server/lib/private/app.php

<?php
/**
 * ownCloud
 *
 * @author Frank Karlitschek
 * @author Jakob Sack
 * @copyright 2012 Frank Karlitschek frank@owncloud.org
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
 *
 * You should have received a copy of the GNU Affero General Public
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/**
 * This class manages the apps. It allows them to register and integrate in the
 * owncloud ecosystem. Furthermore, this class is responsible for installing,
 * upgrading and removing apps.
 */
class OC_App {
	static private $settingsForms = array();
	static private $adminForms = array();
	static private $personalForms = array();
	static private $appInfo = array();
	static private $appTypes = array();
	static private $loadedApps = array();
	static private $checkedApps = array();
	static private $altLogin = array();

	/**
	 * clean the appid
	 * @param string|boolean $app Appid that needs to be cleaned
	 * @return string
	 */
	public static function cleanAppId($app) {
		return str_replace(array('\0', '/', '\\', '..'), '', $app);
	}

	/**
	 * loads all apps
	 * @param array $types
	 * @return bool
	 *
	 * This function walks through the owncloud directory and loads all apps
	 * it can find. A directory contains an app if the file /appinfo/app.php
	 * exists.
	 *
	 * if $types is set, only apps of those types will be loaded
	 */
	public static function loadApps($types = null) {
		// Load the enabled apps here
		$apps = self::getEnabledApps();
		// prevent app.php from printing output
		ob_start();
		foreach ($apps as $app) {
			if ((is_null($types) or self::isType($app, $types)) && !in_array($app, self::$loadedApps)) {
				self::$loadedApps[] = $app;
				self::loadApp($app);
			}
		}
		ob_end_clean();

		return true;
	}

	/**
	 * load a single app
	 *
	 * @param string $app
	 */
	public static function loadApp($app) {
		if (is_file(self::getAppPath($app) . '/appinfo/app.php')) {
			self::checkUpgrade($app);
			require_once $app . '/appinfo/app.php';
		}
	}

	/**
	 * check if an app is of a specific type
	 *
	 * @param string $app
	 * @param string|array $types
	 * @return bool
	 */
	public static function isType($app, $types) {
		if (is_string($types)) {
			$types = array($types);
		}
		$appTypes = self::getAppTypes($app);
		foreach ($types as $type) {
			if (array_search($type, $appTypes) !== false) {
				return true;
			}
		}
		return false;
	}

	/**
	 * get the types of an app
	 *
	 * @param string $app
	 * @return array
	 */
	private static function getAppTypes($app) {
		//load the cache
		if (count(self::$appTypes) == 0) {
			self::$appTypes = OC_Appconfig::getValues(false, 'types');
		}

		if (isset(self::$appTypes[$app])) {
			return explode(',', self::$appTypes[$app]);
		} else {
			return array();
		}
	}

	/**
	 * read app types from info.xml and cache them in the database
	 */
	public static function setAppTypes($app) {
		$appData = self::getAppInfo($app);

		if (isset($appData['types'])) {
			$appTypes = implode(',', $appData['types']);
		} else {
			$appTypes = '';
		}

		OC_Appconfig::setValue($app, 'types', $appTypes);
	}

	/**
	 * check if app is shipped
	 *
	 * @param string $appid the id of the app to check
	 * @return bool
	 *
	 * Check if an app that is installed is a shipped app or installed from the appstore.
	 */
	public static function isShipped($appid) {
		$info = self::getAppInfo($appid);
		if (isset($info['shipped']) && $info['shipped'] == 'true') {
			return true;
		} else {
			return false;
		}
	}

	/**
	 * get all enabled apps
	 */
	private static $enabledAppsCache = array();

	public static function getEnabledApps($forceRefresh = false) {
		if (!OC_Config::getValue('installed', false)) {
			return array();
		}
		if (!$forceRefresh && !empty(self::$enabledAppsCache)) {
			return self::$enabledAppsCache;
		}
		$appConfig = \OC::$server->getAppConfig();
		$appStatus = $appConfig->getValues(false, 'enabled');
		foreach ($appStatus as $app => $enabled) {
			if ($app === 'files') {
				continue;
			}
			if ($enabled === 'yes') {
				$apps[] = $app;
			} else if ($enabled !== 'no') {
				$user = \OC_User::getUser();
				$groups = json_decode($enabled);
				if (is_array($groups)) {
					foreach ($groups as $group) {
						if (\OC_Group::inGroup($user, $group)) {
							$apps[] = $app;
							break;
						}
					}
				}
			}
		}
		sort($apps);
		array_unshift($apps, 'files');
		self::$enabledAppsCache = $apps;
		return $apps;
	}

