owncloud/core

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lib/private/legacy/app.php

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<?php
/**
 * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
 * @author Bart Visscher <bartv@thisnet.nl>
 * @author Bernhard Posselt <dev@bernhard-posselt.com>
 * @author Borjan Tchakaloff <borjan@tchakaloff.fr>
 * @author Brice Maron <brice@bmaron.net>
 * @author Christopher Schäpers <kondou@ts.unde.re>
 * @author Felix Moeller <mail@felixmoeller.de>
 * @author Frank Karlitschek <frank@karlitschek.de>
 * @author Georg Ehrke <georg@owncloud.com>
 * @author Jakob Sack <mail@jakobsack.de>
 * @author Joas Schilling <coding@schilljs.com>
 * @author Jörn Friedrich Dreyer <jfd@butonic.de>
 * @author Kamil Domanski <kdomanski@kdemail.net>
 * @author Lukas Reschke <lukas@statuscode.ch>
 * @author Markus Goetz <markus@woboq.com>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Philipp Schaffrath <github@philippschaffrath.de>
 * @author ppaysant <patrick.paysant@linagora.com>
 * @author RealRancor <Fisch.666@gmx.de>
 * @author Robin Appelman <icewind@owncloud.com>
 * @author Robin McCorkell <robin@mccorkell.me.uk>
 * @author Roeland Jago Douma <rullzer@owncloud.com>
 * @author Sam Tuke <mail@samtuke.com>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 * @author Thomas Tanghus <thomas@tanghus.net>
 * @author Tom Needham <tom@owncloud.com>
 * @author Vincent Petry <pvince81@owncloud.com>
 *
 * @copyright Copyright (c) 2018, ownCloud GmbH
 * @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/>
 *
 */
use OC\App\DependencyAnalyzer;
use OC\App\Platform;
use OC\Installer;
use OC\NeedsUpdateException;
use OC\Repair;

/**
 * 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 {
    private static $adminForms = [];
    private static $personalForms = [];
    private static $appTypes = [];
    private static $loadedApps = [];
    private static $loadedTypes = [];
    private static $altLogin = [];
    public const officialApp = 200;
    public const approvedApp = 100;

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

    /**
     * Check if an app is loaded
     *
     * @param string $app
     * @return bool
     */
    public static function isAppLoaded($app) {
        return \in_array($app, self::$loadedApps, true);
    }

    /**
     * loads all apps
     *
     * @param string[] | string | null $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/info.xml
     * exists.
     *
     * if $types is set, only apps of those types will be loaded
     */
    public static function loadApps($types = null) {
        if (\is_array($types) && !\array_diff($types, self::$loadedTypes)) {
            return true;
        }
        if (\OC::$server->getSystemConfig()->getValue('maintenance', false)) {
            return false;
        }
        // Load the enabled apps here
        $apps = self::getEnabledApps();

        // Add each apps' folder as allowed class path
        foreach ($apps as $app) {
            if (self::isAppLoaded($app)) {
                continue;
            }
            $path = self::getAppPath($app);
            if ($path !== false) {
                self::registerAutoloading($app, $path);
            }
        }

        // prevent app.php from printing output
        \ob_start();
        foreach ($apps as $app) {
            if (($types === null or self::isType($app, $types)) && !\in_array($app, self::$loadedApps)) {
                self::loadApp($app);
            }
        }
        \ob_end_clean();

        // once all authentication apps are loaded we can validate the session
        if ($types === null || \in_array('authentication', $types)) {
            if (\OC::$server->getUserSession()) {
                $request = \OC::$server->getRequest();
                $session = \OC::$server->getUserSession();
                $davUser = \OC::$server->getUserSession()->getSession()->get(\OCA\DAV\Connector\Sabre\Auth::DAV_AUTHENTICATED);
                if ($davUser === null) {
                    $session->validateSession();
                } else {
                    /** @var \OC\Authentication\Token\DefaultTokenProvider $tokenProvider */
                    $tokenProvider = \OC::$server->query('\OC\Authentication\Token\DefaultTokenProvider');
                    $token = null;
                    try {
                        $token = $tokenProvider->getToken($session->getSession()->getId());
                    } catch (\Exception $ex) {
                        $password = null;
                        if (isset($_SERVER['PHP_AUTH_PW'])) {
                            $password = $_SERVER['PHP_AUTH_PW'];
                        }

