Move Files app to PSR-4 (#24569)

* Move lib/ of Files app to PSR-4

* Move tests to PSR-4

15 files changed, 1385 insertions, 0 deletions

diff --git a/apps/files/lib/activity.php b/apps/files/lib/Activity.php
index 1cbd6c3b973..1cbd6c3b973 100644
--- a/apps/files/lib/activity.php
+++ b/apps/files/lib/Activity.php
diff --git a/apps/files/lib/activityhelper.php b/apps/files/lib/ActivityHelper.php
index 046dd59bc76..046dd59bc76 100644
--- a/apps/files/lib/activityhelper.php
+++ b/apps/files/lib/ActivityHelper.php
diff --git a/apps/files/lib/app.php b/apps/files/lib/App.php
index 981c41ff413..981c41ff413 100644
--- a/apps/files/lib/app.php
+++ b/apps/files/lib/App.php
diff --git a/apps/files/lib/AppInfo/Application.php b/apps/files/lib/AppInfo/Application.php
new file mode 100644
index 00000000000..b2faa43cc3c
--- /dev/null
+++ b/apps/files/lib/AppInfo/Application.php
@@ -0,0 +1,94 @@
+<?php
+/**
+ * @author Roeland Jago Douma <rullzer@owncloud.com>
+ * @author Tobias Kaminsky <tobias@kaminsky.me>
+ * @author Vincent Petry <pvince81@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OCA\Files\AppInfo;
+
+use OCA\Files\Controller\ApiController;
+use OCP\AppFramework\App;
+use \OCA\Files\Service\TagService;
+use \OCP\IContainer;
+use OCA\Files\Controller\ViewController;
+
+class Application extends App {
+	public function __construct(array $urlParams=array()) {
+		parent::__construct('files', $urlParams);
+		$container = $this->getContainer();
+		$server = $container->getServer();
+
+		/**
+		 * Controllers
+		 */
+		$container->registerService('APIController', function (IContainer $c) use ($server) {
+			return new ApiController(
+				$c->query('AppName'),
+				$c->query('Request'),
+				$server->getUserSession(),
+				$c->query('TagService'),
+				$server->getPreviewManager(),
+				$server->getShareManager(),
+				$server->getConfig()
+			);
+		});
+
+		$container->registerService('ViewController', function (IContainer $c) use ($server) {
+			return new ViewController(
+				$c->query('AppName'),
+				$c->query('Request'),
+				$server->getURLGenerator(),
+				$server->getNavigationManager(),
+				$c->query('L10N'),
+				$server->getConfig(),
+				$server->getEventDispatcher(),
+				$server->getUserSession(),
+				$server->getAppManager(),
+				$server->getRootFolder()
+			);
+		});
+
+		/**
+		 * Core
+		 */
+		$container->registerService('L10N', function(IContainer $c) {
+			return $c->query('ServerContainer')->getL10N($c->query('AppName'));
+		});
+
+		/**
+		 * Services
+		 */
+		$container->registerService('Tagger', function(IContainer $c)  {
+			return $c->query('ServerContainer')->getTagManager()->load('files');
+		});
+		$container->registerService('TagService', function(IContainer $c)  {
+			$homeFolder = $c->query('ServerContainer')->getUserFolder();
+			return new TagService(
+				$c->query('ServerContainer')->getUserSession(),
+				$c->query('Tagger'),
+				$homeFolder
+			);
+		});
+
+		/*
+		 * Register capabilities
+		 */
+		$container->registerCapability('OCA\Files\Capabilities');
+	}
+}
diff --git a/apps/files/lib/backgroundjob/cleanupfilelocks.php b/apps/files/lib/BackgroundJob/CleanupFileLocks.php
index b5cf8e94551..b5cf8e94551 100644
--- a/apps/files/lib/backgroundjob/cleanupfilelocks.php
+++ b/apps/files/lib/BackgroundJob/CleanupFileLocks.php
diff --git a/apps/files/lib/backgroundjob/deleteorphaneditems.php b/apps/files/lib/BackgroundJob/DeleteOrphanedItems.php
index 1eef9c24e0c..1eef9c24e0c 100644
--- a/apps/files/lib/backgroundjob/deleteorphaneditems.php
+++ b/apps/files/lib/BackgroundJob/DeleteOrphanedItems.php
diff --git a/apps/files/lib/backgroundjob/scanfiles.php b/apps/files/lib/BackgroundJob/ScanFiles.php
index dcc180bcfbe..dcc180bcfbe 100644
--- a/apps/files/lib/backgroundjob/scanfiles.php
+++ b/apps/files/lib/BackgroundJob/ScanFiles.php
diff --git a/apps/files/lib/capabilities.php b/apps/files/lib/Capabilities.php
index dc49ca174b3..dc49ca174b3 100644
--- a/apps/files/lib/capabilities.php
+++ b/apps/files/lib/Capabilities.php
diff --git a/apps/files/lib/Command/DeleteOrphanedFiles.php b/apps/files/lib/Command/DeleteOrphanedFiles.php
new file mode 100644
index 00000000000..91043471ce5
--- /dev/null
+++ b/apps/files/lib/Command/DeleteOrphanedFiles.php
@@ -0,0 +1,84 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCA\Files\Command;
+
+use Doctrine\DBAL\Platforms\PostgreSqlPlatform;
+use Doctrine\DBAL\Platforms\SqlitePlatform;
+use OCP\IDBConnection;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+/**
+ * Delete all file entries that have no matching entries in the storage table.
