Move \OC\App to PSR-4

14 files changed, 2356 insertions, 0 deletions

diff --git a/lib/private/App/AppManager.php b/lib/private/App/AppManager.php
new file mode 100644
index 00000000000..69e5334774e
--- /dev/null
+++ b/lib/private/App/AppManager.php
@@ -0,0 +1,370 @@
+<?php
+/**
+ * @author Arthur Schiwon <blizzz@owncloud.com>
+ * @author Christoph Schaefer <christophł@wolkesicher.de>
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ * @author Lukas Reschke <lukas@owncloud.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Robin Appelman <icewind@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 OC\App;
+
+use OCP\App\IAppManager;
+use OCP\App\ManagerEvent;
+use OCP\IAppConfig;
+use OCP\ICacheFactory;
+use OCP\IGroupManager;
+use OCP\IUser;
+use OCP\IUserSession;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+
+class AppManager implements IAppManager {
+
+	/**
+	 * Apps with these types can not be enabled for certain groups only
+	 * @var string[]
+	 */
+	protected $protectedAppTypes = [
+		'filesystem',
+		'prelogin',
+		'authentication',
+		'logging',
+		'prevent_group_restriction',
+	];
+
+	/** @var \OCP\IUserSession */
+	private $userSession;
+
+	/** @var \OCP\IAppConfig */
+	private $appConfig;
+
+	/** @var \OCP\IGroupManager */
+	private $groupManager;
+
+	/** @var \OCP\ICacheFactory */
+	private $memCacheFactory;
+
+	/** @var string[] $appId => $enabled */
+	private $installedAppsCache;
+
+	/** @var string[] */
+	private $shippedApps;
+
+	/** @var string[] */
+	private $alwaysEnabled;
+
+	/** @var EventDispatcherInterface */
+	private $dispatcher;
+
+	/**
+	 * @param \OCP\IUserSession $userSession
+	 * @param \OCP\IAppConfig $appConfig
+	 * @param \OCP\IGroupManager $groupManager
+	 * @param \OCP\ICacheFactory $memCacheFactory
+	 */
+	public function __construct(IUserSession $userSession,
+								IAppConfig $appConfig,
+								IGroupManager $groupManager,
+								ICacheFactory $memCacheFactory,
+								EventDispatcherInterface $dispatcher) {
+		$this->userSession = $userSession;
+		$this->appConfig = $appConfig;
+		$this->groupManager = $groupManager;
+		$this->memCacheFactory = $memCacheFactory;
+		$this->dispatcher = $dispatcher;
+	}
+
+	/**
+	 * @return string[] $appId => $enabled
+	 */
+	private function getInstalledAppsValues() {
+		if (!$this->installedAppsCache) {
+			$values = $this->appConfig->getValues(false, 'enabled');
+
+			$alwaysEnabledApps = $this->getAlwaysEnabledApps();
+			foreach($alwaysEnabledApps as $appId) {
+				$values[$appId] = 'yes';
+			}
+
+			$this->installedAppsCache = array_filter($values, function ($value) {
+				return $value !== 'no';
+			});
+			ksort($this->installedAppsCache);
+		}
+		return $this->installedAppsCache;
+	}
+
+	/**
+	 * List all installed apps
+	 *
+	 * @return string[]
+	 */
+	public function getInstalledApps() {
+		return array_keys($this->getInstalledAppsValues());
+	}
+
+	/**
+	 * List all apps enabled for a user
+	 *
+	 * @param \OCP\IUser $user
+	 * @return string[]
+	 */
+	public function getEnabledAppsForUser(IUser $user) {
+		$apps = $this->getInstalledAppsValues();
+		$appsForUser = array_filter($apps, function ($enabled) use ($user) {
+			return $this->checkAppForUser($enabled, $user);
+		});
+		return array_keys($appsForUser);
+	}
+
+	/**
+	 * Check if an app is enabled for user
+	 *
+	 * @param string $appId
+	 * @param \OCP\IUser $user (optional) if not defined, the currently logged in user will be used
+	 * @return bool
+	 */
+	public function isEnabledForUser($appId, $user = null) {
+		if ($this->isAlwaysEnabled($appId)) {
+			return true;
+		}
+		if (is_null($user)) {
+			$user = $this->userSession->getUser();
+		}
+		$installedApps = $this->getInstalledAppsValues();
+		if (isset($installedApps[$appId])) {
+			return $this->checkAppForUser($installedApps[$appId], $user);
+		} else {
+			return false;
+		}
+	}
+
+	/**
+	 * @param string $enabled
+	 * @param IUser $user
+	 * @return bool
+	 */
+	private function checkAppForUser($enabled, $user) {
+		if ($enabled === 'yes') {
+			return true;
+		} elseif (is_null($user)) {
+			return false;
+		} else {
+			if(empty($enabled)){
+				return false;
+			}
+
+			$groupIds = json_decode($enabled);
+
+			if (!is_array($groupIds)) {
+				$jsonError = json_last_error();
+				\OC::$server->getLogger()->warning('AppManger::checkAppForUser - can\'t decode group IDs: ' . print_r($enabled, true) . ' - json error code: ' . $jsonError, ['app' => 'lib']);
+				return false;
+			}
+
+			$userGroups = $this->groupManager->getUserGroupIds($user);
+			foreach ($userGroups as $groupId) {
+				if (array_search($groupId, $groupIds) !== false) {
+					return true;
+				}
+			}
+			return false;
+		}
+	}
+
+	/**
+	 * Check if an app is installed in the instance
+	 *
+	 * @param string $appId
+	 * @return bool
+	 */
+	public function isInstalled($appId) {
+		$installedApps = $this->getInstalledAppsValues();
+		return isset($installedApps[$appId]);
+	}
+
+	/**
+	 * Enable an app for every user
+	 *
+	 * @param string $appId
+	 */
+	public function enableApp($appId) {
+		$this->installedAppsCache[$appId] = 'yes';
+		$this->appConfig->setValue($appId, 'enabled', 'yes');
+		$this->dispatcher->dispatch(ManagerEvent::EVENT_APP_ENABLE, new ManagerEvent(
+			ManagerEvent::EVENT_APP_ENABLE, $appId
+		));
+		$this->clearAppsCache();
+	}
+
+	/**
+	 * Enable an app only for specific groups
+	 *
+	 * @param string $appId
+	 * @param \OCP\IGroup[] $groups
+	 * @throws \Exception if app can't be enabled for groups
+	 */
+	public function enableAppForGroups($appId, $groups) {
+		$info = $this->getAppInfo($appId);
+		if (!empty($info['types'])) {
+			$protectedTypes = array_intersect($this->protectedAppTypes, $info['types']);
+			if (!empty($protectedTypes)) {
+				throw new \Exception("$appId can't be enabled for groups.");
+			}
+		}
+
+		$groupIds = array_map(function ($group) {
+			/** @var \OCP\IGroup $group */
+			return $group->getGID();
+		}, $groups);
+		$this->installedAppsCache[$appId] = json_encode($groupIds);
+		$this->appConfig->setValue($appId, 'enabled', json_encode($groupIds));
+		$this->dispatcher->dispatch(ManagerEvent::EVENT_APP_ENABLE_FOR_GROUPS, new ManagerEvent(
+			ManagerEvent::EVENT_APP_ENABLE_FOR_GROUPS, $appId, $groups
+		));
+		$this->clearAppsCache();
+	}
+
+	/**
+	 * Disable an app for every user
+	 *
+	 * @param string $appId
+	 * @throws \Exception if app can't be disabled
+	 */
+	public function disableApp($appId) {
+		if ($this->isAlwaysEnabled($appId)) {
+			throw new \Exception("$appId can't be disabled.");
+		}
+		unset($this->installedAppsCache[$appId]);
+		$this->appConfig->setValue($appId, 'enabled', 'no');
+		$this->dispatcher->dispatch(ManagerEvent::EVENT_APP_ENABLE, new ManagerEvent(
+			ManagerEvent::EVENT_APP_DISABLE, $appId
+		));
+		$this->clearAppsCache();
+	}
+
+	/**
+	 * Clear the cached list of apps when enabling/disabling an app
+	 */
+	public function clearAppsCache() {
+		$settingsMemCache = $this->memCacheFactory->create('settings');
+		$settingsMemCache->clear('listApps');
+	}
+
+	/**
+	 * Returns a list of apps that need upgrade
+	 *
+	 * @param array $version ownCloud version as array of version components
+	 * @return array list of app info from apps that need an upgrade
+	 *
+	 * @internal
+	 */
+	public function getAppsNeedingUpgrade($ocVersion) {
+		$appsToUpgrade = [];
+		$apps = $this->getInstalledApps();
+		foreach ($apps as $appId) {
+			$appInfo = $this->getAppInfo($appId);
+			$appDbVersion = $this->appConfig->getValue($appId, 'installed_version');
+			if ($appDbVersion
+				&& isset($appInfo['version'])
+				&& version_compare($appInfo['version'], $appDbVersion, '>')
+				&& \OC_App::isAppCompatible($ocVersion, $appInfo)
+			) {
+				$appsToUpgrade[] = $appInfo;
+			}
+		}
+
+		return $appsToUpgrade;
+	}
+
+	/**
+	 * Returns the app information from "appinfo/info.xml".