                        $session->createSessionToken($request, $session->getUser()->getUID(), $session->getLoginName(), $password);
                    }

                    if ($token) {
                        $tokenProvider->updateToken($token);
                    }
                }
            }
        }
        if (\is_array($types)) {
            self::$loadedTypes = \array_merge(self::$loadedTypes, $types);
        }

        \OC_Hook::emit('OC_App', 'loadedApps');
        return true;
    }

    /**
     * load a single app
     *
     * @param string $app
     * @param bool $checkUpgrade whether an upgrade check should be done
     * @throws NeedsUpdateException
     */
    public static function loadApp($app, $checkUpgrade = true) {
        self::$loadedApps[] = $app;
        $appPath = self::getAppPath($app);
        if ($appPath === false) {
            return;
        }

        // in case someone calls loadApp() directly
        self::registerAutoloading($app, $appPath);

        self::enableThemeIfApplicable($app);

        if (\is_file($appPath . '/appinfo/app.php')) {
            \OC::$server->getEventLogger()->start('load_app_' . $app, 'Load app: ' . $app);
            if ($checkUpgrade && self::shouldUpgrade($app)) {
                throw new NeedsUpdateException();
            }
            try {
                self::requireAppFile($app);
            } catch (Exception $ex) {
                \OC::$server->getLogger()->logException($ex);
                $blacklist = \OC::$server->getAppManager()->getAlwaysEnabledApps();
                if (!\in_array($app, $blacklist)) {
                    if (!self::isType($app, ['authentication', 'filesystem'])) {
                        \OC::$server->getLogger()->warning('Could not load app "' . $app . '", it will be disabled', ['app' => 'core']);
                        self::disable($app);
                    } else {
                        \OC::$server->getLogger()->warning('Could not load app "' . $app . '", see exception above', ['app' => 'core']);
                    }
                }
                throw $ex;
            }
            if (self::isType($app, ['authentication'])) {
                // since authentication apps affect the "is app enabled for group" check,
                // the enabled apps cache needs to be cleared to make sure that the
                // next time getEnableApps() is called it will also include apps that were
                // enabled for groups
                self::$enabledAppsCache = [];
            }
            \OC::$server->getEventLogger()->end('load_app_' . $app);
        }
    }

    /**
     * Enables the app as a theme if it has the type "theme"
     * @param string $app
     */
    private static function enableThemeIfApplicable($app) {
        if (self::isType($app, 'theme')) {
            /** @var \OCP\Theme\IThemeService $themeService */
            $themeService = \OC::$server->query('ThemeService');
            $themeService->setAppTheme($app);
        }
    }

    /**
     * @internal
     * @param string $app
     * @param string $path
     */
    public static function registerAutoloading($app, $path) {
        // Register on PSR-4 composer autoloader
        $appNamespace = \OC\AppFramework\App::buildAppNamespace($app);
        \OC::$composerAutoloader->addPsr4($appNamespace . '\\', $path . '/lib/', true);
        if (\defined('PHPUNIT_RUN')) {
            \OC::$composerAutoloader->addPsr4($appNamespace . '\\Tests\\', $path . '/tests/', true);
        }

        // Register on legacy autoloader
        \OC::$loader->addValidRoot($path);
    }

    /**
     * Load app.php from the given app
     *
     * @param string $app app name
     */
    private static function requireAppFile($app) {
        // encapsulated here to avoid variable scope conflicts
        require_once self::getAppPath($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)) {
            $types = [$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::$server->getAppConfig()->getValues(false, 'types');
        }