+ */
+class DeleteOrphanedFiles extends Command {
+
+	const CHUNK_SIZE = 200;
+
+	/**
+	 * @var IDBConnection
+	 */
+	protected $connection;
+
+	public function __construct(IDBConnection $connection) {
+		$this->connection = $connection;
+		parent::__construct();
+	}
+
+	protected function configure() {
+		$this
+			->setName('files:cleanup')
+			->setDescription('cleanup filecache');
+	}
+
+	public function execute(InputInterface $input, OutputInterface $output) {
+		$deletedEntries = 0;
+
+		$query = $this->connection->getQueryBuilder();
+		$query->select('fc.fileid')
+			->from('filecache', 'fc')
+			->where($query->expr()->isNull('s.numeric_id'))
+			->leftJoin('fc', 'storages', 's', $query->expr()->eq('fc.storage', 's.numeric_id'))
+			->setMaxResults(self::CHUNK_SIZE);
+
+		$deleteQuery = $this->connection->getQueryBuilder();
+		$deleteQuery->delete('filecache')
+			->where($deleteQuery->expr()->eq('fileid', $deleteQuery->createParameter('objectid')));
+
+		$deletedInLastChunk = self::CHUNK_SIZE;
+		while ($deletedInLastChunk === self::CHUNK_SIZE) {
+			$deletedInLastChunk = 0;
+			$result = $query->execute();
+			while ($row = $result->fetch()) {
+				$deletedInLastChunk++;
+				$deletedEntries += $deleteQuery->setParameter('objectid', (int) $row['fileid'])
+					->execute();
+			}
+			$result->closeCursor();
+		}
+
+		$output->writeln("$deletedEntries orphaned file cache entries deleted");
+	}
+
+}
diff --git a/apps/files/lib/Command/Scan.php b/apps/files/lib/Command/Scan.php
new file mode 100644
index 00000000000..1ae04c585bb
--- /dev/null
+++ b/apps/files/lib/Command/Scan.php
@@ -0,0 +1,310 @@
+<?php
+/**
+ * @author Bart Visscher <bartv@thisnet.nl>
+ * @author Jörn Friedrich Dreyer <jfd@butonic.de>
+ * @author martin.mattel@diemattels.at <martin.mattel@diemattels.at>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Robin Appelman <icewind@owncloud.com>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCA\Files\Command;
+
+use OC\Core\Command\Base;
+use OC\ForbiddenException;
+use OCP\Files\StorageNotAvailableException;
+use OCP\IUserManager;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Helper\Table;
+
+class Scan extends Base {
+
+	/** @var IUserManager $userManager */
+	private $userManager;
+	/** @var float */
+	protected $execTime = 0;
+	/** @var int */
+	protected $foldersCounter = 0;
+	/** @var int */
+	protected $filesCounter = 0;
+
+	public function __construct(IUserManager $userManager) {
+		$this->userManager = $userManager;
+		parent::__construct();
+	}
+
+	protected function configure() {
+		parent::configure();
+
+		$this
+			->setName('files:scan')
+			->setDescription('rescan filesystem')
+			->addArgument(
+				'user_id',
+				InputArgument::OPTIONAL | InputArgument::IS_ARRAY,
+				'will rescan all files of the given user(s)'
+			)
+			->addOption(
+				'path',
+				'p',
+				InputArgument::OPTIONAL,
+				'limit rescan to this path, eg. --path="/alice/files/Music", the user_id is determined by the path and the user_id parameter and --all are ignored'
+			)
+			->addOption(
+				'quiet',
+				'q',
+				InputOption::VALUE_NONE,
+				'suppress any output'
+			)
+			->addOption(
+				'verbose',
+				'-v|vv|vvv',
+				InputOption::VALUE_NONE,
+				'verbose the output'
+			)
+			->addOption(
+				'all',
+				null,
+				InputOption::VALUE_NONE,
+				'will rescan all files of all known users'
+			);
+	}
+
+	public function checkScanWarning($fullPath, OutputInterface $output) {
+		$normalizedPath = basename(\OC\Files\Filesystem::normalizePath($fullPath));
+		$path = basename($fullPath);
+
+		if ($normalizedPath !== $path) {
+			$output->writeln("\t<error>Entry \"" . $fullPath . '" will not be accessible due to incompatible encoding</error>');
+		}
+	}
+
+	protected function scanFiles($user, $path, $verbose, OutputInterface $output) {
+		$scanner = new \OC\Files\Utils\Scanner($user, \OC::$server->getDatabaseConnection(), \OC::$server->getLogger());
+		# check on each file/folder if there was a user interrupt (ctrl-c) and throw an exception
+		# printout and count
+		if ($verbose) {
+			$scanner->listen('\OC\Files\Utils\Scanner', 'scanFile', function ($path) use ($output) {
+				$output->writeln("\tFile   <info>$path</info>");
+				$this->filesCounter += 1;
+				if ($this->hasBeenInterrupted()) {
+					throw new \Exception('ctrl-c');
+				}
+			});
+			$scanner->listen('\OC\Files\Utils\Scanner', 'scanFolder', function ($path) use ($output) {
+				$output->writeln("\tFolder <info>$path</info>");
+				$this->foldersCounter += 1;
+				if ($this->hasBeenInterrupted()) {
+					throw new \Exception('ctrl-c');
+				}
+			});
+			$scanner->listen('\OC\Files\Utils\Scanner', 'StorageNotAvailable', function (StorageNotAvailableException $e) use ($output) {
+				$output->writeln("Error while scanning, storage not available (" . $e->getMessage() . ")");
+			});
+		# count only
+		} else {
+			$scanner->listen('\OC\Files\Utils\Scanner', 'scanFile', function () use ($output) {
+				$this->filesCounter += 1;
+				if ($this->hasBeenInterrupted()) {
+					throw new \Exception('ctrl-c');
+				}
+			});
+			$scanner->listen('\OC\Files\Utils\Scanner', 'scanFolder', function () use ($output) {
+				$this->foldersCounter += 1;
+				if ($this->hasBeenInterrupted()) {
+					throw new \Exception('ctrl-c');
+				}
+			});
+		}
+		$scanner->listen('\OC\Files\Utils\Scanner', 'scanFile', function($path) use ($output) {
+			$this->checkScanWarning($path, $output);
+		});
+		$scanner->listen('\OC\Files\Utils\Scanner', 'scanFolder', function($path) use ($output) {
+			$this->checkScanWarning($path, $output);
+		});
+
+		try {
+			$scanner->scan($path);
+		} catch (ForbiddenException $e) {
+			$output->writeln("<error>Home storage for user $user not writable</error>");
+			$output->writeln("Make sure you're running the scan command only as the user the web server runs as");
+		} catch (\Exception $e) {
+			if ($e->getMessage() !== 'ctrl-c') {
+				$output->writeln('<error>Exception while scanning: ' . $e->getMessage() . "\n" . $e->getTraceAsString() . '</error>');
