Merge branch 'collection-rewrite'

app/lib/api/api_util.dart

@@ -8,7 +8,7 @@ import 'package:nc_photos/account.dart';
 import 'package:nc_photos/entity/file_descriptor.dart';
 import 'package:nc_photos/entity/file_util.dart' as file_util;
 import 'package:nc_photos/exception.dart';
-import 'package:np_api/np_api.dart';
+import 'package:np_api/np_api.dart' hide NcAlbumItem;
 import 'package:to_string/to_string.dart';
 
 part 'api_util.g.dart';
@@ -45,6 +45,11 @@ String getFilePreviewUrlRelative(
   if (file_util.isTrash(account, file)) {
     // trashbin does not support preview.png endpoint
     url = "index.php/apps/files_trashbin/preview?fileId=${file.fdId}";
+  } else if (file_util.isNcAlbumFile(account, file)) {
+    // We can't use the generic file preview url because collaborative albums do
+    // not create a file share for photos not belonging to you, that means you
+    // can only access the file view the Photos API
+    url = "apps/photos/api/v1/preview/${file.fdId}?x=$width&y=$height";
   } else {
     url = "index.php/core/preview?fileId=${file.fdId}";
   }
@@ -76,6 +81,16 @@ String getFilePreviewUrlByFileId(
   return url;
 }
 
+/// Return the preview image URL for [fileId], using the new Photos API in
+/// Nextcloud 25
+String getPhotosApiFilePreviewUrlByFileId(
+  Account account,
+  int fileId, {
+  required int width,
+  required int height,
+}) =>
+    "${account.url}/apps/photos/api/v1/preview/$fileId?x=$width&y=$height";
+
 String getFileUrl(Account account, FileDescriptor file) {
   return "${account.url}/${getFileUrlRelative(file)}";
 }

app/lib/api/entity_converter.dart

@@ -4,7 +4,10 @@ import 'package:logging/logging.dart';
 import 'package:nc_photos/entity/face.dart';
 import 'package:nc_photos/entity/favorite.dart';
 import 'package:nc_photos/entity/file.dart';
+import 'package:nc_photos/entity/nc_album.dart';
+import 'package:nc_photos/entity/nc_album_item.dart';
 import 'package:nc_photos/entity/person.dart';
+import 'package:nc_photos/entity/server_status.dart';
 import 'package:nc_photos/entity/share.dart';
 import 'package:nc_photos/entity/sharee.dart';
 import 'package:nc_photos/entity/tag.dart';
@@ -34,7 +37,6 @@ class ApiFavoriteConverter {
   }
 }
 
-@npLog
 class ApiFileConverter {
   static File fromApi(api.File file) {
     final metadata = file.customProperties?["com.nkming.nc_photos:metadata"]
@@ -78,20 +80,45 @@ class ApiFileConverter {
           ?.run((obj) => ImageLocation.fromJson(jsonDecode(obj))),
     );
   }
+}
 
-  static String _hrefToPath(String href) {
-    final rawPath = href.trimLeftAny("/");
-    final pos = rawPath.indexOf("remote.php");
-    if (pos == -1) {
-      // what?
-      _log.warning("[_hrefToPath] Unknown href value: $rawPath");
-      return rawPath;
-    } else {
-      return rawPath.substring(pos);
-    }
+class ApiNcAlbumConverter {
+  static NcAlbum fromApi(api.NcAlbum album) {
+    return NcAlbum(
+      path: _hrefToPath(album.href),
+      lastPhoto: (album.lastPhoto ?? -1) < 0 ? null : album.lastPhoto,
+      nbItems: album.nbItems ?? 0,
+      location: album.location,
+      dateStart: (album.dateRange?["start"] as int?)
+          ?.run((d) => DateTime.fromMillisecondsSinceEpoch(d * 1000)),
+      dateEnd: (album.dateRange?["end"] as int?)
+          ?.run((d) => DateTime.fromMillisecondsSinceEpoch(d * 1000)),
+      collaborators: album.collaborators
+          .map((c) => NcAlbumCollaborator(
+                id: c.id.toCi(),
+                label: c.label,
+                type: c.type,
+              ))
+          .toList(),
+    );
   }
+}
 
-  static final _log = _$ApiFileConverterNpLog.log;
+class ApiNcAlbumItemConverter {
+  static NcAlbumItem fromApi(api.NcAlbumItem item) {
+    return NcAlbumItem(
+      path: _hrefToPath(item.href),
+      fileId: item.fileId!,
+      contentLength: item.contentLength,
+      contentType: item.contentType,
+      etag: item.etag,
+      lastModified: item.lastModified,
+      hasPreview: item.hasPreview,
+      isFavorite: item.favorite,
+      fileMetadataWidth: item.fileMetadataSize?["width"],
+      fileMetadataHeight: item.fileMetadataSize?["height"],
+    );
+  }
 }
 
 class ApiPersonConverter {
@@ -153,6 +180,16 @@ class ApiShareeConverter {
   };
 }
 
+class ApiStatusConverter {
+  static ServerStatus fromApi(api.Status status) {
+    return ServerStatus(
+      versionRaw: status.version,
+      versionName: status.versionString,
+      productName: status.productName,
+    );
+  }
+}
+
 class ApiTagConverter {
   static Tag fromApi(api.Tag tag) {
     return Tag(
@@ -171,3 +208,19 @@ class ApiTaggedFileConverter {
     );
   }
 }
+
+String _hrefToPath(String href) {
+  final rawPath = href.trimLeftAny("/");
+  final pos = rawPath.indexOf("remote.php");
+  if (pos == -1) {
+    // what?
+    _$_NpLog.log.warning("[_hrefToPath] Unknown href value: $rawPath");
+    return rawPath;
+  } else {
+    return rawPath.substring(pos);
+  }
+}
+
+@npLog
+// ignore: camel_case_types
+class _ {}

app/lib/api/entity_converter.g.dart

@@ -6,9 +6,9 @@ part of 'entity_converter.dart';
 // NpLogGenerator
 // **************************************************************************
 
-extension _$ApiFileConverterNpLog on ApiFileConverter {
+extension _$_NpLog on _ {
   // ignore: unused_element
   Logger get _log => log;
 
-  static final log = Logger("api.entity_converter.ApiFileConverter");
+  static final log = Logger("api.entity_converter._");
 }

app/lib/app_init.dart

@@ -8,6 +8,8 @@ import 'package:nc_photos/debug_util.dart';
 import 'package:nc_photos/di_container.dart';
 import 'package:nc_photos/entity/album.dart';
 import 'package:nc_photos/entity/album/data_source.dart';
+import 'package:nc_photos/entity/album/data_source2.dart';
+import 'package:nc_photos/entity/album/repo2.dart';
 import 'package:nc_photos/entity/face.dart';
 import 'package:nc_photos/entity/face/data_source.dart';
 import 'package:nc_photos/entity/favorite.dart';
@@ -16,6 +18,8 @@ import 'package:nc_photos/entity/file.dart';
 import 'package:nc_photos/entity/file/data_source.dart';
 import 'package:nc_photos/entity/local_file.dart';
 import 'package:nc_photos/entity/local_file/data_source.dart';
+import 'package:nc_photos/entity/nc_album/data_source.dart';
+import 'package:nc_photos/entity/nc_album/repo.dart';
 import 'package:nc_photos/entity/person.dart';
 import 'package:nc_photos/entity/person/data_source.dart';
 import 'package:nc_photos/entity/search.dart';
@@ -198,7 +202,12 @@ Future<void> _initDiContainer(InitIsolateType isolateType) async {
   c.sqliteDb = await _createDb(isolateType);
 
   c.albumRepo = AlbumRepo(AlbumCachedDataSource(c));
+  c.albumRepoRemote = AlbumRepo(AlbumRemoteDataSource());
   c.albumRepoLocal = AlbumRepo(AlbumSqliteDbDataSource(c));
+  c.albumRepo2 = CachedAlbumRepo2(
+      const AlbumRemoteDataSource2(), AlbumSqliteDbDataSource2(c.sqliteDb));
+  c.albumRepo2Remote = const BasicAlbumRepo2(AlbumRemoteDataSource2());
+  c.albumRepo2Local = BasicAlbumRepo2(AlbumSqliteDbDataSource2(c.sqliteDb));
   c.faceRepo = const FaceRepo(FaceRemoteDataSource());
   c.fileRepo = FileRepo(FileCachedDataSource(c));
   c.fileRepoRemote = const FileRepo(FileWebdavDataSource());
@@ -214,6 +223,11 @@ Future<void> _initDiContainer(InitIsolateType isolateType) async {
   c.tagRepoLocal = TagRepo(TagSqliteDbDataSource(c.sqliteDb));
   c.taggedFileRepo = const TaggedFileRepo(TaggedFileRemoteDataSource());
   c.searchRepo = SearchRepo(SearchSqliteDbDataSource(c));
+  c.ncAlbumRepo = CachedNcAlbumRepo(
+      const NcAlbumRemoteDataSource(), NcAlbumSqliteDbDataSource(c.sqliteDb));
+  c.ncAlbumRepoRemote = const BasicNcAlbumRepo(NcAlbumRemoteDataSource());
+  c.ncAlbumRepoLocal = BasicNcAlbumRepo(NcAlbumSqliteDbDataSource(c.sqliteDb));
+
   c.touchManager = TouchManager(c);
 
   if (platform_k.isAndroid) {

app/lib/asset.dart

@@ -0,0 +1,2 @@
+const icAddCollectionsOutlined24 =
+    "assets/ic_add_collections_outlined_24dp.png";

app/lib/bloc/home_search_suggestion.dart

@@ -4,12 +4,14 @@ import 'package:flutter/foundation.dart';
 import 'package:kiwi/kiwi.dart';
 import 'package:logging/logging.dart';
 import 'package:nc_photos/account.dart';
+import 'package:nc_photos/controller/collections_controller.dart';
+import 'package:nc_photos/controller/server_controller.dart';
 import 'package:nc_photos/di_container.dart';
-import 'package:nc_photos/entity/album.dart';
+import 'package:nc_photos/entity/collection.dart';
 import 'package:nc_photos/entity/person.dart';
 import 'package:nc_photos/entity/tag.dart';
 import 'package:nc_photos/iterable_extension.dart';
-import 'package:nc_photos/use_case/list_album.dart';
+import 'package:nc_photos/use_case/collection/list_collection.dart';
 import 'package:nc_photos/use_case/list_location_group.dart';
 import 'package:nc_photos/use_case/list_person.dart';
 import 'package:nc_photos/use_case/list_tag.dart';
@@ -24,13 +26,13 @@ part 'home_search_suggestion.g.dart';
 abstract class HomeSearchResult {}
 
 @toString
-class HomeSearchAlbumResult implements HomeSearchResult {
-  const HomeSearchAlbumResult(this.album);
+class HomeSearchCollectionResult implements HomeSearchResult {
+  const HomeSearchCollectionResult(this.collection);
 
   @override
   String toString() => _$toString();
 
-  final Album album;
+  final Collection collection;
 }
 
 @toString
@@ -125,7 +127,8 @@ class HomeSearchSuggestionBlocFailure extends HomeSearchSuggestionBlocState {
 @npLog
 class HomeSearchSuggestionBloc
     extends Bloc<HomeSearchSuggestionBlocEvent, HomeSearchSuggestionBlocState> {
-  HomeSearchSuggestionBloc(this.account)
+  HomeSearchSuggestionBloc(
+      this.account, this.collectionsController, this.serverController)
       : super(const HomeSearchSuggestionBlocInit()) {
     final c = KiwiContainer().resolve<DiContainer>();
     assert(require(c));
@@ -187,13 +190,21 @@ class HomeSearchSuggestionBloc
       Emitter<HomeSearchSuggestionBlocState> emit) async {
     final product = <_Searcheable>[];
     try {
-      final albums = await ListAlbum(_c)(account)
-          .where((event) => event is Album)
+      var collections = collectionsController
+          .peekStream()
+          .data
+          .map((e) => e.collection)
           .toList();
-      product.addAll(albums.map((a) => _AlbumSearcheable(a)));
-      _log.info("[_onEventPreloadData] Loaded ${albums.length} albums");
+      if (collections.isEmpty) {
+        collections = await ListCollection(_c,
+                serverController: serverController)(account)
+            .last;
+      }
+      product.addAll(collections.map(_CollectionSearcheable.new));
+      _log.info(
+          "[_onEventPreloadData] Loaded ${collections.length} collections");
     } catch (e) {
-      _log.warning("[_onEventPreloadData] Failed while ListAlbum", e);
+      _log.warning("[_onEventPreloadData] Failed while ListCollection", e);
     }
     try {
       final tags = await ListTag(_c)(account);
@@ -239,6 +250,8 @@ class HomeSearchSuggestionBloc
   }
 
   final Account account;
+  final CollectionsController collectionsController;
+  final ServerController serverController;
   late final DiContainer _c;
 
   final _search = Woozy<_Searcheable>(limit: 10);
@@ -249,16 +262,16 @@ abstract class _Searcheable {
   HomeSearchResult toResult();
 }
 
-class _AlbumSearcheable implements _Searcheable {
-  const _AlbumSearcheable(this.album);
+class _CollectionSearcheable implements _Searcheable {
+  const _CollectionSearcheable(this.collection);
 
   @override
-  toKeywords() => [album.name.toCi()];
+  toKeywords() => [collection.name.toCi()];
 
   @override
-  toResult() => HomeSearchAlbumResult(album);
+  toResult() => HomeSearchCollectionResult(collection);
 
-  final Album album;
+  final Collection collection;
 }
 
 class _TagSearcheable implements _Searcheable {

app/lib/bloc/home_search_suggestion.g.dart

@@ -18,10 +18,10 @@ extension _$HomeSearchSuggestionBlocNpLog on HomeSearchSuggestionBloc {
 // ToStringGenerator
 // **************************************************************************
 
-extension _$HomeSearchAlbumResultToString on HomeSearchAlbumResult {
+extension _$HomeSearchCollectionResultToString on HomeSearchCollectionResult {
   String _$toString() {
     // ignore: unnecessary_string_interpolations
-    return "HomeSearchAlbumResult {album: $album}";
+    return "HomeSearchCollectionResult {collection: $collection}";
   }
 }
 

app/lib/bloc/list_album.dart

@@ -1,338 +0,0 @@
-import 'package:bloc/bloc.dart';
-import 'package:flutter/foundation.dart';
-import 'package:kiwi/kiwi.dart';
-import 'package:logging/logging.dart';
-import 'package:nc_photos/account.dart';
-import 'package:nc_photos/bloc/bloc_util.dart' as bloc_util;
-import 'package:nc_photos/di_container.dart';
-import 'package:nc_photos/entity/album.dart';
-import 'package:nc_photos/entity/file_util.dart' as file_util;
-import 'package:nc_photos/entity/share.dart';
-import 'package:nc_photos/event/event.dart';
-import 'package:nc_photos/exception.dart';
-import 'package:nc_photos/exception_event.dart';
-import 'package:nc_photos/or_null.dart';
-import 'package:nc_photos/remote_storage_util.dart' as remote_storage_util;
-import 'package:nc_photos/throttler.dart';
-import 'package:nc_photos/use_case/list_album.dart';
-import 'package:np_codegen/np_codegen.dart';
-import 'package:to_string/to_string.dart';
-
-part 'list_album.g.dart';
-
-class ListAlbumBlocItem {
-  ListAlbumBlocItem(this.album);
-
-  final Album album;
-}
-
-abstract class ListAlbumBlocEvent {
-  const ListAlbumBlocEvent();
-}
-
-@toString
-class ListAlbumBlocQuery extends ListAlbumBlocEvent {
-  const ListAlbumBlocQuery(this.account);
-
-  @override
-  String toString() => _$toString();
-
-  final Account account;
-}
-
-/// An external event has happened and may affect the state of this bloc
-@toString
-class _ListAlbumBlocExternalEvent extends ListAlbumBlocEvent {
-  const _ListAlbumBlocExternalEvent();
-
-  @override
-  String toString() => _$toString();
-}
-
-@toString
-abstract class ListAlbumBlocState {
-  const ListAlbumBlocState(this.account, this.items);
-
-  @override
-  String toString() => _$toString();
-
-  final Account? account;
-  final List<ListAlbumBlocItem> items;
-}
-
-class ListAlbumBlocInit extends ListAlbumBlocState {
-  const ListAlbumBlocInit() : super(null, const []);
-}
-
-class ListAlbumBlocLoading extends ListAlbumBlocState {
-  const ListAlbumBlocLoading(Account? account, List<ListAlbumBlocItem> items)
-      : super(account, items);
-}
-
-class ListAlbumBlocSuccess extends ListAlbumBlocState {
-  const ListAlbumBlocSuccess(Account? account, List<ListAlbumBlocItem> items)
-      : super(account, items);
-}
-
-@toString
-class ListAlbumBlocFailure extends ListAlbumBlocState {
-  const ListAlbumBlocFailure(
-      Account? account, List<ListAlbumBlocItem> items, this.exception)
-      : super(account, items);
-
-  @override
-  String toString() => _$toString();
-
-  final dynamic exception;
-}
-
-/// The state of this bloc is inconsistent. This typically means that the data
-/// may have been changed externally
-class ListAlbumBlocInconsistent extends ListAlbumBlocState {
-  const ListAlbumBlocInconsistent(
-      Account? account, List<ListAlbumBlocItem> items)
-      : super(account, items);
-}
-
-@npLog
-class ListAlbumBloc extends Bloc<ListAlbumBlocEvent, ListAlbumBlocState> {
-  /// Constructor
-  ///
-  /// If [offlineC] is not null, this [DiContainer] will be used when requesting
-  /// offline contents, otherwise [_c] will be used
-  ListAlbumBloc(
-    this._c, [
-    DiContainer? offlineC,
-  ])  : _offlineC = offlineC ?? _c,
-        assert(require(_c)),
-        assert(offlineC == null || require(offlineC)),
-        assert(ListAlbum.require(_c)),
-        assert(offlineC == null || ListAlbum.require(offlineC)),
-        super(const ListAlbumBlocInit()) {
-    _albumUpdatedListener =
-        AppEventListener<AlbumUpdatedEvent>(_onAlbumUpdatedEvent);
-    _fileRemovedListener =
-        AppEventListener<FileRemovedEvent>(_onFileRemovedEvent);
-    _albumCreatedListener =
-        AppEventListener<AlbumCreatedEvent>(_onAlbumCreatedEvent);
-    _albumUpdatedListener.begin();
-    _fileRemovedListener.begin();
-    _albumCreatedListener.begin();
-    _fileMovedListener.begin();
-    _shareCreatedListener.begin();
-    _shareRemovedListener.begin();
-
-    _refreshThrottler = Throttler(
-      onTriggered: (_) {
-        add(const _ListAlbumBlocExternalEvent());
-      },
-      logTag: "ListAlbumBloc.refresh",
-    );
-
-    on<ListAlbumBlocEvent>(_onEvent);
-  }
-
-  static bool require(DiContainer c) => true;
-
-  static ListAlbumBloc of(Account account) {
-    final name = bloc_util.getInstNameForAccount("ListAlbumBloc", account);
-    try {
-      _log.fine("[of] Resolving bloc for '$name'");
-      return KiwiContainer().resolve<ListAlbumBloc>(name);
-    } catch (_) {
-      // no created instance for this account, make a new one
-      _log.info("[of] New bloc instance for account: $account");
-      final c = KiwiContainer().resolve<DiContainer>();
-      final offlineC = c.copyWith(
-        fileRepo: OrNull(c.fileRepoLocal),
-        albumRepo: OrNull(c.albumRepoLocal),
-      );
-      final bloc = ListAlbumBloc(c, offlineC);
-      KiwiContainer().registerInstance<ListAlbumBloc>(bloc, name: name);
-      return bloc;
-    }
-  }
-
-  @override
-  close() {
-    _albumUpdatedListener.end();
-    _fileRemovedListener.end();
-    _albumCreatedListener.end();
-    _fileMovedListener.end();
-    _shareCreatedListener.end();
-    _shareRemovedListener.end();
-    _refreshThrottler.clear();
-    return super.close();
-  }
-
-  Future<void> _onEvent(
-      ListAlbumBlocEvent event, Emitter<ListAlbumBlocState> emit) async {
-    _log.info("[_onEvent] $event");
-    if (event is ListAlbumBlocQuery) {
-      await _onEventQuery(event, emit);
-    } else if (event is _ListAlbumBlocExternalEvent) {
-      await _onExternalEvent(event, emit);
-    }
-  }
-
-  Future<void> _onEventQuery(
-      ListAlbumBlocQuery ev, Emitter<ListAlbumBlocState> emit) async {
-    emit(ListAlbumBlocLoading(ev.account, state.items));
-    bool hasContent = state.items.isNotEmpty;
-
-    if (!hasContent) {
-      // show something instantly on first load
-      final cacheState = await _queryOffline(ev);
-      emit(ListAlbumBlocLoading(ev.account, cacheState.items));
-      hasContent = cacheState.items.isNotEmpty;
-    }
-
-    final newState = await _queryOnline(ev);
-    if (newState is ListAlbumBlocFailure) {
-      emit(ListAlbumBlocFailure(
-          ev.account,
-          newState.items.isNotEmpty ? newState.items : state.items,
-          newState.exception));
-    } else {
-      emit(newState);
-    }
-  }
-
-  Future<void> _onExternalEvent(
-      _ListAlbumBlocExternalEvent ev, Emitter<ListAlbumBlocState> emit) async {
-    emit(ListAlbumBlocInconsistent(state.account, state.items));
-  }
-
-  void _onAlbumUpdatedEvent(AlbumUpdatedEvent ev) {
-    if (state is ListAlbumBlocInit) {
-      // no data in this bloc, ignore
-      return;
-    }
-    if (_isAccountOfInterest(ev.account)) {
-      _refreshThrottler.trigger(
-        maxResponceTime: const Duration(seconds: 3),
-        maxPendingCount: 10,
-      );
-    }
-  }
-
-  void _onFileRemovedEvent(FileRemovedEvent ev) {
-    if (state is ListAlbumBlocInit) {
-      // no data in this bloc, ignore
-      return;
-    }
-    if (_isAccountOfInterest(ev.account) &&
-        file_util.isAlbumFile(ev.account, ev.file)) {
-      _refreshThrottler.trigger(
-        maxResponceTime: const Duration(seconds: 3),
-        maxPendingCount: 10,
-      );
-    }
-  }
-
-  void _onFileMovedEvent(FileMovedEvent ev) {
-    if (state is ListAlbumBlocInit) {
-      // no data in this bloc, ignore
-      return;
-    }
-    if (_isAccountOfInterest(ev.account)) {
-      if (ev.destination
-              .startsWith(remote_storage_util.getRemoteAlbumsDir(ev.account)) ||
-          ev.file.path
-              .startsWith(remote_storage_util.getRemoteAlbumsDir(ev.account))) {
-        // moving from/to album dir
-        _refreshThrottler.trigger(
-          maxResponceTime: const Duration(seconds: 3),
-          maxPendingCount: 10,
-        );
-      }
-    }
-  }
-
-  void _onAlbumCreatedEvent(AlbumCreatedEvent ev) {
-    if (state is ListAlbumBlocInit) {
-      // no data in this bloc, ignore
-      return;
-    }
-    if (_isAccountOfInterest(ev.account)) {
-      add(const _ListAlbumBlocExternalEvent());
-    }
-  }
-
-  void _onShareCreatedEvent(ShareCreatedEvent ev) =>
-      _onShareChanged(ev.account, ev.share);
-
-  void _onShareRemovedEvent(ShareRemovedEvent ev) =>
-      _onShareChanged(ev.account, ev.share);
-
-  void _onShareChanged(Account account, Share share) {
-    if (_isAccountOfInterest(account)) {
-      final webdavPath = file_util.unstripPath(account, share.path);
-      if (webdavPath
-          .startsWith(remote_storage_util.getRemoteAlbumsDir(account))) {
-        _refreshThrottler.trigger(
-          maxResponceTime: const Duration(seconds: 3),
-          maxPendingCount: 10,
-        );
-      }
-    }
-  }
-
-  Future<ListAlbumBlocState> _queryOffline(ListAlbumBlocQuery ev) =>
-      _queryWithAlbumDataSource(_offlineC, ev);
-
-  Future<ListAlbumBlocState> _queryOnline(ListAlbumBlocQuery ev) =>
-      _queryWithAlbumDataSource(_c, ev);
-
-  Future<ListAlbumBlocState> _queryWithAlbumDataSource(
-      DiContainer c, ListAlbumBlocQuery ev) async {
-    try {
-      final albums = <Album>[];
-      final errors = <dynamic>[];
-      await for (final result in ListAlbum(c)(ev.account)) {
-        if (result is ExceptionEvent) {
-          if (result.error is CacheNotFoundException) {
-            _log.info(
-                "[_queryWithAlbumDataSource] Cache not found", result.error);
-          } else {
-            _log.shout("[_queryWithAlbumDataSource] Exception while ListAlbum",
-                result.error, result.stackTrace);
-          }
-          errors.add(result.error);
-        } else if (result is Album) {
-          albums.add(result);
-        }
-      }
-
-      final items = albums.map((e) => ListAlbumBlocItem(e)).toList();
-      if (errors.isEmpty) {
-        return ListAlbumBlocSuccess(ev.account, items);
-      } else {
-        return ListAlbumBlocFailure(ev.account, items, errors.first);
-      }
-    } catch (e, stacktrace) {
-      _log.severe("[_queryWithAlbumDataSource] Exception", e, stacktrace);
-      return ListAlbumBlocFailure(ev.account, [], e);
-    }
-  }
-
-  bool _isAccountOfInterest(Account account) =>
-      state.account == null || state.account!.compareServerIdentity(account);
-
-  final DiContainer _c;
-  final DiContainer _offlineC;
-
-  late AppEventListener<AlbumUpdatedEvent> _albumUpdatedListener;
-  late AppEventListener<FileRemovedEvent> _fileRemovedListener;
-  late AppEventListener<AlbumCreatedEvent> _albumCreatedListener;
-  late final _fileMovedListener =
-      AppEventListener<FileMovedEvent>(_onFileMovedEvent);
-  late final _shareCreatedListener =
-      AppEventListener<ShareCreatedEvent>(_onShareCreatedEvent);
-  late final _shareRemovedListener =
-      AppEventListener<ShareRemovedEvent>(_onShareRemovedEvent);
-
-  late Throttler _refreshThrottler;
-
-  static final _log = _$ListAlbumBlocNpLog.log;
-}

app/lib/bloc/list_album.g.dart

@@ -1,46 +0,0 @@
-// GENERATED CODE - DO NOT MODIFY BY HAND
-
-part of 'list_album.dart';
-
-// **************************************************************************
-// NpLogGenerator
-// **************************************************************************
-
-extension _$ListAlbumBlocNpLog on ListAlbumBloc {
-  // ignore: unused_element
-  Logger get _log => log;
-
-  static final log = Logger("bloc.list_album.ListAlbumBloc");
-}
-
-// **************************************************************************
-// ToStringGenerator
-// **************************************************************************
-
-extension _$ListAlbumBlocQueryToString on ListAlbumBlocQuery {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "ListAlbumBlocQuery {account: $account}";
-  }
-}
-
-extension _$_ListAlbumBlocExternalEventToString on _ListAlbumBlocExternalEvent {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "_ListAlbumBlocExternalEvent {}";
-  }
-}
-
-extension _$ListAlbumBlocStateToString on ListAlbumBlocState {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "${objectRuntimeType(this, "ListAlbumBlocState")} {account: $account, items: [length: ${items.length}]}";
-  }
-}
-
-extension _$ListAlbumBlocFailureToString on ListAlbumBlocFailure {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "ListAlbumBlocFailure {account: $account, items: [length: ${items.length}], exception: $exception}";
-  }
-}