	/**
	 * checks whether or not an app is enabled
	 * @param string $app app
	 * @return bool
	 *
	 * This function checks whether or not an app is enabled.
	 */
	public static function isEnabled($app) {
		if ('files' == $app) {
			return true;
		}
		$enabledApps = self::getEnabledApps();
		return in_array($app, $enabledApps);
	}

	/**
	 * enables an app
	 * @param mixed $app app
	 * @param array $groups (optional) when set, only these groups will have access to the app
	 * @throws \Exception
	 * @return void
	 *
	 * This function set an app as enabled in appconfig.
	 */
	public static function enable($app, $groups = null) {
		self::$enabledAppsCache = array(); // flush
		if (!OC_Installer::isInstalled($app)) {
			// check if app is a shipped app or not. OCS apps have an integer as id, shipped apps use a string
			if (!is_numeric($app)) {
				$app = OC_Installer::installShippedApp($app);
			} else {
				$appdata = OC_OCSClient::getApplication($app);
				$download = OC_OCSClient::getApplicationDownload($app, 1);
				if (isset($download['downloadlink']) and $download['downloadlink'] != '') {
					// Replace spaces in download link without encoding entire URL
					$download['downloadlink'] = str_replace(' ', '%20', $download['downloadlink']);
					$info = array('source' => 'http', 'href' => $download['downloadlink'], 'appdata' => $appdata);
					$app = OC_Installer::installApp($info);
				}
			}
		}
		$l = OC_L10N::get('core');
		if ($app !== false) {
			// check if the app is compatible with this version of ownCloud
			$info = OC_App::getAppInfo($app);
			$version = OC_Util::getVersion();
			if(!self::isAppCompatible($version, $info)) {
				throw new \Exception(
					$l->t("App \"%s\" can't be installed because it is not compatible with this version of ownCloud.",
						array($info['name'])
					)
				);
			} else {
				if (!is_null($groups)) {
					OC_Appconfig::setValue($app, 'enabled', json_encode($groups));
				}else{
					OC_Appconfig::setValue($app, 'enabled', 'yes');
				}
				if (isset($appdata['id'])) {
					OC_Appconfig::setValue($app, 'ocsid', $appdata['id']);
				}
				\OC_Hook::emit('OC_App', 'post_enable', array('app' => $app));
			}
		} else {
			throw new \Exception($l->t("No app name specified"));
		}
	}

	/**
	 * disables an app
	 * @param string $app app
	 * @return boolean|null
	 *
	 * This function set an app as disabled in appconfig.
	 */
	public static function disable($app) {
		self::$enabledAppsCache = array(); // flush
		// check if app is a shipped app or not. if not delete
		\OC_Hook::emit('OC_App', 'pre_disable', array('app' => $app));
		OC_Appconfig::setValue($app, 'enabled', 'no');

		// check if app is a shipped app or not. if not delete
		if (!OC_App::isShipped($app)) {
			OC_Installer::removeApp($app);
		}
	}

	/**
	 * adds an entry to the navigation
	 * @param array $data array containing the data
	 * @return bool
	 *
	 * This function adds a new entry to the navigation visible to users. $data
	 * is an associative array.
	 * The following keys are required:
	 *   - id: unique id for this entry ('addressbook_index')
	 *   - href: link to the page
	 *   - name: Human readable name ('Addressbook')
	 *
	 * The following keys are optional:
	 *   - icon: path to the icon of the app
	 *   - order: integer, that influences the position of your application in
	 *     the navigation. Lower values come first.
	 */
	public static function addNavigationEntry($data) {
		OC::$server->getNavigationManager()->add($data);
		return true;
	}