+			}
+			return;
+		}
+	}
+
+
+	protected function execute(InputInterface $input, OutputInterface $output) {
+		$inputPath = $input->getOption('path');
+		if ($inputPath) {
+			$inputPath = '/' . trim($inputPath, '/');
+			list (, $user,) = explode('/', $inputPath, 3);
+			$users = array($user);
+		} else if ($input->getOption('all')) {
+			$users = $this->userManager->search('');
+		} else {
+			$users = $input->getArgument('user_id');
+		}
+
+		# no messaging level option means: no full printout but statistics
+		# $quiet   means no print at all
+		# $verbose means full printout including statistics
+		# -q	-v	full	stat
+		#  0	 0	no	yes
+		#  0	 1	yes	yes
+		#  1	--	no	no  (quiet overrules verbose)
+		$verbose = $input->getOption('verbose');
+		$quiet = $input->getOption('quiet');
+		# restrict the verbosity level to VERBOSITY_VERBOSE
+		if ($output->getVerbosity()>OutputInterface::VERBOSITY_VERBOSE) {
+			$output->setVerbosity(OutputInterface::VERBOSITY_VERBOSE);
+		}
+		if ($quiet) {
+			$verbose = false;
+		}
+
+		# check quantity of users to be process and show it on the command line
+		$users_total = count($users);
+		if ($users_total === 0) {
+			$output->writeln("<error>Please specify the user id to scan, \"--all\" to scan for all users or \"--path=...\"</error>");
+			return;
+		} else {
+			if ($users_total > 1) {
+				$output->writeln("\nScanning files for $users_total users");
+			}
+		}
+
+		$this->initTools();
+
+		$user_count = 0;
+		foreach ($users as $user) {
+			if (is_object($user)) {
+				$user = $user->getUID();
+			}
+			$path = $inputPath ? $inputPath : '/' . $user;
+			$user_count += 1;
+			if ($this->userManager->userExists($user)) {
+				# add an extra line when verbose is set to optical separate users
+				if ($verbose) {$output->writeln(""); }
+				$output->writeln("Starting scan for user $user_count out of $users_total ($user)");
+				# full: printout data if $verbose was set
+				$this->scanFiles($user, $path, $verbose, $output);
+			} else {
+				$output->writeln("<error>Unknown user $user_count $user</error>");
+			}
+			# check on each user if there was a user interrupt (ctrl-c) and exit foreach
+			if ($this->hasBeenInterrupted()) {
+				break;
+			}
+		}
+
+		# stat: printout statistics if $quiet was not set
+		if (!$quiet) {
+			$this->presentStats($output);
+		}
+	}
+
+	/**
+	 * Initialises some useful tools for the Command
+	 */
+	protected function initTools() {
+		// Start the timer
+		$this->execTime = -microtime(true);
+		// Convert PHP errors to exceptions
+		set_error_handler([$this, 'exceptionErrorHandler'], E_ALL);
+	}
+
+	/**
+	 * Processes PHP errors as exceptions in order to be able to keep track of problems
+	 *
+	 * @see https://secure.php.net/manual/en/function.set-error-handler.php
+	 *
+	 * @param int $severity the level of the error raised
+	 * @param string $message
+	 * @param string $file the filename that the error was raised in
+	 * @param int $line the line number the error was raised
+	 *
+	 * @throws \ErrorException
+	 */
+	public function exceptionErrorHandler($severity, $message, $file, $line) {
+		if (!(error_reporting() & $severity)) {
+			// This error code is not included in error_reporting
+			return;
+		}
+		throw new \ErrorException($message, 0, $severity, $file, $line);
+	}
+
+	/**
+	 * @param OutputInterface $output
+	 */
+	protected function presentStats(OutputInterface $output) {
+		// Stop the timer
+		$this->execTime += microtime(true);
+		$output->writeln("");
+
+		$headers = [
+			'Folders', 'Files', 'Elapsed time'
+		];
+
+		$this->showSummary($headers, null, $output);
+	}
+
+	/**
+	 * Shows a summary of operations
+	 *
+	 * @param string[] $headers
+	 * @param string[] $rows
+	 * @param OutputInterface $output
+	 */
+	protected function showSummary($headers, $rows, OutputInterface $output) {
+		$niceDate = $this->formatExecTime();
+		if (!$rows) {
+			$rows = [
+				$this->foldersCounter,
+				$this->filesCounter,
+				$niceDate,
+			];
+		}
+		$table = new Table($output);
+		$table
+			->setHeaders($headers)
+			->setRows([$rows]);
+		$table->render();
+	}
+
+
+	/**
+	 * Formats microtime into a human readable format
+	 *
+	 * @return string
+	 */
+	protected function formatExecTime() {
+		list($secs, $tens) = explode('.', sprintf("%.1f", ($this->execTime)));
+
+		# if you want to have microseconds add this:   . '.' . $tens;
+		return date('H:i:s', $secs);
+	}
+
+}
diff --git a/apps/files/lib/Command/TransferOwnership.php b/apps/files/lib/Command/TransferOwnership.php
new file mode 100644
index 00000000000..1f46efdde0d
--- /dev/null
+++ b/apps/files/lib/Command/TransferOwnership.php
@@ -0,0 +1,240 @@
+<?php
+/**
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCA\Files\Command;
+
+use OC\Files\Filesystem;
+use OC\Files\View;
+use OCP\Files\FileInfo;
+use OCP\Files\Mount\IMountManager;
+use OCP\IUserManager;
+use OCP\Share\IManager;
+use OCP\Share\IShare;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Helper\ProgressBar;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class TransferOwnership extends Command {
+
+	/** @var IUserManager $userManager */
+	private $userManager;
+
+	/** @var IManager */
+	private $shareManager;
+
+	/** @var IMountManager */
+	private $mountManager;
+
+	/** @var FileInfo[] */
+	private $allFiles = [];
+
+	/** @var FileInfo[] */
+	private $encryptedFiles = [];
+
+	/** @var IShare[] */
+	private $shares = [];
+
+	/** @var string */
+	private $sourceUser;
+
+	/** @var string */
+	private $destinationUser;
+
+	/** @var string */
+	private $finalTarget;
+
+	public function __construct(IUserManager $userManager, IManager $shareManager, IMountManager $mountManager) {
+		$this->userManager = $userManager;
+		$this->shareManager = $shareManager;
+		$this->mountManager = $mountManager;
+		parent::__construct();
+	}
+
+	protected function configure() {
+		$this
+			->setName('files:transfer-ownership')
+			->setDescription('All files and folders are moved to another user - shares are moved as well.')