app/lib/bloc/list_face_file.dart

@@ -1,222 +0,0 @@
-import 'package:bloc/bloc.dart';
-import 'package:flutter/foundation.dart';
-import 'package:logging/logging.dart';
-import 'package:nc_photos/account.dart';
-import 'package:nc_photos/di_container.dart';
-import 'package:nc_photos/entity/file.dart';
-import 'package:nc_photos/entity/file_util.dart' as file_util;
-import 'package:nc_photos/entity/person.dart';
-import 'package:nc_photos/event/event.dart';
-import 'package:nc_photos/throttler.dart';
-import 'package:nc_photos/use_case/populate_person.dart';
-import 'package:np_codegen/np_codegen.dart';
-import 'package:to_string/to_string.dart';
-
-part 'list_face_file.g.dart';
-
-abstract class ListFaceFileBlocEvent {
-  const ListFaceFileBlocEvent();
-}
-
-@toString
-class ListFaceFileBlocQuery extends ListFaceFileBlocEvent {
-  const ListFaceFileBlocQuery(this.account, this.person);
-
-  @override
-  String toString() => _$toString();
-
-  final Account account;
-  final Person person;
-}
-
-/// An external event has happened and may affect the state of this bloc
-@toString
-class _ListFaceFileBlocExternalEvent extends ListFaceFileBlocEvent {
-  const _ListFaceFileBlocExternalEvent();
-
-  @override
-  String toString() => _$toString();
-}
-
-@toString
-abstract class ListFaceFileBlocState {
-  const ListFaceFileBlocState(this.account, this.items);
-
-  @override
-  String toString() => _$toString();
-
-  final Account? account;
-  final List<File> items;
-}
-
-class ListFaceFileBlocInit extends ListFaceFileBlocState {
-  ListFaceFileBlocInit() : super(null, const []);
-}
-
-class ListFaceFileBlocLoading extends ListFaceFileBlocState {
-  const ListFaceFileBlocLoading(Account? account, List<File> items)
-      : super(account, items);
-}
-
-class ListFaceFileBlocSuccess extends ListFaceFileBlocState {
-  const ListFaceFileBlocSuccess(Account? account, List<File> items)
-      : super(account, items);
-}
-
-@toString
-class ListFaceFileBlocFailure extends ListFaceFileBlocState {
-  const ListFaceFileBlocFailure(
-      Account? account, List<File> items, this.exception)
-      : super(account, items);
-
-  @override
-  String toString() => _$toString();
-
-  final Object exception;
-}
-
-/// The state of this bloc is inconsistent. This typically means that the data
-/// may have been changed externally
-class ListFaceFileBlocInconsistent extends ListFaceFileBlocState {
-  const ListFaceFileBlocInconsistent(Account? account, List<File> items)
-      : super(account, items);
-}
-
-/// List all people recognized in an account
-@npLog
-class ListFaceFileBloc
-    extends Bloc<ListFaceFileBlocEvent, ListFaceFileBlocState> {
-  ListFaceFileBloc(this._c)
-      : assert(require(_c)),
-        assert(PopulatePerson.require(_c)),
-        super(ListFaceFileBlocInit()) {
-    _fileRemovedEventListener.begin();
-    _filePropertyUpdatedEventListener.begin();
-
-    on<ListFaceFileBlocEvent>(_onEvent);
-  }
-
-  static bool require(DiContainer c) => DiContainer.has(c, DiType.faceRepo);
-
-  @override
-  close() {
-    _fileRemovedEventListener.end();
-    _filePropertyUpdatedEventListener.end();
-    return super.close();
-  }
-
-  Future<void> _onEvent(
-      ListFaceFileBlocEvent event, Emitter<ListFaceFileBlocState> emit) async {
-    _log.info("[_onEvent] $event");
-    if (event is ListFaceFileBlocQuery) {
-      await _onEventQuery(event, emit);
-    } else if (event is _ListFaceFileBlocExternalEvent) {
-      await _onExternalEvent(event, emit);
-    }
-  }
-
-  Future<void> _onEventQuery(
-      ListFaceFileBlocQuery ev, Emitter<ListFaceFileBlocState> emit) async {
-    try {
-      emit(ListFaceFileBlocLoading(ev.account, state.items));
-      emit(ListFaceFileBlocSuccess(ev.account, await _query(ev)));
-    } catch (e, stackTrace) {
-      _log.severe("[_onEventQuery] Exception while request", e, stackTrace);
-      emit(ListFaceFileBlocFailure(ev.account, state.items, e));
-    }
-  }
-
-  Future<void> _onExternalEvent(_ListFaceFileBlocExternalEvent ev,
-      Emitter<ListFaceFileBlocState> emit) async {
-    emit(ListFaceFileBlocInconsistent(state.account, state.items));
-  }
-
-  void _onFileRemovedEvent(FileRemovedEvent ev) {
-    if (state is ListFaceFileBlocInit) {
-      // no data in this bloc, ignore
-      return;
-    }
-    if (_isFileOfInterest(ev.file)) {
-      _refreshThrottler.trigger(
-        maxResponceTime: const Duration(seconds: 3),
-        maxPendingCount: 10,
-      );
-    }
-  }
-
-  void _onFilePropertyUpdatedEvent(FilePropertyUpdatedEvent ev) {
-    if (!ev.hasAnyProperties([
-      FilePropertyUpdatedEvent.propMetadata,
-      FilePropertyUpdatedEvent.propIsArchived,
-      FilePropertyUpdatedEvent.propOverrideDateTime,
-      FilePropertyUpdatedEvent.propFavorite,
-    ])) {
-      // not interested
-      return;
-    }
-    if (state is ListFaceFileBlocInit) {
-      // no data in this bloc, ignore
-      return;
-    }
-    if (!_isFileOfInterest(ev.file)) {
-      return;
-    }
-
-    if (ev.hasAnyProperties([
-      FilePropertyUpdatedEvent.propIsArchived,
-      FilePropertyUpdatedEvent.propOverrideDateTime,
-      FilePropertyUpdatedEvent.propFavorite,
-    ])) {
-      _refreshThrottler.trigger(
-        maxResponceTime: const Duration(seconds: 3),
-        maxPendingCount: 10,
-      );
-    } else {
-      _refreshThrottler.trigger(
-        maxResponceTime: const Duration(seconds: 10),
-        maxPendingCount: 10,
-      );
-    }
-  }
-
-  Future<List<File>> _query(ListFaceFileBlocQuery ev) async {
-    final faces = await _c.faceRepo.list(ev.account, ev.person);
-    final files = await PopulatePerson(_c)(ev.account, faces);
-    final rootDirs = ev.account.roots
-        .map((e) => File(path: file_util.unstripPath(ev.account, e)))
-        .toList();
-    return files
-        .where((f) =>
-            file_util.isSupportedFormat(f) &&
-            rootDirs.any((dir) => file_util.isUnderDir(f, dir)))
-        .toList();
-  }
-
-  bool _isFileOfInterest(File file) {
-    if (!file_util.isSupportedFormat(file)) {
-      return false;
-    }
-
-    for (final r in state.account?.roots ?? []) {
-      final dir = File(path: file_util.unstripPath(state.account!, r));
-      if (file_util.isUnderDir(file, dir)) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  final DiContainer _c;
-
-  late final _fileRemovedEventListener =
-      AppEventListener<FileRemovedEvent>(_onFileRemovedEvent);
-  late final _filePropertyUpdatedEventListener =
-      AppEventListener<FilePropertyUpdatedEvent>(_onFilePropertyUpdatedEvent);
-
-  late final _refreshThrottler = Throttler(
-    onTriggered: (_) {
-      add(const _ListFaceFileBlocExternalEvent());
-    },
-    logTag: "ListFaceFileBloc.refresh",
-  );
-}

app/lib/bloc/list_face_file.g.dart

@@ -1,47 +0,0 @@
-// GENERATED CODE - DO NOT MODIFY BY HAND
-
-part of 'list_face_file.dart';
-
-// **************************************************************************
-// NpLogGenerator
-// **************************************************************************
-
-extension _$ListFaceFileBlocNpLog on ListFaceFileBloc {
-  // ignore: unused_element
-  Logger get _log => log;
-
-  static final log = Logger("bloc.list_face_file.ListFaceFileBloc");
-}
-
-// **************************************************************************
-// ToStringGenerator
-// **************************************************************************
-
-extension _$ListFaceFileBlocQueryToString on ListFaceFileBlocQuery {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "ListFaceFileBlocQuery {account: $account, person: $person}";
-  }
-}
-
-extension _$_ListFaceFileBlocExternalEventToString
-    on _ListFaceFileBlocExternalEvent {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "_ListFaceFileBlocExternalEvent {}";
-  }
-}
-
-extension _$ListFaceFileBlocStateToString on ListFaceFileBlocState {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "${objectRuntimeType(this, "ListFaceFileBlocState")} {account: $account, items: [length: ${items.length}]}";
-  }
-}
-
-extension _$ListFaceFileBlocFailureToString on ListFaceFileBlocFailure {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "ListFaceFileBlocFailure {account: $account, items: [length: ${items.length}], exception: $exception}";
-  }
-}

app/lib/bloc/list_importable_album.dart

@@ -10,7 +10,7 @@ import 'package:nc_photos/entity/file.dart';
 import 'package:nc_photos/entity/file_util.dart' as file_util;
 import 'package:nc_photos/iterable_extension.dart';
 import 'package:nc_photos/remote_storage_util.dart' as remote_storage_util;
-import 'package:nc_photos/use_case/list_album.dart';
+import 'package:nc_photos/use_case/album/list_album.dart';
 import 'package:nc_photos/use_case/ls.dart';
 import 'package:np_codegen/np_codegen.dart';
 import 'package:to_string/to_string.dart';

app/lib/bloc/list_location.dart

@@ -4,6 +4,7 @@ import 'package:logging/logging.dart';
 import 'package:nc_photos/account.dart';
 import 'package:nc_photos/di_container.dart';
 import 'package:nc_photos/entity/file.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
 import 'package:nc_photos/entity/file_util.dart' as file_util;
 import 'package:nc_photos/event/event.dart';
 import 'package:nc_photos/throttler.dart';
@@ -147,7 +148,7 @@ class ListLocationBloc
   Future<LocationGroupResult> _query(ListLocationBlocQuery ev) =>
       ListLocationGroup(_c.withLocalRepo())(ev.account);
 
-  bool _isFileOfInterest(File file) {
+  bool _isFileOfInterest(FileDescriptor file) {
     if (!file_util.isSupportedFormat(file)) {
       return false;
     }

app/lib/bloc/list_location_file.dart

@@ -1,181 +0,0 @@
-import 'package:bloc/bloc.dart';
-import 'package:flutter/foundation.dart';
-import 'package:logging/logging.dart';
-import 'package:nc_photos/account.dart';
-import 'package:nc_photos/di_container.dart';
-import 'package:nc_photos/entity/file.dart';
-import 'package:nc_photos/entity/file_util.dart' as file_util;
-import 'package:nc_photos/event/event.dart';
-import 'package:nc_photos/throttler.dart';
-import 'package:nc_photos/use_case/list_location_file.dart';
-import 'package:np_codegen/np_codegen.dart';
-import 'package:to_string/to_string.dart';
-
-part 'list_location_file.g.dart';
-
-abstract class ListLocationFileBlocEvent {
-  const ListLocationFileBlocEvent();
-}
-
-@toString
-class ListLocationFileBlocQuery extends ListLocationFileBlocEvent {
-  const ListLocationFileBlocQuery(this.account, this.place, this.countryCode);
-
-  @override
-  String toString() => _$toString();
-
-  final Account account;
-  final String? place;
-  final String countryCode;
-}
-
-/// An external event has happened and may affect the state of this bloc
-@toString
-class _ListLocationFileBlocExternalEvent extends ListLocationFileBlocEvent {
-  const _ListLocationFileBlocExternalEvent();
-
-  @override
-  String toString() => _$toString();
-}
-
-@toString
-abstract class ListLocationFileBlocState {
-  const ListLocationFileBlocState(this.account, this.items);
-
-  @override
-  String toString() => _$toString();
-
-  final Account? account;
-  final List<File> items;
-}
-
-class ListLocationFileBlocInit extends ListLocationFileBlocState {
-  ListLocationFileBlocInit() : super(null, const []);
-}
-
-class ListLocationFileBlocLoading extends ListLocationFileBlocState {
-  const ListLocationFileBlocLoading(Account? account, List<File> items)
-      : super(account, items);
-}
-
-class ListLocationFileBlocSuccess extends ListLocationFileBlocState {
-  const ListLocationFileBlocSuccess(Account? account, List<File> items)
-      : super(account, items);
-}
-
-@toString
-class ListLocationFileBlocFailure extends ListLocationFileBlocState {
-  const ListLocationFileBlocFailure(
-      Account? account, List<File> items, this.exception)
-      : super(account, items);
-
-  @override
-  String toString() => _$toString();
-
-  final Object exception;
-}
-
-/// The state of this bloc is inconsistent. This typically means that the data
-/// may have been changed externally
-class ListLocationFileBlocInconsistent extends ListLocationFileBlocState {
-  const ListLocationFileBlocInconsistent(Account? account, List<File> items)
-      : super(account, items);
-}
-
-/// List all files associated with a specific tag
-@npLog
-class ListLocationFileBloc
-    extends Bloc<ListLocationFileBlocEvent, ListLocationFileBlocState> {
-  ListLocationFileBloc(this._c)
-      : assert(require(_c)),
-        assert(ListLocationFile.require(_c)),
-        super(ListLocationFileBlocInit()) {
-    _fileRemovedEventListener.begin();
-
-    on<ListLocationFileBlocEvent>(_onEvent);
-  }
-
-  static bool require(DiContainer c) =>
-      DiContainer.has(c, DiType.taggedFileRepo);
-
-  @override
-  close() {
-    _fileRemovedEventListener.end();
-    return super.close();
-  }
-
-  Future<void> _onEvent(ListLocationFileBlocEvent event,
-      Emitter<ListLocationFileBlocState> emit) async {
-    _log.info("[_onEvent] $event");
-    if (event is ListLocationFileBlocQuery) {
-      await _onEventQuery(event, emit);
-    } else if (event is _ListLocationFileBlocExternalEvent) {
-      await _onExternalEvent(event, emit);
-    }
-  }
-
-  Future<void> _onEventQuery(ListLocationFileBlocQuery ev,
-      Emitter<ListLocationFileBlocState> emit) async {
-    try {
-      emit(ListLocationFileBlocLoading(ev.account, state.items));
-      emit(ListLocationFileBlocSuccess(ev.account, await _query(ev)));
-    } catch (e, stackTrace) {
-      _log.severe("[_onEventQuery] Exception while request", e, stackTrace);
-      emit(ListLocationFileBlocFailure(ev.account, state.items, e));
-    }
-  }
-
-  Future<void> _onExternalEvent(_ListLocationFileBlocExternalEvent ev,
-      Emitter<ListLocationFileBlocState> emit) async {
-    emit(ListLocationFileBlocInconsistent(state.account, state.items));
-  }
-
-  void _onFileRemovedEvent(FileRemovedEvent ev) {
-    if (state is ListLocationFileBlocInit) {
-      // no data in this bloc, ignore
-      return;
-    }
-    if (_isFileOfInterest(ev.file)) {
-      _refreshThrottler.trigger(
-        maxResponceTime: const Duration(seconds: 3),
-        maxPendingCount: 10,
-      );
-    }
-  }
-
-  Future<List<File>> _query(ListLocationFileBlocQuery ev) async {
-    final files = <File>[];
-    for (final r in ev.account.roots) {
-      final dir = File(path: file_util.unstripPath(ev.account, r));
-      files.addAll(await ListLocationFile(_c)(
-          ev.account, dir, ev.place, ev.countryCode));
-    }
-    return files.where((f) => file_util.isSupportedFormat(f)).toList();
-  }
-
-  bool _isFileOfInterest(File file) {
-    if (!file_util.isSupportedFormat(file)) {
-      return false;
-    }
-
-    for (final r in state.account?.roots ?? []) {
-      final dir = File(path: file_util.unstripPath(state.account!, r));
-      if (file_util.isUnderDir(file, dir)) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  final DiContainer _c;
-
-  late final _fileRemovedEventListener =
-      AppEventListener<FileRemovedEvent>(_onFileRemovedEvent);
-
-  late final _refreshThrottler = Throttler(
-    onTriggered: (_) {
-      add(const _ListLocationFileBlocExternalEvent());
-    },
-    logTag: "ListLocationFileBloc.refresh",
-  );
-}

app/lib/bloc/list_location_file.g.dart

@@ -1,47 +0,0 @@
-// GENERATED CODE - DO NOT MODIFY BY HAND
-
-part of 'list_location_file.dart';
-
-// **************************************************************************
-// NpLogGenerator
-// **************************************************************************
-
-extension _$ListLocationFileBlocNpLog on ListLocationFileBloc {
-  // ignore: unused_element
-  Logger get _log => log;
-
-  static final log = Logger("bloc.list_location_file.ListLocationFileBloc");
-}
-
-// **************************************************************************
-// ToStringGenerator
-// **************************************************************************
-
-extension _$ListLocationFileBlocQueryToString on ListLocationFileBlocQuery {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "ListLocationFileBlocQuery {account: $account, place: $place, countryCode: $countryCode}";
-  }
-}
-
-extension _$_ListLocationFileBlocExternalEventToString
-    on _ListLocationFileBlocExternalEvent {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "_ListLocationFileBlocExternalEvent {}";
-  }
-}
-
-extension _$ListLocationFileBlocStateToString on ListLocationFileBlocState {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "${objectRuntimeType(this, "ListLocationFileBlocState")} {account: $account, items: [length: ${items.length}]}";
-  }
-}
-
-extension _$ListLocationFileBlocFailureToString on ListLocationFileBlocFailure {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "ListLocationFileBlocFailure {account: $account, items: [length: ${items.length}], exception: $exception}";
-  }
-}

app/lib/bloc/list_share.dart

@@ -1,96 +0,0 @@
-import 'package:bloc/bloc.dart';
-import 'package:flutter/foundation.dart';
-import 'package:logging/logging.dart';
-import 'package:nc_photos/account.dart';
-import 'package:nc_photos/entity/file.dart';
-import 'package:nc_photos/entity/share.dart';
-import 'package:nc_photos/entity/share/data_source.dart';
-import 'package:np_codegen/np_codegen.dart';
-import 'package:to_string/to_string.dart';
-
-part 'list_share.g.dart';
-
-abstract class ListShareBlocEvent {
-  const ListShareBlocEvent();
-}
-
-@toString
-class ListShareBlocQuery extends ListShareBlocEvent {
-  const ListShareBlocQuery(this.account, this.file);
-
-  @override
-  String toString() => _$toString();
-
-  final Account account;
-  final File file;
-}
-
-@toString
-abstract class ListShareBlocState {
-  const ListShareBlocState(this.account, this.file, this.items);
-
-  @override
-  String toString() => _$toString();
-
-  final Account? account;
-  final File file;
-  final List<Share> items;
-}
-
-class ListShareBlocInit extends ListShareBlocState {
-  ListShareBlocInit() : super(null, File(path: ""), const []);
-}
-
-class ListShareBlocLoading extends ListShareBlocState {
-  const ListShareBlocLoading(Account? account, File file, List<Share> items)
-      : super(account, file, items);
-}
-
-class ListShareBlocSuccess extends ListShareBlocState {
-  const ListShareBlocSuccess(Account? account, File file, List<Share> items)
-      : super(account, file, items);
-}
-
-@toString
-class ListShareBlocFailure extends ListShareBlocState {
-  const ListShareBlocFailure(
-      Account? account, File file, List<Share> items, this.exception)
-      : super(account, file, items);
-
-  @override
-  String toString() => _$toString();
-
-  final dynamic exception;
-}
-
-/// List all shares from a given file
-@npLog
-class ListShareBloc extends Bloc<ListShareBlocEvent, ListShareBlocState> {
-  ListShareBloc() : super(ListShareBlocInit()) {
-    on<ListShareBlocEvent>(_onEvent);
-  }
-
-  Future<void> _onEvent(
-      ListShareBlocEvent event, Emitter<ListShareBlocState> emit) async {
-    _log.info("[_onEvent] $event");
-    if (event is ListShareBlocQuery) {
-      await _onEventQuery(event, emit);
-    }
-  }
-
-  Future<void> _onEventQuery(
-      ListShareBlocQuery ev, Emitter<ListShareBlocState> emit) async {
-    try {
-      emit(ListShareBlocLoading(ev.account, ev.file, state.items));
-      emit(ListShareBlocSuccess(ev.account, ev.file, await _query(ev)));
-    } catch (e, stackTrace) {
-      _log.severe("[_onEventQuery] Exception while request", e, stackTrace);
-      emit(ListShareBlocFailure(ev.account, ev.file, state.items, e));
-    }
-  }
-
-  Future<List<Share>> _query(ListShareBlocQuery ev) {
-    final shareRepo = ShareRepo(ShareRemoteDataSource());
-    return shareRepo.list(ev.account, ev.file);
-  }
-}

app/lib/bloc/list_share.g.dart

@@ -1,39 +0,0 @@
-// GENERATED CODE - DO NOT MODIFY BY HAND
-
-part of 'list_share.dart';
-
-// **************************************************************************
-// NpLogGenerator
-// **************************************************************************
-
-extension _$ListShareBlocNpLog on ListShareBloc {
-  // ignore: unused_element
-  Logger get _log => log;
-
-  static final log = Logger("bloc.list_share.ListShareBloc");
-}
-
-// **************************************************************************
-// ToStringGenerator
-// **************************************************************************
-
-extension _$ListShareBlocQueryToString on ListShareBlocQuery {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "ListShareBlocQuery {account: $account, file: ${file.path}}";
-  }
-}
-
-extension _$ListShareBlocStateToString on ListShareBlocState {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "${objectRuntimeType(this, "ListShareBlocState")} {account: $account, file: ${file.path}, items: [length: ${items.length}]}";
-  }
-}
-
-extension _$ListShareBlocFailureToString on ListShareBlocFailure {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "ListShareBlocFailure {account: $account, file: ${file.path}, items: [length: ${items.length}], exception: $exception}";
-  }
-}

app/lib/bloc/list_sharee.dart

@@ -1,111 +0,0 @@
-import 'package:bloc/bloc.dart';
-import 'package:flutter/foundation.dart';
-import 'package:kiwi/kiwi.dart';
-import 'package:logging/logging.dart';
-import 'package:nc_photos/account.dart';
-import 'package:nc_photos/bloc/bloc_util.dart' as bloc_util;
-import 'package:nc_photos/entity/sharee.dart';
-import 'package:nc_photos/entity/sharee/data_source.dart';
-import 'package:np_codegen/np_codegen.dart';
-import 'package:to_string/to_string.dart';
-
-part 'list_sharee.g.dart';
-
-abstract class ListShareeBlocEvent {
-  const ListShareeBlocEvent();
-}
-
-@toString
-class ListShareeBlocQuery extends ListShareeBlocEvent {
-  const ListShareeBlocQuery(this.account);
-
-  @override
-  String toString() => _$toString();
-
-  final Account account;
-}
-
-@toString
-abstract class ListShareeBlocState {
-  const ListShareeBlocState(this.account, this.items);
-
-  @override
-  String toString() => _$toString();
-
-  final Account? account;
-  final List<Sharee> items;
-}
-
-class ListShareeBlocInit extends ListShareeBlocState {
-  ListShareeBlocInit() : super(null, const []);
-}
-
-class ListShareeBlocLoading extends ListShareeBlocState {
-  const ListShareeBlocLoading(Account? account, List<Sharee> items)
-      : super(account, items);
-}
-
-class ListShareeBlocSuccess extends ListShareeBlocState {
-  const ListShareeBlocSuccess(Account? account, List<Sharee> items)
-      : super(account, items);
-}
-
-@toString
-class ListShareeBlocFailure extends ListShareeBlocState {
-  const ListShareeBlocFailure(
-      Account? account, List<Sharee> items, this.exception)
-      : super(account, items);
-
-  @override
-  String toString() => _$toString();
-
-  final dynamic exception;
-}
-
-/// List all sharees of this account
-@npLog
-class ListShareeBloc extends Bloc<ListShareeBlocEvent, ListShareeBlocState> {
-  ListShareeBloc() : super(ListShareeBlocInit()) {
-    on<ListShareeBlocEvent>(_onEvent);
-  }
-
-  static ListShareeBloc of(Account account) {
-    final name = bloc_util.getInstNameForAccount("ListShareeBloc", account);
-    try {
-      _log.fine("[of] Resolving bloc for '$name'");
-      return KiwiContainer().resolve<ListShareeBloc>(name);
-    } catch (_) {
-      // no created instance for this account, make a new one
-      _log.info("[of] New bloc instance for account: $account");
-      final bloc = ListShareeBloc();
-      KiwiContainer().registerInstance<ListShareeBloc>(bloc, name: name);
-      return bloc;
-    }
-  }
-
-  Future<void> _onEvent(
-      ListShareeBlocEvent event, Emitter<ListShareeBlocState> emit) async {
-    _log.info("[_onEvent] $event");
-    if (event is ListShareeBlocQuery) {
-      await _onEventQuery(event, emit);
-    }
-  }
-
-  Future<void> _onEventQuery(
-      ListShareeBlocQuery ev, Emitter<ListShareeBlocState> emit) async {
-    try {
-      emit(ListShareeBlocLoading(ev.account, state.items));
-      emit(ListShareeBlocSuccess(ev.account, await _query(ev)));
-    } catch (e, stackTrace) {
-      _log.shout("[_onEventQuery] Exception while request", e, stackTrace);
-      emit(ListShareeBlocFailure(ev.account, state.items, e));
-    }
-  }
-
-  Future<List<Sharee>> _query(ListShareeBlocQuery ev) {
-    final shareeRepo = ShareeRepo(ShareeRemoteDataSource());
-    return shareeRepo.list(ev.account);
-  }
-
-  static final _log = _$ListShareeBlocNpLog.log;
-}

app/lib/bloc/list_sharee.g.dart

@@ -1,39 +0,0 @@
-// GENERATED CODE - DO NOT MODIFY BY HAND
-
-part of 'list_sharee.dart';
-
-// **************************************************************************
-// NpLogGenerator
-// **************************************************************************
-
-extension _$ListShareeBlocNpLog on ListShareeBloc {
-  // ignore: unused_element
-  Logger get _log => log;
-
-  static final log = Logger("bloc.list_sharee.ListShareeBloc");
-}
-
-// **************************************************************************
-// ToStringGenerator
-// **************************************************************************
-
-extension _$ListShareeBlocQueryToString on ListShareeBlocQuery {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "ListShareeBlocQuery {account: $account}";
-  }
-}
-
-extension _$ListShareeBlocStateToString on ListShareeBlocState {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "${objectRuntimeType(this, "ListShareeBlocState")} {account: $account, items: [length: ${items.length}]}";
-  }
-}
-
-extension _$ListShareeBlocFailureToString on ListShareeBlocFailure {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "ListShareeBlocFailure {account: $account, items: [length: ${items.length}], exception: $exception}";
-  }
-}

app/lib/bloc/list_sharing.dart

@@ -304,6 +304,7 @@ class ListSharingBloc extends Bloc<ListSharingBlocEvent, ListSharingBlocState> {
             s,
             File(
               path: webdavPath,
+              fileId: s.itemSource,
               isCollection: true,
             ),
           );

app/lib/bloc/list_tag_file.dart

@@ -1,226 +0,0 @@
-import 'package:bloc/bloc.dart';
-import 'package:flutter/foundation.dart';
-import 'package:logging/logging.dart';
-import 'package:nc_photos/account.dart';
-import 'package:nc_photos/di_container.dart';
-import 'package:nc_photos/entity/file.dart';
-import 'package:nc_photos/entity/file_util.dart' as file_util;
-import 'package:nc_photos/entity/tag.dart';
-import 'package:nc_photos/event/event.dart';
-import 'package:nc_photos/throttler.dart';
-import 'package:nc_photos/use_case/find_file.dart';
-import 'package:np_codegen/np_codegen.dart';
-import 'package:to_string/to_string.dart';
-
-part 'list_tag_file.g.dart';
-
-abstract class ListTagFileBlocEvent {
-  const ListTagFileBlocEvent();
-}
-
-@toString
-class ListTagFileBlocQuery extends ListTagFileBlocEvent {
-  const ListTagFileBlocQuery(this.account, this.tag);
-
-  @override
-  String toString() => _$toString();
-
-  final Account account;
-  final Tag tag;
-}
-
-/// An external event has happened and may affect the state of this bloc
-@toString
-class _ListTagFileBlocExternalEvent extends ListTagFileBlocEvent {
-  const _ListTagFileBlocExternalEvent();
-
-  @override
-  String toString() => _$toString();
-}
-
-@toString
-abstract class ListTagFileBlocState {
-  const ListTagFileBlocState(this.account, this.items);
-
-  @override
-  String toString() => _$toString();
-
-  final Account? account;
-  final List<File> items;
-}
-
-class ListTagFileBlocInit extends ListTagFileBlocState {
-  ListTagFileBlocInit() : super(null, const []);
-}
-
-class ListTagFileBlocLoading extends ListTagFileBlocState {
-  const ListTagFileBlocLoading(Account? account, List<File> items)
-      : super(account, items);
-}
-
-class ListTagFileBlocSuccess extends ListTagFileBlocState {
-  const ListTagFileBlocSuccess(Account? account, List<File> items)
-      : super(account, items);
-}
-
-@toString
-class ListTagFileBlocFailure extends ListTagFileBlocState {
-  const ListTagFileBlocFailure(
-      Account? account, List<File> items, this.exception)
-      : super(account, items);
-
-  @override
-  String toString() => _$toString();
-
-  final Object exception;
-}
-
-/// The state of this bloc is inconsistent. This typically means that the data
-/// may have been changed externally
-class ListTagFileBlocInconsistent extends ListTagFileBlocState {
-  const ListTagFileBlocInconsistent(Account? account, List<File> items)
-      : super(account, items);
-}
-
-/// List all files associated with a specific tag
-@npLog
-class ListTagFileBloc extends Bloc<ListTagFileBlocEvent, ListTagFileBlocState> {
-  ListTagFileBloc(this._c)
-      : assert(require(_c)),
-        // assert(PopulatePerson.require(_c)),
-        super(ListTagFileBlocInit()) {
-    _fileRemovedEventListener.begin();
-    _filePropertyUpdatedEventListener.begin();
-
-    on<ListTagFileBlocEvent>(_onEvent);
-  }
-
-  static bool require(DiContainer c) =>
-      DiContainer.has(c, DiType.taggedFileRepo);
-
-  @override
-  close() {
-    _fileRemovedEventListener.end();
-    _filePropertyUpdatedEventListener.end();
-    return super.close();
-  }
-
-  Future<void> _onEvent(
-      ListTagFileBlocEvent event, Emitter<ListTagFileBlocState> emit) async {
-    _log.info("[_onEvent] $event");
-    if (event is ListTagFileBlocQuery) {
-      await _onEventQuery(event, emit);
-    } else if (event is _ListTagFileBlocExternalEvent) {
-      await _onExternalEvent(event, emit);
-    }
-  }
-
-  Future<void> _onEventQuery(
-      ListTagFileBlocQuery ev, Emitter<ListTagFileBlocState> emit) async {
-    try {
-      emit(ListTagFileBlocLoading(ev.account, state.items));
-      emit(ListTagFileBlocSuccess(ev.account, await _query(ev)));
-    } catch (e, stackTrace) {
-      _log.severe("[_onEventQuery] Exception while request", e, stackTrace);
-      emit(ListTagFileBlocFailure(ev.account, state.items, e));
-    }
-  }
-
-  Future<void> _onExternalEvent(_ListTagFileBlocExternalEvent ev,
-      Emitter<ListTagFileBlocState> emit) async {
-    emit(ListTagFileBlocInconsistent(state.account, state.items));
-  }
-
-  void _onFileRemovedEvent(FileRemovedEvent ev) {
-    if (state is ListTagFileBlocInit) {
-      // no data in this bloc, ignore
-      return;
-    }
-    if (_isFileOfInterest(ev.file)) {
-      _refreshThrottler.trigger(
-        maxResponceTime: const Duration(seconds: 3),
-        maxPendingCount: 10,
-      );
-    }
-  }
-
-  void _onFilePropertyUpdatedEvent(FilePropertyUpdatedEvent ev) {
-    if (!ev.hasAnyProperties([
-      FilePropertyUpdatedEvent.propMetadata,
-      FilePropertyUpdatedEvent.propIsArchived,
-      FilePropertyUpdatedEvent.propOverrideDateTime,
-      FilePropertyUpdatedEvent.propFavorite,
-    ])) {
-      // not interested
-      return;
-    }
-    if (state is ListTagFileBlocInit) {
-      // no data in this bloc, ignore
-      return;
-    }
-    if (!_isFileOfInterest(ev.file)) {
-      return;
-    }
-
-    if (ev.hasAnyProperties([
-      FilePropertyUpdatedEvent.propIsArchived,
-      FilePropertyUpdatedEvent.propOverrideDateTime,
-      FilePropertyUpdatedEvent.propFavorite,
-    ])) {
-      _refreshThrottler.trigger(
-        maxResponceTime: const Duration(seconds: 3),
-        maxPendingCount: 10,
-      );
-    } else {
-      _refreshThrottler.trigger(
-        maxResponceTime: const Duration(seconds: 10),
-        maxPendingCount: 10,
-      );
-    }
-  }
-
-  Future<List<File>> _query(ListTagFileBlocQuery ev) async {
-    final files = <File>[];
-    for (final r in ev.account.roots) {
-      final dir = File(path: file_util.unstripPath(ev.account, r));
-      final taggedFiles =
-          await _c.taggedFileRepo.list(ev.account, dir, [ev.tag]);
-      files.addAll(await FindFile(_c)(
-        ev.account,
-        taggedFiles.map((e) => e.fileId).toList(),
-        onFileNotFound: (id) {
-          _log.warning("[_query] Missing file: $id");
-        },
-      ));
-    }
-    return files.where((f) => file_util.isSupportedFormat(f)).toList();
-  }
-
-  bool _isFileOfInterest(File file) {
-    if (!file_util.isSupportedFormat(file)) {
-      return false;
-    }
-
-    for (final r in state.account?.roots ?? []) {
-      final dir = File(path: file_util.unstripPath(state.account!, r));
-      if (file_util.isUnderDir(file, dir)) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  final DiContainer _c;
-
-  late final _fileRemovedEventListener =
-      AppEventListener<FileRemovedEvent>(_onFileRemovedEvent);
-  late final _filePropertyUpdatedEventListener =
-      AppEventListener<FilePropertyUpdatedEvent>(_onFilePropertyUpdatedEvent);
-
-  late final _refreshThrottler = Throttler(
-    onTriggered: (_) {
-      add(const _ListTagFileBlocExternalEvent());
-    },
-    logTag: "ListTagFileBloc.refresh",
-  );
-}

app/lib/bloc/list_tag_file.g.dart

@@ -1,47 +0,0 @@
-// GENERATED CODE - DO NOT MODIFY BY HAND
-
-part of 'list_tag_file.dart';
-
-// **************************************************************************
-// NpLogGenerator
-// **************************************************************************
-
-extension _$ListTagFileBlocNpLog on ListTagFileBloc {
-  // ignore: unused_element
-  Logger get _log => log;
-
-  static final log = Logger("bloc.list_tag_file.ListTagFileBloc");
-}
-
-// **************************************************************************
-// ToStringGenerator
-// **************************************************************************
-
-extension _$ListTagFileBlocQueryToString on ListTagFileBlocQuery {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "ListTagFileBlocQuery {account: $account, tag: $tag}";
-  }
-}
-
-extension _$_ListTagFileBlocExternalEventToString
-    on _ListTagFileBlocExternalEvent {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "_ListTagFileBlocExternalEvent {}";
-  }
-}
-
-extension _$ListTagFileBlocStateToString on ListTagFileBlocState {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "${objectRuntimeType(this, "ListTagFileBlocState")} {account: $account, items: [length: ${items.length}]}";
-  }
-}
-
-extension _$ListTagFileBlocFailureToString on ListTagFileBlocFailure {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "ListTagFileBlocFailure {account: $account, items: [length: ${items.length}], exception: $exception}";
-  }
-}

app/lib/bloc/scan_account_dir.dart

@@ -481,7 +481,7 @@ class ScanAccountDirBloc
     return files;
   }
 
-  bool _isFileOfInterest(File file) {
+  bool _isFileOfInterest(FileDescriptor file) {
     if (!file_util.isSupportedFormat(file)) {
       return false;
     }

app/lib/bloc/search.dart

@@ -4,6 +4,7 @@ import 'package:logging/logging.dart';
 import 'package:nc_photos/account.dart';
 import 'package:nc_photos/di_container.dart';
 import 'package:nc_photos/entity/file.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
 import 'package:nc_photos/entity/file_util.dart' as file_util;
 import 'package:nc_photos/entity/search.dart';
 import 'package:nc_photos/event/event.dart';
@@ -198,7 +199,7 @@ class SearchBloc extends Bloc<SearchBlocEvent, SearchBlocState> {
   Future<List<File>> _query(SearchBlocQuery ev) =>
       Search(_c)(ev.account, ev.criteria);
 
