Handle node deletion event

lib/Album/AlbumMapper.php

@@ -86,6 +86,22 @@ public function getForUser(string $userId): array {
 		}, $rows);
 	}
 
+	/**
+	 * @param int $fileId
+	 * @return AlbumInfo[]
+	 */
+	public function getForFile(int $fileId): array {
+		$query = $this->connection->getQueryBuilder();
+		$query->select("a.album_id", "name", "user", "location", "created", "last_added_photo")
+			->from("photos_albums", "a")
+			->leftJoin("a", "photos_albums_files", "p", $query->expr()->eq("a.album_id", "p.album_id"))
+			->where($query->expr()->eq('file_id', $query->createNamedParameter($fileId, IQueryBuilder::PARAM_INT)));
+		$rows = $query->executeQuery()->fetchAll();
+		return array_map(function (array $row) {
+			return new AlbumInfo((int)$row['album_id'], $row['user'], $row['name'], $row['location'], (int)$row['created'], (int)$row['last_added_photo']);
+		}, $rows);
+	}
+
 	public function rename(int $id, string $newName): void {
 		$query = $this->connection->getQueryBuilder();
 		$query->update("photos_albums")

lib/AppInfo/Application.php

@@ -30,6 +30,8 @@
 use OCP\AppFramework\Bootstrap\IBootContext;
 use OCP\AppFramework\Bootstrap\IBootstrap;
 use OCP\AppFramework\Bootstrap\IRegistrationContext;
+use OCP\Files\Events\Node\NodeDeletedEvent;
+use OCA\Photos\Event\MoveToTrashListener;
 
 class Application extends App implements IBootstrap {
 	public const APP_ID = 'photos';
@@ -61,6 +63,7 @@ public function __construct() {
 	public function register(IRegistrationContext $context): void {
 		/** Register $principalBackend for the DAV collection */
 		$context->registerServiceAlias('principalBackend', Principal::class);
+		$context->registerEventListener(NodeDeletedEvent::class, MoveToTrashListener::class);
 	}
 
 	public function boot(IBootContext $context): void {

lib/Event/MoveToTrashListener.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace OCA\Photos\Event;
+
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventListener;
+use OCP\Files\Events\Node\NodeDeletedEvent;
+use OCA\Photos\Album\AlbumMapper;
+
+class MoveToTrashListener implements IEventListener {
+	private AlbumMapper $albumMapper;
+
+	public function __construct(AlbumMapper $albumMapper) {
+		$this->albumMapper = $albumMapper;
+	}
+
+	public function handle(Event $event): void {
+		if (!($event instanceof NodeDeletedEvent)) {
+			return;
+		}
+
+		// Remove node from all albums containing it.
+		$albums = $this->albumMapper->getForFile($event->getNode()->getId());
+		foreach ($albums as $album) {
+			$this->albumMapper->removeFile($album->getId(), $event->getNode()->getId());
+		}
+	}
+}

lib/Sabre/Album/PropFindPlugin.php

@@ -34,6 +34,7 @@
 use Sabre\DAV\Server;
 use Sabre\DAV\ServerPlugin;
 use Sabre\DAV\Tree;
+use OCP\Files\NotFoundException;
 
 class PropFindPlugin extends ServerPlugin {
 	public const FILE_NAME_PROPERTYNAME = '{http://nextcloud.org/ns}file-name';
@@ -77,14 +78,22 @@ public function initialize(Server $server) {
 
 	public function propFind(PropFind $propFind, INode $node): void {
 		if ($node instanceof AlbumPhoto) {
+			// Checking if the node is trulely available and ignoring if not
+			// Should be pre-emptively handled by the NodeDeletedEvent
+			try {
+				$fileInfo = $node->getFileInfo();
+			} catch (NotFoundException $e) {
+				return;
+			}
+
 			$propFind->handle(FilesPlugin::INTERNAL_FILEID_PROPERTYNAME, fn () => $node->getFile()->getFileId());
 			$propFind->handle(FilesPlugin::GETETAG_PROPERTYNAME, fn () => $node->getETag());
 			$propFind->handle(self::FILE_NAME_PROPERTYNAME, fn () => $node->getFile()->getName());
-			$propFind->handle(self::REALPATH_PROPERTYNAME, fn () => $node->getFileInfo()->getPath());
+			$propFind->handle(self::REALPATH_PROPERTYNAME, fn () => $fileInfo->getPath());
 			$propFind->handle(self::FAVORITE_PROPERTYNAME, fn () => $node->isFavorite() ? 1 : 0);
 
-			$propFind->handle(FilesPlugin::HAS_PREVIEW_PROPERTYNAME, function () use ($node) {
-				return json_encode($this->previewManager->isAvailable($node->getFileInfo()));
+			$propFind->handle(FilesPlugin::HAS_PREVIEW_PROPERTYNAME, function () use ($fileInfo) {
+				return json_encode($this->previewManager->isAvailable($fileInfo));
 			});
 
 			if ($this->metadataEnabled) {