+			->addArgument(
+				'source-user',
+				InputArgument::REQUIRED,
+				'owner of files which shall be moved'
+			)
+			->addArgument(
+				'destination-user',
+				InputArgument::REQUIRED,
+				'user who will be the new owner of the files'
+			);
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output) {
+		$this->sourceUser = $input->getArgument('source-user');
+		$this->destinationUser = $input->getArgument('destination-user');
+		if (!$this->userManager->userExists($this->sourceUser)) {
+			$output->writeln("<error>Unknown source user $this->sourceUser</error>");
+			return;
+		}
+		if (!$this->userManager->userExists($this->destinationUser)) {
+			$output->writeln("<error>Unknown destination user $this->destinationUser</error>");
+			return;
+		}
+		
+		// target user has to be ready
+		if (!\OC::$server->getEncryptionManager()->isReadyForUser($this->destinationUser)) {
+			$output->writeln("<error>The target user is not ready to accept files. The user has at least to be logged in once.</error>");
+			return;
+		}
+
+		$date = date('c');
+		$this->finalTarget = "$this->destinationUser/files/transferred from $this->sourceUser on $date";
+
+		// setup filesystem
+		Filesystem::initMountPoints($this->sourceUser);
+		Filesystem::initMountPoints($this->destinationUser);
+
+		// analyse source folder
+		$this->analyse($output);
+
+		// collect all the shares
+		$this->collectUsersShares($output);
+
+		// transfer the files
+		$this->transfer($output);
+
+		// restore the shares
+		$this->restoreShares($output);
+	}
+
+	private function walkFiles(View $view, $path, \Closure $callBack) {
+		foreach ($view->getDirectoryContent($path) as $fileInfo) {
+			if (!$callBack($fileInfo)) {
+				return;
+			}
+			if ($fileInfo->getType() === FileInfo::TYPE_FOLDER) {
+				$this->walkFiles($view, $fileInfo->getPath(), $callBack);
+			}
+		}
+	}
+
+	/**
+	 * @param OutputInterface $output
+	 * @throws \Exception
+	 */
+	protected function analyse(OutputInterface $output) {
+		$view = new View();
+		$output->writeln("Analysing files of $this->sourceUser ...");
+		$progress = new ProgressBar($output);
+		$progress->start();
+		$self = $this;
+		$this->walkFiles($view, "$this->sourceUser/files",
+				function (FileInfo $fileInfo) use ($progress, $self) {
+					if ($fileInfo->getType() === FileInfo::TYPE_FOLDER) {
+						return true;
+					}
+					$progress->advance();
+					$this->allFiles[] = $fileInfo;
+					if ($fileInfo->isEncrypted()) {
+						$this->encryptedFiles[] = $fileInfo;
+					}
+					return true;
+				});
+		$progress->finish();
+		$output->writeln('');
+
+		// no file is allowed to be encrypted
+		if (!empty($this->encryptedFiles)) {
+			$output->writeln("<error>Some files are encrypted - please decrypt them first</error>");
+			foreach($this->encryptedFiles as $encryptedFile) {
+				/** @var FileInfo $encryptedFile */
+				$output->writeln("  " . $encryptedFile->getPath());
+			}
+			throw new \Exception('Execution terminated.');
+		}
+
+	}
+
+	/**
+	 * @param OutputInterface $output
+	 */
+	private function collectUsersShares(OutputInterface $output) {
+		$output->writeln("Collecting all share information for files and folder of $this->sourceUser ...");
+
+		$progress = new ProgressBar($output, count($this->shares));
+		foreach([\OCP\Share::SHARE_TYPE_USER, \OCP\Share::SHARE_TYPE_GROUP, \OCP\Share::SHARE_TYPE_LINK, \OCP\Share::SHARE_TYPE_REMOTE] as $shareType) {
+		$offset = 0;
+			while (true) {
+				$sharePage = $this->shareManager->getSharesBy($this->sourceUser, $shareType, null, true, 50, $offset);
+				$progress->advance(count($sharePage));
+				if (empty($sharePage)) {
+					break;
+				}
+				$this->shares = array_merge($this->shares, $sharePage);
+				$offset += 50;
+			}
+		}
+
+		$progress->finish();
+		$output->writeln('');
+	}
+
+	/**
+	 * @param OutputInterface $output
+	 */
+	protected function transfer(OutputInterface $output) {
+		$view = new View();
+		$output->writeln("Transferring files to $this->finalTarget ...");
+		$view->rename("$this->sourceUser/files", $this->finalTarget);
+		// because the files folder is moved away we need to recreate it
+		$view->mkdir("$this->sourceUser/files");
+	}
+
+	/**
+	 * @param OutputInterface $output
+	 */
+	private function restoreShares(OutputInterface $output) {
+		$output->writeln("Restoring shares ...");
+		$progress = new ProgressBar($output, count($this->shares));
+
+		foreach($this->shares as $share) {
+			if ($share->getSharedWith() === $this->destinationUser) {
+				// Unmount the shares before deleting, so we don't try to get the storage later on.