-  bool _isFileOfInterest(File file) {
+  bool _isFileOfInterest(FileDescriptor file) {
     if (!file_util.isSupportedFormat(file)) {
       return false;
     }

app/lib/bloc_util.dart

@@ -0,0 +1,3 @@
+abstract class BlocTag {
+  String get tag;
+}

app/lib/controller/account_controller.dart

@@ -0,0 +1,32 @@
+import 'package:kiwi/kiwi.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/controller/collections_controller.dart';
+import 'package:nc_photos/controller/server_controller.dart';
+import 'package:nc_photos/di_container.dart';
+
+class AccountController {
+  void setCurrentAccount(Account account) {
+    _account = account;
+    _collectionsController?.dispose();
+    _collectionsController = null;
+    _serverController = null;
+  }
+
+  Account get account => _account!;
+
+  CollectionsController get collectionsController =>
+      _collectionsController ??= CollectionsController(
+        KiwiContainer().resolve<DiContainer>(),
+        account: _account!,
+        serverController: serverController,
+      );
+
+  ServerController get serverController =>
+      _serverController ??= ServerController(
+        account: _account!,
+      );
+
+  Account? _account;
+  CollectionsController? _collectionsController;
+  ServerController? _serverController;
+}

app/lib/controller/collection_items_controller.dart

@@ -0,0 +1,348 @@
+import 'dart:async';
+
+import 'package:collection/collection.dart';
+import 'package:copy_with/copy_with.dart';
+import 'package:flutter/foundation.dart';
+import 'package:logging/logging.dart';
+import 'package:mutex/mutex.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/debug_util.dart';
+import 'package:nc_photos/di_container.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/adapter.dart';
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/collection_item/new_item.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:nc_photos/event/event.dart';
+import 'package:nc_photos/exception_event.dart';
+import 'package:nc_photos/list_extension.dart';
+import 'package:nc_photos/object_extension.dart';
+import 'package:nc_photos/rx_extension.dart';
+import 'package:nc_photos/use_case/collection/add_file_to_collection.dart';
+import 'package:nc_photos/use_case/collection/list_collection_item.dart';
+import 'package:nc_photos/use_case/collection/remove_from_collection.dart';
+import 'package:nc_photos/use_case/collection/update_collection_post_load.dart';
+import 'package:nc_photos/use_case/remove.dart';
+import 'package:np_codegen/np_codegen.dart';
+import 'package:rxdart/rxdart.dart';
+
+part 'collection_items_controller.g.dart';
+
+@genCopyWith
+class CollectionItemStreamData {
+  const CollectionItemStreamData({
+    required this.items,
+    required this.hasNext,
+  });
+
+  final List<CollectionItem> items;
+
+  /// If true, the results are intermediate values and may not represent the
+  /// latest state
+  final bool hasNext;
+}
+
+@npLog
+class CollectionItemsController {
+  CollectionItemsController(
+    this._c, {
+    required this.account,
+    required this.collection,
+    required this.onCollectionUpdated,
+  }) {
+    _fileRemovedEventListener.begin();
+  }
+
+  /// Dispose this controller and release all internal resources
+  ///
+  /// MUST be called
+  void dispose() {
+    _fileRemovedEventListener.end();
+    _dataStreamController.close();
+  }
+
+  /// Subscribe to collection items in [collection]
+  ///
+  /// The returned stream will emit new list of items whenever there are changes
+  /// to the items (e.g., new item, removed item, etc)
+  ///
+  /// There's no guarantee that the returned list is always sorted in some ways,
+  /// callers must sort it by themselves if the ordering is important
+  ValueStream<CollectionItemStreamData> get stream {
+    if (!_isDataStreamInited) {
+      _isDataStreamInited = true;
+      unawaited(_load());
+    }
+    return _dataStreamController.stream;
+  }
+
+  /// Peek the stream and return the current value
+  CollectionItemStreamData peekStream() => _dataStreamController.stream.value;
+
+  /// Add list of [files] to [collection]
+  Future<void> addFiles(List<FileDescriptor> files) async {
+    final isInited = _isDataStreamInited;
+    final List<FileDescriptor> toAdd;
+    if (isInited) {
+      toAdd = files
+          .where((a) => _dataStreamController.value.items
+              .whereType<CollectionFileItem>()
+              .every((b) => !a.compareServerIdentity(b.file)))
+          .toList();
+      _log.info("[addFiles] Adding ${toAdd.length} non duplicated files");
+      if (toAdd.isEmpty) {
+        return;
+      }
+      _dataStreamController.addWithValue((value) => value.copyWith(
+            items: [
+              ...toAdd.map((f) => NewCollectionFileItem(f)),
+              ...value.items,
+            ],
+          ));
+    } else {
+      toAdd = files;
+      _log.info("[addFiles] Adding ${toAdd.length} files");
+      if (toAdd.isEmpty) {
+        return;
+      }
+    }
+
+    ExceptionEvent? error;
+    final failed = <FileDescriptor>[];
+    await _mutex.protect(() async {
+      await AddFileToCollection(_c)(
+        account,
+        collection,
+        toAdd,
+        onError: (f, e, stackTrace) {
+          _log.severe("[addFiles] Exception: ${logFilename(f.strippedPath)}", e,
+              stackTrace);
+          error ??= ExceptionEvent(e, stackTrace);
+          failed.add(f);
+        },
+        onCollectionUpdated: (value) {
+          collection = value;
+          onCollectionUpdated(collection);
+        },
+      );
+
+      if (isInited) {
+        error
+            ?.run((e) => _dataStreamController.addError(e.error, e.stackTrace));
+        var finalize = _dataStreamController.value.items.toList();
+        if (failed.isNotEmpty) {
+          // remove failed items
+          finalize.removeWhere((r) {
+            if (r is CollectionFileItem) {
+              return failed.any((f) => r.file.compareServerIdentity(f));
+            } else {
+              return false;
+            }
+          });
+        }
+        // convert intermediate items
+        finalize = (await finalize.asyncMap((e) async {
+          try {
+            if (e is NewCollectionFileItem) {
+              return await CollectionAdapter.of(_c, account, collection)
+                  .adaptToNewItem(e);
+            } else {
+              return e;
+            }
+          } catch (e, stackTrace) {
+            _log.severe("[addFiles] Item not found in resulting collection: $e",
+                e, stackTrace);
+            return null;
+          }
+        }))
+            .whereNotNull()
+            .toList();
+        _dataStreamController.addWithValue((value) => value.copyWith(
+              items: finalize,
+            ));
+      } else if (isInited != _isDataStreamInited) {
+        // stream loaded in between this op, reload
+        unawaited(_load());
+      }
+    });
+    error?.throwMe();
+  }
+
+  /// Remove list of [items] from [collection]
+  ///
+  /// The items are compared with [identical], so it's required that all the
+  /// item instances come from the value stream
+  Future<void> removeItems(List<CollectionItem> items) async {
+    final isInited = _isDataStreamInited;
+    if (isInited) {
+      _dataStreamController.addWithValue((value) => value.copyWith(
+            items: value.items
+                .where((a) => !items.any((b) => identical(a, b)))
+                .toList(),
+          ));
+    }
+
+    ExceptionEvent? error;
+    final failed = <CollectionItem>[];
+    await _mutex.protect(() async {
+      await RemoveFromCollection(_c)(
+        account,
+        collection,
+        items,
+        onError: (_, item, e, stackTrace) {
+          _log.severe("[removeItems] Exception: $item", e, stackTrace);
+          error ??= ExceptionEvent(e, stackTrace);
+          failed.add(item);
+        },
+        onCollectionUpdated: (value) {
+          collection = value;
+          onCollectionUpdated(collection);
+        },
+      );
+
+      if (isInited) {
+        error
+            ?.run((e) => _dataStreamController.addError(e.error, e.stackTrace));
+        if (failed.isNotEmpty) {
+          _dataStreamController.addWithValue((value) => value.copyWith(
+                items: value.items + failed,
+              ));
+        }
+      } else if (isInited != _isDataStreamInited) {
+        // stream loaded in between this op, reload
+        unawaited(_load());
+      }
+    });
+    error?.throwMe();
+  }
+
+  /// Delete list of [files] from your server
+  ///
+  /// This is a temporary workaround and will be moved away
+  Future<void> deleteItems(List<FileDescriptor> files) async {
+    final isInited = _isDataStreamInited;
+    final List<FileDescriptor> toDelete;
+    List<CollectionFileItem>? toDeleteItem;
+    if (isInited) {
+      final groups = _dataStreamController.value.items.groupListsBy((i) {
+        if (i is CollectionFileItem) {
+          return !files.any((f) => i.file.compareServerIdentity(f));
+        } else {
+          return true;
+        }
+      });
+      final retain = groups[true] ?? const [];
+      toDeleteItem = groups[false]?.cast<CollectionFileItem>() ?? const [];
+      if (toDeleteItem.isEmpty) {
+        return;
+      }
+      _dataStreamController.addWithValue((value) => value.copyWith(
+            items: retain,
+          ));
+      toDelete = toDeleteItem.map((e) => e.file).toList();
+    } else {
+      toDelete = files;
+    }
+
+    ExceptionEvent? error;
+    final failed = <CollectionItem>[];
+    await _mutex.protect(() async {
+      await Remove(_c)(
+        account,
+        toDelete,
+        onError: (i, f, e, stackTrace) {
+          _log.severe("[deleteItems] Exception: ${logFilename(f.strippedPath)}",
+              e, stackTrace);
+          error ??= ExceptionEvent(e, stackTrace);
+          if (isInited) {
+            failed.add(toDeleteItem![i]);
+          }
+        },
+      );
+
+      if (isInited) {
+        error
+            ?.run((e) => _dataStreamController.addError(e.error, e.stackTrace));
+        if (failed.isNotEmpty) {
+          _dataStreamController.addWithValue((value) => value.copyWith(
+                items: value.items + failed,
+              ));
+        }
+      } else if (isInited != _isDataStreamInited) {
+        // stream loaded in between this op, reload
+        unawaited(_load());
+      }
+    });
+    error?.throwMe();
+  }
+
+  /// Replace items in the stream, for internal use only
+  void forceReplaceItems(List<CollectionItem> items) {
+    _dataStreamController.addWithValue((v) => v.copyWith(items: items));
+  }
+
+  Future<void> _load() async {
+    try {
+      List<CollectionItem>? items;
+      await for (final r in ListCollectionItem(_c)(account, collection)) {
+        items = r;
+        _dataStreamController.add(CollectionItemStreamData(
+          items: r,
+          hasNext: true,
+        ));
+      }
+      if (items != null) {
+        _dataStreamController.add(CollectionItemStreamData(
+          items: items,
+          hasNext: false,
+        ));
+        final newCollection =
+            await UpdateCollectionPostLoad(_c)(account, collection, items);
+        if (newCollection != null) {
+          onCollectionUpdated(newCollection);
+        }
+      }
+    } catch (e, stackTrace) {
+      _dataStreamController
+        ..addError(e, stackTrace)
+        ..addWithValue((v) => v.copyWith(hasNext: false));
+    }
+  }
+
+  void _onFileRemovedEvent(FileRemovedEvent ev) {
+    // if (account != ev.account) {
+    //   return;
+    // }
+    // final newItems = _dataStreamController.value.items.where((e) {
+    //   if (e is CollectionFileItem) {
+    //     return !e.file.compareServerIdentity(ev.file);
+    //   } else {
+    //     return true;
+    //   }
+    // }).toList();
+    // if (newItems.length != _dataStreamController.value.items.length) {
+    //   // item of interest
+    //   _dataStreamController.addWithValue((value) => value.copyWith(
+    //         items: newItems,
+    //       ));
+    // }
+  }
+
+  final DiContainer _c;
+  final Account account;
+  Collection collection;
+  ValueChanged<Collection> onCollectionUpdated;
+
+  var _isDataStreamInited = false;
+  final _dataStreamController = BehaviorSubject.seeded(
+    const CollectionItemStreamData(
+      items: [],
+      hasNext: true,
+    ),
+  );
+
+  late final _fileRemovedEventListener =
+      AppEventListener<FileRemovedEvent>(_onFileRemovedEvent);
+
+  final _mutex = Mutex();
+}

app/lib/controller/collection_items_controller.g.dart

@@ -0,0 +1,49 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'collection_items_controller.dart';
+
+// **************************************************************************
+// CopyWithLintRuleGenerator
+// **************************************************************************
+
+// ignore_for_file: library_private_types_in_public_api, duplicate_ignore
+
+// **************************************************************************
+// CopyWithGenerator
+// **************************************************************************
+
+abstract class $CollectionItemStreamDataCopyWithWorker {
+  CollectionItemStreamData call({List<CollectionItem>? items, bool? hasNext});
+}
+
+class _$CollectionItemStreamDataCopyWithWorkerImpl
+    implements $CollectionItemStreamDataCopyWithWorker {
+  _$CollectionItemStreamDataCopyWithWorkerImpl(this.that);
+
+  @override
+  CollectionItemStreamData call({dynamic items, dynamic hasNext}) {
+    return CollectionItemStreamData(
+        items: items as List<CollectionItem>? ?? that.items,
+        hasNext: hasNext as bool? ?? that.hasNext);
+  }
+
+  final CollectionItemStreamData that;
+}
+
+extension $CollectionItemStreamDataCopyWith on CollectionItemStreamData {
+  $CollectionItemStreamDataCopyWithWorker get copyWith => _$copyWith;
+  $CollectionItemStreamDataCopyWithWorker get _$copyWith =>
+      _$CollectionItemStreamDataCopyWithWorkerImpl(this);
+}
+
+// **************************************************************************
+// NpLogGenerator
+// **************************************************************************
+
+extension _$CollectionItemsControllerNpLog on CollectionItemsController {
+  // ignore: unused_element
+  Logger get _log => log;
+
+  static final log = Logger(
+      "controller.collection_items_controller.CollectionItemsController");
+}

app/lib/controller/collections_controller.dart

@@ -0,0 +1,379 @@
+import 'dart:async';
+
+import 'package:collection/collection.dart';
+import 'package:copy_with/copy_with.dart';
+import 'package:logging/logging.dart';
+import 'package:mutex/mutex.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/controller/collection_items_controller.dart';
+import 'package:nc_photos/controller/server_controller.dart';
+import 'package:nc_photos/di_container.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/util.dart';
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:nc_photos/entity/sharee.dart';
+import 'package:nc_photos/exception.dart';
+import 'package:nc_photos/or_null.dart';
+import 'package:nc_photos/rx_extension.dart';
+import 'package:nc_photos/use_case/collection/create_collection.dart';
+import 'package:nc_photos/use_case/collection/edit_collection.dart';
+import 'package:nc_photos/use_case/collection/import_pending_shared_collection.dart';
+import 'package:nc_photos/use_case/collection/list_collection.dart';
+import 'package:nc_photos/use_case/collection/remove_collections.dart';
+import 'package:nc_photos/use_case/collection/share_collection.dart';
+import 'package:nc_photos/use_case/collection/unshare_collection.dart';
+import 'package:np_codegen/np_codegen.dart';
+import 'package:np_common/type.dart';
+import 'package:rxdart/rxdart.dart';
+
+part 'collections_controller.g.dart';
+
+@genCopyWith
+class CollectionStreamData {
+  const CollectionStreamData({
+    required this.collection,
+    required this.controller,
+  });
+
+  final Collection collection;
+  final CollectionItemsController controller;
+}
+
+@genCopyWith
+class CollectionStreamEvent {
+  const CollectionStreamEvent({
+    required this.data,
+    required this.hasNext,
+  });
+
+  CollectionItemsController itemsControllerByCollection(Collection collection) {
+    final i = data.indexWhere((d) => collection.compareIdentity(d.collection));
+    return data[i].controller;
+  }
+
+  final List<CollectionStreamData> data;
+
+  /// If true, the results are intermediate values and may not represent the
+  /// latest state
+  final bool hasNext;
+}
+
+@npLog
+class CollectionsController {
+  CollectionsController(
+    this._c, {
+    required this.account,
+    required this.serverController,
+  });
+
+  void dispose() {
+    _dataStreamController.close();
+    for (final c in _itemControllers.values) {
+      c.dispose();
+    }
+  }
+
+  /// Return a stream of collections associated with [account]
+  ///
+  /// The returned stream will emit new list of collections whenever there are
+  /// changes to the collections (e.g., new collection, removed collection, etc)
+  ///
+  /// There's no guarantee that the returned list is always sorted in some ways,
+  /// callers must sort it by themselves if the ordering is important
+  ValueStream<CollectionStreamEvent> get stream {
+    if (!_isDataStreamInited) {
+      _isDataStreamInited = true;
+      unawaited(_load());
+    }
+    return _dataStreamController.stream;
+  }
+
+  /// Peek the stream and return the current value
+  CollectionStreamEvent peekStream() => _dataStreamController.stream.value;
+
+  /// Reload the data
+  ///
+  /// The data will be loaded automatically when the stream is first listened so
+  /// it's not necessary to call this method for that purpose
+  Future<void> reload() async {
+    var results = <Collection>[];
+    final completer = Completer();
+    ListCollection(_c, serverController: serverController)(account).listen(
+      (c) {
+        results = c;
+      },
+      onError: _dataStreamController.addError,
+      onDone: () => completer.complete(),
+    );
+    await completer.future;
+    _dataStreamController.add(CollectionStreamEvent(
+      data: _prepareDataFor(results),
+      hasNext: false,
+    ));
+  }
+
+  Future<Collection> createNew(Collection collection) async {
+    // we can't simply add the collection argument to the stream because
+    // the collection may not be a complete workable instance
+    final created = await CreateCollection(_c)(account, collection);
+    _dataStreamController.addWithValue((v) => v.copyWith(
+          data: _prepareDataFor([
+            created,
+            ...v.data.map((e) => e.collection),
+          ]),
+        ));
+    return created;
+  }
+
+  /// Remove [collections] and return the removed count
+  ///
+  /// If [onError] is not null, you'll get notified about the errors. The future
+  /// will always complete normally
+  Future<int> remove(
+    List<Collection> collections, {
+    ErrorWithValueHandler<Collection>? onError,
+  }) async {
+    final newData = _dataStreamController.value.data.toList();
+    final toBeRemoved = <CollectionStreamData>[];
+    var failedCount = 0;
+    for (final c in collections) {
+      final i = newData.indexWhere((d) => c.compareIdentity(d.collection));
+      if (i == -1) {
+        _log.warning("[remove] Collection not found: $c");
+      } else {
+        toBeRemoved.add(newData.removeAt(i));
+      }
+    }
+    _dataStreamController.addWithValue((v) => v.copyWith(
+          data: newData,
+        ));
+
+    final restore = <CollectionStreamData>[];
+    await _mutex.protect(() async {
+      await RemoveCollections(_c)(
+        account,
+        collections,
+        onError: (c, e, stackTrace) {
+          _log.severe(
+              "[remove] Failed while RemoveCollections: $c", e, stackTrace);
+          final i =
+              toBeRemoved.indexWhere((d) => c.compareIdentity(d.collection));
+          if (i != -1) {
+            restore.add(toBeRemoved.removeAt(i));
+          }
+          ++failedCount;
+          onError?.call(c, e, stackTrace);
+        },
+      );
+    });
+    toBeRemoved
+        .map((d) => _CollectionKey(d.collection))
+        .forEach(_itemControllers.remove);
+    if (restore.isNotEmpty) {
+      _log.severe("[remove] Restoring ${restore.length} collections");
+      _dataStreamController.addWithValue((v) => v.copyWith(
+            data: [
+              ...restore,
+              ...v.data,
+            ],
+          ));
+    }
+    return collections.length - failedCount;
+  }
+
+  /// See [EditCollection]
+  Future<void> edit(
+    Collection collection, {
+    String? name,
+    List<CollectionItem>? items,
+    CollectionItemSort? itemSort,
+    OrNull<FileDescriptor>? cover,
+  }) async {
+    try {
+      final c = await _mutex.protect(() async {
+        final found = _dataStreamController.value.data.firstWhereOrNull(
+            (ev) => ev.collection.compareIdentity(collection));
+        final item = found?.controller.peekStream();
+        return await EditCollection(_c)(
+          account,
+          collection,
+          name: name,
+          items: items,
+          itemSort: itemSort,
+          cover: cover,
+          knownItems: (item?.items.isEmpty ?? true) ? null : item!.items,
+        );
+      });
+      _updateCollection(c, items);
+    } catch (e, stackTrace) {
+      _dataStreamController.addError(e, stackTrace);
+    }
+  }
+
+  Future<void> share(Collection collection, Sharee sharee) async {
+    try {
+      Collection? newCollection;
+      final result = await _mutex.protect(() async {
+        return await ShareCollection(_c)(
+          account,
+          collection,
+          sharee,
+          onCollectionUpdated: (c) {
+            newCollection = c;
+          },
+        );
+      });
+      if (newCollection != null) {
+        _updateCollection(newCollection!);
+      }
+      if (result == CollectionShareResult.partial) {
+        _dataStreamController
+            .addError(CollectionPartialShareException(sharee.shareWith.raw));
+      }
+    } catch (e, stackTrace) {
+      _dataStreamController.addError(e, stackTrace);
+    }
+  }
+
+  Future<void> unshare(Collection collection, CollectionShare share) async {
+    try {
+      Collection? newCollection;
+      final result = await _mutex.protect(() async {
+        return await UnshareCollection(_c)(
+          account,
+          collection,
+          share.userId,
+          onCollectionUpdated: (c) {
+            newCollection = c;
+          },
+        );
+      });
+      if (newCollection != null) {
+        _updateCollection(newCollection!);
+      }
+      if (result == CollectionShareResult.partial) {
+        _dataStreamController
+            .addError(CollectionPartialUnshareException(share.username));
+      }
+    } catch (e, stackTrace) {
+      _dataStreamController.addError(e, stackTrace);
+    }
+  }
+
+  /// See [ImportPendingSharedCollection]
+  Future<Collection?> importPendingSharedCollection(
+      Collection collection) async {
+    try {
+      final newCollection =
+          await ImportPendingSharedCollection(_c)(account, collection);
+      _dataStreamController.addWithValue((v) => v.copyWith(
+            data: _prepareDataFor([
+              newCollection,
+              ...v.data.map((e) => e.collection),
+            ]),
+          ));
+      return newCollection;
+    } catch (e, stackTrace) {
+      _dataStreamController.addError(e, stackTrace);
+      return null;
+    }
+  }
+
+  Future<void> _load() async {
+    var lastData = const CollectionStreamEvent(
+      data: [],
+      hasNext: false,
+    );
+    final completer = Completer();
+    ListCollection(_c, serverController: serverController)(account).listen(
+      (c) {
+        lastData = CollectionStreamEvent(
+          data: _prepareDataFor(c),
+          hasNext: true,
+        );
+        _dataStreamController.add(lastData);
+      },
+      onError: _dataStreamController.addError,
+      onDone: () => completer.complete(),
+    );
+    await completer.future;
+    _dataStreamController.add(lastData.copyWith(hasNext: false));
+  }
+
+  List<CollectionStreamData> _prepareDataFor(List<Collection> collections) {
+    final data = <CollectionStreamData>[];
+    final keys = <_CollectionKey>[];
+    for (final c in collections) {
+      final k = _CollectionKey(c);
+      _itemControllers[k] ??= CollectionItemsController(
+        _c,
+        account: account,
+        collection: k.collection,
+        onCollectionUpdated: _updateCollection,
+      );
+      data.add(CollectionStreamData(
+        collection: c,
+        controller: _itemControllers[k]!,
+      ));
+      keys.add(k);
+    }
+
+    final remove =
+        _itemControllers.keys.where((k) => !keys.contains(k)).toList();
+    for (final k in remove) {
+      _itemControllers[k]?.dispose();
+      _itemControllers.remove(k);
+    }
+
+    return data;
+  }
+
+  void _updateCollection(Collection collection, [List<CollectionItem>? items]) {
+    _log.info("[_updateCollection] Updating collection: $collection");
+    _dataStreamController.addWithValue((v) => v.copyWith(
+          data: v.data.map((d) {
+            if (d.collection.compareIdentity(collection)) {
+              if (items != null) {
+                d.controller.forceReplaceItems(items);
+              }
+              return d.copyWith(collection: collection);
+            } else {
+              return d;
+            }
+          }).toList(),
+        ));
+  }
+
+  final DiContainer _c;
+  final Account account;
+  final ServerController serverController;
+
+  var _isDataStreamInited = false;
+  final _dataStreamController = BehaviorSubject.seeded(
+    const CollectionStreamEvent(
+      data: [],
+      hasNext: true,
+    ),
+  );
+
+  final _itemControllers = <_CollectionKey, CollectionItemsController>{};
+
+  final _mutex = Mutex();
+}
+
+class _CollectionKey {
+  const _CollectionKey(this.collection);
+
+  @override
+  bool operator ==(Object other) {
+    return other is _CollectionKey &&
+        collection.compareIdentity(other.collection);
+  }
+
+  @override
+  int get hashCode => collection.identityHashCode;
+
+  final Collection collection;
+}

app/lib/controller/collections_controller.g.dart

@@ -0,0 +1,75 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'collections_controller.dart';
+
+// **************************************************************************
+// CopyWithLintRuleGenerator
+// **************************************************************************
+
+// ignore_for_file: library_private_types_in_public_api, duplicate_ignore
+
+// **************************************************************************
+// CopyWithGenerator
+// **************************************************************************
+
+abstract class $CollectionStreamDataCopyWithWorker {
+  CollectionStreamData call(
+      {Collection? collection, CollectionItemsController? controller});
+}
+
+class _$CollectionStreamDataCopyWithWorkerImpl
+    implements $CollectionStreamDataCopyWithWorker {
+  _$CollectionStreamDataCopyWithWorkerImpl(this.that);
+
+  @override
+  CollectionStreamData call({dynamic collection, dynamic controller}) {
+    return CollectionStreamData(
+        collection: collection as Collection? ?? that.collection,
+        controller:
+            controller as CollectionItemsController? ?? that.controller);
+  }
+
+  final CollectionStreamData that;
+}
+
+extension $CollectionStreamDataCopyWith on CollectionStreamData {
+  $CollectionStreamDataCopyWithWorker get copyWith => _$copyWith;
+  $CollectionStreamDataCopyWithWorker get _$copyWith =>
+      _$CollectionStreamDataCopyWithWorkerImpl(this);
+}
+
+abstract class $CollectionStreamEventCopyWithWorker {
+  CollectionStreamEvent call({List<CollectionStreamData>? data, bool? hasNext});
+}
+
+class _$CollectionStreamEventCopyWithWorkerImpl
+    implements $CollectionStreamEventCopyWithWorker {
+  _$CollectionStreamEventCopyWithWorkerImpl(this.that);
+
+  @override
+  CollectionStreamEvent call({dynamic data, dynamic hasNext}) {
+    return CollectionStreamEvent(
+        data: data as List<CollectionStreamData>? ?? that.data,
+        hasNext: hasNext as bool? ?? that.hasNext);
+  }
+
+  final CollectionStreamEvent that;
+}
+
+extension $CollectionStreamEventCopyWith on CollectionStreamEvent {
+  $CollectionStreamEventCopyWithWorker get copyWith => _$copyWith;
+  $CollectionStreamEventCopyWithWorker get _$copyWith =>
+      _$CollectionStreamEventCopyWithWorkerImpl(this);
+}
+
+// **************************************************************************
+// NpLogGenerator
+// **************************************************************************
+
+extension _$CollectionsControllerNpLog on CollectionsController {
+  // ignore: unused_element
+  Logger get _log => log;
+
+  static final log =
+      Logger("controller.collections_controller.CollectionsController");
+}

app/lib/controller/pref_controller.dart

@@ -0,0 +1,54 @@
+import 'package:logging/logging.dart';
+import 'package:nc_photos/di_container.dart';
+import 'package:np_codegen/np_codegen.dart';
+import 'package:rxdart/rxdart.dart';
+
+part 'pref_controller.g.dart';
+
+@npLog
+class PrefController {
+  PrefController(this._c);
+
+  ValueStream<int> get albumBrowserZoomLevel =>
+      _albumBrowserZoomLevelController.stream;
+
+  Future<void> setAlbumBrowserZoomLevel(int value) async {
+    final backup = _albumBrowserZoomLevelController.value;
+    _albumBrowserZoomLevelController.add(value);
+    try {
+      if (!await _c.pref.setAlbumBrowserZoomLevel(value)) {
+        throw StateError("Unknown error");
+      }
+    } catch (e, stackTrace) {
+      _log.severe("[setAlbumBrowserZoomLevel] Failed setting preference", e,
+          stackTrace);
+      _albumBrowserZoomLevelController
+        ..addError(e, stackTrace)
+        ..add(backup);
+    }
+  }
+
+  ValueStream<int> get homeAlbumsSort => _homeAlbumsSortController.stream;
+
+  Future<void> setHomeAlbumsSort(int value) async {
+    final backup = _homeAlbumsSortController.value;
+    _homeAlbumsSortController.add(value);
+    try {
+      if (!await _c.pref.setHomeAlbumsSort(value)) {
+        throw StateError("Unknown error");
+      }
+    } catch (e, stackTrace) {
+      _log.severe(
+          "[setHomeAlbumsSort] Failed setting preference", e, stackTrace);
+      _homeAlbumsSortController
+        ..addError(e, stackTrace)
+        ..add(backup);
+    }
+  }
+
+  final DiContainer _c;
+  late final _albumBrowserZoomLevelController =
+      BehaviorSubject.seeded(_c.pref.getAlbumBrowserZoomLevelOr(0));
+  late final _homeAlbumsSortController =
+      BehaviorSubject.seeded(_c.pref.getHomeAlbumsSortOr(0));
+}

app/lib/controller/pref_controller.g.dart

@@ -1,14 +1,14 @@
 // GENERATED CODE - DO NOT MODIFY BY HAND
 
-part of 'album_picker.dart';
+part of 'pref_controller.dart';
 
