remove saved credentails if the user no longer has any storage configured using them

Signed-off-by: Robin Appelman <robin@icewind.nl>

apps/files_external/appinfo/info.xml

@@ -31,6 +31,10 @@ External storage can be configured using the GUI or at the command line. This se
 		<nextcloud min-version="20" max-version="20"/>
 	</dependencies>
 
+	<background-jobs>
+		<job>OCA\Files_External\BackgroundJob\CredentialsCleanup</job>
+	</background-jobs>
+
 	<commands>
 		<command>OCA\Files_External\Command\ListCommand</command>
 		<command>OCA\Files_External\Command\Config</command>

apps/files_external/lib/BackgroundJob/CredentialsCleanup.php

@@ -0,0 +1,69 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2020 Robin Appelman <robin@icewind.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * 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
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\Files_External\BackgroundJob;
+
+use OCA\Files_External\Lib\Auth\Password\LoginCredentials;
+use OCA\Files_External\Lib\StorageConfig;
+use OCA\Files_External\Service\UserGlobalStoragesService;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\BackgroundJob\TimedJob;
+use OCP\Security\ICredentialsManager;
+use OCP\IUser;
+use OCP\IUserManager;
+
+class CredentialsCleanup extends TimedJob {
+	private $credentialsManager;
+	private $userGlobalStoragesService;
+	private $userManager;
+
+	public function __construct(
+		ITimeFactory $time,
+		ICredentialsManager $credentialsManager,
+		UserGlobalStoragesService $userGlobalStoragesService,
+		IUserManager $userManager
+	) {
+		parent::__construct($time);
+
+		$this->credentialsManager = $credentialsManager;
+		$this->userGlobalStoragesService = $userGlobalStoragesService;
+		$this->userManager = $userManager;
+
+		// run every day
+		$this->setInterval(24 * 60 * 60);
+	}
+
+	protected function run($argument) {
+		$this->userManager->callForSeenUsers(function (IUser $user) {
+			$storages = $this->userGlobalStoragesService->getAllStoragesForUser($user);
+
+			$usesLoginCredentials = array_reduce($storages, function (bool $uses, StorageConfig $storage) {
+				return $uses || $storage->getAuthMechanism() instanceof LoginCredentials;
+			}, false);
+
+			if (!$usesLoginCredentials) {
+				$this->credentialsManager->delete($user->getUID(), LoginCredentials::CREDENTIALS_IDENTIFIER);
+			}
+		});
+	}
+}

apps/files_external/lib/Service/UserGlobalStoragesService.php

@@ -27,6 +27,7 @@ namespace OCA\Files_External\Service;
 use OCA\Files_External\Lib\StorageConfig;
 use OCP\Files\Config\IUserMountCache;
 use OCP\IGroupManager;
+use OCP\IUser;
 use OCP\IUserSession;
 
 /**
@@ -177,14 +178,18 @@ class UserGlobalStoragesService extends GlobalStoragesService {
 	/**
 	 * Gets all storages for the user, admin, personal, global, etc
 	 *
+	 * @param IUser|null $user user to get the storages for, if not set the currently logged in user will be used
 	 * @return StorageConfig[] array of storage configs
 	 */
-	public function getAllStoragesForUser() {
-		if (is_null($this->getUser())) {
+	public function getAllStoragesForUser(IUser $user = null) {
+		if (is_null($user)) {
+			$user = $this->getUser();
+		}
+		if (is_null($user)) {
 			return [];
 		}
-		$groupIds = $this->groupManager->getUserGroupIds($this->getUser());
-		$mounts = $this->dbConfig->getMountsForUser($this->getUser()->getUID(), $groupIds);
+		$groupIds = $this->groupManager->getUserGroupIds($user);
+		$mounts = $this->dbConfig->getMountsForUser($user->getUID(), $groupIds);
 		$configs = array_map([$this, 'getStorageConfigFromDBMount'], $mounts);
 		$configs = array_filter($configs, function ($config) {
 			return $config instanceof StorageConfig;