+	 *
+	 * @param string $appId app id
+	 *
+	 * @return array app iinfo
+	 *
+	 * @internal
+	 */
+	public function getAppInfo($appId) {
+		$appInfo = \OC_App::getAppInfo($appId);
+		if (!isset($appInfo['version'])) {
+			// read version from separate file
+			$appInfo['version'] = \OC_App::getAppVersion($appId);
+		}
+		return $appInfo;
+	}
+
+	/**
+	 * Returns a list of apps incompatible with the given version
+	 *
+	 * @param array $version ownCloud version as array of version components
+	 *
+	 * @return array list of app info from incompatible apps
+	 *
+	 * @internal
+	 */
+	public function getIncompatibleApps($version) {
+		$apps = $this->getInstalledApps();
+		$incompatibleApps = array();
+		foreach ($apps as $appId) {
+			$info = $this->getAppInfo($appId);
+			if (!\OC_App::isAppCompatible($version, $info)) {
+				$incompatibleApps[] = $info;
+			}
+		}
+		return $incompatibleApps;
+	}
+
+	/**
+	 * @inheritdoc
+	 */
+	public function isShipped($appId) {
+		$this->loadShippedJson();
+		return in_array($appId, $this->shippedApps);
+	}
+
+	private function isAlwaysEnabled($appId) {
+		$alwaysEnabled = $this->getAlwaysEnabledApps();
+		return in_array($appId, $alwaysEnabled);
+	}
+
+	private function loadShippedJson() {
+		if (is_null($this->shippedApps)) {
+			$shippedJson = \OC::$SERVERROOT . '/core/shipped.json';
+			if (!file_exists($shippedJson)) {
+				throw new \Exception("File not found: $shippedJson");
+			}
+			$content = json_decode(file_get_contents($shippedJson), true);
+			$this->shippedApps = $content['shippedApps'];
+			$this->alwaysEnabled = $content['alwaysEnabled'];
+		}
+	}
+
+	/**
+	 * @inheritdoc
+	 */
+	public function getAlwaysEnabledApps() {
+		$this->loadShippedJson();
+		return $this->alwaysEnabled;
+	}
+}
diff --git a/lib/private/App/CodeChecker/AbstractCheck.php b/lib/private/App/CodeChecker/AbstractCheck.php
new file mode 100644
index 00000000000..ca91d366482
--- /dev/null
+++ b/lib/private/App/CodeChecker/AbstractCheck.php
@@ -0,0 +1,139 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@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 OC\App\CodeChecker;
+
+abstract class AbstractCheck implements ICheck {
+	/** @var ICheck */
+	protected $check;
+
+	/**
+	 * @param ICheck $check
+	 */
+	public function __construct(ICheck $check) {
+		$this->check = $check;
+	}
+
+	/**
+	 * @param int $errorCode
+	 * @param string $errorObject
+	 * @return string
+	 */
+	public function getDescription($errorCode, $errorObject) {
+		switch ($errorCode) {
+			case CodeChecker::STATIC_CALL_NOT_ALLOWED:
+				$functions = $this->getLocalFunctions();
+				$functions = array_change_key_case($functions, CASE_LOWER);
+				if (isset($functions[$errorObject])) {
+					return $this->getLocalDescription();
+				}
+			// no break;
+			case CodeChecker::CLASS_EXTENDS_NOT_ALLOWED:
+			case CodeChecker::CLASS_IMPLEMENTS_NOT_ALLOWED:
+			case CodeChecker::CLASS_NEW_NOT_ALLOWED:
+			case CodeChecker::CLASS_USE_NOT_ALLOWED:
+				$classes = $this->getLocalClasses();
+				$classes = array_change_key_case($classes, CASE_LOWER);
+				if (isset($classes[$errorObject])) {
+					return $this->getLocalDescription();
+				}
+			break;
+
+			case CodeChecker::CLASS_CONST_FETCH_NOT_ALLOWED:
+				$constants = $this->getLocalConstants();
+				$constants = array_change_key_case($constants, CASE_LOWER);
+				if (isset($constants[$errorObject])) {
+					return $this->getLocalDescription();
+				}
+			break;
+
+			case CodeChecker::CLASS_METHOD_CALL_NOT_ALLOWED:
+				$methods = $this->getLocalMethods();
+				$methods = array_change_key_case($methods, CASE_LOWER);
+				if (isset($methods[$errorObject])) {
+					return $this->getLocalDescription();
+				}
+			break;
+		}
+
+		return $this->check->getDescription($errorCode, $errorObject);
+	}
+
+	/**
+	 * @return string
+	 */
+	abstract protected function getLocalDescription();
+
+	/**
+	 * @return array
+	 */
+	abstract protected function getLocalClasses();
+
+	/**
+	 * @return array
+	 */
+	abstract protected function getLocalConstants();
+
+	/**
+	 * @return array
+	 */
+	abstract protected function getLocalFunctions();
+
+	/**
+	 * @return array
+	 */
+	abstract protected function getLocalMethods();
+
+	/**
+	 * @return array E.g.: `'ClassName' => 'oc version',`
+	 */
+	public function getClasses() {
+		return array_merge($this->getLocalClasses(), $this->check->getClasses());
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName::CONSTANT_NAME' => 'oc version',`
+	 */
+	public function getConstants() {
+		return array_merge($this->getLocalConstants(), $this->check->getConstants());
+	}
+
+	/**
+	 * @return array E.g.: `'functionName' => 'oc version',`
+	 */
+	public function getFunctions() {
+		return array_merge($this->getLocalFunctions(), $this->check->getFunctions());
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName::methodName' => 'oc version',`
+	 */
+	public function getMethods() {
+		return array_merge($this->getLocalMethods(), $this->check->getMethods());
+	}
+
+	/**
+	 * @return bool
+	 */
+	public function checkStrongComparisons() {
+		return $this->check->checkStrongComparisons();
+	}
+}
diff --git a/lib/private/App/CodeChecker/CodeChecker.php b/lib/private/App/CodeChecker/CodeChecker.php
new file mode 100644
index 00000000000..0ca597ccb4e
--- /dev/null
+++ b/lib/private/App/CodeChecker/CodeChecker.php
@@ -0,0 +1,125 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @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 OC\App\CodeChecker;
+
+use OC\Hooks\BasicEmitter;
+use PhpParser\Lexer;
+use PhpParser\Node;
+use PhpParser\Node\Name;
+use PhpParser\NodeTraverser;
+use PhpParser\Parser;
+use RecursiveCallbackFilterIterator;
+use RecursiveDirectoryIterator;
+use RecursiveIteratorIterator;
+use RegexIterator;
+use SplFileInfo;
+
+class CodeChecker extends BasicEmitter {
+
+	const CLASS_EXTENDS_NOT_ALLOWED = 1000;
+	const CLASS_IMPLEMENTS_NOT_ALLOWED = 1001;
+	const STATIC_CALL_NOT_ALLOWED = 1002;
+	const CLASS_CONST_FETCH_NOT_ALLOWED = 1003;
+	const CLASS_NEW_NOT_ALLOWED =  1004;
+	const OP_OPERATOR_USAGE_DISCOURAGED =  1005;
+	const CLASS_USE_NOT_ALLOWED =  1006;
+	const CLASS_METHOD_CALL_NOT_ALLOWED =  1007;
+
+	/** @var Parser */
+	private $parser;
+
+	/** @var ICheck */
+	protected $checkList;
+
+	public function __construct(ICheck $checkList) {
+		$this->checkList = $checkList;
+		$this->parser = new Parser(new Lexer);
+	}
+
+	/**
+	 * @param string $appId
+	 * @return array
+	 */
+	public function analyse($appId) {
+		$appPath = \OC_App::getAppPath($appId);
+		if ($appPath === false) {
+			throw new \RuntimeException("No app with given id <$appId> known.");
+		}
+
+		return $this->analyseFolder($appPath);
+	}
+
+	/**
+	 * @param string $folder
+	 * @return array
+	 */
+	public function analyseFolder($folder) {
+		$errors = [];
+
+		$excludes = array_map(function($item) use ($folder) {
+			return $folder . '/' . $item;
+		}, ['vendor', '3rdparty', '.git', 'l10n', 'tests', 'test']);
+
+		$iterator = new RecursiveDirectoryIterator($folder, RecursiveDirectoryIterator::SKIP_DOTS);
+		$iterator = new RecursiveCallbackFilterIterator($iterator, function($item) use ($folder, $excludes){
+			/** @var SplFileInfo $item */
+			foreach($excludes as $exclude) {
+				if (substr($item->getPath(), 0, strlen($exclude)) === $exclude) {
+					return false;
+				}
+			}
+			return true;
+		});
+		$iterator = new RecursiveIteratorIterator($iterator);
+		$iterator = new RegexIterator($iterator, '/^.+\.php$/i');
+
+		foreach ($iterator as $file) {
+			/** @var SplFileInfo $file */
+			$this->emit('CodeChecker', 'analyseFileBegin', [$file->getPathname()]);
+			$fileErrors = $this->analyseFile($file);
+			$this->emit('CodeChecker', 'analyseFileFinished', [$file->getPathname(), $fileErrors]);