 // **************************************************************************
 // NpLogGenerator
 // **************************************************************************
 
-extension _$_AlbumPickerStateNpLog on _AlbumPickerState {
+extension _$PrefControllerNpLog on PrefController {
   // ignore: unused_element
   Logger get _log => log;
 
-  static final log = Logger("widget.album_picker._AlbumPickerState");
+  static final log = Logger("controller.pref_controller.PrefController");
 }

app/lib/controller/server_controller.dart

@@ -0,0 +1,61 @@
+import 'dart:async';
+
+import 'package:logging/logging.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/api/entity_converter.dart';
+import 'package:nc_photos/entity/server_status.dart';
+import 'package:nc_photos/np_api_util.dart';
+import 'package:np_api/np_api.dart' as api;
+import 'package:np_codegen/np_codegen.dart';
+import 'package:rxdart/rxdart.dart';
+
+part 'server_controller.g.dart';
+
+enum ServerFeature {
+  ncAlbum,
+}
+
+@npLog
+class ServerController {
+  ServerController({
+    required this.account,
+  });
+
+  ValueStream<ServerStatus> get status {
+    if (!_statusStreamContorller.hasValue) {
+      unawaited(_load());
+    }
+    return _statusStreamContorller.stream;
+  }
+
+  bool isSupported(ServerFeature feature) {
+    switch (feature) {
+      case ServerFeature.ncAlbum:
+        return !_statusStreamContorller.hasValue ||
+            _statusStreamContorller.value.majorVersion >= 25;
+    }
+  }
+
+  Future<void> _load() => _getStatus();
+
+  Future<void> _getStatus() async {
+    try {
+      final response = await ApiUtil.fromAccount(account).status().get();
+      if (!response.isGood) {
+        _log.severe("[_getStatus] Failed requesting server: $response");
+        return;
+      }
+      final apiStatus = await api.StatusParser().parse(response.body);
+      final status = ApiStatusConverter.fromApi(apiStatus);
+      _log.info("[_getStatus] Server status: $status");
+      _statusStreamContorller.add(status);
+    } catch (e, stackTrace) {
+      _log.severe("[_getStatus] Failed while get", e, stackTrace);
+      return;
+    }
+  }
+
+  final Account account;
+
+  final _statusStreamContorller = BehaviorSubject<ServerStatus>();
+}

app/lib/controller/server_controller.g.dart

@@ -0,0 +1,14 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'server_controller.dart';
+
+// **************************************************************************
+// NpLogGenerator
+// **************************************************************************
+
+extension _$ServerControllerNpLog on ServerController {
+  // ignore: unused_element
+  Logger get _log => log;
+
+  static final log = Logger("controller.server_controller.ServerController");
+}

app/lib/di_container.dart

@@ -1,8 +1,10 @@
 import 'package:nc_photos/entity/album.dart';
+import 'package:nc_photos/entity/album/repo2.dart';
 import 'package:nc_photos/entity/face.dart';
 import 'package:nc_photos/entity/favorite.dart';
 import 'package:nc_photos/entity/file.dart';
 import 'package:nc_photos/entity/local_file.dart';
+import 'package:nc_photos/entity/nc_album/repo.dart';
 import 'package:nc_photos/entity/person.dart';
 import 'package:nc_photos/entity/search.dart';
 import 'package:nc_photos/entity/share.dart';
@@ -16,7 +18,11 @@ import 'package:nc_photos/touch_manager.dart';
 
 enum DiType {
   albumRepo,
+  albumRepoRemote,
   albumRepoLocal,
+  albumRepo2,
+  albumRepo2Remote,
+  albumRepo2Local,
   faceRepo,
   fileRepo,
   fileRepoRemote,
@@ -33,6 +39,9 @@ enum DiType {
   taggedFileRepo,
   localFileRepo,
   searchRepo,
+  ncAlbumRepo,
+  ncAlbumRepoRemote,
+  ncAlbumRepoLocal,
   pref,
   sqliteDb,
   touchManager,
@@ -41,7 +50,11 @@ enum DiType {
 class DiContainer {
   DiContainer({
     AlbumRepo? albumRepo,
+    AlbumRepo? albumRepoRemote,
     AlbumRepo? albumRepoLocal,
+    AlbumRepo2? albumRepo2,
+    AlbumRepo2? albumRepo2Remote,
+    AlbumRepo2? albumRepo2Local,
     FaceRepo? faceRepo,
     FileRepo? fileRepo,
     FileRepo? fileRepoRemote,
@@ -58,11 +71,18 @@ class DiContainer {
     TaggedFileRepo? taggedFileRepo,
     LocalFileRepo? localFileRepo,
     SearchRepo? searchRepo,
+    NcAlbumRepo? ncAlbumRepo,
+    NcAlbumRepo? ncAlbumRepoRemote,
+    NcAlbumRepo? ncAlbumRepoLocal,
     Pref? pref,
     sql.SqliteDb? sqliteDb,
     TouchManager? touchManager,
   })  : _albumRepo = albumRepo,
+        _albumRepoRemote = albumRepoRemote,
         _albumRepoLocal = albumRepoLocal,
+        _albumRepo2 = albumRepo2,
+        _albumRepo2Remote = albumRepo2Remote,
+        _albumRepo2Local = albumRepo2Local,
         _faceRepo = faceRepo,
         _fileRepo = fileRepo,
         _fileRepoRemote = fileRepoRemote,
@@ -79,6 +99,9 @@ class DiContainer {
         _taggedFileRepo = taggedFileRepo,
         _localFileRepo = localFileRepo,
         _searchRepo = searchRepo,
+        _ncAlbumRepo = ncAlbumRepo,
+        _ncAlbumRepoRemote = ncAlbumRepoRemote,
+        _ncAlbumRepoLocal = ncAlbumRepoLocal,
         _pref = pref,
         _sqliteDb = sqliteDb,
         _touchManager = touchManager;
@@ -89,8 +112,16 @@ class DiContainer {
     switch (type) {
       case DiType.albumRepo:
         return contianer._albumRepo != null;
+      case DiType.albumRepoRemote:
+        return contianer._albumRepoRemote != null;
       case DiType.albumRepoLocal:
         return contianer._albumRepoLocal != null;
+      case DiType.albumRepo2:
+        return contianer._albumRepo2 != null;
+      case DiType.albumRepo2Remote:
+        return contianer._albumRepo2Remote != null;
+      case DiType.albumRepo2Local:
+        return contianer._albumRepo2Local != null;
       case DiType.faceRepo:
         return contianer._faceRepo != null;
       case DiType.fileRepo:
@@ -123,6 +154,12 @@ class DiContainer {
         return contianer._localFileRepo != null;
       case DiType.searchRepo:
         return contianer._searchRepo != null;
+      case DiType.ncAlbumRepo:
+        return contianer._ncAlbumRepo != null;
+      case DiType.ncAlbumRepoRemote:
+        return contianer._ncAlbumRepoRemote != null;
+      case DiType.ncAlbumRepoLocal:
+        return contianer._ncAlbumRepoLocal != null;
       case DiType.pref:
         return contianer._pref != null;
       case DiType.sqliteDb:
@@ -134,6 +171,7 @@ class DiContainer {
 
   DiContainer copyWith({
     OrNull<AlbumRepo>? albumRepo,
+    OrNull<AlbumRepo2>? albumRepo2,
     OrNull<FaceRepo>? faceRepo,
     OrNull<FileRepo>? fileRepo,
     OrNull<PersonRepo>? personRepo,
@@ -144,12 +182,14 @@ class DiContainer {
     OrNull<TaggedFileRepo>? taggedFileRepo,
     OrNull<LocalFileRepo>? localFileRepo,
     OrNull<SearchRepo>? searchRepo,
+    OrNull<NcAlbumRepo>? ncAlbumRepo,
     OrNull<Pref>? pref,
     OrNull<sql.SqliteDb>? sqliteDb,
     OrNull<TouchManager>? touchManager,
   }) {
     return DiContainer(
       albumRepo: albumRepo == null ? _albumRepo : albumRepo.obj,
+      albumRepo2: albumRepo2 == null ? _albumRepo2 : albumRepo2.obj,
       faceRepo: faceRepo == null ? _faceRepo : faceRepo.obj,
       fileRepo: fileRepo == null ? _fileRepo : fileRepo.obj,
       personRepo: personRepo == null ? _personRepo : personRepo.obj,
@@ -161,6 +201,7 @@ class DiContainer {
           taggedFileRepo == null ? _taggedFileRepo : taggedFileRepo.obj,
       localFileRepo: localFileRepo == null ? _localFileRepo : localFileRepo.obj,
       searchRepo: searchRepo == null ? _searchRepo : searchRepo.obj,
+      ncAlbumRepo: ncAlbumRepo == null ? _ncAlbumRepo : ncAlbumRepo.obj,
       pref: pref == null ? _pref : pref.obj,
       sqliteDb: sqliteDb == null ? _sqliteDb : sqliteDb.obj,
       touchManager: touchManager == null ? _touchManager : touchManager.obj,
@@ -168,7 +209,11 @@ class DiContainer {
   }
 
   AlbumRepo get albumRepo => _albumRepo!;
+  AlbumRepo get albumRepoRemote => _albumRepoRemote!;
   AlbumRepo get albumRepoLocal => _albumRepoLocal!;
+  AlbumRepo2 get albumRepo2 => _albumRepo2!;
+  AlbumRepo2 get albumRepo2Remote => _albumRepo2Remote!;
+  AlbumRepo2 get albumRepo2Local => _albumRepo2Local!;
   FaceRepo get faceRepo => _faceRepo!;
   FileRepo get fileRepo => _fileRepo!;
   FileRepo get fileRepoRemote => _fileRepoRemote!;
@@ -185,6 +230,9 @@ class DiContainer {
   TaggedFileRepo get taggedFileRepo => _taggedFileRepo!;
   LocalFileRepo get localFileRepo => _localFileRepo!;
   SearchRepo get searchRepo => _searchRepo!;
+  NcAlbumRepo get ncAlbumRepo => _ncAlbumRepo!;
+  NcAlbumRepo get ncAlbumRepoRemote => _ncAlbumRepoRemote!;
+  NcAlbumRepo get ncAlbumRepoLocal => _ncAlbumRepoLocal!;
   TouchManager get touchManager => _touchManager!;
 
   sql.SqliteDb get sqliteDb => _sqliteDb!;
@@ -195,11 +243,31 @@ class DiContainer {
     _albumRepo = v;
   }
 
+  set albumRepoRemote(AlbumRepo v) {
+    assert(_albumRepoRemote == null);
+    _albumRepoRemote = v;
+  }
+
   set albumRepoLocal(AlbumRepo v) {
     assert(_albumRepoLocal == null);
     _albumRepoLocal = v;
   }
 
+  set albumRepo2(AlbumRepo2 v) {
+    assert(_albumRepo2 == null);
+    _albumRepo2 = v;
+  }
+
+  set albumRepo2Remote(AlbumRepo2 v) {
+    assert(_albumRepo2Remote == null);
+    _albumRepo2Remote = v;
+  }
+
+  set albumRepo2Local(AlbumRepo2 v) {
+    assert(_albumRepo2Local == null);
+    _albumRepo2Local = v;
+  }
+
   set faceRepo(FaceRepo v) {
     assert(_faceRepo == null);
     _faceRepo = v;
@@ -280,6 +348,21 @@ class DiContainer {
     _searchRepo = v;
   }
 
+  set ncAlbumRepo(NcAlbumRepo v) {
+    assert(_ncAlbumRepo == null);
+    _ncAlbumRepo = v;
+  }
+
+  set ncAlbumRepoRemote(NcAlbumRepo v) {
+    assert(_ncAlbumRepoRemote == null);
+    _ncAlbumRepoRemote = v;
+  }
+
+  set ncAlbumRepoLocal(NcAlbumRepo v) {
+    assert(_ncAlbumRepoLocal == null);
+    _ncAlbumRepoLocal = v;
+  }
+
   set touchManager(TouchManager v) {
     assert(_touchManager == null);
     _touchManager = v;
@@ -296,9 +379,13 @@ class DiContainer {
   }
 
   AlbumRepo? _albumRepo;
+  AlbumRepo? _albumRepoRemote;
   // Explicitly request a AlbumRepo backed by local source
   AlbumRepo? _albumRepoLocal;
   FaceRepo? _faceRepo;
+  AlbumRepo2? _albumRepo2;
+  AlbumRepo2? _albumRepo2Remote;
+  AlbumRepo2? _albumRepo2Local;
   FileRepo? _fileRepo;
   // Explicitly request a FileRepo backed by remote source
   FileRepo? _fileRepoRemote;
@@ -316,6 +403,9 @@ class DiContainer {
   TaggedFileRepo? _taggedFileRepo;
   LocalFileRepo? _localFileRepo;
   SearchRepo? _searchRepo;
+  NcAlbumRepo? _ncAlbumRepo;
+  NcAlbumRepo? _ncAlbumRepoRemote;
+  NcAlbumRepo? _ncAlbumRepoLocal;
   TouchManager? _touchManager;
 
   sql.SqliteDb? _sqliteDb;
@@ -323,14 +413,28 @@ class DiContainer {
 }
 
 extension DiContainerExtension on DiContainer {
+  /// Uses remote repo if available
+  ///
+  /// Notice that not all repo support this
+  DiContainer withRemoteRepo() => copyWith(
+        albumRepo: OrNull(albumRepoRemote),
+        albumRepo2: OrNull(albumRepo2Remote),
+        fileRepo: OrNull(fileRepoRemote),
+        personRepo: OrNull(personRepoRemote),
+        tagRepo: OrNull(tagRepoRemote),
+        ncAlbumRepo: OrNull(ncAlbumRepoRemote),
+      );
+
   /// Uses local repo if available
   ///
   /// Notice that not all repo support this
   DiContainer withLocalRepo() => copyWith(
         albumRepo: OrNull(albumRepoLocal),
+        albumRepo2: OrNull(albumRepo2Local),
         fileRepo: OrNull(fileRepoLocal),
         personRepo: OrNull(personRepoLocal),
         tagRepo: OrNull(tagRepoLocal),
+        ncAlbumRepo: OrNull(ncAlbumRepoLocal),
       );
 
   DiContainer withLocalAlbumRepo() =>

app/lib/entity/album.dart

@@ -46,49 +46,56 @@ class Album with EquatableMixin {
     final jsonVersion = json["version"];
     JsonObj? result = json;
     if (jsonVersion < 2) {
-      result = upgraderFactory?.buildV1()?.call(result);
+      result = upgraderFactory?.buildV1()?.doJson(result);
       if (result == null) {
         _log.info("[fromJson] Version $jsonVersion not compatible");
         return null;
       }
     }
     if (jsonVersion < 3) {
-      result = upgraderFactory?.buildV2()?.call(result);
+      result = upgraderFactory?.buildV2()?.doJson(result);
       if (result == null) {
         _log.info("[fromJson] Version $jsonVersion not compatible");
         return null;
       }
     }
     if (jsonVersion < 4) {
-      result = upgraderFactory?.buildV3()?.call(result);
+      result = upgraderFactory?.buildV3()?.doJson(result);
       if (result == null) {
         _log.info("[fromJson] Version $jsonVersion not compatible");
         return null;
       }
     }
     if (jsonVersion < 5) {
-      result = upgraderFactory?.buildV4()?.call(result);
+      result = upgraderFactory?.buildV4()?.doJson(result);
       if (result == null) {
         _log.info("[fromJson] Version $jsonVersion not compatible");
         return null;
       }
     }
     if (jsonVersion < 6) {
-      result = upgraderFactory?.buildV5()?.call(result);
+      result = upgraderFactory?.buildV5()?.doJson(result);
       if (result == null) {
         _log.info("[fromJson] Version $jsonVersion not compatible");
         return null;
       }
     }
     if (jsonVersion < 7) {
-      result = upgraderFactory?.buildV6()?.call(result);
+      result = upgraderFactory?.buildV6()?.doJson(result);
       if (result == null) {
         _log.info("[fromJson] Version $jsonVersion not compatible");
         return null;
       }
     }
     if (jsonVersion < 8) {
-      result = upgraderFactory?.buildV7()?.call(result);
+      result = upgraderFactory?.buildV7()?.doJson(result);
+      if (result == null) {
+        _log.info("[fromJson] Version $jsonVersion not compatible");
+        return null;
+      }
+    }
+    if (jsonVersion < 9) {
+      result = upgraderFactory?.buildV8()?.doJson(result);
       if (result == null) {
         _log.info("[fromJson] Version $jsonVersion not compatible");
         return null;
@@ -217,7 +224,7 @@ class Album with EquatableMixin {
   final int savedVersion;
 
   /// versioning of this class, use to upgrade old persisted album
-  static const version = 8;
+  static const version = 9;
 
   static final _log = _$AlbumNpLog.log;
 }

app/lib/entity/album/cover_provider.dart

@@ -26,9 +26,6 @@ abstract class AlbumCoverProvider with EquatableMixin {
       case AlbumManualCoverProvider._type:
         return AlbumManualCoverProvider.fromJson(
             content.cast<String, dynamic>());
-      case AlbumMemoryCoverProvider._type:
-        return AlbumMemoryCoverProvider.fromJson(
-            content.cast<String, dynamic>());
       default:
         _log.shout("[fromJson] Unknown type: $type");
         throw ArgumentError.value(type, "type");
@@ -65,7 +62,7 @@ abstract class AlbumCoverProvider with EquatableMixin {
 /// Cover selected automatically by us
 @toString
 class AlbumAutoCoverProvider extends AlbumCoverProvider {
-  AlbumAutoCoverProvider({
+  const AlbumAutoCoverProvider({
     this.coverFile,
   });
 
@@ -73,48 +70,48 @@ class AlbumAutoCoverProvider extends AlbumCoverProvider {
     return AlbumAutoCoverProvider(
       coverFile: json["coverFile"] == null
           ? null
-          : File.fromJson(json["coverFile"].cast<String, dynamic>()),
+          : FileDescriptor.fromJson(json["coverFile"].cast<String, dynamic>()),
     );
   }
 
+  static FileDescriptor? getCoverByItems(List<AlbumItem> items) {
+    return items
+        .whereType<AlbumFileItem>()
+        .map((e) => e.file)
+        .where((element) =>
+            file_util.isSupportedFormat(element) &&
+            (element.hasPreview ?? false) &&
+            element.fileId != null)
+        .sorted(compareFileDateTimeDescending)
+        .firstOrNull;
+  }
+
   @override
   String toString() => _$toString();
 
   @override
-  getCover(Album album) {
-    if (coverFile == null) {
-      try {
+  FileDescriptor? getCover(Album album) {
+    if (coverFile == null && album.provider is AlbumStaticProvider) {
       // use the latest file as cover
-        return AlbumStaticProvider.of(album)
-            .items
-            .whereType<AlbumFileItem>()
-            .map((e) => e.file)
-            .where((element) =>
-                file_util.isSupportedFormat(element) &&
-                (element.hasPreview ?? false))
-            .sorted(compareFileDateTimeDescending)
-            .first;
-      } catch (_) {
-        return null;
-      }
+      return getCoverByItems(AlbumStaticProvider.of(album).items);
     } else {
       return coverFile;
     }
   }
 
   @override
-  get props => [
+  List<Object?> get props => [
         coverFile,
       ];
 
   @override
-  _toContentJson() {
+  JsonObj _toContentJson() {
     return {
-      if (coverFile != null) "coverFile": coverFile!.toJson(),
+      if (coverFile != null) "coverFile": coverFile!.toFdJson(),
     };
   }
 
-  final File? coverFile;
+  final FileDescriptor? coverFile;
 
   static const _type = "auto";
 }
@@ -122,48 +119,12 @@ class AlbumAutoCoverProvider extends AlbumCoverProvider {
 /// Cover picked by user
 @toString
 class AlbumManualCoverProvider extends AlbumCoverProvider {
-  AlbumManualCoverProvider({
+  const AlbumManualCoverProvider({
     required this.coverFile,
   });
 
   factory AlbumManualCoverProvider.fromJson(JsonObj json) {
     return AlbumManualCoverProvider(
-      coverFile: File.fromJson(json["coverFile"].cast<String, dynamic>()),
-    );
-  }
-
-  @override
-  String toString() => _$toString();
-
-  @override
-  getCover(Album album) => coverFile;
-
-  @override
-  get props => [
-        coverFile,
-      ];
-
-  @override
-  _toContentJson() {
-    return {
-      "coverFile": coverFile.toJson(),
-    };
-  }
-
-  final File coverFile;
-
-  static const _type = "manual";
-}
-
-/// Cover selected when building a Memory album
-@toString
-class AlbumMemoryCoverProvider extends AlbumCoverProvider {
-  AlbumMemoryCoverProvider({
-    required this.coverFile,
-  });
-
-  factory AlbumMemoryCoverProvider.fromJson(JsonObj json) {
-    return AlbumMemoryCoverProvider(
       coverFile:
           FileDescriptor.fromJson(json["coverFile"].cast<String, dynamic>()),
     );
@@ -173,19 +134,21 @@ class AlbumMemoryCoverProvider extends AlbumCoverProvider {
   String toString() => _$toString();
 
   @override
-  getCover(Album album) => coverFile;
+  FileDescriptor? getCover(Album album) => coverFile;
 
   @override
-  get props => [
+  List<Object?> get props => [
         coverFile,
       ];
 
   @override
-  _toContentJson() => {
-        "coverFile": coverFile.toJson(),
+  JsonObj _toContentJson() {
+    return {
+      "coverFile": coverFile.toFdJson(),
     };
+  }
 
   final FileDescriptor coverFile;
 
-  static const _type = "memory";
+  static const _type = "manual";
 }

app/lib/entity/album/cover_provider.g.dart

@@ -20,20 +20,13 @@ extension _$AlbumCoverProviderNpLog on AlbumCoverProvider {
 extension _$AlbumAutoCoverProviderToString on AlbumAutoCoverProvider {
   String _$toString() {
     // ignore: unnecessary_string_interpolations
-    return "AlbumAutoCoverProvider {coverFile: ${coverFile == null ? null : "${coverFile!.path}"}}";
+    return "AlbumAutoCoverProvider {coverFile: ${coverFile == null ? null : "${coverFile!.fdPath}"}}";
   }
 }
 
 extension _$AlbumManualCoverProviderToString on AlbumManualCoverProvider {
   String _$toString() {
     // ignore: unnecessary_string_interpolations
-    return "AlbumManualCoverProvider {coverFile: ${coverFile.path}}";
-  }
-}
-
-extension _$AlbumMemoryCoverProviderToString on AlbumMemoryCoverProvider {
-  String _$toString() {
-    // ignore: unnecessary_string_interpolations
-    return "AlbumMemoryCoverProvider {coverFile: ${coverFile.fdPath}}";
+    return "AlbumManualCoverProvider {coverFile: ${coverFile.fdPath}}";
   }
 }

app/lib/entity/album/data_source.dart

@@ -1,106 +1,76 @@
-import 'dart:convert';
-import 'dart:math';
-
-import 'package:clock/clock.dart';
-import 'package:drift/drift.dart' as sql;
-import 'package:kiwi/kiwi.dart';
 import 'package:logging/logging.dart';
 import 'package:nc_photos/account.dart';
 import 'package:nc_photos/di_container.dart';
 import 'package:nc_photos/entity/album.dart';
-import 'package:nc_photos/entity/album/upgrader.dart';
+import 'package:nc_photos/entity/album/data_source2.dart';
+import 'package:nc_photos/entity/album/repo2.dart';
 import 'package:nc_photos/entity/file.dart';
-import 'package:nc_photos/entity/file/data_source.dart';
 import 'package:nc_photos/entity/file_descriptor.dart';
 import 'package:nc_photos/entity/sqlite/database.dart' as sql;
-import 'package:nc_photos/entity/sqlite/type_converter.dart';
 import 'package:nc_photos/exception.dart';
 import 'package:nc_photos/exception_event.dart';
-import 'package:nc_photos/future_util.dart' as future_util;
 import 'package:nc_photos/iterable_extension.dart';
-import 'package:nc_photos/or_null.dart';
-import 'package:nc_photos/remote_storage_util.dart' as remote_storage_util;
-import 'package:nc_photos/use_case/get_file_binary.dart';
-import 'package:nc_photos/use_case/ls_single_file.dart';
-import 'package:nc_photos/use_case/put_file_binary.dart';
 import 'package:np_codegen/np_codegen.dart';
 
 part 'data_source.g.dart';
 
+/// Backward compatibility only, use [AlbumRemoteDataSource2] instead
 @npLog
 class AlbumRemoteDataSource implements AlbumDataSource {
   @override
   get(Account account, File albumFile) async {
     _log.info("[get] ${albumFile.path}");
-    const fileRepo = FileRepo(FileWebdavDataSource());
-    final data = await GetFileBinary(fileRepo)(account, albumFile);
-    try {
-      return Album.fromJson(
-        jsonDecode(utf8.decode(data)),
-        upgraderFactory: DefaultAlbumUpgraderFactory(
-          account: account,
-          albumFile: albumFile,
-          logFilePath: albumFile.path,
-        ),
-      )!
-          .copyWith(
-        lastUpdated: OrNull(null),
-        albumFile: OrNull(albumFile),
+    final albums = await const AlbumRemoteDataSource2().getAlbums(
+      account,
+      [albumFile],
+      onError: (_, error, stackTrace) {
+        Error.throwWithStackTrace(error, stackTrace ?? StackTrace.current);
+      },
     );
-    } catch (e, stacktrace) {
-      dynamic d = data;
-      try {
-        d = utf8.decode(data);
-      } catch (_) {}
-      _log.severe("[get] Invalid json data: $d", e, stacktrace);
-      throw const FormatException("Invalid album format");
-    }
+    return albums.first;
   }
 
   @override
   getAll(Account account, List<File> albumFiles) async* {
     _log.info(
         "[getAll] ${albumFiles.map((f) => f.filename).toReadableString()}");
-    final results = await future_util.waitOr(
-      albumFiles.map((f) => get(account, f)),
-      (error, stackTrace) => ExceptionEvent(error, stackTrace),
+    final failed = <String, Map>{};
+    final albums = await const AlbumRemoteDataSource2().getAlbums(
+      account,
+      albumFiles,
+      onError: (v, error, stackTrace) {
+        failed[v.path] = {
+          "file": v,
+          "error": error,
+          "stackTrace": stackTrace,
+        };
+      },
     );
-    for (final r in results) {
-      yield r;
+    var i = 0;
+    for (final af in albumFiles) {
+      final v = failed[af.path];
+      if (v != null) {
+        yield ExceptionEvent(v["error"], v["stackTrace"]);
+      } else {
+        yield albums[i++];
+      }
     }
   }
 
   @override
   create(Account account, Album album) async {
     _log.info("[create]");
-    final fileName = _makeAlbumFileName();
-    final filePath =
-        "${remote_storage_util.getRemoteAlbumsDir(account)}/$fileName";
-    final c = KiwiContainer().resolve<DiContainer>();
-    await PutFileBinary(c.fileRepo)(account, filePath,
-        const Utf8Encoder().convert(jsonEncode(album.toRemoteJson())),
-        shouldCreateMissingDir: true);
-    // query album file
-    final newFile = await LsSingleFile(c)(account, filePath);
-    return album.copyWith(albumFile: OrNull(newFile));
+    return const AlbumRemoteDataSource2().create(account, album);
   }
 
   @override
   update(Account account, Album album) async {
     _log.info("[update] ${album.albumFile!.path}");
-    const fileRepo = FileRepo(FileWebdavDataSource());
-    await PutFileBinary(fileRepo)(account, album.albumFile!.path,
-        const Utf8Encoder().convert(jsonEncode(album.toRemoteJson())));
-  }
-
-  String _makeAlbumFileName() {
-    // just make up something
-    final timestamp = clock.now().millisecondsSinceEpoch;
-    final random = Random().nextInt(0xFFFFFF);
-    return "${timestamp.toRadixString(16)}-${random.toRadixString(16).padLeft(6, '0')}.nc_album.json";
+    return const AlbumRemoteDataSource2().update(account, album);
   }
 }
 
