when a user was delete remove them from applicable list, unless

it is the only user, then remove the mount

Signed-off-by: Arthur Schiwon <blizzz@arthur-schiwon.de>

apps/files_external/appinfo/app.php

@@ -34,6 +34,8 @@ require_once __DIR__ . '/../3rdparty/autoload.php';
 
 // register Application object singleton
 \OC_Mount_Config::$app = \OC::$server->query(\OCA\Files_External\AppInfo\Application::class);
+\OC_Mount_Config::$app->registerListeners();
+
 $appContainer = \OC_Mount_Config::$app->getContainer();
 
 \OCA\Files\App::getNavigationManager()->add(function () {

apps/files_external/lib/AppInfo/Application.php

@@ -30,6 +30,7 @@
 namespace OCA\Files_External\AppInfo;
 
 use OCA\Files_External\Config\UserPlaceholderHandler;
+use OCA\Files_External\Service\DBConfigService;
 use OCA\Files_External\Lib\Auth\AmazonS3\AccessKey;
 use OCA\Files_External\Lib\Auth\Builtin;
 use OCA\Files_External\Lib\Auth\NullMechanism;
@@ -63,6 +64,8 @@ use OCA\Files_External\Service\BackendService;
 use OCP\AppFramework\App;
 use OCP\AppFramework\IAppContainer;
 use OCP\Files\Config\IUserMountCache;
+use OCP\IUser;
+use Symfony\Component\EventDispatcher\GenericEvent;
 
 /**
  * @package OCA\Files_External\AppInfo
@@ -96,6 +99,20 @@ class Application extends App implements IBackendProvider, IAuthMechanismProvide
 		$this->getAuthMechanisms();
 	}
 
+	public function registerListeners() {
+		$dispatcher = $this->getContainer()->getServer()->getEventDispatcher();
+		$dispatcher->addListener(
+			IUser::class . '::postDelete',
+			function (GenericEvent $event) {
+				/** @var IUser $user */
+				$user = $event->getSubject();
+				/** @var DBConfigService $config */
+				$config = $this->getContainer()->query(DBConfigService::class);
+				$config->modifyMountsOnUserDelete($user->getUID());
+			}
+		);
+	}
+
 	/**
 	 * @{inheritdoc}
 	 */

apps/files_external/lib/Service/DBConfigService.php

@@ -114,6 +114,30 @@ class DBConfigService {
 		return $this->getMountsFromQuery($query);
 	}
 
+	public function modifyMountsOnUserDelete(string $uid) {
+		$builder = $this->connection->getQueryBuilder();
+		$query = $builder->select(['a.mount_id', $builder->func()->count('a.mount_id', 'count')])
+			->from('external_applicable', 'a')
+			->rightJoin('a', 'external_applicable', 'b', $builder->expr()->eq('a.mount_id', 'b.mount_id'))
+			->where($builder->expr()->andX( // mounts for user
+					$builder->expr()->eq('a.type', $builder->createNamedParameter(self::APPLICABLE_TYPE_USER, IQueryBuilder::PARAM_INT)),
+					$builder->expr()->eq('a.value', $builder->createNamedParameter($uid))
+				)
+			)
+			->groupBy(['a.mount_id']);
+		$stmt = $query->execute();
+		$result = $stmt->fetchAll();
+		$stmt->closeCursor();
+
+		foreach ($result as $row) {
+			if((int)$row['count'] > 1) {
+				$this->removeApplicable($row['mount_id'], self::APPLICABLE_TYPE_USER, $uid);
+			} else {
+				$this->removeMount($row['mount_id']);
+			}
+		}
+	}
+
 	/**
 	 * Get admin defined mounts
 	 *