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

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

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

        \OC::$server->getAppConfig()->setValue($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) {
        return \OC::$server->getAppManager()->isShipped($appId);
    }

    /**
     * get all enabled apps
     */
    protected static $enabledAppsCache = [];

    /**
     * Returns apps enabled for the current user.
     *
     * @param bool $forceRefresh whether to refresh the cache
     * @param bool $all whether to return apps for all users, not only the
     * currently logged in one
     * @return string[]
     */
    public static function getEnabledApps($forceRefresh = false, $all = false) {
        if (!\OC::$server->getSystemConfig()->getValue('installed', false)) {
            return [];
        }
        // in incognito mode or when logged out, $user will be false,
        // which is also the case during an upgrade
        $appManager = \OC::$server->getAppManager();
        if ($all) {
            $user = null;
        } else {
            $user = \OC::$server->getUserSession()->getUser();
        }

        if ($user === null) {
            $apps = $appManager->getInstalledApps();
        } else {
            $apps = $appManager->getEnabledAppsForUser($user);
        }
        $apps = \array_filter($apps, function ($app) {
            return $app !== 'files';//we add this manually
        });
        \sort($apps);
        \array_unshift($apps, 'files');
        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) {
        return \OC::$server->getAppManager()->isEnabledForUser($app);
    }

    /**
     * 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 = []; // flush

        // check for required dependencies
        $config = \OC::$server->getConfig();
        $l = \OC::$server->getL10N('lib');
        $info = self::getAppInfo($app);
        if ($info === null) {
            throw new \Exception("$app can't be enabled since it is not installed.");
        }

        self::checkAppDependencies($config, $l, $info);

        $appManager = \OC::$server->getAppManager();
        if ($groups !== null) {
            $groupManager = \OC::$server->getGroupManager();
            $groupsList = [];
            foreach ($groups as $group) {
                $groupItem = $groupManager->get($group);
                if ($groupItem instanceof \OCP\IGroup) {
                    $groupsList[] = $groupManager->get($group);
                }
            }
            $appManager->enableAppForGroups($app, $groupsList);
        } else {
            $appManager->enableApp($app);
        }
    }

    /**
     * @param string $app
     * @return bool
     */
    public static function removeApp($app) {
        if (self::isShipped($app)) {
            return false;
        }

        return Installer::removeApp($app);
    }

    /**
     * This function set an app as disabled in appconfig.
     *
     * @param string $app app
     * @throws Exception
     */
    public static function disable($app) {
        // flush
        self::$enabledAppsCache = [];

        // run uninstall steps
        $appData = OC_App::getAppInfo($app);
        if ($appData !== null) {
            OC_App::executeRepairSteps($app, $appData['repair-steps']['uninstall']);
        }

        // emit disable hook - needed anymore ?
        \OC_Hook::emit('OC_App', 'pre_disable', ['app' => $app]);

        // finally disable it
        $appManager = \OC::$server->getAppManager();
        $appManager->disableApp($app);
    }

    /**
     * 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() {
        $l = \OC::$server->getL10N('lib');
        $urlGenerator = \OC::$server->getURLGenerator();

        $settings = [];

        // if the user is logged-in
        if (OC_User::isLoggedIn()) {
            // personal menu
            $settings[] = [
                "id" => "settings",
                "order" => 1,
                "href" => $urlGenerator->linkToRoute('settings.SettingsPage.getPersonal'),
                "name" => $l->t("Settings"),
                "icon" => $urlGenerator->imagePath("settings", "admin.svg")
            ];