+/// Backward compatibility only, use [AlbumSqliteDbDataSource2] instead
 @npLog
 class AlbumSqliteDbDataSource implements AlbumDataSource {
   AlbumSqliteDbDataSource(this._c);
@@ -119,64 +89,29 @@ class AlbumSqliteDbDataSource implements AlbumDataSource {
   getAll(Account account, List<File> albumFiles) async* {
     _log.info(
         "[getAll] ${albumFiles.map((f) => f.filename).toReadableString()}");
-    late final List<sql.CompleteFile> dbFiles;
-    late final List<sql.AlbumWithShare> albumWithShares;
-    await _c.sqliteDb.use((db) async {
-      dbFiles = await db.completeFilesByFileIds(
-        albumFiles.map((f) => f.fileId!),
-        appAccount: account,
-      );
-      final query = db.select(db.albums).join([
-        sql.leftOuterJoin(
-            db.albumShares, db.albumShares.album.equalsExp(db.albums.rowId)),
-      ])
-        ..where(db.albums.file.isIn(dbFiles.map((f) => f.file.rowId)));
-      albumWithShares = await query
-          .map((r) => sql.AlbumWithShare(
-              r.readTable(db.albums), r.readTableOrNull(db.albumShares)))
-          .get();
-    });
-
-    // group entries together
-    final fileRowIdMap = <int, sql.CompleteFile>{};
-    for (var f in dbFiles) {
-      fileRowIdMap[f.file.rowId] = f;
-    }
-    final fileIdMap = <int, Map>{};
-    for (final s in albumWithShares) {
-      final f = fileRowIdMap[s.album.file];
-      if (f == null) {
-        _log.severe("[getAll] File missing for album (rowId: ${s.album.rowId}");
-      } else {
-        if (!fileIdMap.containsKey(f.file.fileId)) {
-          fileIdMap[f.file.fileId] = {
-            "file": f,
-            "album": s.album,
+    final failed = <String, Map>{};
+    final albums = await AlbumSqliteDbDataSource2(_c.sqliteDb).getAlbums(
+      account,
+      albumFiles,
+      onError: (v, error, stackTrace) {
+        failed[v.path] = {
+          "file": v,
+          "error": error,
+          "stackTrace": stackTrace,
         };
-        }
-        if (s.share != null) {
-          (fileIdMap[f.file.fileId]!["shares"] ??= <sql.AlbumShare>[])
-              .add(s.share!);
-        }
-      }
-    }
-
-    // sort as the input list
-    for (final item in albumFiles.map((f) => fileIdMap[f.fileId])) {
-      if (item == null) {
-        // cache not found
-        yield CacheNotFoundException();
+      },
+    );
+    var i = 0;
+    for (final af in albumFiles) {
+      final v = failed[af.path];
+      if (v != null) {
+        if (v["error"] is CacheNotFoundException) {
+          yield const CacheNotFoundException();
         } else {
-        try {
-          final f = SqliteFileConverter.fromSql(
-              account.userId.toString(), item["file"]);
-          yield SqliteAlbumConverter.fromSql(
-              item["album"], f, item["shares"] ?? []);
-        } catch (e, stackTrace) {
-          _log.severe(
-              "[getAll] Failed while converting DB entry", e, stackTrace);
-          yield ExceptionEvent(e, stackTrace);
+          yield ExceptionEvent(v["error"], v["stackTrace"]);
         }
+      } else {
+        yield albums[i++];
       }
     }
   }
@@ -184,64 +119,22 @@ class AlbumSqliteDbDataSource implements AlbumDataSource {
   @override
   create(Account account, Album album) async {
     _log.info("[create]");
-    throw UnimplementedError();
+    return AlbumSqliteDbDataSource2(_c.sqliteDb).create(account, album);
   }
 
   @override
   update(Account account, Album album) async {
     _log.info("[update] ${album.albumFile!.path}");
-    await _c.sqliteDb.use((db) async {
-      final rowIds =
-          await db.accountFileRowIdsOf(album.albumFile!, appAccount: account);
-      final insert = SqliteAlbumConverter.toSql(
-          album, rowIds.fileRowId, album.albumFile!.etag!);
-      var rowId = await _updateCache(db, rowIds.fileRowId, insert.album);
-      if (rowId == null) {
-        // new album, need insert
-        _log.info("[update] Insert new album");
-        final insertedAlbum =
-            await db.into(db.albums).insertReturning(insert.album);
-        rowId = insertedAlbum.rowId;
-      } else {
-        await (db.delete(db.albumShares)..where((t) => t.album.equals(rowId)))
-            .go();
-      }
-      if (insert.albumShares.isNotEmpty) {
-        await db.batch((batch) {
-          batch.insertAll(
-            db.albumShares,
-            insert.albumShares.map((s) => s.copyWith(album: sql.Value(rowId!))),
-          );
-        });
-      }
-    });
-  }
-
-  Future<int?> _updateCache(
-      sql.SqliteDb db, int dbFileRowId, sql.AlbumsCompanion dbAlbum) async {
-    final rowIdQuery = db.selectOnly(db.albums)
-      ..addColumns([db.albums.rowId])
-      ..where(db.albums.file.equals(dbFileRowId))
-      ..limit(1);
-    final rowId =
-        await rowIdQuery.map((r) => r.read(db.albums.rowId)!).getSingleOrNull();
-    if (rowId == null) {
-      // new album
-      return null;
-    }
-
-    await (db.update(db.albums)..where((t) => t.rowId.equals(rowId)))
-        .write(dbAlbum);
-    return rowId;
+    return AlbumSqliteDbDataSource2(_c.sqliteDb).update(account, album);
   }
 
   final DiContainer _c;
 }
 
+/// Backward compatibility only, use [CachedAlbumRepo2] instead
 @npLog
 class AlbumCachedDataSource implements AlbumDataSource {
-  AlbumCachedDataSource(DiContainer c)
-      : _sqliteDbSrc = AlbumSqliteDbDataSource(c);
+  AlbumCachedDataSource(DiContainer c) : sqliteDb = c.sqliteDb;
 
   @override
   get(Account account, File albumFile) async {
@@ -251,58 +144,31 @@ class AlbumCachedDataSource implements AlbumDataSource {
 
   @override
   getAll(Account account, List<File> albumFiles) async* {
-    var i = 0;
-    await for (final cache in _sqliteDbSrc.getAll(account, albumFiles)) {
-      final albumFile = albumFiles[i++];
-      if (_validateCache(cache, albumFile)) {
-        yield cache;
-      } else {
-        // no cache
-        final remote = await _remoteSrc.get(account, albumFile);
-        await _cacheResult(account, remote);
-        yield remote;
-      }
+    final repo = CachedAlbumRepo2(
+      const AlbumRemoteDataSource2(),
+      AlbumSqliteDbDataSource2(sqliteDb),
+    );
+    final albums = await repo.getAlbums(account, albumFiles).last;
+    for (final a in albums) {
+      yield a;
     }
   }
 
   @override
-  update(Account account, Album album) async {
-    await _remoteSrc.update(account, album);
-    await _sqliteDbSrc.update(account, album);
+  update(Account account, Album album) {
+    return CachedAlbumRepo2(
+      const AlbumRemoteDataSource2(),
+      AlbumSqliteDbDataSource2(sqliteDb),
+    ).update(account, album);
   }
 
   @override
-  create(Account account, Album album) => _remoteSrc.create(account, album);
-
-  Future<void> _cacheResult(Account account, Album result) {
-    return _sqliteDbSrc.update(account, result);
+  create(Account account, Album album) {
+    return CachedAlbumRepo2(
+      const AlbumRemoteDataSource2(),
+      AlbumSqliteDbDataSource2(sqliteDb),
+    ).create(account, album);
   }
 
-  bool _validateCache(dynamic cache, File albumFile) {
-    if (cache is Album) {
-      if (cache.albumFile!.etag?.isNotEmpty == true &&
-          cache.albumFile!.etag == albumFile.etag) {
-        // cache is good
-        _log.fine("[_validateCache] etag matched for ${albumFile.path}");
-        return true;
-      } else {
-        _log.info(
-            "[_validateCache] Remote content updated for ${albumFile.path}");
-        return false;
-      }
-    } else if (cache is CacheNotFoundException) {
-      // normal when there's no cache
-      return false;
-    } else if (cache is ExceptionEvent) {
-      _log.shout(
-          "[_validateCache] Cache failure", cache.error, cache.stackTrace);
-      return false;
-    } else {
-      _log.shout("[_validateCache] Unknown type: ${cache.runtimeType}");
-      return false;
-    }
-  }
-
-  final _remoteSrc = AlbumRemoteDataSource();
-  final AlbumSqliteDbDataSource _sqliteDbSrc;
+  final sql.SqliteDb sqliteDb;
 }

app/lib/entity/album/data_source2.dart

@@ -0,0 +1,252 @@
+import 'dart:convert';
+import 'dart:math';
+
+import 'package:clock/clock.dart';
+import 'package:collection/collection.dart';
+import 'package:drift/drift.dart' as sql;
+import 'package:kiwi/kiwi.dart';
+import 'package:logging/logging.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/di_container.dart';
+import 'package:nc_photos/entity/album.dart';
+import 'package:nc_photos/entity/album/repo2.dart';
+import 'package:nc_photos/entity/album/upgrader.dart';
+import 'package:nc_photos/entity/file.dart';
+import 'package:nc_photos/entity/file/data_source.dart';
+import 'package:nc_photos/entity/sqlite/database.dart' as sql;
+import 'package:nc_photos/entity/sqlite/type_converter.dart' as sql;
+import 'package:nc_photos/exception.dart';
+import 'package:nc_photos/or_null.dart';
+import 'package:nc_photos/remote_storage_util.dart' as remote_storage_util;
+import 'package:nc_photos/use_case/get_file_binary.dart';
+import 'package:nc_photos/use_case/ls_single_file.dart';
+import 'package:nc_photos/use_case/put_file_binary.dart';
+import 'package:np_codegen/np_codegen.dart';
+import 'package:np_common/type.dart';
+
+part 'data_source2.g.dart';
+
+@npLog
+class AlbumRemoteDataSource2 implements AlbumDataSource2 {
+  const AlbumRemoteDataSource2();
+
+  @override
+  Future<List<Album>> getAlbums(
+    Account account,
+    List<File> albumFiles, {
+    ErrorWithValueHandler<File>? onError,
+  }) async {
+    final results = await Future.wait(albumFiles.map((f) async {
+      try {
+        return await _getSingle(account, f);
+      } catch (e, stackTrace) {
+        onError?.call(f, e, stackTrace);
+        return null;
+      }
+    }));
+    return results.whereNotNull().toList();
+  }
+
+  @override
+  Future<Album> create(Account account, Album album) async {
+    _log.info("[create] ${album.name}");
+    final fileName = _makeAlbumFileName();
+    final filePath =
+        "${remote_storage_util.getRemoteAlbumsDir(account)}/$fileName";
+    final c = KiwiContainer().resolve<DiContainer>();
+    await PutFileBinary(c.fileRepo)(
+      account,
+      filePath,
+      const Utf8Encoder().convert(jsonEncode(album.toRemoteJson())),
+      shouldCreateMissingDir: true,
+    );
+    // query album file
+    final newFile = await LsSingleFile(c)(account, filePath);
+    return album.copyWith(albumFile: OrNull(newFile));
+  }
+
+  @override
+  Future<void> update(Account account, Album album) async {
+    _log.info("[update] ${album.albumFile!.path}");
+    const fileRepo = FileRepo(FileWebdavDataSource());
+    await PutFileBinary(fileRepo)(
+      account,
+      album.albumFile!.path,
+      const Utf8Encoder().convert(jsonEncode(album.toRemoteJson())),
+    );
+  }
+
+  Future<Album> _getSingle(Account account, File albumFile) async {
+    _log.info("[_getSingle] Getting ${albumFile.path}");
+    const fileRepo = FileRepo(FileWebdavDataSource());
+    final data = await GetFileBinary(fileRepo)(account, albumFile);
+    try {
+      final album = Album.fromJson(
+        jsonDecode(utf8.decode(data)),
+        upgraderFactory: DefaultAlbumUpgraderFactory(
+          account: account,
+          albumFile: albumFile,
+          logFilePath: albumFile.path,
+        ),
+      );
+      return album!.copyWith(
+        lastUpdated: OrNull(null),
+        albumFile: OrNull(albumFile),
+      );
+    } catch (e, stacktrace) {
+      dynamic d = data;
+      try {
+        d = utf8.decode(data);
+      } catch (_) {}
+      _log.severe("[_getSingle] Invalid json data: $d", e, stacktrace);
+      throw const FormatException("Invalid album format");
+    }
+  }
+
+  String _makeAlbumFileName() {
+    // just make up something
+    final timestamp = clock.now().millisecondsSinceEpoch;
+    final random = Random().nextInt(0xFFFFFF);
+    return "${timestamp.toRadixString(16)}-${random.toRadixString(16).padLeft(6, '0')}.nc_album.json";
+  }
+}
+
+@npLog
+class AlbumSqliteDbDataSource2 implements AlbumDataSource2 {
+  const AlbumSqliteDbDataSource2(this.sqliteDb);
+
+  @override
+  Future<List<Album>> getAlbums(
+    Account account,
+    List<File> albumFiles, {
+    ErrorWithValueHandler<File>? onError,
+  }) async {
+    late final List<sql.CompleteFile> dbFiles;
+    late final List<sql.AlbumWithShare> albumWithShares;
+    await sqliteDb.use((db) async {
+      dbFiles = await db.completeFilesByFileIds(
+        albumFiles.map((f) => f.fileId!),
+        appAccount: account,
+      );
+      final query = db.select(db.albums).join([
+        sql.leftOuterJoin(
+            db.albumShares, db.albumShares.album.equalsExp(db.albums.rowId)),
+      ])
+        ..where(db.albums.file.isIn(dbFiles.map((f) => f.file.rowId)));
+      albumWithShares = await query
+          .map((r) => sql.AlbumWithShare(
+              r.readTable(db.albums), r.readTableOrNull(db.albumShares)))
+          .get();
+    });
+
+    // group entries together
+    final fileRowIdMap = <int, sql.CompleteFile>{};
+    for (var f in dbFiles) {
+      fileRowIdMap[f.file.rowId] = f;
+    }
+    final fileIdMap = <int, Map>{};
+    for (final s in albumWithShares) {
+      final f = fileRowIdMap[s.album.file];
+      if (f == null) {
+        _log.severe(
+            "[getAlbums] File missing for album (rowId: ${s.album.rowId}");
+      } else {
+        fileIdMap[f.file.fileId] ??= {
+          "file": f,
+          "album": s.album,
+        };
+        if (s.share != null) {
+          (fileIdMap[f.file.fileId]!["shares"] ??= <sql.AlbumShare>[])
+              .add(s.share!);
+        }
+      }
+    }
+
+    // sort as the input list
+    return albumFiles
+        .map((f) {
+          final item = fileIdMap[f.fileId];
+          if (item == null) {
+            // cache not found
+            onError?.call(
+                f, const CacheNotFoundException(), StackTrace.current);
+            return null;
+          } else {
+            try {
+              final queriedFile = sql.SqliteFileConverter.fromSql(
+                  account.userId.toString(), item["file"]);
+              var dbAlbum = item["album"] as sql.Album;
+              if (dbAlbum.version < 9) {
+                dbAlbum = AlbumUpgraderV8(logFilePath: queriedFile.path)
+                    .doDb(dbAlbum)!;
+              }
+              return sql.SqliteAlbumConverter.fromSql(
+                  dbAlbum, queriedFile, item["shares"] ?? []);
+            } catch (e, stackTrace) {
+              _log.severe("[getAlbums] Failed while converting DB entry", e,
+                  stackTrace);
+              onError?.call(f, e, stackTrace);
+              return null;
+            }
+          }
+        })
+        .whereNotNull()
+        .toList();
+  }
+
+  @override
+  Future<Album> create(Account account, Album album) async {
+    _log.info("[create] ${album.name}");
+    throw UnimplementedError();
+  }
+
+  @override
+  Future<void> update(Account account, Album album) async {
+    _log.info("[update] ${album.albumFile!.path}");
+    await sqliteDb.use((db) async {
+      final rowIds =
+          await db.accountFileRowIdsOf(album.albumFile!, appAccount: account);
+      final insert = sql.SqliteAlbumConverter.toSql(
+          album, rowIds.fileRowId, album.albumFile!.etag!);
+      var rowId = await _updateCache(db, rowIds.fileRowId, insert.album);
+      if (rowId == null) {
+        // new album, need insert
+        _log.info("[update] Insert new album");
+        final insertedAlbum =
+            await db.into(db.albums).insertReturning(insert.album);
+        rowId = insertedAlbum.rowId;
+      } else {
+        await (db.delete(db.albumShares)..where((t) => t.album.equals(rowId)))
+            .go();
+      }
+      if (insert.albumShares.isNotEmpty) {
+        await db.batch((batch) {
+          batch.insertAll(
+            db.albumShares,
+            insert.albumShares.map((s) => s.copyWith(album: sql.Value(rowId!))),
+          );
+        });
+      }
+    });
+  }
+
+  Future<int?> _updateCache(
+      sql.SqliteDb db, int dbFileRowId, sql.AlbumsCompanion dbAlbum) async {
+    final rowIdQuery = db.selectOnly(db.albums)
+      ..addColumns([db.albums.rowId])
+      ..where(db.albums.file.equals(dbFileRowId))
+      ..limit(1);
+    final rowId =
+        await rowIdQuery.map((r) => r.read(db.albums.rowId)!).getSingleOrNull();
+    if (rowId == null) {
+      // new album
+      return null;
+    }
+
+    await (db.update(db.albums)..where((t) => t.rowId.equals(rowId)))
+        .write(dbAlbum);
+    return rowId;
+  }
+
+  final sql.SqliteDb sqliteDb;
+}

app/lib/entity/album/data_source2.g.dart

@@ -0,0 +1,22 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'data_source2.dart';
+
+// **************************************************************************
+// NpLogGenerator
+// **************************************************************************
+
+extension _$AlbumRemoteDataSource2NpLog on AlbumRemoteDataSource2 {
+  // ignore: unused_element
+  Logger get _log => log;
+
+  static final log = Logger("entity.album.data_source2.AlbumRemoteDataSource2");
+}
+
+extension _$AlbumSqliteDbDataSource2NpLog on AlbumSqliteDbDataSource2 {
+  // ignore: unused_element
+  Logger get _log => log;
+
+  static final log =
+      Logger("entity.album.data_source2.AlbumSqliteDbDataSource2");
+}

app/lib/entity/album/provider.dart

@@ -263,49 +263,3 @@ class AlbumTagProvider extends AlbumDynamicProvider {
 
   static const _type = "tag";
 }
-
-/// Smart albums are created only by the app and not the user
-abstract class AlbumSmartProvider extends AlbumProviderBase {
-  AlbumSmartProvider({
-    DateTime? latestItemTime,
-  }) : super(latestItemTime: latestItemTime);
-
-  @override
-  AlbumSmartProvider copyWith({
-    OrNull<DateTime>? latestItemTime,
-  }) {
-    // Smart albums do not support copying
-    throw UnimplementedError();
-  }
-
-  @override
-  toContentJson() {
-    // Smart albums do not support saving
-    throw UnimplementedError();
-  }
-}
-
-/// Memory album is created based on dates
-@ToString(extraParams: r"{bool isDeep = false}")
-class AlbumMemoryProvider extends AlbumSmartProvider {
-  AlbumMemoryProvider({
-    required this.year,
-    required this.month,
-    required this.day,
-  }) : super(latestItemTime: DateTime(year, month, day));
-
-  @override
-  String toString({bool isDeep = false}) => _$toString(isDeep: isDeep);
-
-  @override
-  get props => [
-        ...super.props,
-        year,
-        month,
-        day,
-      ];
-
-  final int year;
-  final int month;
-  final int day;
-}

app/lib/entity/album/provider.g.dart

@@ -37,10 +37,3 @@ extension _$AlbumTagProviderToString on AlbumTagProvider {
     return "AlbumTagProvider {latestItemTime: $latestItemTime, tags: ${tags.map((t) => t.displayName).toReadableString()}}";
   }
 }
-
-extension _$AlbumMemoryProviderToString on AlbumMemoryProvider {
-  String _$toString({bool isDeep = false}) {
-    // ignore: unnecessary_string_interpolations
-    return "AlbumMemoryProvider {latestItemTime: $latestItemTime, year: $year, month: $month, day: $day}";
-  }
-}

app/lib/entity/album/repo2.dart

@@ -0,0 +1,152 @@
+import 'dart:async';
+
+import 'package:collection/collection.dart';
+import 'package:logging/logging.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/entity/album.dart';
+import 'package:nc_photos/entity/file.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:nc_photos/exception.dart';
+import 'package:np_codegen/np_codegen.dart';
+import 'package:np_common/type.dart';
+
+part 'repo2.g.dart';
+
+abstract class AlbumRepo2 {
+  /// Query all [Album]s defined by [albumFiles]
+  Stream<List<Album>> getAlbums(
+    Account account,
+    List<File> albumFiles, {
+    ErrorWithValueHandler<File>? onError,
+  });
+
+  /// Create a new [album]
+  Future<Album> create(Account account, Album album);
+
+  /// Update an [album]
+  Future<void> update(Account account, Album album);
+}
+
+class BasicAlbumRepo2 implements AlbumRepo2 {
+  const BasicAlbumRepo2(this.dataSrc);
+
+  @override
+  Stream<List<Album>> getAlbums(
+    Account account,
+    List<File> albumFiles, {
+    ErrorWithValueHandler<File>? onError,
+  }) async* {
+    yield await dataSrc.getAlbums(account, albumFiles, onError: onError);
+  }
+
+  @override
+  Future<Album> create(Account account, Album album) =>
+      dataSrc.create(account, album);
+
+  @override
+  Future<void> update(Account account, Album album) =>
+      dataSrc.update(account, album);
+
+  final AlbumDataSource2 dataSrc;
+}
+
+@npLog
+class CachedAlbumRepo2 implements AlbumRepo2 {
+  const CachedAlbumRepo2(this.remoteDataSrc, this.cacheDataSrc);
+
+  @override
+  Stream<List<Album>> getAlbums(
+    Account account,
+    List<File> albumFiles, {
+    ErrorWithValueHandler<File>? onError,
+  }) async* {
+    // get cache
+    final cached = <Album>[];
+    final failed = <File>[];
+    try {
+      cached.addAll(await cacheDataSrc.getAlbums(
+        account,
+        albumFiles,
+        onError: (f, e, stackTrace) {
+          failed.add(f);
+          if (e is CacheNotFoundException) {
+            // not in cache, normal
+          } else {
+            _log.shout("[getAlbums] Cache failure", e, stackTrace);
+          }
+        },
+      ));
+      yield cached;
+    } catch (e, stackTrace) {
+      _log.shout("[getAlbums] Failed while getAlbums", e, stackTrace);
+    }
+    final cachedGroup = cached.groupListsBy((c) {
+      try {
+        return _validateCache(
+            c, albumFiles.firstWhere(c.albumFile!.compareServerIdentity));
+      } catch (_) {
+        return false;
+      }
+    });
+
+    // query remote
+    final outdated = [
+      ...failed,
+      ...cachedGroup[false]?.map((e) =>
+              albumFiles.firstWhere(e.albumFile!.compareServerIdentity)) ??
+          const <File>[],
+    ];
+    final remote =
+        await remoteDataSrc.getAlbums(account, outdated, onError: onError);
+    yield (cachedGroup[true] ?? []) + remote;
+
+    // update cache
+    for (final a in remote) {
+      unawaited(cacheDataSrc.update(account, a));
+    }
+  }
+
+  @override
+  Future<Album> create(Account account, Album album) =>
+      remoteDataSrc.create(account, album);
+
+  @override
+  Future<void> update(Account account, Album album) async {
+    await remoteDataSrc.update(account, album);
+    try {
+      await cacheDataSrc.update(account, album);
+    } catch (e, stackTrace) {
+      _log.warning("[update] Failed to update cache", e, stackTrace);
+    }
+  }
+
+  /// Return true if the cached album is considered up to date
+  bool _validateCache(Album cache, File albumFile) {
+    if (cache.albumFile!.etag?.isNotEmpty == true &&
+        cache.albumFile!.etag == albumFile.etag) {
+      // cache is good
+      _log.fine("[_validateCache] etag matched for ${albumFile.path}");
+      return true;
+    } else {
+      _log.info(
+          "[_validateCache] Remote content updated for ${albumFile.path}");
+      return false;
+    }
+  }
+
+  final AlbumDataSource2 remoteDataSrc;
+  final AlbumDataSource2 cacheDataSrc;
+}
+
+abstract class AlbumDataSource2 {
+  /// Query all [Album]s defined by [albumFiles]
+  Future<List<Album>> getAlbums(
+    Account account,
+    List<File> albumFiles, {
+    ErrorWithValueHandler<File>? onError,
+  });
+
+  Future<Album> create(Account account, Album album);
+
+  Future<void> update(Account account, Album album);
+}

app/lib/entity/album/repo2.g.dart

@@ -1,14 +1,14 @@
 // GENERATED CODE - DO NOT MODIFY BY HAND
 
-part of 'list_favorite.dart';
+part of 'repo2.dart';
 
 // **************************************************************************
 // NpLogGenerator
 // **************************************************************************
 
-extension _$ListFavoriteNpLog on ListFavorite {
+extension _$CachedAlbumRepo2NpLog on CachedAlbumRepo2 {
   // ignore: unused_element
   Logger get _log => log;
 
-  static final log = Logger("use_case.list_favorite.ListFavorite");
+  static final log = Logger("entity.album.repo2.CachedAlbumRepo2");
 }

app/lib/entity/album/sort_provider.dart

@@ -1,14 +1,12 @@
-import 'package:collection/collection.dart';
 import 'package:equatable/equatable.dart';
 import 'package:logging/logging.dart';
 import 'package:nc_photos/entity/album/item.dart';
-import 'package:nc_photos/entity/file.dart';
-import 'package:nc_photos/entity/file_descriptor.dart';
-import 'package:nc_photos/iterable_extension.dart';
+import 'package:nc_photos/entity/collection_item/album_item_adapter.dart';
+import 'package:nc_photos/entity/collection_item/sorter.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
 import 'package:np_codegen/np_codegen.dart';
 import 'package:np_common/type.dart';
 import 'package:to_string/to_string.dart';
-import 'package:tuple/tuple.dart';
 
 part 'sort_provider.g.dart';
 
@@ -33,6 +31,22 @@ abstract class AlbumSortProvider with EquatableMixin {
     }
   }
 
+  factory AlbumSortProvider.fromCollectionItemSort(
+      CollectionItemSort itemSort) {
+    switch (itemSort) {
+      case CollectionItemSort.manual:
+        return const AlbumNullSortProvider();
+      case CollectionItemSort.dateAscending:
+        return const AlbumTimeSortProvider(isAscending: true);
+      case CollectionItemSort.dateDescending:
+        return const AlbumTimeSortProvider(isAscending: false);
+      case CollectionItemSort.nameAscending:
+        return const AlbumFilenameSortProvider(isAscending: true);
+      case CollectionItemSort.nameDescending:
+        return const AlbumFilenameSortProvider(isAscending: false);
+    }
+  }
+
   JsonObj toJson() {
     String getType() {
       if (this is AlbumNullSortProvider) {
@@ -53,7 +67,31 @@ abstract class AlbumSortProvider with EquatableMixin {
   }
 
   /// Return a sorted copy of [items]
-  List<AlbumItem> sort(List<AlbumItem> items);
+  List<AlbumItem> sort(List<AlbumItem> items) {
+    final type = toCollectionItemSort();
+    final sorter = CollectionSorter.fromSortType(type);
+    return sorter(items.map(AlbumAdaptedCollectionItem.fromItem).toList())
+        .whereType<AlbumAdaptedCollectionItem>()
+        .map((e) => e.albumItem)
+        .toList();
+  }
+
+  CollectionItemSort toCollectionItemSort() {
+    final that = this;
+    if (that is AlbumNullSortProvider) {
+      return CollectionItemSort.manual;
+    } else if (that is AlbumTimeSortProvider) {
+      return that.isAscending
+          ? CollectionItemSort.dateAscending
+          : CollectionItemSort.dateDescending;
+    } else if (that is AlbumFilenameSortProvider) {
+      return that.isAscending
+          ? CollectionItemSort.nameAscending
+          : CollectionItemSort.nameDescending;
+    } else {
+      throw StateError("Unknown type: ${sort.runtimeType}");
+    }
+  }
 
   JsonObj _toContentJson();
 
@@ -72,11 +110,6 @@ class AlbumNullSortProvider extends AlbumSortProvider {
   @override
   String toString() => _$toString();
 
-  @override
-  sort(List<AlbumItem> items) {
-    return List.from(items);
-  }
-
   @override
   get props => [];
 
@@ -124,37 +157,6 @@ class AlbumTimeSortProvider extends AlbumReversibleSortProvider {
   @override
   String toString() => _$toString();
 
-  @override
-  sort(List<AlbumItem> items) {
-    DateTime? prevFileTime;
-    return items
-        .map((e) {
-          if (e is AlbumFileItem) {
-            // take the file time
-            prevFileTime = e.file.bestDateTime;
-          }
-          // for non file items, use the sibling file's time
-          return Tuple2(prevFileTime, e);
-        })
-        .stableSorted((x, y) {
-          if (x.item1 == null && y.item1 == null) {
-            return 0;
-          } else if (x.item1 == null) {
-            return -1;
-          } else if (y.item1 == null) {
-            return 1;
-          } else {
-            if (isAscending) {
-              return x.item1!.compareTo(y.item1!);
-            } else {
-              return y.item1!.compareTo(x.item1!);
-            }
-          }
-        })
-        .map((e) => e.item2)
-        .toList();
-  }
-
   static const _type = "time";
 }
 
@@ -174,36 +176,5 @@ class AlbumFilenameSortProvider extends AlbumReversibleSortProvider {
   @override
   String toString() => _$toString();
 
-  @override
-  sort(List<AlbumItem> items) {
-    String? prevFilename;
-    return items
-        .map((e) {
-          if (e is AlbumFileItem) {
-            // take the file name
-            prevFilename = e.file.filename;
-          }
-          // for non file items, use the sibling file's name
-          return Tuple2(prevFilename, e);
-        })
-        .stableSorted((x, y) {
-          if (x.item1 == null && y.item1 == null) {
-            return 0;
-          } else if (x.item1 == null) {
-            return -1;
-          } else if (y.item1 == null) {
-            return 1;
-          } else {
-            if (isAscending) {
-              return compareNatural(x.item1!, y.item1!);
-            } else {
-              return compareNatural(y.item1!, x.item1!);
-            }
-          }
-        })
-        .map((e) => e.item2)
-        .toList();
-  }
-
   static const _type = "filename";
 }

app/lib/entity/album/upgrader.dart

@@ -1,8 +1,13 @@
+import 'dart:convert';
+
+import 'package:clock/clock.dart';
 import 'package:collection/collection.dart';
 import 'package:logging/logging.dart';
 import 'package:nc_photos/account.dart';
 import 'package:nc_photos/entity/exif.dart';
 import 'package:nc_photos/entity/file.dart';
+import 'package:nc_photos/entity/sqlite/database.dart' as sql;
+import 'package:nc_photos/object_extension.dart';
 import 'package:np_codegen/np_codegen.dart';
 import 'package:np_common/ci_string.dart';
 import 'package:np_common/type.dart';
@@ -11,7 +16,8 @@ import 'package:tuple/tuple.dart';
 part 'upgrader.g.dart';
 
 abstract class AlbumUpgrader {
-  JsonObj? call(JsonObj json);
+  JsonObj? doJson(JsonObj json);
+  sql.Album? doDb(sql.Album dbObj);
 }
 
 /// Upgrade v1 Album to v2
@@ -22,14 +28,17 @@ class AlbumUpgraderV1 implements AlbumUpgrader {
   });
 
