath) {

		// it shouldn't be possible to move a Shared storage into another one
		list($targetStorage, ) = \OC\Files\Filesystem::resolvePath($targetPath);
		if ($targetStorage->instanceOfStorage('\OC\Files\Storage\Shared')) {
			\OCP\Util::writeLog('file sharing',
					'It is not allowed to move one mount point into another one',
					\OCP\Util::DEBUG);
			return false;
		}

		$relTargetPath = $this->stripUserFilesPath($targetPath);

		if ($relTargetPath === false) {
			\OCP\Util::writeLog('file sharing', 'Wrong target path given: ' . $targetPath, \OCP\Util::ERROR);
			return false;
		}

		$result = self::updateFileTarget($relTargetPath, $this->share);

		if ($result) {
			// update the mount manager with the new paths
			$mountManager = \OC\Files\Filesystem::getMountManager();
			$mount = $mountManager->find($sourcePath);
			$mount->setMountPoint($targetPath . '/');
			$mountManager->addMount($mount);
			$mountManager->removeMount($sourcePath . '/');
			$this->setUniqueName();
			$this->setMountPoint($relTargetPath);

		} else {
			\OCP\Util::writeLog('file sharing',
					'Could not rename mount point for shared folder "' . $sourcePath . '" to "' . $targetPath . '"',
					\OCP\Util::ERROR);
		}

		return (bool)$result;
	}

	/**
	 * @update fileTarget in the database if the mount point changed
	 * @param string $newPath
	 * @param array $share reference to the share which should be modified
	 * @return type
	 */
	private static function updateFileTarget($newPath, &$share) {
		// if the user renames a mount point from a group share we need to create a new db entry
		// for the unique name
		if ($share['share_type'] === \OCP\Share::SHARE_TYPE_GROUP &&
				(isset($share['unique_name']) && $share['unique_name'])) {
			$query = \OC_DB::prepare('INSERT INTO `*PREFIX*share` (`item_type`, `item_source`, `item_target`,'
			.' `share_type`, `share_with`, `uid_owner`, `permissions`, `stime`, `file_source`,'
			.' `file_target`, `token`, `parent`) VALUES (?,?,?,?,?,?,?,?,?,?,?,?)');
			$arguments = array($share['item_type'], $share['item_source'], $share['item_target'],
				2, \OCP\User::getUser(), $share['uid_owner'], $share['permissions'], $share['stime'], $share['file_source'],
				$newPath, $share['token'], $share['id']);

		} else {
			// rename mount point
			$query = \OC_DB::prepare(
					'Update `*PREFIX*share`
						SET `file_target` = ?
						WHERE `id` = ?'
					);
			$arguments = array($newPath, $share['id']);
		}

		return $query->execute($arguments);
	}

	public function rename($path1, $path2) {

		$sourceMountPoint = \OC\Files\Filesystem::getMountPoint($path1);
		$targetMountPoint = \OC\Files\Filesystem::getMountPoint($path2);
		$relPath1 = \OCA\Files_Sharing\Helper::stripUserFilesPath($path1);
		$relPath2 = \OCA\Files_Sharing\Helper::stripUserFilesPath($path2);

		// if we renamed the mount point we need to adjust the file_target in the
		// database
		if (\OC\Files\Filesystem::normalizePath($sourceMountPoint) === \OC\Files\Filesystem::normalizePath($path1)) {
			return $this->renameMountPoint($path1, $path2);
		}


		if (	// Within the same mount point, we only need UPDATE permissions
				($sourceMountPoint === $targetMountPoint && $this->isUpdatable($sourceMountPoint)) ||
				// otherwise DELETE and CREATE permissions required
				($this->isDeletable($path1) && $this->isCreatable(dirname($path2)))) {

			$pathinfo = pathinfo($relPath1);
			// for part files we need to ask for the owner and path from the parent directory because
			// the file cache doesn't return any results for part files
			if ($pathinfo['extension'] === 'part') {
				list($user1, $path1) = \OCA\Files_Sharing\Helper::getUidAndFilename($pathinfo['dirname']);
				$path1 = $path1 . '/' . $pathinfo['basename'];
			} else {
				list($user1, $path1) = \OCA\Files_Sharing\Helper::getUidAndFilename($relPath1);
			}
			$targetFilename = basename($relPath2);
			list($user2, $path2) = \OCA\Files_Sharing\Helper::getUidAndFilename(dirname($relPath2));
			$rootView = new \OC\Files\View('');
			return $rootView->rename('/' . $user1 . '/files/' . $path1, '/' . $user2 . '/files/' . $path2 . '/' . $targetFilename);
		}

		return false;
	}

	public function copy($path1, $path2) {
		// Copy the file if CREATE permission is granted
		if ($this->isCreatable(dirname($path2))) {
			$oldSource = $this->getSourcePath($path1);
			$newSource = $this->getSourcePath(dirname($path2)) . '/' . basename($path2);
			$rootView = new \OC\Files\View('');
			return $rootView->copy($oldSource, $newSource);
		}
		return false;
	}