+			$errors = array_merge($fileErrors, $errors);
+		}
+
+		return $errors;
+	}
+
+
+	/**
+	 * @param string $file
+	 * @return array
+	 */
+	public function analyseFile($file) {
+		$code = file_get_contents($file);
+		$statements = $this->parser->parse($code);
+
+		$visitor = new NodeVisitor($this->checkList);
+		$traverser = new NodeTraverser;
+		$traverser->addVisitor($visitor);
+
+		$traverser->traverse($statements);
+
+		return $visitor->errors;
+	}
+}
diff --git a/lib/private/App/CodeChecker/DeprecationCheck.php b/lib/private/App/CodeChecker/DeprecationCheck.php
new file mode 100644
index 00000000000..fa5eae8ab1d
--- /dev/null
+++ b/lib/private/App/CodeChecker/DeprecationCheck.php
@@ -0,0 +1,168 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@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 OC\App\CodeChecker;
+
+class DeprecationCheck extends AbstractCheck implements ICheck {
+	/**
+	 * @return string
+	 */
+	protected function getLocalDescription() {
+		return 'deprecated';
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName' => 'oc version',`
+	 */
+	protected function getLocalClasses() {
+		return [
+			'OC_JSON' => '8.2.0',
+
+			'OCP\Config' => '8.0.0',
+			'OCP\Contacts' => '8.1.0',
+			'OCP\DB' => '8.1.0',
+			'OCP\IHelper' => '8.1.0',
+			'OCP\JSON' => '8.1.0',
+			'OCP\Response' => '8.1.0',
+			'OCP\AppFramework\IApi' => '8.0.0',
+		];
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName::CONSTANT_NAME' => 'oc version',`
+	 */
+	protected function getLocalConstants() {
+		return [
+			'OC_API::GUEST_AUTH' => '8.2.0',
+			'OC_API::USER_AUTH' => '8.2.0',
+			'OC_API::SUBADMIN_AUTH' => '8.2.0',
+			'OC_API::ADMIN_AUTH' => '8.2.0',
+			'OC_API::RESPOND_UNAUTHORISED' => '8.2.0',
+			'OC_API::RESPOND_SERVER_ERROR' => '8.2.0',
+			'OC_API::RESPOND_NOT_FOUND' => '8.2.0',
+			'OC_API::RESPOND_UNKNOWN_ERROR' => '8.2.0',
+
+			'OCP::PERMISSION_CREATE' => '8.0.0',
+			'OCP::PERMISSION_READ' => '8.0.0',
+			'OCP::PERMISSION_UPDATE' => '8.0.0',
+			'OCP::PERMISSION_DELETE' => '8.0.0',
+			'OCP::PERMISSION_SHARE' => '8.0.0',
+			'OCP::PERMISSION_ALL' => '8.0.0',
+			'OCP::FILENAME_INVALID_CHARS' => '8.0.0',
+		];
+	}
+
+	/**
+	 * @return array E.g.: `'functionName' => 'oc version',`
+	 */
+	protected function getLocalFunctions() {
+		return [
+			'OCP::image_path' => '8.0.0',
+			'OCP::mimetype_icon' => '8.0.0',
+			'OCP::preview_icon' => '8.0.0',
+			'OCP::publicPreview_icon' => '8.0.0',
+			'OCP::human_file_size' => '8.0.0',
+			'OCP::relative_modified_date' => '8.0.0',
+			'OCP::simple_file_size' => '8.0.0',
+			'OCP::html_select_options' => '8.0.0',
+		];
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName::methodName' => 'oc version',`
+	 */
+	protected function getLocalMethods() {
+		return [
+			'OC_L10N::get' => '8.2.0',
+
+			'OCP\Activity\IManager::publishActivity' => '8.2.0',
+
+			'OCP\App::register' => '8.1.0',
+			'OCP\App::addNavigationEntry' => '8.1.0',
+			'OCP\App::getActiveNavigationEntry' => '8.2.0',
+			'OCP\App::setActiveNavigationEntry' => '8.1.0',
+
+			'OCP\AppFramework\Controller::params' => '7.0.0',
+			'OCP\AppFramework\Controller::getParams' => '7.0.0',
+			'OCP\AppFramework\Controller::method' => '7.0.0',
+			'OCP\AppFramework\Controller::getUploadedFile' => '7.0.0',
+			'OCP\AppFramework\Controller::env' => '7.0.0',
+			'OCP\AppFramework\Controller::cookie' => '7.0.0',
+			'OCP\AppFramework\Controller::render' => '7.0.0',
+
+			'OCP\AppFramework\IAppContainer::getCoreApi' => '8.0.0',
+			'OCP\AppFramework\IAppContainer::isLoggedIn' => '8.0.0',
+			'OCP\AppFramework\IAppContainer::isAdminUser' => '8.0.0',
+			'OCP\AppFramework\IAppContainer::log' => '8.0.0',
+
+			'OCP\BackgroundJob::addQueuedTask' => '6.0.0',
+			'OCP\BackgroundJob::addRegularTask' => '6.0.0',
+			'OCP\BackgroundJob::allQueuedTasks' => '6.0.0',
+			'OCP\BackgroundJob::allRegularTasks' => '6.0.0',
+			'OCP\BackgroundJob::deleteQueuedTask' => '6.0.0',
+			'OCP\BackgroundJob::findQueuedTask' => '6.0.0',
+			'OCP\BackgroundJob::queuedTaskWhereAppIs' => '6.0.0',
+			'OCP\BackgroundJob::registerJob' => '8.1.0',
+
+			'OCP\Files::tmpFile' => '8.1.0',
+			'OCP\Files::tmpFolder' => '8.1.0',
+
+			'OCP\IAppConfig::getValue' => '8.0.0',
+			'OCP\IAppConfig::deleteKey' => '8.0.0',
+			'OCP\IAppConfig::getKeys' => '8.0.0',
+			'OCP\IAppConfig::setValue' => '8.0.0',
+			'OCP\IAppConfig::deleteApp' => '8.0.0',
+
+			'OCP\IDBConnection::createQueryBuilder' => '8.2.0',
+			'OCP\IDBConnection::getExpressionBuilder' => '8.2.0',
+
+			'OCP\ISearch::search' => '8.0.0',
+
+			'OCP\IServerContainer::getCache' => '8.2.0',
+			'OCP\IServerContainer::getDb' => '8.1.0',
+			'OCP\IServerContainer::getHTTPHelper' => '8.1.0',
+
+			'OCP\User::getUser' => '8.0.0',
+			'OCP\User::getUsers' => '8.1.0',
+			'OCP\User::getDisplayName' => '8.1.0',
+			'OCP\User::getDisplayNames' => '8.1.0',
+			'OCP\User::userExists' => '8.1.0',
+			'OCP\User::logout' => '8.1.0',
+			'OCP\User::checkPassword' => '8.1.0',
+
+			'OCP\Util::encryptedFiles' => '8.1.0',
+			'OCP\Util::formatDate' => '8.0.0',
+			'OCP\Util::generateRandomBytes' => '8.1.0',
+			'OCP\Util::getServerHost' => '8.1.0',
+			'OCP\Util::getServerProtocol' => '8.1.0',
+			'OCP\Util::getRequestUri' => '8.1.0',
+			'OCP\Util::getScriptName' => '8.1.0',
+			'OCP\Util::imagePath' => '8.1.0',
+			'OCP\Util::isValidFileName' => '8.1.0',
+			'OCP\Util::linkToRoute' => '8.1.0',
+			'OCP\Util::linkTo' => '8.1.0',
+			'OCP\Util::logException' => '8.2.0',
+			'OCP\Util::mb_str_replace' => '8.2.0',
+			'OCP\Util::mb_substr_replace' => '8.2.0',
+			'OCP\Util::sendMail' => '8.1.0',
+		];
+	}
+}
diff --git a/lib/private/App/CodeChecker/EmptyCheck.php b/lib/private/App/CodeChecker/EmptyCheck.php
new file mode 100644
index 00000000000..b779926d5e4
--- /dev/null
+++ b/lib/private/App/CodeChecker/EmptyCheck.php
@@ -0,0 +1,67 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@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 OC\App\CodeChecker;
+
+class EmptyCheck implements ICheck {
+	/**
+	 * @param int $errorCode
+	 * @param string $errorObject
+	 * @return string
+	 */
+	public function getDescription($errorCode, $errorObject) {
+		return '';
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName' => 'oc version',`
+	 */
+	public function getClasses() {
+		return [];
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName::CONSTANT_NAME' => 'oc version',`
+	 */
+	public function getConstants() {
+		return [];
+	}
+
+	/**
+	 * @return array E.g.: `'functionName' => 'oc version',`
+	 */
+	public function getFunctions() {
+		return [];
+	}
+
+	/**
+	 * @return array E.g.: `'ClassName::methodName' => 'oc version',`
+	 */
+	public function getMethods() {
+		return [];
+	}
+
+	/**
+	 * @return bool
+	 */
+	public function checkStrongComparisons() {
+		return false;
+	}
+}
diff --git a/lib/private/App/CodeChecker/ICheck.php b/lib/private/App/CodeChecker/ICheck.php
new file mode 100644
index 00000000000..97e0bc9b8a0
--- /dev/null
+++ b/lib/private/App/CodeChecker/ICheck.php
@@ -0,0 +1,55 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@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 OC\App\CodeChecker;
+
+interface ICheck {
+	/**
+	 * @param int $errorCode
+	 * @param string $errorObject
+	 * @return string
+	 */
+	public function getDescription($errorCode, $errorObject);
+
+	/**
+	 * @return array E.g.: `'ClassName' => 'oc version',`
+	 */
+	public function getClasses();
+
+	/**
+	 * @return array E.g.: `'ClassName::CONSTANT_NAME' => 'oc version',`
+	 */
+	public function getConstants();
+
+	/**
+	 * @return array E.g.: `'functionName' => 'oc version',`
+	 */
+	public function getFunctions();
+
+	/**