   @override
-  call(JsonObj json) {
+  doJson(JsonObj json) {
     // v1 album items are corrupted in one of the updates, drop it
-    _log.fine("[call] Upgrade v1 Album for file: $logFilePath");
+    _log.fine("[doJson] Upgrade v1 Album for file: $logFilePath");
     final result = JsonObj.from(json);
     result["items"] = [];
     return result;
   }
 
+  @override
+  sql.Album? doDb(sql.Album dbObj) => null;
+
   /// File path for logging only
   final String? logFilePath;
 }
@@ -42,9 +51,9 @@ class AlbumUpgraderV2 implements AlbumUpgrader {
   });
 
   @override
-  call(JsonObj json) {
+  doJson(JsonObj json) {
     // move v2 items to v3 provider
-    _log.fine("[call] Upgrade v2 Album for file: $logFilePath");
+    _log.fine("[doJson] Upgrade v2 Album for file: $logFilePath");
     final result = JsonObj.from(json);
     result["provider"] = <String, dynamic>{
       "type": "static",
@@ -62,6 +71,9 @@ class AlbumUpgraderV2 implements AlbumUpgrader {
     return result;
   }
 
+  @override
+  sql.Album? doDb(sql.Album dbObj) => null;
+
   /// File path for logging only
   final String? logFilePath;
 }
@@ -74,9 +86,9 @@ class AlbumUpgraderV3 implements AlbumUpgrader {
   });
 
   @override
-  call(JsonObj json) {
+  doJson(JsonObj json) {
     // move v3 items to v4 provider
-    _log.fine("[call] Upgrade v3 Album for file: $logFilePath");
+    _log.fine("[doJson] Upgrade v3 Album for file: $logFilePath");
     final result = JsonObj.from(json);
     // add the descending time sort provider
     result["sortProvider"] = <String, dynamic>{
@@ -88,6 +100,9 @@ class AlbumUpgraderV3 implements AlbumUpgrader {
     return result;
   }
 
+  @override
+  sql.Album? doDb(sql.Album dbObj) => null;
+
   /// File path for logging only
   final String? logFilePath;
 }
@@ -100,8 +115,8 @@ class AlbumUpgraderV4 implements AlbumUpgrader {
   });
 
   @override
-  call(JsonObj json) {
-    _log.fine("[call] Upgrade v4 Album for file: $logFilePath");
+  doJson(JsonObj json) {
+    _log.fine("[doJson] Upgrade v4 Album for file: $logFilePath");
     final result = JsonObj.from(json);
     try {
       if (result["provider"]["type"] != "static") {
@@ -151,11 +166,14 @@ class AlbumUpgraderV4 implements AlbumUpgrader {
     } catch (e, stackTrace) {
       // this upgrade is not a must, if it failed then just leave it and it'll
       // be upgraded the next time the album is saved
-      _log.shout("[call] Failed while upgrade", e, stackTrace);
+      _log.shout("[doJson] Failed while upgrade", e, stackTrace);
     }
     return result;
   }
 
+  @override
+  sql.Album? doDb(sql.Album dbObj) => null;
+
   /// File path for logging only
   final String? logFilePath;
 }
@@ -170,8 +188,8 @@ class AlbumUpgraderV5 implements AlbumUpgrader {
   });
 
   @override
-  call(JsonObj json) {
-    _log.fine("[call] Upgrade v5 Album for file: $logFilePath");
+  doJson(JsonObj json) {
+    _log.fine("[doJson] Upgrade v5 Album for file: $logFilePath");
     final result = JsonObj.from(json);
     try {
       if (result["provider"]["type"] != "static") {
@@ -192,11 +210,14 @@ class AlbumUpgraderV5 implements AlbumUpgrader {
     } catch (e, stackTrace) {
       // this upgrade is not a must, if it failed then just leave it and it'll
       // be upgraded the next time the album is saved
-      _log.shout("[call] Failed while upgrade", e, stackTrace);
+      _log.shout("[doJson] Failed while upgrade", e, stackTrace);
     }
     return result;
   }
 
+  @override
+  sql.Album? doDb(sql.Album dbObj) => null;
+
   final Account account;
   final File? albumFile;
 
@@ -212,11 +233,14 @@ class AlbumUpgraderV6 implements AlbumUpgrader {
   });
 
   @override
-  call(JsonObj json) {
-    _log.fine("[call] Upgrade v6 Album for file: $logFilePath");
+  doJson(JsonObj json) {
+    _log.fine("[doJson] Upgrade v6 Album for file: $logFilePath");
     return json;
   }
 
+  @override
+  sql.Album? doDb(sql.Album dbObj) => null;
+
   /// File path for logging only
   final String? logFilePath;
 }
@@ -229,11 +253,103 @@ class AlbumUpgraderV7 implements AlbumUpgrader {
   });
 
   @override
-  call(JsonObj json) {
-    _log.fine("[call] Upgrade v7 Album for file: $logFilePath");
+  doJson(JsonObj json) {
+    _log.fine("[doJson] Upgrade v7 Album for file: $logFilePath");
     return json;
   }
 
+  @override
+  sql.Album? doDb(sql.Album dbObj) => null;
+
+  /// File path for logging only
+  final String? logFilePath;
+}
+
+/// Upgrade v8 Album to v9
+@npLog
+class AlbumUpgraderV8 implements AlbumUpgrader {
+  const AlbumUpgraderV8({
+    this.logFilePath,
+  });
+
+  @override
+  JsonObj? doJson(JsonObj json) {
+    _log.fine("[doJson] Upgrade v8 Album for file: $logFilePath");
+    final result = JsonObj.from(json);
+    if (result["coverProvider"]["type"] == "manual") {
+      final content = (result["coverProvider"]["content"]["coverFile"] as Map)
+          .cast<String, dynamic>();
+      final fd = _fileJsonToFileDescriptorJson(content);
+      // some very old album file may contain files w/o id
+      if (fd["fdId"] != null) {
+        result["coverProvider"]["content"]["coverFile"] = fd;
+      } else {
+        result["coverProvider"]["content"] = {};
+      }
+    } else if (result["coverProvider"]["type"] == "auto") {
+      final content = (result["coverProvider"]["content"]["coverFile"] as Map?)
+          ?.cast<String, dynamic>();
+      if (content != null) {
+        final fd = _fileJsonToFileDescriptorJson(content);
+        if (fd["fdId"] != null) {
+          result["coverProvider"]["content"]["coverFile"] = fd;
+        } else {
+          result["coverProvider"]["content"] = {};
+        }
+      }
+    }
+    return result;
+  }
+
+  @override
+  sql.Album? doDb(sql.Album dbObj) {
+    _log.fine("[doDb] Upgrade v8 Album for file: $logFilePath");
+    if (dbObj.coverProviderType == "manual") {
+      final content = (jsonDecode(dbObj.coverProviderContent) as Map)
+          .cast<String, dynamic>();
+      final converted = _fileJsonToFileDescriptorJson(
+          (content["coverFile"] as Map).cast<String, dynamic>());
+      if (converted["fdId"] != null) {
+        return dbObj.copyWith(
+          coverProviderContent: jsonEncode({"coverFile": converted}),
+        );
+      } else {
+        return dbObj.copyWith(coverProviderContent: "{}");
+      }
+    } else if (dbObj.coverProviderType == "auto") {
+      final content = (jsonDecode(dbObj.coverProviderContent) as Map)
+          .cast<String, dynamic>();
+      if (content["coverFile"] != null) {
+        final converted = _fileJsonToFileDescriptorJson(
+            (content["coverFile"] as Map).cast<String, dynamic>());
+        if (converted["fdId"] != null) {
+          return dbObj.copyWith(
+            coverProviderContent: jsonEncode({"coverFile": converted}),
+          );
+        } else {
+          return dbObj.copyWith(coverProviderContent: "{}");
+        }
+      }
+    }
+    return dbObj;
+  }
+
+  static JsonObj _fileJsonToFileDescriptorJson(JsonObj json) {
+    return {
+      "fdPath": json["path"],
+      "fdId": json["fileId"],
+      "fdMime": json["contentType"],
+      "fdIsArchived": json["isArchived"] ?? false,
+      // File.isFavorite is serialized as int
+      "fdIsFavorite": json["isFavorite"] == 1,
+      "fdDateTime": json["overrideDateTime"] ??
+          (json["metadata"]?["exif"]?["DateTimeOriginal"] as String?)?.run(
+              (d) => Exif.dateTimeFormat.parse(d).toUtc().toIso8601String()) ??
+          json["lastModified"] ??
+          clock.now().toUtc().toIso8601String(),
+    };
+  }
+
   /// File path for logging only
   final String? logFilePath;
 }
@@ -248,6 +364,7 @@ abstract class AlbumUpgraderFactory {
   AlbumUpgraderV5? buildV5();
   AlbumUpgraderV6? buildV6();
   AlbumUpgraderV7? buildV7();
+  AlbumUpgraderV8? buildV8();
 }
 
 class DefaultAlbumUpgraderFactory extends AlbumUpgraderFactory {
@@ -282,6 +399,9 @@ class DefaultAlbumUpgraderFactory extends AlbumUpgraderFactory {
   @override
   buildV7() => AlbumUpgraderV7(logFilePath: logFilePath);
 
+  @override
+  AlbumUpgraderV8? buildV8() => AlbumUpgraderV8(logFilePath: logFilePath);
+
   final Account account;
   final File? albumFile;
 

app/lib/entity/album/upgrader.g.dart

@@ -54,3 +54,10 @@ extension _$AlbumUpgraderV7NpLog on AlbumUpgraderV7 {
 
   static final log = Logger("entity.album.upgrader.AlbumUpgraderV7");
 }
+
+extension _$AlbumUpgraderV8NpLog on AlbumUpgraderV8 {
+  // ignore: unused_element
+  Logger get _log => log;
+
+  static final log = Logger("entity.album.upgrader.AlbumUpgraderV8");
+}

app/lib/entity/album_util.dart

@@ -1,41 +0,0 @@
-import 'package:collection/collection.dart';
-import 'package:nc_photos/entity/album.dart';
-import 'package:tuple/tuple.dart';
-
-enum AlbumSort {
-  dateDescending,
-  dateAscending,
-  nameAscending,
-  nameDescending,
-}
-
-List<Album> sorted(List<Album> albums, AlbumSort by) {
-  final isAscending = _isSortAscending(by);
-  return albums
-      .map<Tuple2<dynamic, Album>>((e) {
-        switch (by) {
-          case AlbumSort.nameAscending:
-          case AlbumSort.nameDescending:
-            return Tuple2(e.name, e);
-
-          case AlbumSort.dateAscending:
-          case AlbumSort.dateDescending:
-            return Tuple2(e.provider.latestItemTime ?? e.lastUpdated, e);
-        }
-      })
-      .sorted((a, b) {
-        final x = isAscending ? a : b;
-        final y = isAscending ? b : a;
-        final tmp = x.item1.compareTo(y.item1);
-        if (tmp != 0) {
-          return tmp;
-        } else {
-          return x.item2.name.compareTo(y.item2.name);
-        }
-      })
-      .map((e) => e.item2)
-      .toList();
-}
-
-bool _isSortAscending(AlbumSort sort) =>
-    sort == AlbumSort.dateAscending || sort == AlbumSort.nameAscending;

app/lib/entity/collection.dart

@@ -0,0 +1,148 @@
+import 'package:copy_with/copy_with.dart';
+import 'package:equatable/equatable.dart';
+import 'package:nc_photos/entity/collection/util.dart';
+import 'package:nc_photos/entity/collection_item/sorter.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
+import 'package:to_string/to_string.dart';
+
+part 'collection.g.dart';
+
+/// Describe a group of items
+@genCopyWith
+@toString
+class Collection with EquatableMixin {
+  const Collection({
+    required this.name,
+    required this.contentProvider,
+  });
+
+  @override
+  String toString() => _$toString();
+
+  bool compareIdentity(Collection other) => other.id == id;
+
+  int get identityHashCode => id.hashCode;
+
+  /// A unique id for each collection. The value is divided into two parts in
+  /// the format XXXX-YYY...YYY, where XXXX is a four-character code
+  /// representing the content provider type, and YYY is an implementation
+  /// detail of each providers
+  String get id => "${contentProvider.fourCc}-${contentProvider.id}";
+
+  /// See [CollectionContentProvider.count]
+  int? get count => contentProvider.count;
+
+  /// See [CollectionContentProvider.lastModified]
+  DateTime get lastModified => contentProvider.lastModified;
+
+  /// See [CollectionContentProvider.capabilities]
+  List<CollectionCapability> get capabilities => contentProvider.capabilities;
+
+  /// See [CollectionContentProvider.itemSort]
+  CollectionItemSort get itemSort => contentProvider.itemSort;
+
+  /// See [CollectionContentProvider.shares]
+  List<CollectionShare> get shares => contentProvider.shares;
+
+  /// See [CollectionContentProvider.getCoverUrl]
+  String? getCoverUrl(
+    int width,
+    int height, {
+    bool? isKeepAspectRatio,
+  }) =>
+      contentProvider.getCoverUrl(
+        width,
+        height,
+        isKeepAspectRatio: isKeepAspectRatio,
+      );
+
+  CollectionSorter getSorter() => CollectionSorter.fromSortType(itemSort);
+
+  /// See [CollectionContentProvider.isDynamicCollection]
+  bool get isDynamicCollection => contentProvider.isDynamicCollection;
+
+  /// See [CollectionContentProvider.isPendingSharedAlbum]
+  bool get isPendingSharedAlbum => contentProvider.isPendingSharedAlbum;
+
+  @override
+  List<Object?> get props => [
+        name,
+        contentProvider,
+      ];
+
+  final String name;
+  final CollectionContentProvider contentProvider;
+}
+
+enum CollectionCapability {
+  // add/remove items
+  manualItem,
+  // sort the items
+  sort,
+  // rearrange item manually
+  manualSort,
+  // can freely rename album
+  rename,
+  // text labels
+  labelItem,
+  // set the cover image
+  manualCover,
+  // share the collection with other user on the same server
+  share,
+}
+
+/// Provide the actual content of a collection
+abstract class CollectionContentProvider with EquatableMixin {
+  const CollectionContentProvider();
+
+  /// Unique FourCC of this provider type
+  String get fourCc;
+
+  /// Return the unique id of this collection
+  String get id;
+
+  /// Return the number of items in this collection, or null if not supported
+  int? get count;
+
+  /// Return the date time of this collection. Generally this is the date time
+  /// of the latest child
+  DateTime get lastModified;
+
+  /// Return the capabilities of the collection
+  ///
+  /// Notice that the capabilities returned here represent all the capabilities
+  /// that this implementation supports. In practice there may be extra runtime
+  /// requirements that mask some of them (e.g., user permissions)
+  List<CollectionCapability> get capabilities;
+
+  /// Return the sort type
+  CollectionItemSort get itemSort;
+
+  /// Return list of users who have access to this collection, excluding the
+  /// current user
+  List<CollectionShare> get shares;
+
+  /// Return the URL of the cover image if available
+  ///
+  /// The [width] and [height] are provided as a hint only, implementations are
+  /// free to ignore them if it's not supported
+  ///
+  /// [isKeepAspectRatio] is only a hint and implementations may ignore it
+  String? getCoverUrl(
+    int width,
+    int height, {
+    bool? isKeepAspectRatio,
+  });
+
+  /// Return whether this is a dynamic collection
+  ///
+  /// A collection is defined as a dynamic one when the items are not specified
+  /// explicitly by the user, but rather derived from some conditions
+  bool get isDynamicCollection;
+
+  /// Return whether this is a shared album pending to be added
+  ///
+  /// In some implementation, shared album does not immediately get added to the
+  /// collections list
+  bool get isPendingSharedAlbum;
+}

app/lib/entity/collection.g.dart

@@ -0,0 +1,48 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'collection.dart';
+
+// **************************************************************************
+// CopyWithLintRuleGenerator
+// **************************************************************************
+
+// ignore_for_file: library_private_types_in_public_api, duplicate_ignore
+
+// **************************************************************************
+// CopyWithGenerator
+// **************************************************************************
+
+abstract class $CollectionCopyWithWorker {
+  Collection call({String? name, CollectionContentProvider? contentProvider});
+}
+
+class _$CollectionCopyWithWorkerImpl implements $CollectionCopyWithWorker {
+  _$CollectionCopyWithWorkerImpl(this.that);
+
+  @override
+  Collection call({dynamic name, dynamic contentProvider}) {
+    return Collection(
+        name: name as String? ?? that.name,
+        contentProvider: contentProvider as CollectionContentProvider? ??
+            that.contentProvider);
+  }
+
+  final Collection that;
+}
+
+extension $CollectionCopyWith on Collection {
+  $CollectionCopyWithWorker get copyWith => _$copyWith;
+  $CollectionCopyWithWorker get _$copyWith =>
+      _$CollectionCopyWithWorkerImpl(this);
+}
+
+// **************************************************************************
+// ToStringGenerator
+// **************************************************************************
+
+extension _$CollectionToString on Collection {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "Collection {name: $name, contentProvider: $contentProvider}";
+  }
+}

app/lib/entity/collection/adapter.dart

@@ -0,0 +1,115 @@
+import 'package:flutter/foundation.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/di_container.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/adapter/album.dart';
+import 'package:nc_photos/entity/collection/adapter/location_group.dart';
+import 'package:nc_photos/entity/collection/adapter/memory.dart';
+import 'package:nc_photos/entity/collection/adapter/nc_album.dart';
+import 'package:nc_photos/entity/collection/adapter/person.dart';
+import 'package:nc_photos/entity/collection/adapter/tag.dart';
+import 'package:nc_photos/entity/collection/content_provider/album.dart';
+import 'package:nc_photos/entity/collection/content_provider/location_group.dart';
+import 'package:nc_photos/entity/collection/content_provider/memory.dart';
+import 'package:nc_photos/entity/collection/content_provider/nc_album.dart';
+import 'package:nc_photos/entity/collection/content_provider/person.dart';
+import 'package:nc_photos/entity/collection/content_provider/tag.dart';
+import 'package:nc_photos/entity/collection/util.dart';
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/collection_item/new_item.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:nc_photos/entity/sharee.dart';
+import 'package:nc_photos/or_null.dart';
+import 'package:np_common/ci_string.dart';
+import 'package:np_common/type.dart';
+
+abstract class CollectionAdapter {
+  const CollectionAdapter();
+
+  static CollectionAdapter of(
+      DiContainer c, Account account, Collection collection) {
+    switch (collection.contentProvider.runtimeType) {
+      case CollectionAlbumProvider:
+        return CollectionAlbumAdapter(c, account, collection);
+      case CollectionLocationGroupProvider:
+        return CollectionLocationGroupAdapter(c, account, collection);
+      case CollectionMemoryProvider:
+        return CollectionMemoryAdapter(c, account, collection);
+      case CollectionNcAlbumProvider:
+        return CollectionNcAlbumAdapter(c, account, collection);
+      case CollectionPersonProvider:
+        return CollectionPersonAdapter(c, account, collection);
+      case CollectionTagProvider:
+        return CollectionTagAdapter(c, account, collection);
+      default:
+        throw UnsupportedError(
+            "Unknown type: ${collection.contentProvider.runtimeType}");
+    }
+  }
+
+  /// List items inside this collection
+  Stream<List<CollectionItem>> listItem();
+
+  /// Add [files] to this collection and return the added count
+  Future<int> addFiles(
+    List<FileDescriptor> files, {
+    ErrorWithValueHandler<FileDescriptor>? onError,
+    required ValueChanged<Collection> onCollectionUpdated,
+  });
+
+  /// Edit this collection
+  Future<Collection> edit({
+    String? name,
+    List<CollectionItem>? items,
+    CollectionItemSort? itemSort,
+    OrNull<FileDescriptor>? cover,
+    List<CollectionItem>? knownItems,
+  });
+
+  /// Remove [items] from this collection and return the removed count
+  Future<int> removeItems(
+    List<CollectionItem> items, {
+    ErrorWithValueIndexedHandler<CollectionItem>? onError,
+    required ValueChanged<Collection> onCollectionUpdated,
+  });
+
+  /// Share the collection with [sharee]
+  Future<CollectionShareResult> share(
+    Sharee sharee, {
+    required ValueChanged<Collection> onCollectionUpdated,
+  });
+
+  /// Unshare the collection with a user
+  Future<CollectionShareResult> unshare(
+    CiString userId, {
+    required ValueChanged<Collection> onCollectionUpdated,
+  });
+
+  /// Import a pending shared collection and return the resulting collection
+  Future<Collection> importPendingShared();
+
+  /// Convert a [NewCollectionItem] to an adapted one
+  Future<CollectionItem> adaptToNewItem(NewCollectionItem original);
+
+  bool isItemRemovable(CollectionItem item);
+
+  /// Remove this collection
+  Future<void> remove();
+
+  /// Return if this capability is allowed
+  bool isPermitted(CollectionCapability capability);
+
+  /// Return if the cover of this collection has been manually set
+  bool isManualCover();
+
+  /// Called when the collection items belonging to this collection is first
+  /// loaded
+  Future<Collection?> updatePostLoad(List<CollectionItem> items);
+}
+
+abstract class CollectionItemAdapter {
+  const CollectionItemAdapter();
+
+  CollectionItem toItem();
+}

app/lib/entity/collection/adapter/adapter_mixin.dart

@@ -0,0 +1,83 @@
+import 'package:flutter/foundation.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/adapter.dart';
+import 'package:nc_photos/entity/collection/util.dart';
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:nc_photos/entity/sharee.dart';
+import 'package:nc_photos/or_null.dart';
+import 'package:np_common/ci_string.dart';
+import 'package:np_common/type.dart';
+
+/// A read-only collection that does not support modifying its items
+mixin CollectionAdapterReadOnlyTag implements CollectionAdapter {
+  @override
+  Future<int> addFiles(
+    List<FileDescriptor> files, {
+    ErrorWithValueHandler<FileDescriptor>? onError,
+    required ValueChanged<Collection> onCollectionUpdated,
+  }) {
+    throw UnsupportedError("Operation not supported");
+  }
+
+  @override
+  Future<Collection> edit({
+    String? name,
+    List<CollectionItem>? items,
+    CollectionItemSort? itemSort,
+    OrNull<FileDescriptor>? cover,
+    List<CollectionItem>? knownItems,
+  }) {
+    throw UnsupportedError("Operation not supported");
+  }
+
+  @override
+  Future<int> removeItems(
+    List<CollectionItem> items, {
+    ErrorWithValueIndexedHandler<CollectionItem>? onError,
+    required ValueChanged<Collection> onCollectionUpdated,
+  }) {
+    throw UnsupportedError("Operation not supported");
+  }
+
+  @override
+  bool isItemRemovable(CollectionItem item) => false;
+
+  @override
+  bool isManualCover() => false;
+
+  @override
+  Future<Collection?> updatePostLoad(List<CollectionItem> items) =>
+      Future.value(null);
+}
+
+mixin CollectionAdapterUnremovableTag implements CollectionAdapter {
+  @override
+  Future<void> remove() {
+    throw UnsupportedError("Operation not supported");
+  }
+}
+
+mixin CollectionAdapterUnshareableTag implements CollectionAdapter {
+  @override
+  Future<CollectionShareResult> share(
+    Sharee sharee, {
+    required ValueChanged<Collection> onCollectionUpdated,
+  }) {
+    throw UnsupportedError("Operation not supported");
+  }
+
+  @override
+  Future<CollectionShareResult> unshare(
+    CiString userId, {
+    required ValueChanged<Collection> onCollectionUpdated,
+  }) {
+    throw UnsupportedError("Operation not supported");
+  }
+
+  @override
+  Future<Collection> importPendingShared() {
+    throw UnsupportedError("Operation not supported");
+  }
+}

app/lib/entity/collection/adapter/album.dart

@@ -0,0 +1,318 @@
+import 'package:collection/collection.dart';
+import 'package:flutter/foundation.dart';
+import 'package:logging/logging.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/debug_util.dart';
+import 'package:nc_photos/di_container.dart';
+import 'package:nc_photos/entity/album/cover_provider.dart';
+import 'package:nc_photos/entity/album/item.dart';
+import 'package:nc_photos/entity/album/provider.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/adapter.dart';
+import 'package:nc_photos/entity/collection/builder.dart';
+import 'package:nc_photos/entity/collection/content_provider/album.dart';
+import 'package:nc_photos/entity/collection/util.dart';
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/collection_item/album_item_adapter.dart';
+import 'package:nc_photos/entity/collection_item/new_item.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
+import 'package:nc_photos/entity/file.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:nc_photos/entity/sharee.dart';
+import 'package:nc_photos/iterable_extension.dart';
+import 'package:nc_photos/object_extension.dart';
+import 'package:nc_photos/or_null.dart';
+import 'package:nc_photos/use_case/album/add_file_to_album.dart';
+import 'package:nc_photos/use_case/album/edit_album.dart';
+import 'package:nc_photos/use_case/album/remove_album.dart';
+import 'package:nc_photos/use_case/album/remove_from_album.dart';
+import 'package:nc_photos/use_case/album/share_album_with_user.dart';
+import 'package:nc_photos/use_case/album/unshare_album_with_user.dart';
+import 'package:nc_photos/use_case/import_pending_shared_album.dart';
+import 'package:nc_photos/use_case/preprocess_album.dart';
+import 'package:nc_photos/use_case/unimport_shared_album.dart';
+import 'package:nc_photos/use_case/update_album_with_actual_items.dart';
+import 'package:np_codegen/np_codegen.dart';
+import 'package:np_common/ci_string.dart';
+import 'package:np_common/type.dart';
+import 'package:tuple/tuple.dart';
+
+part 'album.g.dart';
+
+@npLog
+class CollectionAlbumAdapter implements CollectionAdapter {
+  CollectionAlbumAdapter(this._c, this.account, this.collection)
+      : assert(require(_c)),
+        _provider = collection.contentProvider as CollectionAlbumProvider;
+
+  static bool require(DiContainer c) => PreProcessAlbum.require(c);
+
+  @override
+  Stream<List<CollectionItem>> listItem() async* {
+    final items = await PreProcessAlbum(_c)(account, _provider.album);
+    yield items.map<CollectionItem>((i) {
+      if (i is AlbumFileItem) {
+        return CollectionFileItemAlbumAdapter(i);
+      } else if (i is AlbumLabelItem) {
+        return CollectionLabelItemAlbumAdapter(i);
+      } else {
+        _log.shout("[listItem] Unknown item type: ${i.runtimeType}");
+        throw UnimplementedError("Unknown item type: ${i.runtimeType}");
+      }
+    }).toList();
+  }
+
+  @override
+  Future<int> addFiles(
+    List<FileDescriptor> files, {
+    ErrorWithValueHandler<FileDescriptor>? onError,
+    required ValueChanged<Collection> onCollectionUpdated,
+  }) async {
+    try {
+      final newAlbum =
+          await AddFileToAlbum(_c)(account, _provider.album, files);
+      onCollectionUpdated(CollectionBuilder.byAlbum(account, newAlbum));
+      return files.length;
+    } catch (e, stackTrace) {
+      for (final f in files) {
+        onError?.call(f, e, stackTrace);
+      }
+      return 0;
+    }
+  }
+
+  @override
+  Future<Collection> edit({
+    String? name,
+    List<CollectionItem>? items,
+    CollectionItemSort? itemSort,
+    OrNull<FileDescriptor>? cover,
+    List<CollectionItem>? knownItems,
+  }) async {
+    assert(name != null || items != null || itemSort != null || cover != null);
+    final newItems = items?.run((items) => items
+        .map((e) {
+          if (e is AlbumAdaptedCollectionItem) {
+            return e.albumItem;
+          } else if (e is NewCollectionLabelItem) {
+            // new labels
+            return AlbumLabelItem(
+              addedBy: account.userId,
+              addedAt: e.createdAt,
+              text: e.text,
+            );
+          } else {
+            _log.severe("[edit] Unsupported type: ${e.runtimeType}");
+            return null;
+          }
+        })
+        .whereNotNull()
+        .toList());
+    final newAlbum = await EditAlbum(_c)(
+      account,
+      _provider.album,
+      name: name,
+      items: newItems,
+      itemSort: itemSort,
+      cover: cover,
+      knownItems: knownItems
+          ?.whereType<AlbumAdaptedCollectionItem>()
+          .map((e) => e.albumItem)
+          .toList(),
+    );
+    return collection.copyWith(
+      name: name,
+      contentProvider: _provider.copyWith(album: newAlbum),
+    );
+  }
+
+  @override
+  Future<int> removeItems(
+    List<CollectionItem> items, {
+    ErrorWithValueIndexedHandler<CollectionItem>? onError,
+    required ValueChanged<Collection> onCollectionUpdated,
+  }) async {
+    try {
+      final group = items
+          .withIndex()
+          .groupListsBy((e) => e.item2 is AlbumAdaptedCollectionItem);
+      var failed = 0;
+      if (group[true]?.isNotEmpty ?? false) {
+        final newAlbum = await RemoveFromAlbum(_c)(
+          account,
+          _provider.album,
+          group[true]!
+              .map((e) => e.item2)
+              .cast<AlbumAdaptedCollectionItem>()
+              .map((e) => e.albumItem)
+              .toList(),
+          onError: (i, item, e, stackTrace) {
+            ++failed;
+            final actualIndex = group[true]![i].item1;
+            try {
+              onError?.call(actualIndex, items[actualIndex], e, stackTrace);
+            } catch (e, stackTrace) {
+              _log.severe("[removeItems] Unknown error", e, stackTrace);
+            }
+          },
+        );
+        onCollectionUpdated(collection.copyWith(
+          contentProvider: _provider.copyWith(
+            album: newAlbum,
+          ),
+        ));
+      }
+      for (final pair in (group[false] ?? const <Tuple2<int, int>>[])) {
+        final actualIndex = pair.item1;
+        onError?.call(
+          actualIndex,
+          items[actualIndex],
+          UnsupportedError(
+              "Unsupported item type: ${items[actualIndex].runtimeType}"),
+          StackTrace.current,
+        );
+      }
+      return (group[true] ?? []).length - failed;
+    } catch (e, stackTrace) {
+      for (final pair in items.withIndex()) {
+        onError?.call(pair.item1, pair.item2, e, stackTrace);
+      }
+      return 0;
+    }
+  }
+
+  @override
+  Future<CollectionShareResult> share(
+    Sharee sharee, {
+    required ValueChanged<Collection> onCollectionUpdated,
+  }) async {
+    var fileFailed = false;
+    final newAlbum = await ShareAlbumWithUser(_c.shareRepo, _c.albumRepo)(
+      account,
+      _provider.album,
+      sharee,
+      onShareFileFailed: (f, e, stackTrace) {
+        _log.severe("[share] Failed to share file: ${logFilename(f.path)}", e,
+            stackTrace);
+        fileFailed = true;
+      },
+    );
+    onCollectionUpdated(CollectionBuilder.byAlbum(account, newAlbum));
+    return fileFailed
+        ? CollectionShareResult.partial
+        : CollectionShareResult.ok;
+  }
+
+  @override
+  Future<CollectionShareResult> unshare(
+    CiString userId, {
+    required ValueChanged<Collection> onCollectionUpdated,
+  }) async {
+    var fileFailed = false;
+    final newAlbum = await UnshareAlbumWithUser(_c)(
+      account,
+      _provider.album,
+      userId,
+      onUnshareFileFailed: (f, e, stackTrace) {
+        _log.severe("[unshare] Failed to unshare file: ${logFilename(f.path)}",
+            e, stackTrace);
+        fileFailed = true;
+      },
+    );
+    onCollectionUpdated(CollectionBuilder.byAlbum(account, newAlbum));
+    return fileFailed
+        ? CollectionShareResult.partial
+        : CollectionShareResult.ok;
+  }
+
+  @override
+  Future<Collection> importPendingShared() async {
+    final newAlbum =
+        await ImportPendingSharedAlbum(_c)(account, _provider.album);
+    return CollectionBuilder.byAlbum(account, newAlbum);
+  }
+
+  @override
+  Future<CollectionItem> adaptToNewItem(NewCollectionItem original) async {
+    if (original is NewCollectionFileItem) {
+      final item = AlbumStaticProvider.of(_provider.album)
+          .items
+          .whereType<AlbumFileItem>()
+          .firstWhere((e) => e.file.compareServerIdentity(original.file));
+      return CollectionFileItemAlbumAdapter(item);
+    } else if (original is NewCollectionLabelItem) {
+      final item = AlbumStaticProvider.of(_provider.album)
+          .items
+          .whereType<AlbumLabelItem>()
+          .sorted((a, b) => a.addedAt.compareTo(b.addedAt))
+          .reversed
+          .firstWhere((e) => e.text == original.text);
+      return CollectionLabelItemAlbumAdapter(item);
+    } else {
+      throw UnsupportedError("Unsupported type: ${original.runtimeType}");
+    }
+  }
+
+  @override
+  bool isItemRemovable(CollectionItem item) {
+    if (_provider.album.provider is! AlbumStaticProvider) {
+      return false;
+    }
+    if (_provider.album.albumFile?.isOwned(account.userId) == true) {
+      return true;
+    }
+    if (item is! AlbumAdaptedCollectionItem) {
+      _log.warning("[isItemRemovable] Unknown item type: ${item.runtimeType}");
+      return true;
+    }
+    return item.albumItem.addedBy == account.userId;
+  }
+
+  @override
+  Future<void> remove() {
+    if (_provider.album.albumFile?.isOwned(account.userId) == true) {
+      return RemoveAlbum(_c)(account, _provider.album);
+    } else {
+      return UnimportSharedAlbum(_c)(account, _provider.album);
+    }
+  }
+
+  @override
+  bool isPermitted(CollectionCapability capability) {
+    if (!_provider.capabilities.contains(capability)) {
+      return false;
+    }
+    if (_provider.album.albumFile?.isOwned(account.userId) == true) {
+      return true;
+    } else {
+      return _provider.guestCapabilities.contains(capability);
+    }
+  }
+
+  @override
+  bool isManualCover() =>
+      _provider.album.coverProvider is AlbumManualCoverProvider;
+
+  @override
+  Future<Collection?> updatePostLoad(List<CollectionItem> items) async {
+    final album = await UpdateAlbumWithActualItems(_c.albumRepo)(
+      account,
+      _provider.album,
+      items
+          .whereType<AlbumAdaptedCollectionItem>()
+          .map((e) => e.albumItem)
+          .toList(),
+    );
+    if (!identical(album, _provider.album)) {
+      return CollectionBuilder.byAlbum(account, album);
+    } else {
+      return null;
+    }
+  }
+
+  final DiContainer _c;
+  final Account account;
+  final Collection collection;
+
+  final CollectionAlbumProvider _provider;
+}