+				$shareMountPoint = $this->mountManager->find('/' . $this->destinationUser . '/files' . $share->getTarget());
+				if ($shareMountPoint) {
+					$this->mountManager->removeMount($shareMountPoint->getMountPoint());
+				}
+				$this->shareManager->deleteShare($share);
+			} else {
+				if ($share->getShareOwner() === $this->sourceUser) {
+					$share->setShareOwner($this->destinationUser);
+				}
+				if ($share->getSharedBy() === $this->sourceUser) {
+					$share->setSharedBy($this->destinationUser);
+				}
+
+				$this->shareManager->updateShare($share);
+			}
+			$progress->advance();
+		}
+		$progress->finish();
+		$output->writeln('');
+	}
+}
diff --git a/apps/files/lib/Controller/ApiController.php b/apps/files/lib/Controller/ApiController.php
new file mode 100644
index 00000000000..072498c7b5f
--- /dev/null
+++ b/apps/files/lib/Controller/ApiController.php
@@ -0,0 +1,239 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ * @author Christoph Wurst <christoph@winzerhof-wurst.at>
+ * @author Lukas Reschke <lukas@owncloud.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Roeland Jago Douma <rullzer@owncloud.com>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ * @author Tobias Kaminsky <tobias@kaminsky.me>
+ * @author Vincent Petry <pvince81@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCA\Files\Controller;
+
+use OCP\AppFramework\Http;
+use OCP\AppFramework\Controller;
+use OCP\IConfig;
+use OCP\IRequest;
+use OCP\AppFramework\Http\DataResponse;
+use OCP\AppFramework\Http\DataDisplayResponse;
+use OCP\AppFramework\Http\Response;
+use OCA\Files\Service\TagService;
+use OCP\IPreview;
+use OCP\Share\IManager;
+use OCP\Files\Node;
+use OCP\IUserSession;
+
+/**
+ * Class ApiController
+ *
+ * @package OCA\Files\Controller
+ */
+class ApiController extends Controller {
+	/** @var TagService */
+	private $tagService;
+	/** @var IManager **/
+	private $shareManager;
+	/** @var IPreview */
+	private $previewManager;
+	/** IUserSession */
+	private $userSession;
+	/** IConfig */
+	private $config;
+
+	/**
+	 * @param string $appName
+	 * @param IRequest $request
+	 * @param TagService $tagService
+	 * @param IPreview $previewManager
+	 */
+	public function __construct($appName,
+								IRequest $request,
+								IUserSession $userSession,
+								TagService $tagService,
+								IPreview $previewManager,
+								IManager $shareManager,
+								IConfig $config) {
+		parent::__construct($appName, $request);
+		$this->userSession = $userSession;
+		$this->tagService = $tagService;
+		$this->previewManager = $previewManager;
+		$this->shareManager = $shareManager;
+		$this->config = $config;
+	}
+
+	/**
+	 * Gets a thumbnail of the specified file
+	 *
+	 * @since API version 1.0
+	 *
+	 * @NoAdminRequired
+	 * @NoCSRFRequired
+	 *
+	 * @param int $x
+	 * @param int $y
+	 * @param string $file URL-encoded filename
+	 * @return DataResponse|DataDisplayResponse
+	 */
+	public function getThumbnail($x, $y, $file) {
+		if($x < 1 || $y < 1) {
+			return new DataResponse(['message' => 'Requested size must be numeric and a positive value.'], Http::STATUS_BAD_REQUEST);
+		}
+
+		$preview = $this->previewManager->createPreview('files/'.$file, $x, $y, true);
+		if ($preview->valid()) {
+			return new DataDisplayResponse($preview->data(), Http::STATUS_OK, ['Content-Type' => 'image/png']);
+		} else {
+			return new DataResponse(['message' => 'File not found.'], Http::STATUS_NOT_FOUND);
+		}
+	}
+
+	/**
+	 * Updates the info of the specified file path
+	 * The passed tags are absolute, which means they will
+	 * replace the actual tag selection.
+	 *
+	 * @NoAdminRequired
+	 *
+	 * @param string $path path
+	 * @param array|string $tags array of tags
+	 * @return DataResponse
+	 */
+	public function updateFileTags($path, $tags = null) {
+		$result = [];
+		// if tags specified or empty array, update tags
+		if (!is_null($tags)) {
+			try {
+				$this->tagService->updateFileTags($path, $tags);
+			} catch (\OCP\Files\NotFoundException $e) {
+				return new DataResponse([
+					'message' => $e->getMessage()
+				], Http::STATUS_NOT_FOUND);
+			} catch (\OCP\Files\StorageNotAvailableException $e) {
+				return new DataResponse([
+					'message' => $e->getMessage()
+				], Http::STATUS_SERVICE_UNAVAILABLE);
+			} catch (\Exception $e) {
+				return new DataResponse([
+					'message' => $e->getMessage()
+				], Http::STATUS_NOT_FOUND);
+			}
+			$result['tags'] = $tags;
+		}
+		return new DataResponse($result);
+	}
+
+	/**
+	 * Returns a list of all files tagged with the given tag.