            //SubAdmins are also allowed to access user management
            $userObject = \OC::$server->getUserSession()->getUser();
            $isSubAdmin = false;
            if ($userObject !== null) {
                $isSubAdmin = \OC::$server->getGroupManager()->getSubAdmin()->isSubAdmin($userObject);
            }
            if ($isSubAdmin) {
                // admin users menu
                $settings[] = [
                    "id" => "core_users",
                    "order" => 2,
                    "href" => $urlGenerator->linkToRoute('settings_users'),
                    "name" => $l->t("Users"),
                    "icon" => $urlGenerator->imagePath("settings", "users.svg")
                ];
            }
        }

        return self::proceedNavigation($settings);
    }

    // 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($list, function ($a, $b) {
            if ($a["order"] == $b["order"]) {
                return 0;
            }

            if ($a["order"] < $b["order"]) {
                return -1;
            }

            return 1;
        });

        return $list;
    }

    /**
     * Get the path where to install apps
     *
     * @return string|null
     */
    public static function getInstallPath() {
        foreach (OC::$APPSROOTS as $dir) {
            if (isset($dir['writable']) && $dir['writable'] === true) {
                return $dir['path'];
            }
        }

        \OCP\Util::writeLog('core', 'No application directories are marked as writable.', \OCP\Util::ERROR);
        return null;
    }

    /**
     * Get the directory for the given app.
     * If the app exists in multiple directories, the most recent version is taken.
     * (false if not found)
     *
     * @param string $appId
     * @return string|false
     */
    public static function getAppPath($appId) {
        return \OC::$server->getAppManager()->getAppPath($appId);
    }

    /**
     * Get the web path for the given app.
     * If the app exists in multiple directories, the most recent version is taken.
     * (false if not found)
     *
     * @param string $appId
     * @return string|false
     */
    public static function getAppWebPath($appId) {
        return \OC::$server->getAppManager()->getAppWebPath($appId);
    }

    /**
     * check if an app's directory is writable
     *
     * @param string $appId
     * @return bool
     */
    public static function isAppDirWritable($appId) {
        $path = self::getAppPath($appId);
        // Check if the parent directory is marked as writable in config.php
        if ($path !== false) {
            $appDir = \substr($path, 0, -\strlen("/$appId"));
            foreach (OC::$APPSROOTS as $dir) {
                if ($dir['path'] !== $appDir) {
                    continue;
                }
                if (!isset($dir['writable'])
                    || $dir['writable'] !== true
                ) {
                    return false;
                }
            }
        }
        return ($path !== false) ? \is_writable($path) : false;
    }

    /**
     * get the last version of the app from appinfo/info.xml
     *
     * @param string $appId
     * @return string
     * @deprecated use \OC::$server->getAppManager()->getAppInfo($appId)
     */
    public static function getAppVersion($appId) {
        $info = \OC::$server->getAppManager()->getAppInfo($appId);
        if (isset($info['version'])) {
            return $info['version'];
        }
        return '0';
    }

    /**
     * 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 bool $path
     * @return array|null
     * @note all data is read from info.xml, not just pre-defined fields
     * @deprecated use \OC::$server->getAppManager()->getAppInfo($appId)
     */
    public static function getAppInfo($appId, $path = false) {
        /** @var \OC\App\AppManager $am */
        $am = \OC::$server->getAppManager();
        '@phan-var \OC\App\AppManager $am';
        if ($path) {
            return $am->getAppInfoByPath($appId);
        }
        return $am->getAppInfo($appId);
    }

    /**
     * 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();
        return self::proceedNavigation($entries);
    }

    /**
     * get the id of loaded app
     *
     * @return string
     */
    public static function getCurrentApp() {
        $request = \OC::$server->getRequest();
        $script = \substr($request->getScriptName(), \strlen(OC::$WEBROOT) + 1);
        $topFolder = \substr($script, 0, \strpos($script, '/'));
        if (empty($topFolder)) {
            $path_info = $request->getPathInfo();
            if ($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;
        }
    }