	/**
	 * marks a navigation entry as active
	 * @param string $id id of the entry
	 * @return bool
	 *
	 * This function sets a navigation entry as active and removes the 'active'
	 * property from all other entries. The templates can use this for
	 * highlighting the current position of the user.
	 */
	public static function setActiveNavigationEntry($id) {
		OC::$server->getNavigationManager()->setActiveEntry($id);
		return true;
	}

	/**
	 * Get the navigation entries for the $app
	 * @param string $app app
	 * @return array an array of the $data added with addNavigationEntry
	 *
	 * Warning: destroys the existing entries
	 */
	public static function getAppNavigationEntries($app) {
		if (is_file(self::getAppPath($app) . '/appinfo/app.php')) {
			OC::$server->getNavigationManager()->clear();
			require $app . '/appinfo/app.php';
			return OC::$server->getNavigationManager()->getAll();
		}
		return array();
	}

	/**
	 * gets the active Menu entry
	 * @return string id or empty string
	 *
	 * This function returns the id of the active navigation entry (set by
	 * setActiveNavigationEntry
	 */
	public static function getActiveNavigationEntry() {
		return OC::$server->getNavigationManager()->getActiveEntry();
	}

	/**
	 * Returns the Settings Navigation
	 * @return string
	 *
	 * This function returns an array containing all settings pages added. The
	 * entries are sorted by the key 'order' ascending.
	 */
	public static function getSettingsNavigation() {
		$l = OC_L10N::get('lib');

		$settings = array();
		// by default, settings only contain the help menu
		if (OC_Util::getEditionString() === '' &&
			OC_Config::getValue('knowledgebaseenabled', true) == true
		) {
			$settings = array(
				array(
					"id" => "help",
					"order" => 1000,
					"href" => OC_Helper::linkToRoute("settings_help"),
					"name" => $l->t("Help"),
					"icon" => OC_Helper::imagePath("settings", "help.svg")
				)
			);
		}

		// if the user is logged-in
		if (OC_User::isLoggedIn()) {
			// personal menu
			$settings[] = array(
				"id" => "personal",
				"order" => 1,
				"href" => OC_Helper::linkToRoute("settings_personal"),
				"name" => $l->t("Personal"),
				"icon" => OC_Helper::imagePath("settings", "personal.svg")
			);

			// if there are some settings forms
			if (!empty(self::$settingsForms)) {
				// settings menu
				$settings[] = array(
					"id" => "settings",
					"order" => 1000,
					"href" => OC_Helper::linkToRoute("settings_settings"),
					"name" => $l->t("Settings"),
					"icon" => OC_Helper::imagePath("settings", "settings.svg")
				);
			}

			//SubAdmins are also allowed to access user management
			if (OC_SubAdmin::isSubAdmin(OC_User::getUser())) {
				// admin users menu
				$settings[] = array(
					"id" => "core_users",
					"order" => 2,
					"href" => OC_Helper::linkToRoute("settings_users"),
					"name" => $l->t("Users"),
					"icon" => OC_Helper::imagePath("settings", "users.svg")
				);
			}


			// if the user is an admin
			if (OC_User::isAdminUser(OC_User::getUser())) {
				// admin settings
				$settings[] = array(
					"id" => "admin",
					"order" => 1000,
					"href" => OC_Helper::linkToRoute("settings_admin"),
					"name" => $l->t("Admin"),
					"icon" => OC_Helper::imagePath("settings", "admin.svg")
				);
			}
		}

		$navigation = self::proceedNavigation($settings);
		return $navigation;
	}

	// This is private as well. It simply works, so don't ask for more details
	private static function proceedNavigation($list) {
		$activeapp = OC::$server->getNavigationManager()->getActiveEntry();
		foreach ($list as &$naventry) {
			if ($naventry['id'] == $activeapp) {
				$naventry['active'] = true;
			} else {
				$naventry['active'] = false;
			}
		}
		unset($naventry);

		usort($list, create_function('$a, $b', 'if( $a["order"] == $b["order"] ) {return 0;}elseif( $a["order"] < $b["order"] ) {return -1;}else{return 1;}'));

		return $list;
	}

	/**
	 * Get the path where to install apps
	 *
	 * @return string
	 */
	public static function getInstallPath() {
		if (OC_Config::getValue('appstoreenabled', true) == false) {
			return false;
		}

		foreach (OC::$APPSROOTS as $dir) {
			if (isset($dir['writable']) && $dir['writable'] === true) {
				return $dir['path'];
			}
		}