+	 * @return array E.g.: `'ClassName::methodName' => 'oc version',`
+	 */
+	public function getMethods();
+
+	/**
+	 * @return bool
+	 */
+	public function checkStrongComparisons();
+}
diff --git a/lib/private/App/CodeChecker/InfoChecker.php b/lib/private/App/CodeChecker/InfoChecker.php
new file mode 100644
index 00000000000..812007d8839
--- /dev/null
+++ b/lib/private/App/CodeChecker/InfoChecker.php
@@ -0,0 +1,160 @@
+<?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 OC\App\CodeChecker;
+
+use OC\App\InfoParser;
+use OC\Hooks\BasicEmitter;
+
+class InfoChecker extends BasicEmitter {
+
+	/** @var InfoParser */
+	private $infoParser;
+
+	private $mandatoryFields = [
+		'author',
+		'description',
+		'id',
+		'licence',
+		'name',
+	];
+	private $optionalFields = [
+		'bugs',
+		'category',
+		'default_enable',
+		'dependencies', // TODO: Mandatory as of ownCloud 11
+		'documentation',
+		'namespace',
+		'ocsid',
+		'public',
+		'remote',
+		'repository',
+		'types',
+		'version',
+		'website',
+	];
+	private $deprecatedFields = [
+		'info',
+		'require',
+		'requiremax',
+		'requiremin',
+		'shipped',
+		'standalone',
+	];
+
+	public function __construct(InfoParser $infoParser) {
+		$this->infoParser = $infoParser;
+	}
+
+	/**
+	 * @param string $appId
+	 * @return array
+	 */
+	public function analyse($appId) {
+		$appPath = \OC_App::getAppPath($appId);
+		if ($appPath === false) {
+			throw new \RuntimeException("No app with given id <$appId> known.");
+		}
+
+		$errors = [];
+
+		$info = $this->infoParser->parse($appPath . '/appinfo/info.xml');
+
+		if (isset($info['dependencies']['owncloud']['@attributes']['min-version']) && ($info['requiremin'] || $info['require'])) {
+			$this->emit('InfoChecker', 'duplicateRequirement', ['min']);
+			$errors[] = [
+				'type' => 'duplicateRequirement',
+				'field' => 'min',
+			];
+		} else if (!isset($info['dependencies']['owncloud']['@attributes']['min-version'])) {
+			$this->emit('InfoChecker', 'missingRequirement', ['min']);
+		}
+
+		if (isset($info['dependencies']['owncloud']['@attributes']['max-version']) && $info['requiremax']) {
+			$this->emit('InfoChecker', 'duplicateRequirement', ['max']);
+			$errors[] = [
+				'type' => 'duplicateRequirement',
+				'field' => 'max',
+			];
+		} else if (!isset($info['dependencies']['owncloud']['@attributes']['max-version'])) {
+			$this->emit('InfoChecker', 'missingRequirement', ['max']);
+		}
+
+		foreach ($info as $key => $value) {
+			if(is_array($value)) {
+				$value = json_encode($value);
+			}
+			if (in_array($key, $this->mandatoryFields)) {
+				$this->emit('InfoChecker', 'mandatoryFieldFound', [$key, $value]);
+				continue;
+			}
+
+			if (in_array($key, $this->optionalFields)) {
+				$this->emit('InfoChecker', 'optionalFieldFound', [$key, $value]);
+				continue;
+			}
+
+			if (in_array($key, $this->deprecatedFields)) {
+				// skip empty arrays - empty arrays for remote and public are always added
+				if($value === '[]' && in_array($key, ['public', 'remote', 'info'])) {
+					continue;
+				}
+				$this->emit('InfoChecker', 'deprecatedFieldFound', [$key, $value]);
+				continue;
+			}
+
+			$this->emit('InfoChecker', 'unusedFieldFound', [$key, $value]);
+		}
+
+		foreach ($this->mandatoryFields as $key) {
+			if(!isset($info[$key])) {
+				$this->emit('InfoChecker', 'mandatoryFieldMissing', [$key]);
+				$errors[] = [
+					'type' => 'mandatoryFieldMissing',
+					'field' => $key,
+				];
+			}
+		}
+
+		$versionFile = $appPath . '/appinfo/version';
+		if (is_file($versionFile)) {
+			$version = trim(file_get_contents($versionFile));
+			if (isset($info['version'])) {
+				if($info['version'] !== $version) {
+					$this->emit('InfoChecker', 'differentVersions',
+						[$version, $info['version']]);
+					$errors[] = [
+						'type' => 'differentVersions',
+						'message' => 'appinfo/version: ' . $version .
+							' - appinfo/info.xml: ' . $info['version'],
+					];
+				} else {
+					$this->emit('InfoChecker', 'sameVersions', [$versionFile]);
+				}
+			} else {
+				$this->emit('InfoChecker', 'migrateVersion', [$version]);
+			}
+		}
+
+		return $errors;
+	}
+}
diff --git a/lib/private/App/CodeChecker/NodeVisitor.php b/lib/private/App/CodeChecker/NodeVisitor.php
new file mode 100644
index 00000000000..f9386caeeae
--- /dev/null
+++ b/lib/private/App/CodeChecker/NodeVisitor.php
@@ -0,0 +1,307 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @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 OC\App\CodeChecker;
+
+use PhpParser\Node;
+use PhpParser\Node\Name;
+use PhpParser\NodeVisitorAbstract;
+
+class NodeVisitor extends NodeVisitorAbstract {
+	/** @var ICheck */
+	protected $list;
+
+	/** @var string */
+	protected $blackListDescription;
+	/** @var string[] */
+	protected $blackListedClassNames;
+	/** @var string[] */
+	protected $blackListedConstants;
+	/** @var string[] */
+	protected $blackListedFunctions;
+	/** @var string[] */
+	protected $blackListedMethods;
+	/** @var bool */
+	protected $checkEqualOperatorUsage;
+	/** @var string[] */
+	protected $errorMessages;
+
+	/**
+	 * @param ICheck $list
+	 */
+	public function __construct(ICheck $list) {
+		$this->list = $list;
+
+		$this->blackListedClassNames = [];
+		foreach ($list->getClasses() as $class => $blackListInfo) {
+			if (is_numeric($class) && is_string($blackListInfo)) {
+				$class = $blackListInfo;
+				$blackListInfo = null;
+			}
+
+			$class = strtolower($class);
+			$this->blackListedClassNames[$class] = $class;
+		}
+
+		$this->blackListedConstants = [];
+		foreach ($list->getConstants() as $constantName => $blackListInfo) {
+			$constantName = strtolower($constantName);
+			$this->blackListedConstants[$constantName] = $constantName;
+		}
+
+		$this->blackListedFunctions = [];
+		foreach ($list->getFunctions() as $functionName => $blackListInfo) {
+			$functionName = strtolower($functionName);
+			$this->blackListedFunctions[$functionName] = $functionName;
+		}
+
+		$this->blackListedMethods = [];
+		foreach ($list->getMethods() as $functionName => $blackListInfo) {
+			$functionName = strtolower($functionName);
+			$this->blackListedMethods[$functionName] = $functionName;
+		}
+
+		$this->checkEqualOperatorUsage = $list->checkStrongComparisons();
+
+		$this->errorMessages = [
+			CodeChecker::CLASS_EXTENDS_NOT_ALLOWED => "%s class must not be extended",
+			CodeChecker::CLASS_IMPLEMENTS_NOT_ALLOWED => "%s interface must not be implemented",
+			CodeChecker::STATIC_CALL_NOT_ALLOWED => "Static method of %s class must not be called",
+			CodeChecker::CLASS_CONST_FETCH_NOT_ALLOWED => "Constant of %s class must not not be fetched",
+			CodeChecker::CLASS_NEW_NOT_ALLOWED => "%s class must not be instantiated",
+			CodeChecker::CLASS_USE_NOT_ALLOWED => "%s class must not be imported with a use statement",
+			CodeChecker::CLASS_METHOD_CALL_NOT_ALLOWED => "Method of %s class must not be called",
+
+			CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED => "is discouraged",
+		];
+	}
+
+	/** @var array */
+	public $errors = [];
+
+	public function enterNode(Node $node) {
+		if ($this->checkEqualOperatorUsage && $node instanceof Node\Expr\BinaryOp\Equal) {
+			$this->errors[]= [
+				'disallowedToken' => '==',
+				'errorCode' => CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED,
+				'line' => $node->getLine(),
+				'reason' => $this->buildReason('==', CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED)
+			];
+		}
+		if ($this->checkEqualOperatorUsage && $node instanceof Node\Expr\BinaryOp\NotEqual) {
+			$this->errors[]= [
+				'disallowedToken' => '!=',
+				'errorCode' => CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED,
+				'line' => $node->getLine(),