    /**
     * @param string $type
     * @return array
     */
    public static function getForms($type) {
        $forms = [];
        switch ($type) {
            case 'admin':
                $source = self::$adminForms;
                break;
            case 'personal':
                $source = self::$personalForms;
                break;
            default:
                return [];
        }
        foreach ($source as $form) {
            $page = include $form['page'];
            $forms[] = [
                'appId' => $form['appId'],
                'page' => $page,
            ];
        }
        return $forms;
    }

    /**
     * register an admin form to be shown
     *
     * @param string $app
     * @param string $page
     * @deprecated Register settings panels in info.xml
     */
    public static function registerAdmin($app, $page) {
        self::$adminForms[] = [
            'appId' => $app,
            'page' => $app . '/' . $page . '.php',
        ];
    }

    /**
     * register a personal form to be shown
     * @param string $app
     * @param string $page
     * @deprecated Register settings panels in info.xml
     */
    public static function registerPersonal($app, $page) {
        self::$personalForms[] = [
            'appId' => $app,
            'page' => $app . '/' . $page . '.php',
        ];
    }

    /**
     * @param array $entry
     */
    public static function registerLogIn(array $entry) {
        self::$altLogin[] = $entry;
    }

    /**
     * @return array
     */
    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 = [];

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

            if (\is_resource($dh)) {
                while (($file = \readdir($dh)) !== false) {
                    if ($file[0] != '.' and \is_dir($apps_dir['path'] . '/' . $file) and \is_file($apps_dir['path'] . '/' . $file . '/appinfo/info.xml')) {
                        $apps[] = $file;
                    }
                }
            }
        }

        return $apps;
    }

    /**
     * List all apps, this is used in apps.php
     *
     * @param bool $listEveryApp including always-enabled apps
     * @return array
     */
    public static function listAllApps(bool $listEveryApp = false) {
        $installedApps = OC_App::getAllApps();

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

        if ($listEveryApp) {
            $blacklist = [];
        } else {
            //we don't want to show configuration for these
            $blacklist = \OC::$server->getAppManager()->getAlwaysEnabledApps();
        }
        $appList = [];
        $urlGenerator = \OC::$server->getURLGenerator();

        foreach ($installedApps as $app) {
            if (\array_search($app, $blacklist) === false) {
                $info = OC_App::getAppInfo($app);
                if (!\is_array($info)) {
                    \OCP\Util::writeLog('core', 'Could not read app info file for app "' . $app . '"', \OCP\Util::ERROR);
                    continue;
                }

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

                $enabled = \OC::$server->getAppConfig()->getValue($app, 'enabled', 'no');
                $info['groups'] = null;
                if ($enabled === 'yes') {
                    $active = true;
                } elseif ($enabled === 'no') {
                    $active = false;
                } else {
                    $active = true;
                    $info['groups'] = $enabled;
                }

                $info['active'] = $active;

                if (self::isShipped($app)) {
                    $info['internal'] = true;
                    $info['level'] = self::officialApp;
                    $info['removable'] = false;
                } else {
                    $result = \OC::$server->getIntegrityCodeChecker()->getVerifiedAppsFromCache($app, '', true);
                    if (empty($result)) {
                        $info['level'] = self::approvedApp;
                        $info['removable'] = false;
                    }

                    $info['internal'] = false;
                    $info['removable'] = true;
                }

                $appPath = self::getAppPath($app);
                if ($appPath !== false) {
                    $appIcon = $appPath . '/img/' . $app . '.svg';
                    if (\file_exists($appIcon)) {
                        $info['preview'] = \OC::$server->getURLGenerator()->imagePath($app, $app . '.svg');
                        $info['previewAsIcon'] = true;
                    } else {
                        $appIcon = $appPath . '/img/app.svg';
                        if (\file_exists($appIcon)) {
                            $info['preview'] = \OC::$server->getURLGenerator()->imagePath($app, 'app.svg');
                            $info['previewAsIcon'] = true;
                        }
                    }
                }
                // fix documentation
                if (isset($info['documentation']) && \is_array($info['documentation'])) {
                    foreach ($info['documentation'] as $key => $url) {
                        // If it is not an absolute URL we assume it is a key
                        // i.e. admin-ldap will get converted to go.php?to=admin-ldap
                        if (\stripos($url, 'https://') !== 0 && \stripos($url, 'http://') !== 0) {
                            $url = $urlGenerator->linkToDocs($url);
                        }