		OC_Log::write('core', 'No application directories are marked as writable.', OC_Log::ERROR);
		return null;
	}


	protected static function findAppInDirectories($appid) {
		static $app_dir = array();
		if (isset($app_dir[$appid])) {
			return $app_dir[$appid];
		}
		foreach (OC::$APPSROOTS as $dir) {
			if (file_exists($dir['path'] . '/' . $appid)) {
				return $app_dir[$appid] = $dir;
			}
		}
		return false;
	}

	/**
	 * Get the directory for the given app.
	 * If the app is defined in multiple directories, the first one is taken. (false if not found)
	 * @param string $appid
	 * @return string|false
	 */
	public static function getAppPath($appid) {
		if (($dir = self::findAppInDirectories($appid)) != false) {
			return $dir['path'] . '/' . $appid;
		}
		return false;
	}

	/**
	 * Get the path for the given app on the access
	 * If the app is defined in multiple directories, the first one is taken. (false if not found)
	 * @param string $appid
	 * @return string|false
	 */
	public static function getAppWebPath($appid) {
		if (($dir = self::findAppInDirectories($appid)) != false) {
			return OC::$WEBROOT . $dir['url'] . '/' . $appid;
		}
		return false;
	}

	/**
	 * get the last version of the app, either from appinfo/version or from appinfo/info.xml
	 * @param string $appid
	 * @return string
	 */
	public static function getAppVersion($appid) {
		$file = self::getAppPath($appid) . '/appinfo/version';
		if (is_file($file) && $version = trim(file_get_contents($file))) {
			return $version;
		} else {
			$appData = self::getAppInfo($appid);
			return isset($appData['version']) ? $appData['version'] : '';
		}
	}

	/**
	 * Read all app metadata from the info.xml file
	 * @param string $appid id of the app or the path of the info.xml file
	 * @param boolean $path (optional)
	 * @return array
	 * @note all data is read from info.xml, not just pre-defined fields
	 */
	public static function getAppInfo($appid, $path = false) {
		if ($path) {
			$file = $appid;
		} else {
			if (isset(self::$appInfo[$appid])) {
				return self::$appInfo[$appid];
			}
			$file = self::getAppPath($appid) . '/appinfo/info.xml';
		}
		$data = array();
		$content = @file_get_contents($file);
		if (!$content) {
			return null;
		}
		$xml = new SimpleXMLElement($content);
		$data['info'] = array();
		$data['remote'] = array();
		$data['public'] = array();
		foreach ($xml->children() as $child) {
			/**
			 * @var $child SimpleXMLElement
			 */
			if ($child->getName() == 'remote') {
				foreach ($child->children() as $remote) {
					/**
					 * @var $remote SimpleXMLElement
					 */
					$data['remote'][$remote->getName()] = (string)$remote;
				}
			} elseif ($child->getName() == 'public') {
				foreach ($child->children() as $public) {
					/**
					 * @var $public SimpleXMLElement
					 */
					$data['public'][$public->getName()] = (string)$public;
				}
			} elseif ($child->getName() == 'types') {
				$data['types'] = array();
				foreach ($child->children() as $type) {
					/**
					 * @var $type SimpleXMLElement
					 */
					$data['types'][] = $type->getName();
				}
			} elseif ($child->getName() == 'description') {
				$xml = (string)$child->asXML();
				$data[$child->getName()] = substr($xml, 13, -14); //script <description> tags
			} elseif ($child->getName() == 'documentation') {
				foreach ($child as $subchild) {
					$data["documentation"][$subchild->getName()] = (string)$subchild;
				}
			} else {
				$data[$child->getName()] = (string)$child;
			}
		}
		self::$appInfo[$appid] = $data;

		return $data;
	}

	/**
	 * Returns the navigation
	 * @return array
	 *
	 * This function returns an array containing all entries added. The
	 * entries are sorted by the key 'order' ascending. Additional to the keys
	 * given for each app the following keys exist:
	 *   - active: boolean, signals if the user is on this navigation entry
	 */
	public static function getNavigation() {
		$entries = OC::$server->getNavigationManager()->getAll();
		$navigation = self::proceedNavigation($entries);
		return $navigation;
	}