+				'reason' => $this->buildReason('!=', CodeChecker::OP_OPERATOR_USAGE_DISCOURAGED)
+			];
+		}
+		if ($node instanceof Node\Stmt\Class_) {
+			if (!is_null($node->extends)) {
+				$this->checkBlackList($node->extends->toString(), CodeChecker::CLASS_EXTENDS_NOT_ALLOWED, $node);
+			}
+			foreach ($node->implements as $implements) {
+				$this->checkBlackList($implements->toString(), CodeChecker::CLASS_IMPLEMENTS_NOT_ALLOWED, $node);
+			}
+		}
+		if ($node instanceof Node\Expr\StaticCall) {
+			if (!is_null($node->class)) {
+				if ($node->class instanceof Name) {
+					$this->checkBlackList($node->class->toString(), CodeChecker::STATIC_CALL_NOT_ALLOWED, $node);
+
+					$this->checkBlackListFunction($node->class->toString(), $node->name, $node);
+					$this->checkBlackListMethod($node->class->toString(), $node->name, $node);
+				}
+
+				if ($node->class instanceof Node\Expr\Variable) {
+					/**
+					 * TODO: find a way to detect something like this:
+					 *       $c = "OC_API";
+					 *       $n = $c::call();
+					 */
+					// $this->checkBlackListMethod($node->class->..., $node->name, $node);
+				}
+			}
+		}
+		if ($node instanceof Node\Expr\MethodCall) {
+			if (!is_null($node->var)) {
+				if ($node->var instanceof Node\Expr\Variable) {
+					/**
+					 * TODO: find a way to detect something like this:
+					 *       $c = new OC_API();
+					 *       $n = $c::call();
+					 *       $n = $c->call();
+					 */
+					// $this->checkBlackListMethod($node->var->..., $node->name, $node);
+				}
+			}
+		}
+		if ($node instanceof Node\Expr\ClassConstFetch) {
+			if (!is_null($node->class)) {
+				if ($node->class instanceof Name) {
+					$this->checkBlackList($node->class->toString(), CodeChecker::CLASS_CONST_FETCH_NOT_ALLOWED, $node);
+				}
+				if ($node->class instanceof Node\Expr\Variable) {
+					/**
+					 * TODO: find a way to detect something like this:
+					 *       $c = "OC_API";
+					 *       $n = $i::ADMIN_AUTH;
+					 */
+				} else {
+					$this->checkBlackListConstant($node->class->toString(), $node->name, $node);
+				}
+			}
+		}
+		if ($node instanceof Node\Expr\New_) {
+			if (!is_null($node->class)) {
+				if ($node->class instanceof Name) {
+					$this->checkBlackList($node->class->toString(), CodeChecker::CLASS_NEW_NOT_ALLOWED, $node);
+				}
+				if ($node->class instanceof Node\Expr\Variable) {
+					/**
+					 * TODO: find a way to detect something like this:
+					 *       $c = "OC_API";
+					 *       $n = new $i;
+					 */
+				}
+			}
+		}
+		if ($node instanceof Node\Stmt\UseUse) {
+			$this->checkBlackList($node->name->toString(), CodeChecker::CLASS_USE_NOT_ALLOWED, $node);
+			if ($node->alias) {
+				$this->addUseNameToBlackList($node->name->toString(), $node->alias);
+			} else {
+				$this->addUseNameToBlackList($node->name->toString(), $node->name->getLast());
+			}
+		}
+	}
+
+	/**
+	 * Check whether an alias was introduced for a namespace of a blacklisted class
+	 *
+	 * Example:
+	 * - Blacklist entry:      OCP\AppFramework\IApi
+	 * - Name:                 OCP\AppFramework
+	 * - Alias:                OAF
+	 * =>  new blacklist entry:  OAF\IApi
+	 *
+	 * @param string $name
+	 * @param string $alias
+	 */
+	private function addUseNameToBlackList($name, $alias) {
+		$name = strtolower($name);
+		$alias = strtolower($alias);
+
+		foreach ($this->blackListedClassNames as $blackListedAlias => $blackListedClassName) {
+			if (strpos($blackListedClassName, $name . '\\') === 0) {
+				$aliasedClassName = str_replace($name, $alias, $blackListedClassName);
+				$this->blackListedClassNames[$aliasedClassName] = $blackListedClassName;
+			}
+		}
+
+		foreach ($this->blackListedConstants as $blackListedAlias => $blackListedConstant) {
+			if (strpos($blackListedConstant, $name . '\\') === 0 || strpos($blackListedConstant, $name . '::') === 0) {
+				$aliasedConstantName = str_replace($name, $alias, $blackListedConstant);
+				$this->blackListedConstants[$aliasedConstantName] = $blackListedConstant;
+			}
+		}
+
+		foreach ($this->blackListedFunctions as $blackListedAlias => $blackListedFunction) {
+			if (strpos($blackListedFunction, $name . '\\') === 0 || strpos($blackListedFunction, $name . '::') === 0) {
+				$aliasedFunctionName = str_replace($name, $alias, $blackListedFunction);
+				$this->blackListedFunctions[$aliasedFunctionName] = $blackListedFunction;
+			}
+		}
+
+		foreach ($this->blackListedMethods as $blackListedAlias => $blackListedMethod) {
+			if (strpos($blackListedMethod, $name . '\\') === 0 || strpos($blackListedMethod, $name . '::') === 0) {
+				$aliasedMethodName = str_replace($name, $alias, $blackListedMethod);
+				$this->blackListedMethods[$aliasedMethodName] = $blackListedMethod;
+			}
+		}
+	}
+
+	private function checkBlackList($name, $errorCode, Node $node) {
+		$lowerName = strtolower($name);
+
+		if (isset($this->blackListedClassNames[$lowerName])) {
+			$this->errors[]= [
+				'disallowedToken' => $name,
+				'errorCode' => $errorCode,
+				'line' => $node->getLine(),
+				'reason' => $this->buildReason($this->blackListedClassNames[$lowerName], $errorCode)
+			];
+		}
+	}
+
+	private function checkBlackListConstant($class, $constantName, Node $node) {
+		$name = $class . '::' . $constantName;
+		$lowerName = strtolower($name);
+
+		if (isset($this->blackListedConstants[$lowerName])) {
+			$this->errors[]= [
+				'disallowedToken' => $name,
+				'errorCode' => CodeChecker::CLASS_CONST_FETCH_NOT_ALLOWED,
+				'line' => $node->getLine(),
+				'reason' => $this->buildReason($this->blackListedConstants[$lowerName], CodeChecker::CLASS_CONST_FETCH_NOT_ALLOWED)
+			];
+		}
+	}
+
+	private function checkBlackListFunction($class, $functionName, Node $node) {
+		$name = $class . '::' . $functionName;
+		$lowerName = strtolower($name);
+
+		if (isset($this->blackListedFunctions[$lowerName])) {
+			$this->errors[]= [
+				'disallowedToken' => $name,
+				'errorCode' => CodeChecker::STATIC_CALL_NOT_ALLOWED,
+				'line' => $node->getLine(),
+				'reason' => $this->buildReason($this->blackListedFunctions[$lowerName], CodeChecker::STATIC_CALL_NOT_ALLOWED)
+			];
+		}
+	}
+
+	private function checkBlackListMethod($class, $functionName, Node $node) {
+		$name = $class . '::' . $functionName;
+		$lowerName = strtolower($name);
+
+		if (isset($this->blackListedMethods[$lowerName])) {
+			$this->errors[]= [
+				'disallowedToken' => $name,
+				'errorCode' => CodeChecker::CLASS_METHOD_CALL_NOT_ALLOWED,
+				'line' => $node->getLine(),
+				'reason' => $this->buildReason($this->blackListedMethods[$lowerName], CodeChecker::CLASS_METHOD_CALL_NOT_ALLOWED)
+			];
+		}
+	}
+
+	private function buildReason($name, $errorCode) {
+		if (isset($this->errorMessages[$errorCode])) {
+			$desc = $this->list->getDescription($errorCode, $name);
+			return sprintf($this->errorMessages[$errorCode], $desc);
+		}
+
+		return "$name usage not allowed - error: $errorCode";
+	}
+}
diff --git a/lib/private/App/CodeChecker/PrivateCheck.php b/lib/private/App/CodeChecker/PrivateCheck.php
new file mode 100644
index 00000000000..32248ab21e2
--- /dev/null
+++ b/lib/private/App/CodeChecker/PrivateCheck.php
@@ -0,0 +1,84 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@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 OC\App\CodeChecker;
+
+class PrivateCheck extends AbstractCheck implements ICheck {
+	/**
+	 * @return string
+	 */
+	protected function getLocalDescription() {
+		return 'private';
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getLocalClasses() {
+		return [
+			// classes replaced by the public api
+			'OC_API' => '6.0.0',
+			'OC_App' => '6.0.0',
+			'OC_AppConfig' => '6.0.0',
+			'OC_Avatar' => '6.0.0',
+			'OC_BackgroundJob' => '6.0.0',
+			'OC_Config' => '6.0.0',
+			'OC_DB' => '6.0.0',