+	 *
+	 * @NoAdminRequired
+	 *
+	 * @param string $tagName tag name to filter by
+	 * @return DataResponse
+	 */
+	public function getFilesByTag($tagName) {
+		$files = array();
+		$nodes = $this->tagService->getFilesByTag($tagName);
+		foreach ($nodes as &$node) {
+			$shareTypes = $this->getShareTypes($node);
+			$fileInfo = $node->getFileInfo();
+			$file = \OCA\Files\Helper::formatFileInfo($fileInfo);
+			$parts = explode('/', dirname($fileInfo->getPath()), 4);
+			if(isset($parts[3])) {
+				$file['path'] = '/' . $parts[3];
+			} else {
+				$file['path'] = '/';
+			}
+			$file['tags'] = [$tagName];
+			if (!empty($shareTypes)) {
+				$file['shareTypes'] = $shareTypes;
+			}
+			$files[] = $file;
+		}
+		return new DataResponse(['files' => $files]);
+	}
+
+	/**
+	 * Return a list of share types for outgoing shares
+	 *
+	 * @param Node $node file node
+	 *
+	 * @return int[] array of share types
+	 */
+	private function getShareTypes(Node $node) {
+		$userId = $this->userSession->getUser()->getUID();
+		$shareTypes = [];
+		$requestedShareTypes = [
+			\OCP\Share::SHARE_TYPE_USER,
+			\OCP\Share::SHARE_TYPE_GROUP,
+			\OCP\Share::SHARE_TYPE_LINK,
+			\OCP\Share::SHARE_TYPE_REMOTE
+		];
+		foreach ($requestedShareTypes as $requestedShareType) {
+			// one of each type is enough to find out about the types
+			$shares = $this->shareManager->getSharesBy(
+				$userId,
+				$requestedShareType,
+				$node,
+				false,
+				1
+			);
+			if (!empty($shares)) {
+				$shareTypes[] = $requestedShareType;
+			}
+		}
+		return $shareTypes;
+	}
+
+	/**
+	 * Change the default sort mode
+	 *
+	 * @NoAdminRequired
+	 *
+	 * @param string $mode
+	 * @param string $direction
+	 * @return Response
+	 */
+	public function updateFileSorting($mode, $direction) {
+		$allowedMode = ['name', 'size', 'mtime'];
+		$allowedDirection = ['asc', 'desc'];
+		if (!in_array($mode, $allowedMode) || !in_array($direction, $allowedDirection)) {
+			$response = new Response();
+			$response->setStatus(Http::STATUS_UNPROCESSABLE_ENTITY);
+			return $response;
+		}
+		$this->config->setUserValue($this->userSession->getUser()->getUID(), 'files', 'file_sorting', $mode);
+		$this->config->setUserValue($this->userSession->getUser()->getUID(), 'files', 'file_sorting_direction', $direction);
+		return new Response();
+	}
+
+	/**
+	 * Toggle default for showing/hiding hidden files
+	 *
+	 * @NoAdminRequired
+	 *
+	 * @param bool $show
+	 */
+	public function showHiddenFiles($show) {
+		$this->config->setUserValue($this->userSession->getUser()->getUID(), 'files', 'show_hidden', (int) $show);
+		return new Response();
+	}
+
+}
diff --git a/apps/files/lib/Controller/ViewController.php b/apps/files/lib/Controller/ViewController.php
new file mode 100644
index 00000000000..7539a3ab649
--- /dev/null
+++ b/apps/files/lib/Controller/ViewController.php
@@ -0,0 +1,304 @@
+<?php
+/**
+ * @author Christoph Wurst <christoph@winzerhof-wurst.at>
+ * @author Lukas Reschke <lukas@owncloud.com>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ * @author Vincent Petry <pvince81@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCA\Files\Controller;
+
+use OC\AppFramework\Http\Request;
+use OCP\AppFramework\Controller;
+use OCP\AppFramework\Http\ContentSecurityPolicy;
+use OCP\AppFramework\Http\Response;
+use OCP\AppFramework\Http\RedirectResponse;
+use OCP\AppFramework\Http\TemplateResponse;
+use OCP\IConfig;
+use OCP\IL10N;
+use OCP\INavigationManager;
+use OCP\IRequest;
+use OCP\IURLGenerator;
+use OCP\IUserSession;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use OCP\AppFramework\Http\NotFoundResponse;
+use OCP\Files\Folder;
+use OCP\App\IAppManager;
+
+/**
+ * Class ViewController
+ *
+ * @package OCA\Files\Controller
+ */
+class ViewController extends Controller {
+	/** @var string */
+	protected $appName;
+	/** @var IRequest */
+	protected $request;
+	/** @var IURLGenerator */
+	protected $urlGenerator;
+	/** @var INavigationManager */
+	protected $navigationManager;
+	/** @var IL10N */
+	protected $l10n;
+	/** @var IConfig */
+	protected $config;
+	/** @var EventDispatcherInterface */
+	protected $eventDispatcher;
+	/** @var IUserSession */
+	protected $userSession;
+	/** @var IAppManager */
+	protected $appManager;
+	/** @var \OCP\Files\Folder */
+	protected $rootFolder;
+
+	/**
+	 * @param string $appName
+	 * @param IRequest $request
+	 * @param IURLGenerator $urlGenerator
+	 * @param INavigationManager $navigationManager
+	 * @param IL10N $l10n
+	 * @param IConfig $config
+	 * @param EventDispatcherInterface $eventDispatcherInterface
+	 * @param IUserSession $userSession
+	 * @param IAppManager $appManager
+	 * @param Folder $rootFolder
+	 */
+	public function __construct($appName,
+								IRequest $request,
+								IURLGenerator $urlGenerator,
+								INavigationManager $navigationManager,
+								IL10N $l10n,
+								IConfig $config,
+								EventDispatcherInterface $eventDispatcherInterface,
+								IUserSession $userSession,
+								IAppManager $appManager,
+								Folder $rootFolder
+	) {
+		parent::__construct($appName, $request);
+		$this->appName = $appName;
+		$this->request = $request;
+		$this->urlGenerator = $urlGenerator;
+		$this->navigationManager = $navigationManager;
+		$this->l10n = $l10n;
+		$this->config = $config;
+		$this->eventDispatcher = $eventDispatcherInterface;
+		$this->userSession = $userSession;
+		$this->appManager = $appManager;
+		$this->rootFolder = $rootFolder;
+	}
+
+	/**
+	 * @param string $appName
+	 * @param string $scriptName
+	 * @return string
+	 */
+	protected function renderScript($appName, $scriptName) {
+		$content = '';
+		$appPath = \OC_App::getAppPath($appName);
+		$scriptPath = $appPath . '/' . $scriptName;
+		if (file_exists($scriptPath)) {
+			// TODO: sanitize path / script name ?