	/**
	 * get the id of loaded app
	 *
	 * @return string
	 */
	public static function getCurrentApp() {
		$script = substr(OC_Request::scriptName(), strlen(OC::$WEBROOT) + 1);
		$topFolder = substr($script, 0, strpos($script, '/'));
		if (empty($topFolder)) {
			$path_info = OC_Request::getPathInfo();
			if ($path_info) {
				$topFolder = substr($path_info, 1, strpos($path_info, '/', 1) - 1);
			}
		}
		if ($topFolder == 'apps') {
			$length = strlen($topFolder);
			return substr($script, $length + 1, strpos($script, '/', $length + 1) - $length - 1);
		} else {
			return $topFolder;
		}
	}


	/**
	 * get the forms for either settings, admin or personal
	 */
	public static function getForms($type) {
		$forms = array();
		switch ($type) {
			case 'settings':
				$source = self::$settingsForms;
				break;
			case 'admin':
				$source = self::$adminForms;
				break;
			case 'personal':
				$source = self::$personalForms;
				break;
			default:
				return array();
		}
		foreach ($source as $form) {
			$forms[] = include $form;
		}
		return $forms;
	}

	/**
	 * register a settings form to be shown
	 */
	public static function registerSettings($app, $page) {
		self::$settingsForms[] = $app . '/' . $page . '.php';
	}

	/**
	 * register an admin form to be shown
	 *
	 * @param string $app
	 * @param string $page
	 */
	public static function registerAdmin($app, $page) {
		self::$adminForms[] = $app . '/' . $page . '.php';
	}

	/**
	 * register a personal form to be shown
	 */
	public static function registerPersonal($app, $page) {
		self::$personalForms[] = $app . '/' . $page . '.php';
	}

	public static function registerLogIn($entry) {
		self::$altLogin[] = $entry;
	}

	public static function getAlternativeLogIns() {
		return self::$altLogin;
	}

	/**
	 * get a list of all apps in the apps folder
	 * @return array an array of app names (string IDs)
	 * @todo: change the name of this method to getInstalledApps, which is more accurate
	 */
	public static function getAllApps() {

		$apps = array();

		foreach (OC::$APPSROOTS as $apps_dir) {
			if (!is_readable($apps_dir['path'])) {
				OC_Log::write('core', 'unable to read app folder : ' . $apps_dir['path'], OC_Log::WARN);
				continue;
			}
			$dh = opendir($apps_dir['path']);

			if (is_resource($dh)) {
				while (($file = readdir($dh)) !== false) {

					if ($file[0] != '.' and is_file($apps_dir['path'] . '/' . $file . '/appinfo/app.php')) {

						$apps[] = $file;

					}

				}
			}

		}

		return $apps;
	}

	/**
	 * Lists all apps, this is used in apps.php
	 * @return array
	 */
	public static function listAllApps() {
		$installedApps = OC_App::getAllApps();

		//TODO which apps do we want to blacklist and how do we integrate
		// blacklisting with the multi apps folder feature?

		$blacklist = array('files'); //we dont want to show configuration for these
		$appList = array();

		foreach ($installedApps as $app) {
			if (array_search($app, $blacklist) === false) {

				$info = OC_App::getAppInfo($app);

				if (!isset($info['name'])) {
					OC_Log::write('core', 'App id "' . $app . '" has no name in appinfo', OC_Log::ERROR);
					continue;
				}

				$enabled = OC_Appconfig::getValue($app, 'enabled', 'no');
				$info['groups'] = null;
				if ($enabled === 'yes') {
					$active = true;
				} else if($enabled === 'no') {
					$active = false;
				} else {
					$active = true;
					$info['groups'] = $enabled;
				}

				$info['active'] = $active;

				if (isset($info['shipped']) and ($info['shipped'] == 'true')) {
					$info['internal'] = true;
					$info['internallabel'] = 'Internal App';
					$info['internalclass'] = '';
					$info['update'] = false;
				} else {
					$info['internal'] = false;
					$info['internallabel'] = '3rd Party';
					$info['internalclass'] = 'externalapp';
					$info['update'] = OC_Installer::isUpdateAvailable($app);
				}