app/lib/entity/collection/adapter/album.g.dart

@@ -0,0 +1,15 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'album.dart';
+
+// **************************************************************************
+// NpLogGenerator
+// **************************************************************************
+
+extension _$CollectionAlbumAdapterNpLog on CollectionAlbumAdapter {
+  // ignore: unused_element
+  Logger get _log => log;
+
+  static final log =
+      Logger("entity.collection.adapter.album.CollectionAlbumAdapter");
+}

app/lib/entity/collection/adapter/location_group.dart

@@ -0,0 +1,58 @@
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/di_container.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/adapter.dart';
+import 'package:nc_photos/entity/collection/adapter/adapter_mixin.dart';
+import 'package:nc_photos/entity/collection/content_provider/location_group.dart';
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/collection_item/basic_item.dart';
+import 'package:nc_photos/entity/file.dart';
+import 'package:nc_photos/entity/file_util.dart' as file_util;
+import 'package:nc_photos/use_case/list_location_file.dart';
+
+class CollectionLocationGroupAdapter
+    with
+        CollectionAdapterReadOnlyTag,
+        CollectionAdapterUnremovableTag,
+        CollectionAdapterUnshareableTag
+    implements CollectionAdapter {
+  CollectionLocationGroupAdapter(this._c, this.account, this.collection)
+      : assert(require(_c)),
+        _provider =
+            collection.contentProvider as CollectionLocationGroupProvider;
+
+  static bool require(DiContainer c) => ListLocationFile.require(c);
+
+  @override
+  Stream<List<CollectionItem>> listItem() async* {
+    final files = <File>[];
+    for (final r in account.roots) {
+      final dir = File(path: file_util.unstripPath(account, r));
+      files.addAll(await ListLocationFile(_c)(account, dir,
+          _provider.location.place, _provider.location.countryCode));
+    }
+    yield files
+        .where((f) => file_util.isSupportedFormat(f))
+        .map((f) => BasicCollectionFileItem(f))
+        .toList();
+  }
+
+  @override
+  Future<CollectionItem> adaptToNewItem(CollectionItem original) async {
+    if (original is CollectionFileItem) {
+      return BasicCollectionFileItem(original.file);
+    } else {
+      throw UnsupportedError("Unsupported type: ${original.runtimeType}");
+    }
+  }
+
+  @override
+  bool isPermitted(CollectionCapability capability) =>
+      _provider.capabilities.contains(capability);
+
+  final DiContainer _c;
+  final Account account;
+  final Collection collection;
+
+  final CollectionLocationGroupProvider _provider;
+}

app/lib/entity/collection/adapter/memory.dart

@@ -0,0 +1,57 @@
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/di_container.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/adapter.dart';
+import 'package:nc_photos/entity/collection/adapter/adapter_mixin.dart';
+import 'package:nc_photos/entity/collection/content_provider/memory.dart';
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/collection_item/basic_item.dart';
+import 'package:nc_photos/entity/file/data_source.dart';
+import 'package:nc_photos/entity/file_util.dart' as file_util;
+import 'package:nc_photos/use_case/list_location_file.dart';
+
+class CollectionMemoryAdapter
+    with
+        CollectionAdapterReadOnlyTag,
+        CollectionAdapterUnremovableTag,
+        CollectionAdapterUnshareableTag
+    implements CollectionAdapter {
+  CollectionMemoryAdapter(this._c, this.account, this.collection)
+      : assert(require(_c)),
+        _provider = collection.contentProvider as CollectionMemoryProvider;
+
+  static bool require(DiContainer c) => ListLocationFile.require(c);
+
+  @override
+  Stream<List<CollectionItem>> listItem() async* {
+    final date = DateTime(_provider.year, _provider.month, _provider.day);
+    final dayRange = _c.pref.getMemoriesRangeOr();
+    final from = date.subtract(Duration(days: dayRange));
+    final to = date.add(Duration(days: dayRange + 1));
+    final files = await FileSqliteDbDataSource(_c).listByDate(
+        account, from.millisecondsSinceEpoch, to.millisecondsSinceEpoch);
+    yield files
+        .where((f) => file_util.isSupportedFormat(f))
+        .map((f) => BasicCollectionFileItem(f))
+        .toList();
+  }
+
+  @override
+  Future<CollectionItem> adaptToNewItem(CollectionItem original) async {
+    if (original is CollectionFileItem) {
+      return BasicCollectionFileItem(original.file);
+    } else {
+      throw UnsupportedError("Unsupported type: ${original.runtimeType}");
+    }
+  }
+
+  @override
+  bool isPermitted(CollectionCapability capability) =>
+      _provider.capabilities.contains(capability);
+
+  final DiContainer _c;
+  final Account account;
+  final Collection collection;
+
+  final CollectionMemoryProvider _provider;
+}

app/lib/entity/collection/adapter/nc_album.dart

@@ -0,0 +1,173 @@
+import 'package:collection/collection.dart';
+import 'package:flutter/foundation.dart';
+import 'package:logging/logging.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/di_container.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/adapter.dart';
+import 'package:nc_photos/entity/collection/adapter/adapter_mixin.dart';
+import 'package:nc_photos/entity/collection/content_provider/nc_album.dart';
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/collection_item/basic_item.dart';
+import 'package:nc_photos/entity/collection_item/nc_album_item_adapter.dart';
+import 'package:nc_photos/entity/collection_item/new_item.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:nc_photos/entity/nc_album.dart';
+import 'package:nc_photos/object_extension.dart';
+import 'package:nc_photos/or_null.dart';
+import 'package:nc_photos/use_case/find_file_descriptor.dart';
+import 'package:nc_photos/use_case/nc_album/add_file_to_nc_album.dart';
+import 'package:nc_photos/use_case/nc_album/edit_nc_album.dart';
+import 'package:nc_photos/use_case/nc_album/list_nc_album.dart';
+import 'package:nc_photos/use_case/nc_album/list_nc_album_item.dart';
+import 'package:nc_photos/use_case/nc_album/remove_from_nc_album.dart';
+import 'package:nc_photos/use_case/nc_album/remove_nc_album.dart';
+import 'package:np_codegen/np_codegen.dart';
+import 'package:np_common/type.dart';
+
+part 'nc_album.g.dart';
+
+@npLog
+class CollectionNcAlbumAdapter
+    with CollectionAdapterUnshareableTag
+    implements CollectionAdapter {
+  CollectionNcAlbumAdapter(this._c, this.account, this.collection)
+      : assert(require(_c)),
+        _provider = collection.contentProvider as CollectionNcAlbumProvider;
+
+  static bool require(DiContainer c) =>
+      ListNcAlbumItem.require(c) && FindFileDescriptor.require(c);
+
+  @override
+  Stream<List<CollectionItem>> listItem() {
+    return ListNcAlbumItem(_c)(account, _provider.album)
+        .asyncMap((items) async {
+      final found = await FindFileDescriptor(_c)(
+        account,
+        items.map((e) => e.fileId).toList(),
+        onFileNotFound: (fileId) {
+          // happens when this is a file shared with you
+          _log.warning("[listItem] File not found: $fileId");
+        },
+      );
+      return items.map((i) {
+        final f = found.firstWhereOrNull((e) => e.fdId == i.fileId);
+        return CollectionFileItemNcAlbumItemAdapter(i, f);
+      }).toList();
+    });
+  }
+
+  @override
+  Future<int> addFiles(
+    List<FileDescriptor> files, {
+    ErrorWithValueHandler<FileDescriptor>? onError,
+    required ValueChanged<Collection> onCollectionUpdated,
+  }) async {
+    final count = await AddFileToNcAlbum(_c)(account, _provider.album, files,
+        onError: onError);
+    if (count > 0) {
+      try {
+        final newAlbum = await _syncRemote();
+        onCollectionUpdated(collection.copyWith(
+          contentProvider: _provider.copyWith(
+            album: newAlbum,
+          ),
+        ));
+      } catch (e, stackTrace) {
+        _log.severe("[addFiles] Failed while _syncRemote", e, stackTrace);
+      }
+    }
+    return count;
+  }
+
+  @override
+  Future<Collection> edit({
+    String? name,
+    List<CollectionItem>? items,
+    CollectionItemSort? itemSort,
+    OrNull<FileDescriptor>? cover,
+    List<CollectionItem>? knownItems,
+  }) async {
+    assert(name != null);
+    if (items != null || itemSort != null || cover != null) {
+      _log.warning(
+          "[edit] Nextcloud album does not support editing item or sort");
+    }
+    final newItems = items?.run((items) => items
+        .map((e) => e is CollectionFileItem ? e.file : null)
+        .whereNotNull()
+        .toList());
+    final newAlbum = await EditNcAlbum(_c)(
+      account,
+      _provider.album,
+      name: name,
+      items: newItems,
+      itemSort: itemSort,
+    );
+    return collection.copyWith(
+      name: name,
+      contentProvider: _provider.copyWith(album: newAlbum),
+    );
+  }
+
+  @override
+  Future<int> removeItems(
+    List<CollectionItem> items, {
+    ErrorWithValueIndexedHandler<CollectionItem>? onError,
+    required ValueChanged<Collection> onCollectionUpdated,
+  }) async {
+    final count = await RemoveFromNcAlbum(_c)(account, _provider.album, items,
+        onError: onError);
+    if (count > 0) {
+      try {
+        final newAlbum = await _syncRemote();
+        onCollectionUpdated(collection.copyWith(
+          contentProvider: _provider.copyWith(
+            album: newAlbum,
+          ),
+        ));
+      } catch (e, stackTrace) {
+        _log.severe("[removeItems] Failed while _syncRemote", e, stackTrace);
+      }
+    }
+    return count;
+  }
+
+  @override
+  Future<CollectionItem> adaptToNewItem(NewCollectionItem original) async {
+    if (original is NewCollectionFileItem) {
+      return BasicCollectionFileItem(original.file);
+    } else {
+      throw UnsupportedError("Unsupported type: ${original.runtimeType}");
+    }
+  }
+
+  @override
+  bool isItemRemovable(CollectionItem item) => true;
+
+  @override
+  Future<void> remove() => RemoveNcAlbum(_c)(account, _provider.album);
+
+  @override
+  bool isPermitted(CollectionCapability capability) =>
+      _provider.capabilities.contains(capability);
+
+  @override
+  bool isManualCover() => false;
+
+  @override
+  Future<Collection?> updatePostLoad(List<CollectionItem> items) =>
+      Future.value(null);
+
+  Future<NcAlbum> _syncRemote() async {
+    final remote = await ListNcAlbum(_c)(account).last;
+    return remote.firstWhere((e) => e.compareIdentity(_provider.album));
+  }
+
+  final DiContainer _c;
+  final Account account;
+  final Collection collection;
+
+  final CollectionNcAlbumProvider _provider;
+}

app/lib/entity/collection/adapter/nc_album.g.dart

@@ -0,0 +1,15 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'nc_album.dart';
+
+// **************************************************************************
+// NpLogGenerator
+// **************************************************************************
+
+extension _$CollectionNcAlbumAdapterNpLog on CollectionNcAlbumAdapter {
+  // ignore: unused_element
+  Logger get _log => log;
+
+  static final log =
+      Logger("entity.collection.adapter.nc_album.CollectionNcAlbumAdapter");
+}

app/lib/entity/collection/adapter/person.dart

@@ -0,0 +1,60 @@
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/di_container.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/adapter.dart';
+import 'package:nc_photos/entity/collection/adapter/adapter_mixin.dart';
+import 'package:nc_photos/entity/collection/content_provider/person.dart';
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/collection_item/basic_item.dart';
+import 'package:nc_photos/entity/file.dart';
+import 'package:nc_photos/entity/file_util.dart' as file_util;
+import 'package:nc_photos/use_case/list_face.dart';
+import 'package:nc_photos/use_case/populate_person.dart';
+
+class CollectionPersonAdapter
+    with
+        CollectionAdapterReadOnlyTag,
+        CollectionAdapterUnremovableTag,
+        CollectionAdapterUnshareableTag
+    implements CollectionAdapter {
+  CollectionPersonAdapter(this._c, this.account, this.collection)
+      : assert(require(_c)),
+        _provider = collection.contentProvider as CollectionPersonProvider;
+
+  static bool require(DiContainer c) =>
+      ListFace.require(c) && PopulatePerson.require(c);
+
+  @override
+  Stream<List<CollectionItem>> listItem() async* {
+    final faces = await ListFace(_c)(account, _provider.person);
+    final files = await PopulatePerson(_c)(account, faces);
+    final rootDirs = account.roots
+        .map((e) => File(path: file_util.unstripPath(account, e)))
+        .toList();
+    yield files
+        .where((f) =>
+            file_util.isSupportedFormat(f) &&
+            rootDirs.any((dir) => file_util.isUnderDir(f, dir)))
+        .map((f) => BasicCollectionFileItem(f))
+        .toList();
+  }
+
+  @override
+  Future<CollectionItem> adaptToNewItem(CollectionItem original) async {
+    if (original is CollectionFileItem) {
+      return BasicCollectionFileItem(original.file);
+    } else {
+      throw UnsupportedError("Unsupported type: ${original.runtimeType}");
+    }
+  }
+
+  @override
+  bool isPermitted(CollectionCapability capability) =>
+      _provider.capabilities.contains(capability);
+
+  final DiContainer _c;
+  final Account account;
+  final Collection collection;
+
+  final CollectionPersonProvider _provider;
+}

app/lib/entity/collection/adapter/tag.dart

@@ -0,0 +1,47 @@
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/di_container.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/adapter.dart';
+import 'package:nc_photos/entity/collection/adapter/adapter_mixin.dart';
+import 'package:nc_photos/entity/collection/content_provider/tag.dart';
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/collection_item/basic_item.dart';
+import 'package:nc_photos/use_case/list_tagged_file.dart';
+
+class CollectionTagAdapter
+    with
+        CollectionAdapterReadOnlyTag,
+        CollectionAdapterUnremovableTag,
+        CollectionAdapterUnshareableTag
+    implements CollectionAdapter {
+  CollectionTagAdapter(this._c, this.account, this.collection)
+      : assert(require(_c)),
+        _provider = collection.contentProvider as CollectionTagProvider;
+
+  static bool require(DiContainer c) => true;
+
+  @override
+  Stream<List<CollectionItem>> listItem() async* {
+    final files = await ListTaggedFile(_c)(account, _provider.tags);
+    yield files.map((f) => BasicCollectionFileItem(f)).toList();
+  }
+
+  @override
+  Future<CollectionItem> adaptToNewItem(CollectionItem original) async {
+    if (original is CollectionFileItem) {
+      return BasicCollectionFileItem(original.file);
+    } else {
+      throw UnsupportedError("Unsupported type: ${original.runtimeType}");
+    }
+  }
+
+  @override
+  bool isPermitted(CollectionCapability capability) =>
+      _provider.capabilities.contains(capability);
+
+  final DiContainer _c;
+  final Account account;
+  final Collection collection;
+
+  final CollectionTagProvider _provider;
+}

app/lib/entity/collection/builder.dart

@@ -0,0 +1,64 @@
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/entity/album.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/content_provider/album.dart';
+import 'package:nc_photos/entity/collection/content_provider/location_group.dart';
+import 'package:nc_photos/entity/collection/content_provider/nc_album.dart';
+import 'package:nc_photos/entity/collection/content_provider/person.dart';
+import 'package:nc_photos/entity/collection/content_provider/tag.dart';
+import 'package:nc_photos/entity/nc_album.dart';
+import 'package:nc_photos/entity/person.dart';
+import 'package:nc_photos/entity/tag.dart';
+import 'package:nc_photos/use_case/list_location_group.dart';
+
+class CollectionBuilder {
+  static Collection byAlbum(Account account, Album album) {
+    return Collection(
+      name: album.name,
+      contentProvider: CollectionAlbumProvider(
+        account: account,
+        album: album,
+      ),
+    );
+  }
+
+  static Collection byLocationGroup(Account account, LocationGroup location) {
+    return Collection(
+      name: location.place,
+      contentProvider: CollectionLocationGroupProvider(
+        account: account,
+        location: location,
+      ),
+    );
+  }
+
+  static Collection byNcAlbum(Account account, NcAlbum album) {
+    return Collection(
+      name: album.strippedPath,
+      contentProvider: CollectionNcAlbumProvider(
+        account: account,
+        album: album,
+      ),
+    );
+  }
+
+  static Collection byPerson(Account account, Person person) {
+    return Collection(
+      name: person.name,
+      contentProvider: CollectionPersonProvider(
+        account: account,
+        person: person,
+      ),
+    );
+  }
+
+  static Collection byTags(Account account, List<Tag> tags) {
+    return Collection(
+      name: tags.first.displayName,
+      contentProvider: CollectionTagProvider(
+        account: account,
+        tags: tags,
+      ),
+    );
+  }
+}

app/lib/entity/collection/content_provider/album.dart

@@ -0,0 +1,117 @@
+import 'package:copy_with/copy_with.dart';
+import 'package:equatable/equatable.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/api/api_util.dart' as api_util;
+import 'package:nc_photos/entity/album.dart';
+import 'package:nc_photos/entity/album/provider.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/util.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
+import 'package:nc_photos/remote_storage_util.dart' as remote_storage_util;
+import 'package:to_string/to_string.dart';
+
+part 'album.g.dart';
+
+/// Album provided by our app
+@genCopyWith
+@toString
+class CollectionAlbumProvider
+    with EquatableMixin
+    implements CollectionContentProvider {
+  const CollectionAlbumProvider({
+    required this.account,
+    required this.album,
+  });
+
+  @override
+  String toString() => _$toString();
+
+  @override
+  String get fourCc => "ALBM";
+
+  @override
+  String get id => album.albumFile!.fileId!.toString();
+
+  @override
+  int? get count {
+    if (album.provider is AlbumStaticProvider) {
+      return (album.provider as AlbumStaticProvider).items.length;
+    } else {
+      return null;
+    }
+  }
+
+  @override
+  DateTime get lastModified =>
+      album.provider.latestItemTime ?? album.lastUpdated;
+
+  @override
+  List<CollectionCapability> get capabilities => [
+        CollectionCapability.sort,
+        CollectionCapability.rename,
+        CollectionCapability.manualCover,
+        if (album.provider is AlbumStaticProvider) ...[
+          CollectionCapability.manualItem,
+          CollectionCapability.manualSort,
+          CollectionCapability.labelItem,
+          CollectionCapability.share,
+        ],
+      ];
+
+  /// Capabilities when this album is shared to this user by someone else
+  List<CollectionCapability> get guestCapabilities => [
+        if (album.provider is AlbumStaticProvider) ...[
+          CollectionCapability.manualItem,
+          CollectionCapability.labelItem,
+        ],
+      ];
+
+  @override
+  CollectionItemSort get itemSort => album.sortProvider.toCollectionItemSort();
+
+  @override
+  List<CollectionShare> get shares =>
+      album.shares
+          ?.where((s) => s.userId != account.userId)
+          .map((s) => CollectionShare(
+                userId: s.userId,
+                username: s.displayName ?? s.userId.raw,
+              ))
+          .toList() ??
+      const [];
+
+  @override
+  String? getCoverUrl(
+    int width,
+    int height, {
+    bool? isKeepAspectRatio,
+  }) {
+    final fd = album.coverProvider.getCover(album);
+    if (fd == null) {
+      return null;
+    } else {
+      return api_util.getFilePreviewUrlByFileId(
+        account,
+        fd.fdId,
+        width: width,
+        height: height,
+        isKeepAspectRatio: isKeepAspectRatio ?? false,
+      );
+    }
+  }
+
+  @override
+  bool get isDynamicCollection => album.provider is! AlbumStaticProvider;
+
+  @override
+  bool get isPendingSharedAlbum =>
+      album.albumFile?.path.startsWith(
+          remote_storage_util.getRemotePendingSharedAlbumsDir(account)) ==
+      true;
+
+  @override
+  List<Object?> get props => [account, album];
+
+  final Account account;
+  final Album album;
+}

app/lib/entity/collection/content_provider/album.g.dart

@@ -0,0 +1,48 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'album.dart';
+
+// **************************************************************************
+// CopyWithLintRuleGenerator
+// **************************************************************************
+
+// ignore_for_file: library_private_types_in_public_api, duplicate_ignore
+
+// **************************************************************************
+// CopyWithGenerator
+// **************************************************************************
+
+abstract class $CollectionAlbumProviderCopyWithWorker {
+  CollectionAlbumProvider call({Account? account, Album? album});
+}
+
+class _$CollectionAlbumProviderCopyWithWorkerImpl
+    implements $CollectionAlbumProviderCopyWithWorker {
+  _$CollectionAlbumProviderCopyWithWorkerImpl(this.that);
+
+  @override
+  CollectionAlbumProvider call({dynamic account, dynamic album}) {
+    return CollectionAlbumProvider(
+        account: account as Account? ?? that.account,
+        album: album as Album? ?? that.album);
+  }
+
+  final CollectionAlbumProvider that;
+}
+
+extension $CollectionAlbumProviderCopyWith on CollectionAlbumProvider {
+  $CollectionAlbumProviderCopyWithWorker get copyWith => _$copyWith;
+  $CollectionAlbumProviderCopyWithWorker get _$copyWith =>
+      _$CollectionAlbumProviderCopyWithWorkerImpl(this);
+}
+
+// **************************************************************************
+// ToStringGenerator
+// **************************************************************************
+
+extension _$CollectionAlbumProviderToString on CollectionAlbumProvider {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "CollectionAlbumProvider {account: $account, album: $album}";
+  }
+}

app/lib/entity/collection/content_provider/location_group.dart

@@ -0,0 +1,64 @@
+import 'package:equatable/equatable.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/api/api_util.dart' as api_util;
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/util.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
+import 'package:nc_photos/use_case/list_location_group.dart';
+
+class CollectionLocationGroupProvider
+    with EquatableMixin
+    implements CollectionContentProvider {
+  const CollectionLocationGroupProvider({
+    required this.account,
+    required this.location,
+  });
+
+  @override
+  String get fourCc => "LOCG";
+
+  @override
+  String get id => location.place;
+
+  @override
+  int? get count => location.count;
+
+  @override
+  DateTime get lastModified => location.latestDateTime;
+
+  @override
+  List<CollectionCapability> get capabilities => [];
+
+  @override
+  CollectionItemSort get itemSort => CollectionItemSort.dateDescending;
+
+  @override
+  List<CollectionShare> get shares => [];
+
+  @override
+  String? getCoverUrl(
+    int width,
+    int height, {
+    bool? isKeepAspectRatio,
+  }) {
+    return api_util.getFilePreviewUrlByFileId(
+      account,
+      location.latestFileId,
+      width: width,
+      height: height,
+      isKeepAspectRatio: isKeepAspectRatio ?? false,
+    );
+  }
+
+  @override
+  bool get isDynamicCollection => true;
+
+  @override
+  bool get isPendingSharedAlbum => false;
+
+  @override
+  List<Object?> get props => [account, location];
+
+  final Account account;
+  final LocationGroup location;
+}

app/lib/entity/collection/content_provider/memory.dart

@@ -0,0 +1,78 @@
+import 'package:equatable/equatable.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/api/api_util.dart' as api_util;
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/util.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:nc_photos/object_extension.dart';
+import 'package:to_string/to_string.dart';
+
+part 'memory.g.dart';
+
+@toString
+class CollectionMemoryProvider
+    with EquatableMixin
+    implements CollectionContentProvider {
+  const CollectionMemoryProvider({
+    required this.account,
+    required this.year,
+    required this.month,
+    required this.day,
+    this.cover,
+  });
+
+  @override
+  String get fourCc => "MEMY";
+
+  @override
+  String get id => "$year-$month-$day";
+
+  @override
+  int? get count => null;
+
+  @override
+  DateTime get lastModified => DateTime(year, month, day);
+
+  @override
+  List<CollectionCapability> get capabilities => [];
+
+  @override
+  CollectionItemSort get itemSort => CollectionItemSort.dateDescending;
+
+  @override
+  List<CollectionShare> get shares => [];
+
+  @override
+  String? getCoverUrl(
+    int width,
+    int height, {
+    bool? isKeepAspectRatio,
+  }) {
+    return cover?.run((cover) => api_util.getFilePreviewUrl(
+          account,
+          cover,
+          width: width,
+          height: height,
+          isKeepAspectRatio: isKeepAspectRatio ?? false,
+        ));
+  }
+
+  @override
+  bool get isDynamicCollection => true;
+
+  @override
+  bool get isPendingSharedAlbum => false;
+
+  @override
+  String toString() => _$toString();
+
+  @override
+  List<Object?> get props => [account, year, month, day, cover];
+
+  final Account account;
+  final int year;
+  final int month;
+  final int day;
+  final FileDescriptor? cover;
+}

app/lib/entity/collection/content_provider/memory.g.dart

@@ -0,0 +1,14 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'memory.dart';
+
+// **************************************************************************
+// ToStringGenerator
+// **************************************************************************
+
+extension _$CollectionMemoryProviderToString on CollectionMemoryProvider {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "CollectionMemoryProvider {account: $account, year: $year, month: $month, day: $day, cover: ${cover == null ? null : "${cover!.fdPath}"}}";
+  }
+}

app/lib/entity/collection/content_provider/nc_album.dart

@@ -0,0 +1,87 @@
+import 'package:clock/clock.dart';
+import 'package:copy_with/copy_with.dart';
+import 'package:equatable/equatable.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/api/api_util.dart' as api_util;
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/util.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
+import 'package:nc_photos/entity/nc_album.dart';
+import 'package:to_string/to_string.dart';
+
+part 'nc_album.g.dart';
+
+/// Album provided by our app
+@genCopyWith
+@toString
+class CollectionNcAlbumProvider
+    with EquatableMixin
+    implements CollectionContentProvider {
+  const CollectionNcAlbumProvider({
+    required this.account,
+    required this.album,
+  });
+
+  @override
+  String toString() => _$toString();
+
+  @override
+  String get fourCc => "NC25";
+
+  @override
+  String get id => album.path;
+
+  @override
+  int? get count => album.count;
+
+  @override
+  DateTime get lastModified => album.dateEnd ?? clock.now().toUtc();
+
+  @override
+  List<CollectionCapability> get capabilities => [
+        CollectionCapability.manualItem,
+        CollectionCapability.rename,
+        // CollectionCapability.share,
+      ];
+
+  @override
+  CollectionItemSort get itemSort => CollectionItemSort.dateDescending;
+
+  @override
+  List<CollectionShare> get shares => album.collaborators
+      .map((c) => CollectionShare(
+            userId: c.id,
+            username: c.label,
+          ))
+      .toList();
+
+  @override
+  String? getCoverUrl(
+    int width,
+    int height, {
+    bool? isKeepAspectRatio,
+  }) {
+    if (album.lastPhoto == null) {
+      return null;
+    } else {
+      return api_util.getPhotosApiFilePreviewUrlByFileId(
+        account,
+        album.lastPhoto!,
+        width: width,
+        height: height,
+      );
+    }
+  }
+
+  @override
+  bool get isDynamicCollection => false;
+
+  @override
+  bool get isPendingSharedAlbum => false;
+
+  @override
+  List<Object?> get props => [account, album];
+
+  final Account account;
+  final NcAlbum album;
+}