	public function fopen($path, $mode) {
		if ($source = $this->getSourcePath($path)) {
			switch ($mode) {
				case 'r+':
				case 'rb+':
				case 'w+':
				case 'wb+':
				case 'x+':
				case 'xb+':
				case 'a+':
				case 'ab+':
				case 'w':
				case 'wb':
				case 'x':
				case 'xb':
				case 'a':
				case 'ab':
					$exists = $this->file_exists($path);
					if ($exists && !$this->isUpdatable($path)) {
						return false;
					}
					if (!$exists && !$this->isCreatable(dirname($path))) {
						return false;
					}
			}
			$info = array(
				'target' => $this->getMountPoint() . $path,
				'source' => $source,
				'mode' => $mode,
			);
			\OCP\Util::emitHook('\OC\Files\Storage\Shared', 'fopen', $info);
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			return $storage->fopen($internalPath, $mode);
		}
		return false;
	}

	public function getMimeType($path) {
		if ($source = $this->getSourcePath($path)) {
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			return $storage->getMimeType($internalPath);
		}
		return false;
	}

	public function free_space($path) {
		$source = $this->getSourcePath($path);
		if ($source) {
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			return $storage->free_space($internalPath);
		}
		return \OC\Files\SPACE_UNKNOWN;
	}

	public function getLocalFile($path) {
		if ($source = $this->getSourcePath($path)) {
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			return $storage->getLocalFile($internalPath);
		}
		return false;
	}

	public function touch($path, $mtime = null) {
		if ($source = $this->getSourcePath($path)) {
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			return $storage->touch($internalPath, $mtime);
		}
		return false;
	}

	public static function setup($options) {
		$shares = \OCP\Share::getItemsSharedWith('file');
		if (!\OCP\User::isLoggedIn() || \OCP\User::getUser() != $options['user']
			|| $shares
		) {
			foreach ($shares as $share) {
				self::verifyMountPoint($share);
				\OC\Files\Filesystem::mount('\OC\Files\Storage\Shared',
						array(
							'share' => $share,
							),
						$options['user_dir'] . '/' . $share['file_target']);
			}
		}
	}

	/**
	 * check if the parent folder exists otherwise move the mount point up
	 *
	 * @param array $share reference to the share we want to check
	 */
	private static function verifyMountPoint(&$share) {
		$mountPoint = basename($share['file_target']);
		$parent = dirname($share['file_target']);

		while (!\OC\Files\Filesystem::is_dir($parent)) {
			$parent = dirname($parent);
		}

		$newMountPoint = \OCA\Files_Sharing\Helper::generateUniqueTarget(
				\OC\Files\Filesystem::normalizePath($parent . '/' . $mountPoint),
				array(),
				new \OC\Files\View('/' . \OCP\User::getUser() . '/files')
				);

		if($newMountPoint !== $share['file_target']) {

			self::updateFileTarget($newMountPoint, $share);
			$share['file_target'] = $newMountPoint;

		}
	}

	/**
	 * return mount point of share, relative to data/user/files
	 *
	 * @return string
	 */
	public function getMountPoint() {
		return $this->share['file_target'];
	}

	private function setMountPoint($path) {
		$this->share['file_target'] = $path;
	}

	/**
	 * the share now uses a unique name of this user
	 *
	 * @brief the share now uses a unique name of this user
	 */
	private function setUniqueName() {
		$this->share['unique_name'] = true;
	}

	/**
	 * @brief get the user who shared the file
	 *
	 * @return string
	 */
	public function getSharedFrom() {
		return $this->share['uid_owner'];
	}

	/**
	 * return share type, can be "file" or "folder"
	 * @return string
	 */
	public function getItemType() {
		return $this->share['item_type'];
	}

	public function hasUpdated($path, $time) {
		return $this->filemtime($path) > $time;
	}

	public function getCache($path = '') {
		return new \OC\Files\Cache\Shared_Cache($this);
	}

	public function getScanner($path = '') {
		return new \OC\Files\Cache\Scanner($this);
	}

	public function getPermissionsCache($path = '') {
		return new \OC\Files\Cache\Shared_Permissions($this);
	}

	public function getWatcher($path = '') {
		return new \OC\Files\Cache\Shared_Watcher($this);
	}

	public function getOwner($path) {
		if ($path == '') {
			$path = $this->getMountPoint();
		}
		$source = $this->getFile($path);
		if ($source) {
			return $source['fileOwner'];
		}
		return false;
	}

	public function getETag($path) {
		if ($path == '') {
			$path = $this->getMountPoint();
		}
		if ($source = $this->getSourcePath($path)) {
			list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($source);
			return $storage->getETag($internalPath);
		}
		return null;
	}

}