				$info['preview'] = OC_Helper::imagePath('settings', 'trans.png');
				$info['version'] = OC_App::getAppVersion($app);
				$appList[] = $info;
			}
		}
		$remoteApps = OC_App::getAppstoreApps();
		if ($remoteApps) {
			// Remove duplicates
			foreach ($appList as $app) {
				foreach ($remoteApps AS $key => $remote) {
					if (
						$app['name'] == $remote['name']
						// To set duplicate detection to use OCS ID instead of string name,
						// enable this code, remove the line of code above,
						// and add <ocs_id>[ID]</ocs_id> to info.xml of each 3rd party app:
						// OR $app['ocs_id'] == $remote['ocs_id']
					) {
						unset($remoteApps[$key]);
					}
				}
			}
			$combinedApps = array_merge($appList, $remoteApps);
		} else {
			$combinedApps = $appList;
		}
		// bring the apps into the right order with a custom sort funtion
		usort($combinedApps, '\OC_App::customSort');

		return $combinedApps;
	}

	/**
	 * Internal custom sort funtion to bring the app into the right order. Should only be called by listAllApps
	 * @return array
	 */
	private static function customSort($a, $b) {

		// prio 1: active
		if ($a['active'] != $b['active']) {
			return $b['active'] - $a['active'];
		}

		// prio 2: shipped
		$ashipped = (array_key_exists('shipped', $a) && $a['shipped'] === 'true') ? 1 : 0;
		$bshipped = (array_key_exists('shipped', $b) && $b['shipped'] === 'true') ? 1 : 0;
		if ($ashipped !== $bshipped) {
			return ($bshipped - $ashipped);
		}

		// prio 3: recommended
		if ($a['internalclass'] != $b['internalclass']) {
			$atemp = ($a['internalclass'] == 'recommendedapp' ? 1 : 0);
			$btemp = ($b['internalclass'] == 'recommendedapp' ? 1 : 0);
			return ($btemp - $atemp);
		}

		// prio 4: alphabetical
		return strcasecmp($a['name'], $b['name']);

	}

	/**
	 * get a list of all apps on apps.owncloud.com
	 * @return array, multi-dimensional array of apps.
	 *     Keys: id, name, type, typename, personid, license, detailpage, preview, changed, description
	 */
	public static function getAppstoreApps($filter = 'approved') {
		$categoryNames = OC_OCSClient::getCategories();
		if (is_array($categoryNames)) {
			// Check that categories of apps were retrieved correctly
			if (!$categories = array_keys($categoryNames)) {
				return false;
			}

			$page = 0;
			$remoteApps = OC_OCSClient::getApplications($categories, $page, $filter);
			$app1 = array();
			$i = 0;
			foreach ($remoteApps as $app) {
				$app1[$i] = $app;
				$app1[$i]['author'] = $app['personid'];
				$app1[$i]['ocs_id'] = $app['id'];
				$app1[$i]['internal'] = $app1[$i]['active'] = 0;
				$app1[$i]['update'] = false;
				if ($app['label'] == 'recommended') {
					$app1[$i]['internallabel'] = 'Recommended';
					$app1[$i]['internalclass'] = 'recommendedapp';
				} else {
					$app1[$i]['internallabel'] = '3rd Party';
					$app1[$i]['internalclass'] = 'externalapp';
				}


				// rating img
				if ($app['score'] >= 0 and $app['score'] < 5) $img = OC_Helper::imagePath("core", "rating/s1.png");
				elseif ($app['score'] >= 5 and $app['score'] < 15) $img = OC_Helper::imagePath("core", "rating/s2.png");
				elseif ($app['score'] >= 15 and $app['score'] < 25) $img = OC_Helper::imagePath("core", "rating/s3.png");
				elseif ($app['score'] >= 25 and $app['score'] < 35) $img = OC_Helper::imagePath("core", "rating/s4.png");
				elseif ($app['score'] >= 35 and $app['score'] < 45) $img = OC_Helper::imagePath("core", "rating/s5.png");
				elseif ($app['score'] >= 45 and $app['score'] < 55) $img = OC_Helper::imagePath("core", "rating/s6.png");
				elseif ($app['score'] >= 55 and $app['score'] < 65) $img = OC_Helper::imagePath("core", "rating/s7.png");
				elseif ($app['score'] >= 65 and $app['score'] < 75) $img = OC_Helper::imagePath("core", "rating/s8.png");
				elseif ($app['score'] >= 75 and $app['score'] < 85) $img = OC_Helper::imagePath("core", "rating/s9.png");
				elseif ($app['score'] >= 85 and $app['score'] < 95) $img = OC_Helper::imagePath("core", "rating/s10.png");
				elseif ($app['score'] >= 95 and $app['score'] < 100) $img = OC_Helper::imagePath("core", "rating/s11.png");