+			'OC_Files' => '6.0.0',
+			'OC_Helper' => '6.0.0',
+			'OC_Hook' => '6.0.0',
+			'OC_Image' => '6.0.0',
+			'OC_JSON' => '6.0.0',
+			'OC_L10N' => '6.0.0',
+			'OC_Log' => '6.0.0',
+			'OC_Mail' => '6.0.0',
+			'OC_Preferences' => '6.0.0',
+			'OC_Search_Provider' => '6.0.0',
+			'OC_Search_Result' => '6.0.0',
+			'OC_Request' => '6.0.0',
+			'OC_Response' => '6.0.0',
+			'OC_Template' => '6.0.0',
+			'OC_User' => '6.0.0',
+			'OC_Util' => '6.0.0',
+		];
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getLocalConstants() {
+		return [];
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getLocalFunctions() {
+		return [];
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getLocalMethods() {
+		return [];
+	}
+}
diff --git a/lib/private/App/CodeChecker/StrongComparisonCheck.php b/lib/private/App/CodeChecker/StrongComparisonCheck.php
new file mode 100644
index 00000000000..919647a6a54
--- /dev/null
+++ b/lib/private/App/CodeChecker/StrongComparisonCheck.php
@@ -0,0 +1,78 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@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 OC\App\CodeChecker;
+
+class StrongComparisonCheck implements ICheck {
+	/** @var ICheck */
+	protected $check;
+
+	/**
+	 * @param ICheck $check
+	 */
+	public function __construct(ICheck $check) {
+		$this->check = $check;
+	}
+
+	/**
+	 * @param int $errorCode
+	 * @param string $errorObject
+	 * @return string
+	 */
+	public function getDescription($errorCode, $errorObject) {
+		return $this->check->getDescription($errorCode, $errorObject);
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getClasses() {
+		return $this->check->getClasses();
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getConstants() {
+		return $this->check->getConstants();
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getFunctions() {
+		return $this->check->getFunctions();
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getMethods() {
+		return $this->check->getMethods();
+	}
+
+	/**
+	 * @return bool
+	 */
+	public function checkStrongComparisons() {
+		return true;
+	}
+}
diff --git a/lib/private/App/DependencyAnalyzer.php b/lib/private/App/DependencyAnalyzer.php
new file mode 100644
index 00000000000..6519e15bd8b
--- /dev/null
+++ b/lib/private/App/DependencyAnalyzer.php
@@ -0,0 +1,319 @@
+<?php
+/**
+ * @author Bernhard Posselt <dev@bernhard-posselt.com>
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ * @author Lukas Reschke <lukas@owncloud.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @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 OC\App;
+
+use OCP\IL10N;
+
+class DependencyAnalyzer {
+
+	/** @var Platform */
+	private $platform;
+	/** @var \OCP\IL10N */
+	private $l;
+	/** @var array */
+	private $appInfo;
+
+	/**
+	 * @param Platform $platform
+	 * @param \OCP\IL10N $l
+	 */
+	function __construct(Platform $platform, IL10N $l) {
+		$this->platform = $platform;
+		$this->l = $l;
+	}
+
+	/**
+	 * @param array $app
+	 * @returns array of missing dependencies
+	 */
+	public function analyze(array $app) {
+		$this->appInfo = $app;
+		if (isset($app['dependencies'])) {
+			$dependencies = $app['dependencies'];
+		} else {
+			$dependencies = [];
+		}
+
+		return array_merge(
+			$this->analyzePhpVersion($dependencies),
+			$this->analyzeDatabases($dependencies),
+			$this->analyzeCommands($dependencies),
+			$this->analyzeLibraries($dependencies),
+			$this->analyzeOS($dependencies),
+			$this->analyzeOC($dependencies, $app)
+		);
+	}
+
+	/**
+	 * Truncates both versions to the lowest common version, e.g.
+	 * 5.1.2.3 and 5.1 will be turned into 5.1 and 5.1,
+	 * 5.2.6.5 and 5.1 will be turned into 5.2 and 5.1
+	 * @param string $first
+	 * @param string $second
+	 * @return string[] first element is the first version, second element is the
+	 * second version
+	 */
+	private function normalizeVersions($first, $second) {
+		$first = explode('.', $first);
+		$second = explode('.', $second);
+
+		// get both arrays to the same minimum size
+		$length = min(count($second), count($first));
+		$first = array_slice($first, 0, $length);
+		$second = array_slice($second, 0, $length);
+
+		return [implode('.', $first), implode('.', $second)];
+	}
+
+	/**
+	 * Parameters will be normalized and then passed into version_compare
+	 * in the same order they are specified in the method header
+	 * @param string $first
+	 * @param string $second
+	 * @param string $operator
+	 * @return bool result similar to version_compare
+	 */
+	private function compare($first, $second, $operator) {
+		// we can't normalize versions if one of the given parameters is not a
+		// version string but null. In case one parameter is null normalization
+		// will therefore be skipped
+		if ($first !== null && $second !== null) {
+			list($first, $second) = $this->normalizeVersions($first, $second);
+		}
+
+		return version_compare($first, $second, $operator);
+	}
+
+	/**
+	 * Checks if a version is bigger than another version
+	 * @param string $first
+	 * @param string $second
+	 * @return bool true if the first version is bigger than the second
+	 */
+	private function compareBigger($first, $second) {
+		return $this->compare($first, $second, '>');
+	}
+
+	/**
+	 * Checks if a version is smaller than another version
+	 * @param string $first
+	 * @param string $second
+	 * @return bool true if the first version is smaller than the second
+	 */
+	private function compareSmaller($first, $second) {
+		return $this->compare($first, $second, '<');
+	}
+
+	/**
+	 * @param array $dependencies
+	 * @return array
+	 */
+	private function analyzePhpVersion(array $dependencies) {
+		$missing = [];
+		if (isset($dependencies['php']['@attributes']['min-version'])) {
+			$minVersion = $dependencies['php']['@attributes']['min-version'];
+			if ($this->compareSmaller($this->platform->getPhpVersion(), $minVersion)) {
+				$missing[] = (string)$this->l->t('PHP %s or higher is required.', $minVersion);
+			}
+		}
+		if (isset($dependencies['php']['@attributes']['max-version'])) {
+			$maxVersion = $dependencies['php']['@attributes']['max-version'];
+			if ($this->compareBigger($this->platform->getPhpVersion(), $maxVersion)) {
+				$missing[] = (string)$this->l->t('PHP with a version lower than %s is required.', $maxVersion);
+			}
+		}
+		return $missing;
+	}
+
+	/**
+	 * @param array $dependencies
+	 * @return array
+	 */
+	private function analyzeDatabases(array $dependencies) {
+		$missing = [];
+		if (!isset($dependencies['database'])) {
+			return $missing;
+		}
+
+		$supportedDatabases = $dependencies['database'];
+		if (empty($supportedDatabases)) {
+			return $missing;
+		}
+		if (!is_array($supportedDatabases)) {
+			$supportedDatabases = array($supportedDatabases);
+		}
+		$supportedDatabases = array_map(function ($db) {
+			return $this->getValue($db);
+		}, $supportedDatabases);
+		$currentDatabase = $this->platform->getDatabase();
+		if (!in_array($currentDatabase, $supportedDatabases)) {
+			$missing[] = (string)$this->l->t('Following databases are supported: %s', join(', ', $supportedDatabases));
+		}
+		return $missing;
+	}
+
+	/**
+	 * @param array $dependencies
+	 * @return array
+	 */
+	private function analyzeCommands(array $dependencies) {
+		$missing = [];
+		if (!isset($dependencies['command'])) {
+			return $missing;
+		}
+
+		$commands = $dependencies['command'];
+		if (!is_array($commands)) {
+			$commands = array($commands);
+		}
+		$os = $this->platform->getOS();
+		foreach ($commands as $command) {
+			if (isset($command['@attributes']['os']) && $command['@attributes']['os'] !== $os) {
+				continue;
+			}
+			$commandName = $this->getValue($command);
+			if (!$this->platform->isCommandKnown($commandName)) {