+			ob_start();
+			include $scriptPath;
+			$content = ob_get_contents();
+			@ob_end_clean();
+		}
+		return $content;
+	}
+
+	/**
+	 * FIXME: Replace with non static code
+	 *
+	 * @return array
+	 * @throws \OCP\Files\NotFoundException
+	 */
+	protected function getStorageInfo() {
+		$dirInfo = \OC\Files\Filesystem::getFileInfo('/', false);
+		return \OC_Helper::getStorageInfo('/', $dirInfo);
+	}
+
+	/**
+	 * @NoCSRFRequired
+	 * @NoAdminRequired
+	 *
+	 * @param string $dir
+	 * @param string $view
+	 * @param string $fileid
+	 * @return TemplateResponse
+	 * @throws \OCP\Files\NotFoundException
+	 */
+	public function index($dir = '', $view = '', $fileid = null) {
+		if ($fileid !== null) {
+			return $this->showFile($fileid);
+		}
+
+		$nav = new \OCP\Template('files', 'appnavigation', '');
+
+		// Load the files we need
+		\OCP\Util::addStyle('files', 'files');
+		\OCP\Util::addStyle('files', 'upload');
+		\OCP\Util::addStyle('files', 'mobile');
+		\OCP\Util::addscript('files', 'app');
+		\OCP\Util::addscript('files', 'file-upload');
+		\OCP\Util::addscript('files', 'newfilemenu');
+		\OCP\Util::addscript('files', 'jquery.fileupload');
+		\OCP\Util::addscript('files', 'jquery-visibility');
+		\OCP\Util::addscript('files', 'fileinfomodel');
+		\OCP\Util::addscript('files', 'filesummary');
+		\OCP\Util::addscript('files', 'breadcrumb');
+		\OCP\Util::addscript('files', 'filelist');
+		\OCP\Util::addscript('files', 'search');
+
+		\OCP\Util::addScript('files', 'favoritesfilelist');
+		\OCP\Util::addScript('files', 'tagsplugin');
+		\OCP\Util::addScript('files', 'favoritesplugin');
+
+		\OCP\Util::addScript('files', 'detailfileinfoview');
+		\OCP\Util::addScript('files', 'detailtabview');
+		\OCP\Util::addScript('files', 'mainfileinfodetailview');
+		\OCP\Util::addScript('files', 'detailsview');
+		\OCP\Util::addStyle('files', 'detailsView');
+
+		\OC_Util::addVendorScript('core', 'handlebars/handlebars');
+
+		\OCP\Util::addscript('files', 'fileactions');
+		\OCP\Util::addscript('files', 'fileactionsmenu');
+		\OCP\Util::addscript('files', 'files');
+		\OCP\Util::addscript('files', 'keyboardshortcuts');
+		\OCP\Util::addscript('files', 'navigation');
+
+		// if IE8 and "?dir=path&view=someview" was specified, reformat the URL to use a hash like "#?dir=path&view=someview"
+		$isIE8 = $this->request->isUserAgent([Request::USER_AGENT_IE_8]);
+		if ($isIE8 && ($dir !== '' || $view !== '')) {
+			$dir = !empty($dir) ? $dir : '/';
+			$view = !empty($view) ? $view : 'files';
+			$hash = '#?dir=' . \OCP\Util::encodePath($dir);
+			if ($view !== 'files') {
+				$hash .= '&view=' . urlencode($view);
+			}
+			return new RedirectResponse($this->urlGenerator->linkToRoute('files.view.index') . $hash);
+		}
+
+		// mostly for the home storage's free space
+		// FIXME: Make non static
+		$storageInfo = $this->getStorageInfo();
+
+		\OCA\Files\App::getNavigationManager()->add(
+			[
+				'id' => 'favorites',
+				'appname' => 'files',
+				'script' => 'simplelist.php',
+				'order' => 5,
+				'name' => $this->l10n->t('Favorites')
+			]
+		);
+
+		$navItems = \OCA\Files\App::getNavigationManager()->getAll();
+		usort($navItems, function($item1, $item2) {
+			return $item1['order'] - $item2['order'];
+		});
+		$nav->assign('navigationItems', $navItems);
+
+		$contentItems = [];
+
+		// render the container content for every navigation item
+		foreach ($navItems as $item) {
+			$content = '';
+			if (isset($item['script'])) {
+				$content = $this->renderScript($item['appname'], $item['script']);
+			}
+			$contentItem = [];
+			$contentItem['id'] = $item['id'];
+			$contentItem['content'] = $content;
+			$contentItems[] = $contentItem;
+		}
+
+		$this->eventDispatcher->dispatch('OCA\Files::loadAdditionalScripts');
+
+		$params = [];
+		$params['usedSpacePercent'] = (int)$storageInfo['relative'];
+		$params['owner'] = $storageInfo['owner'];
+		$params['ownerDisplayName'] = $storageInfo['ownerDisplayName'];
+		$params['isPublic'] = false;
+		$params['mailNotificationEnabled'] = $this->config->getAppValue('core', 'shareapi_allow_mail_notification', 'no');
+		$params['mailPublicNotificationEnabled'] = $this->config->getAppValue('core', 'shareapi_allow_public_notification', 'no');
+		$params['allowShareWithLink'] = $this->config->getAppValue('core', 'shareapi_allow_links', 'yes');
+		$user = $this->userSession->getUser()->getUID();
+		$params['defaultFileSorting'] = $this->config->getUserValue($user, 'files', 'file_sorting', 'name');
+		$params['defaultFileSortingDirection'] = $this->config->getUserValue($user, 'files', 'file_sorting_direction', 'asc');