				$app1[$i]['score'] = '<img src="' . $img . '"> Score: ' . $app['score'] . '%';
				$i++;
			}
		}

		if (empty($app1)) {
			return false;
		} else {
			return $app1;
		}
	}

	public static function shouldUpgrade($app) {
		$versions = self::getAppVersions();
		$currentVersion = OC_App::getAppVersion($app);
		if ($currentVersion) {
			$installedVersion = $versions[$app];
			if (version_compare($currentVersion, $installedVersion, '>')) {
				return true;
			}
		}
		return false;
	}

	/**
	 * check if the app needs updating and update when needed
	 *
	 * @param string $app
	 */
	public static function checkUpgrade($app) {
		if (in_array($app, self::$checkedApps)) {
			return;
		}
		self::$checkedApps[] = $app;
		if (!self::shouldUpgrade($app)) {
			return;
		}
		$versions = self::getAppVersions();
		$installedVersion = $versions[$app];
		$currentVersion = OC_App::getAppVersion($app);
		OC_Log::write(
			$app,
			'starting app upgrade from ' . $installedVersion . ' to ' . $currentVersion,
			OC_Log::DEBUG
		);
		$info = self::getAppInfo($app);
		try {
			OC_App::updateApp($app);
			OC_Hook::emit('update', 'success', 'Updated ' . $info['name'] . ' app');
		} catch (Exception $e) {
			OC_Hook::emit('update', 'failure', 'Failed to update ' . $info['name'] . ' app: ' . $e->getMessage());
			$l = OC_L10N::get('lib');
			throw new RuntimeException($l->t('Failed to upgrade "%s".', array($app)), 0, $e);
		}
		OC_Appconfig::setValue($app, 'installed_version', OC_App::getAppVersion($app));
	}

	/**
	 * check if the current enabled apps are compatible with the current
	 * ownCloud version. disable them if not.
	 * This is important if you upgrade ownCloud and have non ported 3rd
	 * party apps installed.
	 *
	 * @param array $apps optional app id list to check, uses all enabled apps
	 * when not specified
	 *
	 * @return array containing the list of ids of the disabled apps
	 */
	public static function checkAppsRequirements($apps = array()) {
		$disabledApps = array();
		if (empty($apps)) {
			$apps = OC_App::getEnabledApps();
		}
		$version = OC_Util::getVersion();
		foreach ($apps as $app) {
			// check if the app is compatible with this version of ownCloud
			$info = OC_App::getAppInfo($app);
			if(!self::isAppCompatible($version, $info)) {
				OC_Log::write('core',
					'App "' . $info['name'] . '" (' . $app . ') can\'t be used because it is'
					. ' not compatible with this version of ownCloud',
					OC_Log::ERROR);
				OC_App::disable($app);
				OC_Hook::emit('update', 'success', 'Disabled ' . $info['name'] . ' app because it is not compatible');
				$disabledApps[] = $app;
			}
		}
		return $disabledApps;
	}

	/**
	 * Ajust the number of version parts of $version1 to match
	 * the number of version parts of $version2.
	 *
	 * @param string $version1 version to adjust
	 * @param string $version2 version to take the number of parts from
	 * @return string shortened $version1
	 */
	private static function adjustVersionParts($version1, $version2) {
		$version1 = explode('.', $version1);
		$version2 = explode('.', $version2);
		// reduce $version1 to match the number of parts in $version2
		while (count($version1) > count($version2)) {
			array_pop($version1);
		}
		// if $version1 does not have enough parts, add some
		while (count($version1) < count($version2)) {
			$version1[] = '0';
		}
		return implode('.', $version1);
	}