                        $info['documentation'][$key] = $url;
                    }
                }
                $appList[] = $info;
            }
        }

        return $appList;
    }

    public static function shouldUpgrade($app) {
        $versions = self::getAppVersions();
        $info = \OC::$server->getAppManager()->getAppInfo($app);

        if ($info && isset($versions[$app])) {
            if ($info['version'] === $versions[$app]) {
                return false;
            }

            if (self::atLeastMinorVersionLevelChanged($info['version'], $versions[$app])) {
                return true;
            }
            // update app version in db
            \OC::$server->getConfig()->setAppValue($app, 'installed_version', $info['version']);
        }
        return false;
    }

    /**
     * Adjust 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|array $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['dependencies']['owncloud']['@attributes']['min-version'])) {
            $requireMin = $appInfo['dependencies']['owncloud']['@attributes']['min-version'];
        } elseif (isset($appInfo['requiremin'])) {
            $requireMin = $appInfo['requiremin'];
        } elseif (isset($appInfo['require'])) {
            $requireMin = $appInfo['require'];
        }

        if (isset($appInfo['dependencies']['owncloud']['@attributes']['max-version'])) {
            $requireMax = $appInfo['dependencies']['owncloud']['@attributes']['max-version'];
        } elseif (isset($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 (!$versions) {
            $appConfig = \OC::$server->getAppConfig();
            $versions = $appConfig->getValues(false, 'installed_version');
        }
        return $versions;
    }

    /**
     * update the database for the app and call the update script
     *
     * @param string $appId
     * @return bool
     */
    public static function updateApp($appId) {
        \OC::$server->getAppManager()->clearAppsCache();
        $appPath = self::getAppPath($appId);
        if ($appPath === false) {
            return false;
        }
        $appData = self::getAppInfo($appId);
        self::executeRepairSteps($appId, $appData['repair-steps']['pre-migration']);
        if (isset($appData['use-migrations']) && $appData['use-migrations'] === 'true') {
            $ms = new \OC\DB\MigrationService($appId, \OC::$server->getDatabaseConnection());
            $ms->migrate();
        } else {
            if (\file_exists($appPath . '/appinfo/database.xml')) {
                OC_DB::updateDbFromStructure($appPath . '/appinfo/database.xml');
            }
        }
        self::executeRepairSteps($appId, $appData['repair-steps']['post-migration']);
        self::setupLiveMigrations($appId, $appData['repair-steps']['live-migration']);
        // run upgrade code
        if (\file_exists($appPath . '/appinfo/update.php')) {
            self::loadApp($appId, false);
            include $appPath . '/appinfo/update.php';
        }
        self::setupBackgroundJobs($appData['background-jobs']);

        //set remote/public handlers
        foreach ($appData['remote'] as $name => $path) {
            \OC::$server->getConfig()->setAppValue('core', 'remote_' . $name, $appId . '/' . $path);
        }
        foreach ($appData['public'] as $name => $path) {
            \OC::$server->getConfig()->setAppValue('core', 'public_' . $name, $appId . '/' . $path);
        }

        self::setAppTypes($appId);

        \OC::$server->getConfig()->setAppValue($appId, 'installed_version', $appData['version']);

        return true;
    }

    /**
     * @param string $appId
     * @param string[] $steps
     * @throws NeedsUpdateException
     */
    public static function executeRepairSteps($appId, array $steps) {
        if (empty($steps)) {
            return;
        }
        // load the app
        self::loadApp($appId, false);