+				$missing[] = (string)$this->l->t('The command line tool %s could not be found', $commandName);
+			}
+		}
+		return $missing;
+	}
+
+	/**
+	 * @param array $dependencies
+	 * @return array
+	 */
+	private function analyzeLibraries(array $dependencies) {
+		$missing = [];
+		if (!isset($dependencies['lib'])) {
+			return $missing;
+		}
+
+		$libs = $dependencies['lib'];
+		if (!is_array($libs)) {
+			$libs = array($libs);
+		}
+		foreach ($libs as $lib) {
+			$libName = $this->getValue($lib);
+			$libVersion = $this->platform->getLibraryVersion($libName);
+			if (is_null($libVersion)) {
+				$missing[] = (string)$this->l->t('The library %s is not available.', $libName);
+				continue;
+			}
+
+			if (is_array($lib)) {
+				if (isset($lib['@attributes']['min-version'])) {
+					$minVersion = $lib['@attributes']['min-version'];
+					if ($this->compareSmaller($libVersion, $minVersion)) {
+						$missing[] = (string)$this->l->t('Library %s with a version higher than %s is required - available version %s.',
+							array($libName, $minVersion, $libVersion));
+					}
+				}
+				if (isset($lib['@attributes']['max-version'])) {
+					$maxVersion = $lib['@attributes']['max-version'];
+					if ($this->compareBigger($libVersion, $maxVersion)) {
+						$missing[] = (string)$this->l->t('Library %s with a version lower than %s is required - available version %s.',
+							array($libName, $maxVersion, $libVersion));
+					}
+				}
+			}
+		}
+		return $missing;
+	}
+
+	/**
+	 * @param array $dependencies
+	 * @return array
+	 */
+	private function analyzeOS(array $dependencies) {
+		$missing = [];
+		if (!isset($dependencies['os'])) {
+			return $missing;
+		}
+
+		$oss = $dependencies['os'];
+		if (empty($oss)) {
+			return $missing;
+		}
+		if (is_array($oss)) {
+			$oss = array_map(function ($os) {
+				return $this->getValue($os);
+			}, $oss);
+		} else {
+			$oss = array($oss);
+		}
+		$currentOS = $this->platform->getOS();
+		if (!in_array($currentOS, $oss)) {
+			$missing[] = (string)$this->l->t('Following platforms are supported: %s', join(', ', $oss));
+		}
+		return $missing;
+	}
+
+	/**
+	 * @param array $dependencies
+	 * @param array $appInfo
+	 * @return array
+	 */
+	private function analyzeOC(array $dependencies, array $appInfo) {
+		$missing = [];
+		$minVersion = null;
+		if (isset($dependencies['owncloud']['@attributes']['min-version'])) {
+			$minVersion = $dependencies['owncloud']['@attributes']['min-version'];
+		} elseif (isset($appInfo['requiremin'])) {
+			$minVersion = $appInfo['requiremin'];
+		} elseif (isset($appInfo['require'])) {
+			$minVersion = $appInfo['require'];
+		}
+		$maxVersion = null;
+		if (isset($dependencies['owncloud']['@attributes']['max-version'])) {
+			$maxVersion = $dependencies['owncloud']['@attributes']['max-version'];
+		} elseif (isset($appInfo['requiremax'])) {
+			$maxVersion = $appInfo['requiremax'];
+		}
+
+		if (!is_null($minVersion)) {
+			if ($this->compareSmaller($this->platform->getOcVersion(), $minVersion)) {
+				$missing[] = (string)$this->l->t('ownCloud %s or higher is required.', $minVersion);
+			}
+		}
+		if (!is_null($maxVersion)) {
+			if ($this->compareBigger($this->platform->getOcVersion(), $maxVersion)) {
+				$missing[] = (string)$this->l->t('ownCloud %s or lower is required.', $maxVersion);
+			}
+		}
+		return $missing;
+	}
+
+	/**
+	 * @param $element
+	 * @return mixed
+	 */
+	private function getValue($element) {
+		if (isset($element['@value']))
+			return $element['@value'];
+		return (string)$element;
+	}
+}
diff --git a/lib/private/App/InfoParser.php b/lib/private/App/InfoParser.php
new file mode 100644
index 00000000000..c33e5349f3b
--- /dev/null
+++ b/lib/private/App/InfoParser.php
@@ -0,0 +1,164 @@
+<?php
+/**
+ * @author Andreas Fischer <bantu@owncloud.com>
+ * @author Lukas Reschke <lukas@owncloud.com>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @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 OC\App;
+
+use OCP\IURLGenerator;
+
+class InfoParser {
+	/**
+	 * @var \OC\HTTPHelper
+	 */
+	private $httpHelper;
+
+	/**
+	 * @var IURLGenerator
+	 */
+	private $urlGenerator;
+
+	/**
+	 * @param \OC\HTTPHelper $httpHelper
+	 * @param IURLGenerator $urlGenerator
+	 */
+	public function __construct(\OC\HTTPHelper $httpHelper, IURLGenerator $urlGenerator) {
+		$this->httpHelper = $httpHelper;
+		$this->urlGenerator = $urlGenerator;
+	}
+
+	/**
+	 * @param string $file the xml file to be loaded
+	 * @return null|array where null is an indicator for an error
+	 */
+	public function parse($file) {
+		if (!file_exists($file)) {
+			return null;
+		}
+
+		libxml_use_internal_errors(true);
+		$loadEntities = libxml_disable_entity_loader(false);
+		$xml = simplexml_load_file($file);
+		libxml_disable_entity_loader($loadEntities);
+		if ($xml == false) {
+			libxml_clear_errors();
+			return null;
+		}
+		$array = $this->xmlToArray($xml);
+		if (is_null($array)) {
+			return null;
+		}
+		if (!array_key_exists('info', $array)) {
+			$array['info'] = array();
+		}
+		if (!array_key_exists('remote', $array)) {
+			$array['remote'] = array();
+		}
+		if (!array_key_exists('public', $array)) {
+			$array['public'] = array();
+		}
+		if (!array_key_exists('types', $array)) {
+			$array['types'] = array();
+		}
+
+		if (array_key_exists('documentation', $array) && is_array($array['documentation'])) {
+			foreach ($array['documentation'] as $key => $url) {
+				// If it is not an absolute URL we assume it is a key
+				// i.e. admin-ldap will get converted to go.php?to=admin-ldap
+				if (!$this->httpHelper->isHTTPURL($url)) {
+					$url = $this->urlGenerator->linkToDocs($url);
+				}
+
+				$array['documentation'][$key] = $url;
+			}
+		}
+		if (array_key_exists('types', $array)) {
+			if (is_array($array['types'])) {
+				foreach ($array['types'] as $type => $v) {
+					unset($array['types'][$type]);
+					if (is_string($type)) {
+						$array['types'][] = $type;
+					}
+				}
+			} else {
+				$array['types'] = array();
+			}
+		}
+
+		return $array;
+	}
+
+	/**
+	 * @param \SimpleXMLElement $xml
+	 * @return array
+	 */
+	function xmlToArray($xml) {
+		if (!$xml->children()) {
+			return (string)$xml;
+		}
+
+		$array = array();
+		foreach ($xml->children() as $element => $node) {
+			$totalElement = count($xml->{$element});
+
+			if (!isset($array[$element])) {
+				$array[$element] = "";
+			}
+			/**
+			 * @var \SimpleXMLElement $node
+			 */
+
+			// Has attributes
+			if ($attributes = $node->attributes()) {
+				$data = array(
+					'@attributes' => array(),
+				);
+				if (!count($node->children())){
+					$value = (string)$node;
+					if (!empty($value)) {
+						$data['@value'] = (string)$node;
+					}
+				} else {
+					$data = array_merge($data, $this->xmlToArray($node));
+				}
+				foreach ($attributes as $attr => $value) {
+					$data['@attributes'][$attr] = (string)$value;
+				}
+
+				if ($totalElement > 1) {
+					$array[$element][] = $data;
+				} else {
+					$array[$element] = $data;
+				}
+				// Just a value
+			} else {
+				if ($totalElement > 1) {
+					$array[$element][] = $this->xmlToArray($node);
+				} else {
+					$array[$element] = $this->xmlToArray($node);
+				}
+			}
+		}
+
+		return $array;
+	}
+}
diff --git a/lib/private/App/Platform.php b/lib/private/App/Platform.php
new file mode 100644
index 00000000000..1d4c3767121
--- /dev/null
+++ b/lib/private/App/Platform.php
@@ -0,0 +1,92 @@
+<?php
+/**
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @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 OC\App;
+
+use OC_Util;
+use OCP\IConfig;
+
+/**
+ * Class Platform
+ *
+ * This class basically abstracts any kind of information which can be retrieved from the underlying system.