+		$showHidden = (bool) $this->config->getUserValue($this->userSession->getUser()->getUID(), 'files', 'show_hidden', false);
+		$params['showHiddenFiles'] = $showHidden ? 1 : 0;
+		$params['appNavigation'] = $nav;
+		$params['appContents'] = $contentItems;
+		$this->navigationManager->setActiveEntry('files_index');
+
+		$response = new TemplateResponse(
+			$this->appName,
+			'index',
+			$params
+		);
+		$policy = new ContentSecurityPolicy();
+		$policy->addAllowedFrameDomain('\'self\'');
+		$response->setContentSecurityPolicy($policy);
+
+		return $response;
+	}
+
+	/**
+	 * Redirects to the file list and highlight the given file id
+	 *
+	 * @param string $fileId file id to show
+	 * @return Response redirect response or not found response
+	 *
+	 * @NoCSRFRequired
+	 * @NoAdminRequired
+	 */
+	public function showFile($fileId) {
+		try {
+			$uid = $this->userSession->getUser()->getUID();
+			$baseFolder = $this->rootFolder->get($uid . '/files/');
+			$files = $baseFolder->getById($fileId);
+			$params = [];
+
+			if (empty($files) && $this->appManager->isEnabledForUser('files_trashbin')) {
+				$baseFolder = $this->rootFolder->get($uid . '/files_trashbin/files/');
+				$files = $baseFolder->getById($fileId);
+				$params['view'] = 'trashbin';
+			}
+
+			if (!empty($files)) {
+				$file = current($files);
+				if ($file instanceof Folder) {
+					// set the full path to enter the folder
+					$params['dir'] = $baseFolder->getRelativePath($file->getPath());
+				} else {
+					// set parent path as dir
+					$params['dir'] = $baseFolder->getRelativePath($file->getParent()->getPath());
+					// and scroll to the entry
+					$params['scrollto'] = $file->getName();
+				}
+				return new RedirectResponse($this->urlGenerator->linkToRoute('files.view.index', $params));
+			}
+		} catch (\OCP\Files\NotFoundException $e) {
+			return new NotFoundResponse();
+		}
+		return new NotFoundResponse();
+	}
+}
diff --git a/apps/files/lib/helper.php b/apps/files/lib/Helper.php
index d21a65afcee..d21a65afcee 100644
--- a/apps/files/lib/helper.php
+++ b/apps/files/lib/Helper.php
diff --git a/apps/files/lib/Service/TagService.php b/apps/files/lib/Service/TagService.php
new file mode 100644
index 00000000000..57cad43a539
--- /dev/null
+++ b/apps/files/lib/Service/TagService.php
@@ -0,0 +1,114 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ * @author Vincent Petry <pvince81@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCA\Files\Service;
+
+use OC\Files\FileInfo;
+use OCP\Files\Node;
+
+/**
+ * Service class to manage tags on files.
+ */
+class TagService {
+
+	/**
+	 * @var \OCP\IUserSession
+	 */
+	private $userSession;
+
+	/**
+	 * @var \OCP\ITags
+	 */
+	private $tagger;
+
+	/**
+	 * @var \OCP\Files\Folder
+	 */
+	private $homeFolder;
+
+	public function __construct(
+		\OCP\IUserSession $userSession,
+		\OCP\ITags $tagger,
+		\OCP\Files\Folder $homeFolder
+	) {
+		$this->userSession = $userSession;
+		$this->tagger = $tagger;
+		$this->homeFolder = $homeFolder;
+	}
+
+	/**
+	 * Updates the tags of the specified file path.
+	 * The passed tags are absolute, which means they will
+	 * replace the actual tag selection.
+	 *
+	 * @param string $path path
+	 * @param array  $tags array of tags
+	 * @return array list of tags
+	 * @throws \OCP\Files\NotFoundException if the file does not exist
+	 */
+	public function updateFileTags($path, $tags) {
+		$fileId = $this->homeFolder->get($path)->getId();
+
+		$currentTags = $this->tagger->getTagsForObjects(array($fileId));
+
+		if (!empty($currentTags)) {
+			$currentTags = current($currentTags);
+		}
+
+		$newTags = array_diff($tags, $currentTags);
+		foreach ($newTags as $tag) {
+			$this->tagger->tagAs($fileId, $tag);
+		}
+		$deletedTags = array_diff($currentTags, $tags);
+		foreach ($deletedTags as $tag) {
+			$this->tagger->unTag($fileId, $tag);
+		}
+
+		// TODO: re-read from tagger to make sure the
+		// list is up to date, in case of concurrent changes ?
+		return $tags;
+	}
+
+	/**
+	 * Get all files for the given tag
+	 *
+	 * @param string $tagName tag name to filter by
+	 * @return Node[] list of matching files
+	 * @throws \Exception if the tag does not exist
+	 */
+	public function getFilesByTag($tagName) {
+		try {
+			$fileIds = $this->tagger->getIdsForTag($tagName);
+		} catch (\Exception $e) {
+			return [];
+		}
+
+		$allNodes = [];
+		foreach ($fileIds as $fileId) {
+			$allNodes = array_merge($allNodes, $this->homeFolder->getById((int) $fileId));
+		}
+		return $allNodes;
+	}
+}
+