        $dispatcher = OC::$server->getEventDispatcher();

        // load the steps
        $r = new Repair([], $dispatcher);
        foreach ($steps as $step) {
            try {
                $r->addStep($step);
            } catch (Exception $ex) {
                $r->emit('\OC\Repair', 'error', [$ex->getMessage()]);
                \OC::$server->getLogger()->logException($ex);
            }
        }
        // run the steps
        $r->run();
    }

    public static function setupBackgroundJobs(array $jobs) {
        $queue = \OC::$server->getJobList();
        foreach ($jobs as $job) {
            $queue->add($job);
        }
        // TODO remove jobs that no longer exist in this app version
    }

    /**
     * @param string $appId
     * @param string[] $steps
     */
    private static function setupLiveMigrations($appId, array $steps) {
        $queue = \OC::$server->getJobList();
        foreach ($steps as $step) {
            $queue->add('OC\Migration\BackgroundRepair', [
                'app' => $appId,
                'step' => $step]);
        }
    }

    /**
     * @param string $appId
     * @return \OC\Files\View|false
     */
    public static function getStorage($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 {
                \OCP\Util::writeLog('core', 'Can\'t get app storage, app ' . $appId . ', user not logged in', \OCP\Util::ERROR);
                return false;
            }
        } else {
            \OCP\Util::writeLog('core', 'Can\'t get app storage, app ' . $appId . ' not enabled', \OCP\Util::ERROR);
            return false;
        }
    }

    /**
     * parses the app data array and enhanced the 'description' value
     *
     * @param array $data the app data
     * @return array improved app data
     */
    public static function parseAppInfo(array $data) {
        // just modify the description if it is available
        // otherwise this will create a $data element with an empty 'description'
        if (isset($data['description'])) {
            if (\is_string($data['description'])) {
                // sometimes the description contains line breaks and they are then also
                // shown in this way in the app management which isn't wanted as HTML
                // manages line breaks itself

                // first of all we split on empty lines
                $paragraphs = \preg_split("!\n[[:space:]]*\n!mu", $data['description']);

                $result = [];
                foreach ($paragraphs as $value) {
                    // replace multiple whitespace (tabs, space, newlines) inside a paragraph
                    // with a single space - also trims whitespace
                    $result[] = \trim(\preg_replace('![[:space:]]+!mu', ' ', $value));
                }

                // join the single paragraphs with a empty line in between
                $data['description'] = \implode("\n\n", $result);
            } else {
                $data['description'] = '';
            }
        }

        return $data;
    }

    /**
     * @param OCP\IConfig $config
     * @param OCP\IL10N $l
     * @param array $info
     * @throws Exception
     */
    protected static function checkAppDependencies($config, $l, $info) {
        $dependencyAnalyzer = new DependencyAnalyzer(new Platform($config), $l);
        $missing = $dependencyAnalyzer->analyze($info);
        if (!empty($missing)) {
            $missingMsg = \join(PHP_EOL, $missing);
            throw new \Exception(
                $l->t(
                    'App "%s" cannot be installed because the following dependencies are not fulfilled: %s',
                    [$info['name'], $missingMsg]
                )
            );
        }
    }

    /**
     * @param $currentVersion
     * @param $installedVersion
     * @return bool
     */
    public static function atLeastMinorVersionLevelChanged($currentVersion, $installedVersion) {
        if ($currentVersion === $installedVersion) {
            return false;
        }

        $p = new \Composer\Semver\VersionParser();
        $currentVersion = $p->normalize($currentVersion);
        $installedVersion = $p->normalize($installedVersion);

        $currentVersion = \explode('.', $currentVersion);
        $installedVersion = \explode('.', $installedVersion);

        if ($currentVersion[0] === $installedVersion[0] &&
            $currentVersion[1] === $installedVersion[1]) {
            return false;
        }

        return true;
    }
}