	/**
	 * Check whether the current ownCloud version matches the given
	 * application's version requirements.
	 *
	 * The comparison is made based on the number of parts that the
	 * app info version has. For example for ownCloud 6.0.3 if the
	 * app info version is expecting version 6.0, the comparison is
	 * made on the first two parts of the ownCloud version.
	 * This means that it's possible to specify "requiremin" => 6
	 * and "requiremax" => 6 and it will still match ownCloud 6.0.3.
	 *
	 * @param string $ocVersion ownCloud version to check against
	 * @param array  $appInfo app info (from xml)
	 *
	 * @return boolean true if compatible, otherwise false
	 */
	public static function isAppCompatible($ocVersion, $appInfo){
		$requireMin = '';
		$requireMax = '';
		if (isset($appInfo['requiremin'])) {
			$requireMin = $appInfo['requiremin'];
		} else if (isset($appInfo['require'])) {
			$requireMin = $appInfo['require'];
		}

		if (isset($appInfo['requiremax'])) {
			$requireMax = $appInfo['requiremax'];
		}

		if (is_array($ocVersion)) {
			$ocVersion = implode('.', $ocVersion);
		}

		if (!empty($requireMin)
			&& version_compare(self::adjustVersionParts($ocVersion, $requireMin), $requireMin, '<')
		) {

			return false;
		}

		if (!empty($requireMax)
			&& version_compare(self::adjustVersionParts($ocVersion, $requireMax), $requireMax, '>')
		) {

			return false;
		}

		return true;
	}

	/**
	 * get the installed version of all apps
	 */
	public static function getAppVersions() {
		static $versions;
		if (isset($versions)) { // simple cache, needs to be fixed
			return $versions; // when function is used besides in checkUpgrade
		}
		$versions = array();
		$query = OC_DB::prepare('SELECT `appid`, `configvalue` FROM `*PREFIX*appconfig`'
			. ' WHERE `configkey` = \'installed_version\'');
		$result = $query->execute();
		while ($row = $result->fetchRow()) {
			$versions[$row['appid']] = $row['configvalue'];
		}
		return $versions;
	}

	/**
	 * update the database for the app and call the update script
	 *
	 * @param string $appid
	 */
	public static function updateApp($appid) {
		if (file_exists(self::getAppPath($appid) . '/appinfo/preupdate.php')) {
			self::loadApp($appid);
			include self::getAppPath($appid) . '/appinfo/preupdate.php';
		}
		if (file_exists(self::getAppPath($appid) . '/appinfo/database.xml')) {
			OC_DB::updateDbFromStructure(self::getAppPath($appid) . '/appinfo/database.xml');
		}
		if (!self::isEnabled($appid)) {
			return;
		}
		if (file_exists(self::getAppPath($appid) . '/appinfo/update.php')) {
			self::loadApp($appid);
			include self::getAppPath($appid) . '/appinfo/update.php';
		}

		//set remote/public handlers
		$appData = self::getAppInfo($appid);
		foreach ($appData['remote'] as $name => $path) {
			OCP\CONFIG::setAppValue('core', 'remote_' . $name, $appid . '/' . $path);
		}
		foreach ($appData['public'] as $name => $path) {
			OCP\CONFIG::setAppValue('core', 'public_' . $name, $appid . '/' . $path);
		}

		self::setAppTypes($appid);
	}

	/**
	 * @param string $appid
	 * @return \OC\Files\View
	 */
	public static function getStorage($appid) {
		if (OC_App::isEnabled($appid)) { //sanity check
			if (OC_User::isLoggedIn()) {
				$view = new \OC\Files\View('/' . OC_User::getUser());
				if (!$view->file_exists($appid)) {
					$view->mkdir($appid);
				}
				return new \OC\Files\View('/' . OC_User::getUser() . '/' . $appid);
			} else {
				OC_Log::write('core', 'Can\'t get app storage, app ' . $appid . ', user not logged in', OC_Log::ERROR);
				return false;
			}
		} else {
			OC_Log::write('core', 'Can\'t get app storage, app ' . $appid . ' not enabled', OC_Log::ERROR);
			return false;
		}
	}
}