+ *
+ * @package OC\App
+ */
+class Platform {
+
+	/**
+	 * @param IConfig $config
+	 */
+	function __construct(IConfig $config) {
+		$this->config = $config;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getPhpVersion() {
+		return phpversion();
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getOcVersion() {
+		$v = \OCP\Util::getVersion();
+		return join('.', $v);
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getDatabase() {
+		$dbType = $this->config->getSystemValue('dbtype', 'sqlite');
+		if ($dbType === 'sqlite3') {
+			$dbType = 'sqlite';
+		}
+
+		return $dbType;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getOS() {
+		return php_uname('s');
+	}
+
+	/**
+	 * @param $command
+	 * @return bool
+	 */
+	public function isCommandKnown($command) {
+		$path = \OC_Helper::findBinaryPath($command);
+		return ($path !== null);
+	}
+
+	public function getLibraryVersion($name) {
+		$repo = new PlatformRepository();
+		$lib = $repo->findLibrary($name);
+		return $lib;
+	}
+}
diff --git a/lib/private/App/PlatformRepository.php b/lib/private/App/PlatformRepository.php
new file mode 100644
index 00000000000..7363b2a44b1
--- /dev/null
+++ b/lib/private/App/PlatformRepository.php
@@ -0,0 +1,228 @@
+<?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 OC\App;
+
+/**
+ * Class PlatformRepository
+ *
+ * Inspired by the composer project - licensed under MIT
+ * https://github.com/composer/composer/blob/master/src/Composer/Repository/PlatformRepository.php#L82
+ *
+ * @package OC\App
+ */
+class PlatformRepository {
+	public function __construct() {
+		$this->packages = $this->initialize();
+	}
+
+	protected function initialize() {
+		$loadedExtensions = get_loaded_extensions();
+		$packages = array();
+
+		// Extensions scanning
+		foreach ($loadedExtensions as $name) {
+			if (in_array($name, array('standard', 'Core'))) {
+				continue;
+			}
+
+			$ext = new \ReflectionExtension($name);
+			try {
+				$prettyVersion = $ext->getVersion();
+				$prettyVersion = $this->normalizeVersion($prettyVersion);
+			} catch (\UnexpectedValueException $e) {
+				$prettyVersion = '0';
+				$prettyVersion = $this->normalizeVersion($prettyVersion);
+			}
+
+			$packages[$this->buildPackageName($name)] = $prettyVersion;
+		}
+
+		foreach ($loadedExtensions as $name) {
+			$prettyVersion = null;
+			switch ($name) {
+				case 'curl':
+					$curlVersion = curl_version();
+					$prettyVersion = $curlVersion['version'];
+					break;
+
+				case 'iconv':
+					$prettyVersion = ICONV_VERSION;
+					break;
+
+				case 'intl':
+					$name = 'ICU';
+					if (defined('INTL_ICU_VERSION')) {
+						$prettyVersion = INTL_ICU_VERSION;
+					} else {
+						$reflector = new \ReflectionExtension('intl');
+
+						ob_start();
+						$reflector->info();
+						$output = ob_get_clean();
+
+						preg_match('/^ICU version => (.*)$/m', $output, $matches);
+						$prettyVersion = $matches[1];
+					}
+
+					break;
+
+				case 'libxml':
+					$prettyVersion = LIBXML_DOTTED_VERSION;
+					break;
+
+				case 'openssl':
+					$prettyVersion = preg_replace_callback('{^(?:OpenSSL\s*)?([0-9.]+)([a-z]?).*}', function ($match) {
+						return $match[1] . (empty($match[2]) ? '' : '.' . (ord($match[2]) - 96));
+					}, OPENSSL_VERSION_TEXT);
+					break;
+
+				case 'pcre':
+					$prettyVersion = preg_replace('{^(\S+).*}', '$1', PCRE_VERSION);
+					break;
+
+				case 'uuid':
+					$prettyVersion = phpversion('uuid');
+					break;
+
+				case 'xsl':
+					$prettyVersion = LIBXSLT_DOTTED_VERSION;
+					break;
+
+				default:
+					// None handled extensions have no special cases, skip
+					continue 2;
+			}
+
+			try {
+				$prettyVersion = $this->normalizeVersion($prettyVersion);
+			} catch (\UnexpectedValueException $e) {
+				continue;
+			}
+
+			$packages[$this->buildPackageName($name)] = $prettyVersion;
+		}
+
+		return $packages;
+	}
+
+	private function buildPackageName($name) {
+		return str_replace(' ', '-', $name);
+	}
+
+	/**
+	 * @param $name
+	 * @return string
+	 */
+	public function findLibrary($name) {
+		$extName = $this->buildPackageName($name);
+		if (isset($this->packages[$extName])) {
+			return $this->packages[$extName];
+		}
+		return null;
+	}
+
+	private static $modifierRegex = '[._-]?(?:(stable|beta|b|RC|alpha|a|patch|pl|p)(?:[.-]?(\d+))?)?([.-]?dev)?';
+
+	/**
+	 * Normalizes a version string to be able to perform comparisons on it
+	 *
+	 * https://github.com/composer/composer/blob/master/src/Composer/Package/Version/VersionParser.php#L94
+	 *
+	 * @param string $version
+	 * @param string $fullVersion optional complete version string to give more context
+	 * @throws \UnexpectedValueException
+	 * @return string
+	 */
+	public function normalizeVersion($version, $fullVersion = null) {
+		$version = trim($version);
+		if (null === $fullVersion) {
+			$fullVersion = $version;
+		}
+		// ignore aliases and just assume the alias is required instead of the source
+		if (preg_match('{^([^,\s]+) +as +([^,\s]+)$}', $version, $match)) {
+			$version = $match[1];
+		}
+		// match master-like branches
+		if (preg_match('{^(?:dev-)?(?:master|trunk|default)$}i', $version)) {
+			return '9999999-dev';
+		}
+		if ('dev-' === strtolower(substr($version, 0, 4))) {
+			return 'dev-' . substr($version, 4);
+		}
+		// match classical versioning
+		if (preg_match('{^v?(\d{1,3})(\.\d+)?(\.\d+)?(\.\d+)?' . self::$modifierRegex . '$}i', $version, $matches)) {
+			$version = $matches[1]
+				. (!empty($matches[2]) ? $matches[2] : '.0')
+				. (!empty($matches[3]) ? $matches[3] : '.0')
+				. (!empty($matches[4]) ? $matches[4] : '.0');
+			$index = 5;
+		} elseif (preg_match('{^v?(\d{4}(?:[.:-]?\d{2}){1,6}(?:[.:-]?\d{1,3})?)' . self::$modifierRegex . '$}i', $version, $matches)) { // match date-based versioning
+			$version = preg_replace('{\D}', '-', $matches[1]);
+			$index = 2;
+		} elseif (preg_match('{^v?(\d{4,})(\.\d+)?(\.\d+)?(\.\d+)?' . self::$modifierRegex . '$}i', $version, $matches)) {
+			$version = $matches[1]
+				. (!empty($matches[2]) ? $matches[2] : '.0')
+				. (!empty($matches[3]) ? $matches[3] : '.0')
+				. (!empty($matches[4]) ? $matches[4] : '.0');
+			$index = 5;
+		}
+		// add version modifiers if a version was matched
+		if (isset($index)) {
+			if (!empty($matches[$index])) {
+				if ('stable' === $matches[$index]) {
+					return $version;
+				}
+				$version .= '-' . $this->expandStability($matches[$index]) . (!empty($matches[$index + 1]) ? $matches[$index + 1] : '');
+			}
+			if (!empty($matches[$index + 2])) {
+				$version .= '-dev';
+			}
+			return $version;
+		}
+		$extraMessage = '';
+		if (preg_match('{ +as +' . preg_quote($version) . '$}', $fullVersion)) {
+			$extraMessage = ' in "' . $fullVersion . '", the alias must be an exact version';
+		} elseif (preg_match('{^' . preg_quote($version) . ' +as +}', $fullVersion)) {
+			$extraMessage = ' in "' . $fullVersion . '", the alias source must be an exact version, if it is a branch name you should prefix it with dev-';
+		}
+		throw new \UnexpectedValueException('Invalid version string "' . $version . '"' . $extraMessage);
+	}
+
+	/**
+	 * @param string $stability
+	 */
+	private function expandStability($stability) {
+		$stability = strtolower($stability);
+		switch ($stability) {
+			case 'a':
+				return 'alpha';
+			case 'b':
+				return 'beta';
+			case 'p':
+			case 'pl':
+				return 'patch';
+			case 'rc':
+				return 'RC';
+			default:
+				return $stability;
+		}
+	}
+}