app/lib/entity/collection/content_provider/nc_album.g.dart

@@ -0,0 +1,48 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'nc_album.dart';
+
+// **************************************************************************
+// CopyWithLintRuleGenerator
+// **************************************************************************
+
+// ignore_for_file: library_private_types_in_public_api, duplicate_ignore
+
+// **************************************************************************
+// CopyWithGenerator
+// **************************************************************************
+
+abstract class $CollectionNcAlbumProviderCopyWithWorker {
+  CollectionNcAlbumProvider call({Account? account, NcAlbum? album});
+}
+
+class _$CollectionNcAlbumProviderCopyWithWorkerImpl
+    implements $CollectionNcAlbumProviderCopyWithWorker {
+  _$CollectionNcAlbumProviderCopyWithWorkerImpl(this.that);
+
+  @override
+  CollectionNcAlbumProvider call({dynamic account, dynamic album}) {
+    return CollectionNcAlbumProvider(
+        account: account as Account? ?? that.account,
+        album: album as NcAlbum? ?? that.album);
+  }
+
+  final CollectionNcAlbumProvider that;
+}
+
+extension $CollectionNcAlbumProviderCopyWith on CollectionNcAlbumProvider {
+  $CollectionNcAlbumProviderCopyWithWorker get copyWith => _$copyWith;
+  $CollectionNcAlbumProviderCopyWithWorker get _$copyWith =>
+      _$CollectionNcAlbumProviderCopyWithWorkerImpl(this);
+}
+
+// **************************************************************************
+// ToStringGenerator
+// **************************************************************************
+
+extension _$CollectionNcAlbumProviderToString on CollectionNcAlbumProvider {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "CollectionNcAlbumProvider {account: $account, album: $album}";
+  }
+}

app/lib/entity/collection/content_provider/person.dart

@@ -0,0 +1,62 @@
+import 'dart:math' as math;
+
+import 'package:clock/clock.dart';
+import 'package:equatable/equatable.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/api/api_util.dart' as api_util;
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/util.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
+import 'package:nc_photos/entity/person.dart';
+
+class CollectionPersonProvider
+    with EquatableMixin
+    implements CollectionContentProvider {
+  const CollectionPersonProvider({
+    required this.account,
+    required this.person,
+  });
+
+  @override
+  String get fourCc => "PERS";
+
+  @override
+  String get id => person.name;
+
+  @override
+  int? get count => person.count;
+
+  @override
+  DateTime get lastModified => clock.now().toUtc();
+
+  @override
+  List<CollectionCapability> get capabilities => [];
+
+  @override
+  CollectionItemSort get itemSort => CollectionItemSort.dateDescending;
+
+  @override
+  List<CollectionShare> get shares => [];
+
+  @override
+  String? getCoverUrl(
+    int width,
+    int height, {
+    bool? isKeepAspectRatio,
+  }) {
+    return api_util.getFacePreviewUrl(account, person.thumbFaceId,
+        size: math.max(width, height));
+  }
+
+  @override
+  bool get isDynamicCollection => true;
+
+  @override
+  bool get isPendingSharedAlbum => false;
+
+  @override
+  List<Object?> get props => [account, person];
+
+  final Account account;
+  final Person person;
+}

app/lib/entity/collection/content_provider/tag.dart

@@ -0,0 +1,57 @@
+import 'package:clock/clock.dart';
+import 'package:equatable/equatable.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/util.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
+import 'package:nc_photos/entity/tag.dart';
+
+class CollectionTagProvider
+    with EquatableMixin
+    implements CollectionContentProvider {
+  CollectionTagProvider({
+    required this.account,
+    required this.tags,
+  }) : assert(tags.isNotEmpty);
+
+  @override
+  String get fourCc => "TAG-";
+
+  @override
+  String get id => tags.first.displayName;
+
+  @override
+  int? get count => null;
+
+  @override
+  DateTime get lastModified => clock.now().toUtc();
+
+  @override
+  List<CollectionCapability> get capabilities => [];
+
+  @override
+  CollectionItemSort get itemSort => CollectionItemSort.dateDescending;
+
+  @override
+  List<CollectionShare> get shares => [];
+
+  @override
+  String? getCoverUrl(
+    int width,
+    int height, {
+    bool? isKeepAspectRatio,
+  }) =>
+      null;
+
+  @override
+  bool get isDynamicCollection => true;
+
+  @override
+  bool get isPendingSharedAlbum => false;
+
+  @override
+  List<Object?> get props => [account, tags];
+
+  final Account account;
+  final List<Tag> tags;
+}

app/lib/entity/collection/exporter.dart

@@ -0,0 +1,108 @@
+import 'package:clock/clock.dart';
+import 'package:collection/collection.dart';
+import 'package:kiwi/kiwi.dart';
+import 'package:logging/logging.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/controller/collections_controller.dart';
+import 'package:nc_photos/di_container.dart';
+import 'package:nc_photos/entity/album.dart';
+import 'package:nc_photos/entity/album/cover_provider.dart';
+import 'package:nc_photos/entity/album/item.dart';
+import 'package:nc_photos/entity/album/provider.dart';
+import 'package:nc_photos/entity/album/sort_provider.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:nc_photos/entity/collection/content_provider/album.dart';
+import 'package:nc_photos/entity/collection/content_provider/nc_album.dart';
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:nc_photos/entity/nc_album.dart';
+import 'package:nc_photos/use_case/find_file.dart';
+import 'package:np_codegen/np_codegen.dart';
+
+part 'exporter.g.dart';
+
+@npLog
+class CollectionExporter {
+  const CollectionExporter(this.account, this.collectionsController,
+      this.collection, this.items, this.exportName);
+
+  /// Export as a new collection backed by our client side album
+  Future<Collection> asAlbum() async {
+    final files = await FindFile(KiwiContainer().resolve<DiContainer>())(
+      account,
+      items.whereType<CollectionFileItem>().map((e) => e.file.fdId).toList(),
+      onFileNotFound: (fileId) {
+        _log.severe("[asAlbum] File not found: $fileId");
+      },
+    );
+    final newAlbum = Album(
+      name: exportName,
+      provider: AlbumStaticProvider(
+        items: items
+            .map((e) {
+              if (e is CollectionFileItem) {
+                final f = files
+                    .firstWhereOrNull((f) => f.compareServerIdentity(e.file));
+                if (f == null) {
+                  return null;
+                } else {
+                  return AlbumFileItem(
+                    addedBy: account.userId,
+                    addedAt: clock.now().toUtc(),
+                    file: f,
+                  );
+                }
+              } else if (e is CollectionLabelItem) {
+                return AlbumLabelItem(
+                  addedBy: account.userId,
+                  addedAt: clock.now().toUtc(),
+                  text: e.text,
+                );
+              } else {
+                return null;
+              }
+            })
+            .whereNotNull()
+            .toList(),
+        latestItemTime: collection.lastModified,
+      ),
+      coverProvider: const AlbumAutoCoverProvider(),
+      sortProvider: const AlbumTimeSortProvider(isAscending: false),
+    );
+    var newCollection = Collection(
+      name: exportName,
+      contentProvider: CollectionAlbumProvider(
+        account: account,
+        album: newAlbum,
+      ),
+    );
+    return await collectionsController.createNew(newCollection);
+  }
+
+  /// Export as a new collection backed by Nextcloud album
+  Future<Collection> asNcAlbum() async {
+    var newCollection = Collection(
+      name: exportName,
+      contentProvider: CollectionNcAlbumProvider(
+        account: account,
+        album: NcAlbum.createNew(account: account, name: exportName),
+      ),
+    );
+    newCollection = await collectionsController.createNew(newCollection);
+    // only files are supported in NcAlbum
+    final newFiles =
+        items.whereType<CollectionFileItem>().map((e) => e.file).toList();
+    final data = collectionsController
+        .peekStream()
+        .data
+        .firstWhere((e) => e.collection.compareIdentity(newCollection));
+    await data.controller.addFiles(newFiles);
+    return newCollection;
+  }
+
+  final Account account;
+  final CollectionsController collectionsController;
+  final Collection collection;
+  final List<CollectionItem> items;
+  final String exportName;
+}

app/lib/entity/collection/exporter.g.dart

@@ -0,0 +1,14 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'exporter.dart';
+
+// **************************************************************************
+// NpLogGenerator
+// **************************************************************************
+
+extension _$CollectionExporterNpLog on CollectionExporter {
+  // ignore: unused_element
+  Logger get _log => log;
+
+  static final log = Logger("entity.collection.exporter.CollectionExporter");
+}

app/lib/entity/collection/util.dart

@@ -0,0 +1,70 @@
+import 'package:collection/collection.dart';
+import 'package:equatable/equatable.dart';
+import 'package:nc_photos/entity/collection.dart';
+import 'package:np_common/ci_string.dart';
+import 'package:to_string/to_string.dart';
+import 'package:tuple/tuple.dart';
+
+part 'util.g.dart';
+
+enum CollectionSort {
+  dateDescending,
+  dateAscending,
+  nameAscending,
+  nameDescending;
+
+  bool isAscending() {
+    return this == CollectionSort.dateAscending ||
+        this == CollectionSort.nameAscending;
+  }
+}
+
+@toString
+class CollectionShare with EquatableMixin {
+  const CollectionShare({
+    required this.userId,
+    required this.username,
+  });
+
+  @override
+  String toString() => _$toString();
+
+  @override
+  List<Object?> get props => [userId, username];
+
+  final CiString userId;
+  final String username;
+}
+
+enum CollectionShareResult {
+  ok,
+  partial,
+}
+
+extension CollectionListExtension on Iterable<Collection> {
+  List<Collection> sortedBy(CollectionSort by) {
+    return map<Tuple2<Comparable, Collection>>((e) {
+      switch (by) {
+        case CollectionSort.nameAscending:
+        case CollectionSort.nameDescending:
+          return Tuple2(e.name.toLowerCase(), e);
+
+        case CollectionSort.dateAscending:
+        case CollectionSort.dateDescending:
+          return Tuple2(e.contentProvider.lastModified, e);
+      }
+    })
+        .sorted((a, b) {
+          final x = by.isAscending() ? a : b;
+          final y = by.isAscending() ? b : a;
+          final tmp = x.item1.compareTo(y.item1);
+          if (tmp != 0) {
+            return tmp;
+          } else {
+            return x.item2.name.compareTo(y.item2.name);
+          }
+        })
+        .map((e) => e.item2)
+        .toList();
+  }
+}

app/lib/entity/collection/util.g.dart

@@ -0,0 +1,14 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'util.dart';
+
+// **************************************************************************
+// ToStringGenerator
+// **************************************************************************
+
+extension _$CollectionShareToString on CollectionShare {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "CollectionShare {userId: $userId, username: $username}";
+  }
+}

app/lib/entity/collection_item.dart

@@ -0,0 +1,22 @@
+import 'package:nc_photos/entity/file_descriptor.dart';
+
+/// An item in a [Collection]
+abstract class CollectionItem {
+  const CollectionItem();
+}
+
+abstract class CollectionFileItem implements CollectionItem {
+  const CollectionFileItem();
+
+  FileDescriptor get file;
+}
+
+abstract class CollectionLabelItem implements CollectionItem {
+  const CollectionLabelItem();
+
+  /// An object used to identify this instance
+  ///
+  /// [id] should be unique and stable
+  Object get id;
+  String get text;
+}

app/lib/entity/collection_item/album_item_adapter.dart

@@ -0,0 +1,57 @@
+import 'package:nc_photos/entity/album/item.dart';
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:to_string/to_string.dart';
+
+part 'album_item_adapter.g.dart';
+
+mixin AlbumAdaptedCollectionItem on CollectionItem {
+  static AlbumAdaptedCollectionItem fromItem(AlbumItem item) {
+    if (item is AlbumFileItem) {
+      return CollectionFileItemAlbumAdapter(item);
+    } else if (item is AlbumLabelItem) {
+      return CollectionLabelItemAlbumAdapter(item);
+    } else {
+      throw ArgumentError("Unknown type: ${item.runtimeType}");
+    }
+  }
+
+  AlbumItem get albumItem;
+}
+
+@toString
+class CollectionFileItemAlbumAdapter extends CollectionFileItem
+    with AlbumAdaptedCollectionItem {
+  const CollectionFileItemAlbumAdapter(this.item);
+
+  @override
+  String toString() => _$toString();
+
+  @override
+  FileDescriptor get file => item.file;
+
+  @override
+  AlbumItem get albumItem => item;
+
+  final AlbumFileItem item;
+}
+
+@toString
+class CollectionLabelItemAlbumAdapter extends CollectionLabelItem
+    with AlbumAdaptedCollectionItem {
+  const CollectionLabelItemAlbumAdapter(this.item);
+
+  @override
+  String toString() => _$toString();
+
+  @override
+  Object get id => item.addedAt;
+
+  @override
+  String get text => item.text;
+
+  @override
+  AlbumItem get albumItem => item;
+
+  final AlbumLabelItem item;
+}

app/lib/entity/collection_item/album_item_adapter.g.dart

@@ -0,0 +1,23 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'album_item_adapter.dart';
+
+// **************************************************************************
+// ToStringGenerator
+// **************************************************************************
+
+extension _$CollectionFileItemAlbumAdapterToString
+    on CollectionFileItemAlbumAdapter {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "CollectionFileItemAlbumAdapter {item: $item}";
+  }
+}
+
+extension _$CollectionLabelItemAlbumAdapterToString
+    on CollectionLabelItemAlbumAdapter {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "CollectionLabelItemAlbumAdapter {item: $item}";
+  }
+}

app/lib/entity/collection_item/basic_item.dart

@@ -0,0 +1,17 @@
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:to_string/to_string.dart';
+
+part 'basic_item.g.dart';
+
+/// The basic form of [CollectionFileItem]
+@toString
+class BasicCollectionFileItem implements CollectionFileItem {
+  const BasicCollectionFileItem(this.file);
+
+  @override
+  String toString() => _$toString();
+
+  @override
+  final FileDescriptor file;
+}

app/lib/entity/collection_item/basic_item.g.dart

@@ -0,0 +1,14 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'basic_item.dart';
+
+// **************************************************************************
+// ToStringGenerator
+// **************************************************************************
+
+extension _$BasicCollectionFileItemToString on BasicCollectionFileItem {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "BasicCollectionFileItem {file: ${file.fdPath}}";
+  }
+}

app/lib/entity/collection_item/nc_album_item_adapter.dart

@@ -0,0 +1,20 @@
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:nc_photos/entity/nc_album_item.dart';
+import 'package:to_string/to_string.dart';
+
+part 'nc_album_item_adapter.g.dart';
+
+@toString
+class CollectionFileItemNcAlbumItemAdapter extends CollectionFileItem {
+  const CollectionFileItemNcAlbumItemAdapter(this.item, [this.localFile]);
+
+  @override
+  String toString() => _$toString();
+
+  @override
+  FileDescriptor get file => localFile ?? item.toFile();
+
+  final NcAlbumItem item;
+  final FileDescriptor? localFile;
+}

app/lib/entity/collection_item/nc_album_item_adapter.g.dart

@@ -0,0 +1,15 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'nc_album_item_adapter.dart';
+
+// **************************************************************************
+// ToStringGenerator
+// **************************************************************************
+
+extension _$CollectionFileItemNcAlbumItemAdapterToString
+    on CollectionFileItemNcAlbumItemAdapter {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "CollectionFileItemNcAlbumItemAdapter {item: $item, localFile: ${localFile == null ? null : "${localFile!.fdPath}"}}";
+  }
+}

app/lib/entity/collection_item/new_item.dart

@@ -0,0 +1,42 @@
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:to_string/to_string.dart';
+
+part 'new_item.g.dart';
+
+abstract class NewCollectionItem implements CollectionItem {}
+
+/// A new [CollectionFileItem]
+///
+/// This class is for marking an intermediate item that has recently been added
+/// but not necessarily persisted yet to the provider of this collection
+@toString
+class NewCollectionFileItem implements CollectionFileItem, NewCollectionItem {
+  const NewCollectionFileItem(this.file);
+
+  @override
+  String toString() => _$toString();
+
+  @override
+  final FileDescriptor file;
+}
+
+/// A new [CollectionLabelItem]
+///
+/// This class is for marking an intermediate item that has recently been added
+/// but not necessarily persisted yet to the provider of this collection
+@toString
+class NewCollectionLabelItem implements CollectionLabelItem, NewCollectionItem {
+  const NewCollectionLabelItem(this.text, this.createdAt);
+
+  @override
+  String toString() => _$toString();
+
+  @override
+  Object get id => createdAt;
+
+  @override
+  final String text;
+
+  final DateTime createdAt;
+}

app/lib/entity/collection_item/new_item.g.dart

@@ -0,0 +1,21 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'new_item.dart';
+
+// **************************************************************************
+// ToStringGenerator
+// **************************************************************************
+
+extension _$NewCollectionFileItemToString on NewCollectionFileItem {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "NewCollectionFileItem {file: ${file.fdPath}}";
+  }
+}
+
+extension _$NewCollectionLabelItemToString on NewCollectionLabelItem {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "NewCollectionLabelItem {text: $text, createdAt: $createdAt}";
+  }
+}

app/lib/entity/collection_item/sorter.dart

@@ -0,0 +1,148 @@
+import 'package:collection/collection.dart';
+import 'package:logging/logging.dart';
+import 'package:nc_photos/entity/album/sort_provider.dart';
+import 'package:nc_photos/entity/collection_item.dart';
+import 'package:nc_photos/entity/collection_item/util.dart';
+import 'package:nc_photos/entity/file_descriptor.dart';
+import 'package:nc_photos/iterable_extension.dart';
+import 'package:np_codegen/np_codegen.dart';
+import 'package:tuple/tuple.dart';
+
+part 'sorter.g.dart';
+
+abstract class CollectionSorter {
+  const CollectionSorter();
+
+  static CollectionSorter fromSortType(CollectionItemSort type) {
+    switch (type) {
+      case CollectionItemSort.dateDescending:
+        return const CollectionTimeSorter(isAscending: false);
+      case CollectionItemSort.dateAscending:
+        return const CollectionTimeSorter(isAscending: true);
+      case CollectionItemSort.nameAscending:
+        return const CollectionFilenameSorter(isAscending: true);
+      case CollectionItemSort.nameDescending:
+        return const CollectionFilenameSorter(isAscending: false);
+      case CollectionItemSort.manual:
+        return const CollectionNullSorter();
+    }
+  }
+
+  /// Return a sorted copy of [items]
+  List<CollectionItem> call(List<CollectionItem> items);
+}
+
+/// Sort provider that does nothing
+class CollectionNullSorter implements CollectionSorter {
+  const CollectionNullSorter();
+
+  @override
+  List<CollectionItem> call(List<CollectionItem> items) {
+    return List.of(items);
+  }
+}
+
+/// Sort based on the time of the files
+class CollectionTimeSorter implements CollectionSorter {
+  const CollectionTimeSorter({
+    required this.isAscending,
+  });
+
+  @override
+  List<CollectionItem> call(List<CollectionItem> items) {
+    DateTime? prevFileTime;
+    return items
+        .map((e) {
+          if (e is CollectionFileItem) {
+            // take the file time
+            prevFileTime = e.file.fdDateTime;
+          }
+          // for non file items, use the sibling file's time
+          return Tuple2(prevFileTime, e);
+        })
+        .stableSorted((x, y) {
+          if (x.item1 == null && y.item1 == null) {
+            return 0;
+          } else if (x.item1 == null) {
+            return -1;
+          } else if (y.item1 == null) {
+            return 1;
+          } else {
+            if (isAscending) {
+              return x.item1!.compareTo(y.item1!);
+            } else {
+              return y.item1!.compareTo(x.item1!);
+            }
+          }
+        })
+        .map((e) => e.item2)
+        .toList();
+  }
+
+  final bool isAscending;
+}
+
+/// Sort based on the name of the files
+class CollectionFilenameSorter implements CollectionSorter {
+  const CollectionFilenameSorter({
+    required this.isAscending,
+  });
+
+  @override
+  List<CollectionItem> call(List<CollectionItem> items) {
+    String? prevFilename;
+    return items
+        .map((e) {
+          if (e is CollectionFileItem) {
+            // take the file name
+            prevFilename = e.file.filename;
+          }
+          // for non file items, use the sibling file's name
+          return Tuple2(prevFilename, e);
+        })
+        .stableSorted((x, y) {
+          if (x.item1 == null && y.item1 == null) {
+            return 0;
+          } else if (x.item1 == null) {
+            return -1;
+          } else if (y.item1 == null) {
+            return 1;
+          } else {
+            if (isAscending) {
+              return compareNatural(x.item1!, y.item1!);
+            } else {
+              return compareNatural(y.item1!, x.item1!);
+            }
+          }
+        })
+        .map((e) => e.item2)
+        .toList();
+  }
+
+  final bool isAscending;
+}
+
+@npLog
+class CollectionAlbumSortAdapter implements CollectionSorter {
+  const CollectionAlbumSortAdapter(this.sort);
+
+  @override
+  List<CollectionItem> call(List<CollectionItem> items) {
+    final CollectionSorter sorter;
+    if (sort is AlbumNullSortProvider) {
+      sorter = const CollectionNullSorter();
+    } else if (sort is AlbumTimeSortProvider) {
+      sorter = CollectionTimeSorter(
+          isAscending: (sort as AlbumTimeSortProvider).isAscending);
+    } else if (sort is AlbumFilenameSortProvider) {
+      sorter = CollectionFilenameSorter(
+          isAscending: (sort as AlbumFilenameSortProvider).isAscending);
+    } else {
+      _log.shout("[call] Unknown type: ${sort.runtimeType}");
+      throw UnsupportedError("Unknown type: ${sort.runtimeType}");
+    }
+    return sorter(items);
+  }
+
+  final AlbumSortProvider sort;
+}

app/lib/entity/collection_item/sorter.g.dart

@@ -0,0 +1,15 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'sorter.dart';
+
+// **************************************************************************
+// NpLogGenerator
+// **************************************************************************
+
+extension _$CollectionAlbumSortAdapterNpLog on CollectionAlbumSortAdapter {
+  // ignore: unused_element
+  Logger get _log => log;
+
+  static final log =
+      Logger("entity.collection_item.sorter.CollectionAlbumSortAdapter");
+}

app/lib/entity/collection_item/util.dart

@@ -0,0 +1,7 @@
+enum CollectionItemSort {
+  dateDescending,
+  dateAscending,
+  nameAscending,
+  nameDescending,
+  manual;
+}

app/lib/entity/file.dart

@@ -390,7 +390,6 @@ class File with EquatableMixin implements FileDescriptor {
   @override
   String toString() => _$toString();
 
-  @override
   JsonObj toJson() {
     return {
       "path": path,
@@ -419,6 +418,9 @@ class File with EquatableMixin implements FileDescriptor {
     };
   }
 
+  @override
+  JsonObj toFdJson() => FileDescriptor.toJson(this);
+
   File copyWith({
     String? path,
     int? contentLength,
@@ -537,6 +539,15 @@ extension FileExtension on File {
       );
 
   bool isOwned(CiString userId) => ownerId == null || ownerId == userId;
+
+  FileDescriptor toDescriptor() => FileDescriptor(
+        fdPath: path,
+        fdId: fileId!,
+        fdMime: contentType,
+        fdIsArchived: isArchived ?? false,
+        fdIsFavorite: isFavorite ?? false,
+        fdDateTime: bestDateTime,
+      );
 }
 
 class FileServerIdentityComparator {
@@ -575,7 +586,7 @@ class FileRepo {
       dataSrc.listMinimal(account, dir);
 
   /// See [FileDataSource.remove]
-  Future<void> remove(Account account, File file) =>
+  Future<void> remove(Account account, FileDescriptor file) =>
       dataSrc.remove(account, file);
 
   /// See [FileDataSource.getBinary]
@@ -659,7 +670,7 @@ abstract class FileDataSource {
   Future<List<File>> listMinimal(Account account, File dir);
 
   /// Remove file
-  Future<void> remove(Account account, File f);
+  Future<void> remove(Account account, FileDescriptor f);
 
   /// Read file as binary array
   Future<Uint8List> getBinary(Account account, File f);

app/lib/entity/file/data_source.dart

@@ -90,10 +90,10 @@ class FileWebdavDataSource implements FileDataSource {
   }
 
   @override
-  remove(Account account, File f) async {
-    _log.info("[remove] ${f.path}");
+  remove(Account account, FileDescriptor f) async {
+    _log.info("[remove] ${f.fdPath}");
     final response =
-        await ApiUtil.fromAccount(account).files().delete(path: f.path);
+        await ApiUtil.fromAccount(account).files().delete(path: f.fdPath);
     if (!response.isGood) {
       _log.severe("[remove] Failed requesting server: $response");
       throw ApiException(
@@ -435,8 +435,8 @@ class FileSqliteDbDataSource implements FileDataSource {
   }
 
   @override
-  remove(Account account, File f) {
-    _log.info("[remove] ${f.path}");
+  remove(Account account, FileDescriptor f) {
+    _log.info("[remove] ${f.fdPath}");
     return FileSqliteCacheRemover(_c)(account, f);
   }
 
@@ -549,13 +549,20 @@ class FileSqliteDbDataSource implements FileDataSource {
   }
 
   @override
-  move(
+  Future<void> move(
     Account account,
     File f,
     String destination, {
     bool? shouldOverwrite,
   }) async {
-    // do nothing
+    _log.info("[move] ${f.path} to $destination");
+    await _c.sqliteDb.use((db) async {
+      await db.moveFileByFileId(
+        sql.ByAccount.app(account),
+        f.fileId!,
+        File(path: destination).strippedPathWithEmpty,
+      );
+    });
   }
 
   @override
@@ -719,7 +726,7 @@ class FileCachedDataSource implements FileDataSource {
   }
 
   @override
-  remove(Account account, File f) async {
+  remove(Account account, FileDescriptor f) async {
     await _remoteSrc.remove(account, f);
     try {
       await _sqliteDbSrc.remove(account, f);
@@ -786,7 +793,7 @@ class FileCachedDataSource implements FileDataSource {
   }
 
   @override
-  move(
+  Future<void> move(
     Account account,
     File f,
     String destination, {
@@ -794,6 +801,13 @@ class FileCachedDataSource implements FileDataSource {
   }) async {
     await _remoteSrc.move(account, f, destination,
         shouldOverwrite: shouldOverwrite);
+    try {
+      await _sqliteDbSrc.move(account, f, destination);
+    } catch (e, stackTrace) {
+      // ignore cache failure
+      _log.warning(
+          "Failed while move: ${logFilename(f.strippedPath)}", e, stackTrace);
+    }
   }
 
   @override

app/lib/entity/file/file_cache_manager.dart

@@ -191,9 +191,7 @@ class FileSqliteCacheUpdater {
   ) async {
     // query list of rowIds for files in [remoteFiles]
     final rowIds = await db.accountFileRowIdsByFileIds(
-      remoteFiles.map((f) => f.fileId!),
-      sqlAccount: dbAccount,
-    );
+        sql.ByAccount.sql(dbAccount), remoteFiles.map((f) => f.fileId!));
     final rowIdsMap = Map.fromEntries(rowIds.map((e) => MapEntry(e.fileId, e)));
 
     final inserts = <sql.CompleteFileCompanion>[];
@@ -359,7 +357,7 @@ class FileSqliteCacheRemover {
   static bool require(DiContainer c) => DiContainer.has(c, DiType.sqliteDb);
 
   /// Remove a file/dir from cache
-  Future<void> call(Account account, File f) async {
+  Future<void> call(Account account, FileDescriptor f) async {
     await _c.sqliteDb.use((db) async {
       final dbAccount = await db.accountOf(account);
       final rowIds = await db.accountFileRowIdsOf(f, sqlAccount: dbAccount);

app/lib/entity/file_descriptor.dart

@@ -1,6 +1,10 @@
 import 'package:equatable/equatable.dart';
+import 'package:nc_photos/entity/file.dart';
 import 'package:np_common/type.dart';
 import 'package:path/path.dart' as path_lib;
+import 'package:to_string/to_string.dart';
+
+part 'file_descriptor.g.dart';
 
 int compareFileDescriptorDateTimeDescending(
     FileDescriptor x, FileDescriptor y) {
@@ -13,6 +17,7 @@ int compareFileDescriptorDateTimeDescending(
   }
 }
 
+@toString
 class FileDescriptor with EquatableMixin {
   const FileDescriptor({
     required this.fdPath,
@@ -29,18 +34,23 @@ class FileDescriptor with EquatableMixin {
         fdMime: json["fdMime"],
         fdIsArchived: json["fdIsArchived"],
         fdIsFavorite: json["fdIsFavorite"],
-        fdDateTime: json["fdDateTime"],
+        fdDateTime: DateTime.parse(json["fdDateTime"]),
       );
 
-  JsonObj toJson() => {
-        "fdPath": fdPath,
-        "fdId": fdId,
-        "fdMime": fdMime,
-        "fdIsArchived": fdIsArchived,
-        "fdIsFavorite": fdIsFavorite,
-        "fdDateTime": fdDateTime,
+  static JsonObj toJson(FileDescriptor that) => {
+        "fdPath": that.fdPath,
+        "fdId": that.fdId,
+        "fdMime": that.fdMime,
+        "fdIsArchived": that.fdIsArchived,
+        "fdIsFavorite": that.fdIsFavorite,
+        "fdDateTime": that.fdDateTime.toUtc().toIso8601String(),
       };
 
+  @override
+  String toString() => _$toString();
+
+  JsonObj toFdJson() => toJson(this);
+
   @override
   get props => [
         fdPath,
@@ -107,4 +117,14 @@ extension FileDescriptorExtension on FileDescriptor {
 
   /// hashCode to be used with [compareServerIdentity]
   int get identityHashCode => fdId.hashCode;
+
+  File toFile() {
+    return File(
+      path: fdPath,
+      fileId: fdId,
+      contentType: fdMime,
+      isArchived: fdIsArchived,
+      isFavorite: fdIsFavorite,
+    );
+  }
 }

app/lib/entity/file_descriptor.g.dart

@@ -0,0 +1,14 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'file_descriptor.dart';
+
+// **************************************************************************
+// ToStringGenerator
+// **************************************************************************
+
+extension _$FileDescriptorToString on FileDescriptor {
+  String _$toString() {
+    // ignore: unnecessary_string_interpolations
+    return "FileDescriptor {fdPath: $fdPath, fdId: $fdId, fdMime: $fdMime, fdIsArchived: $fdIsArchived, fdIsFavorite: $fdIsFavorite, fdDateTime: $fdDateTime}";
+  }
+}

app/lib/entity/file_util.dart

@@ -5,6 +5,7 @@ import 'package:nc_photos/entity/file.dart';
 import 'package:nc_photos/entity/file_descriptor.dart';
 import 'package:nc_photos/platform/k.dart' as platform_k;
 import 'package:nc_photos/remote_storage_util.dart' as remote_storage_util;
+import 'package:np_api/np_api.dart' as api;
 import 'package:np_common/ci_string.dart';
 import 'package:np_common/string_extension.dart';
 import 'package:path/path.dart' as path_lib;
@@ -20,8 +21,11 @@ bool isSupportedImageMime(String mime) =>
 bool isSupportedImageFormat(FileDescriptor file) =>
     isSupportedImageMime(file.fdMime ?? "");
 
+bool isSupportedVideoMime(String mime) =>
+    supportedVideoFormatMimes.contains(mime);
+
 bool isSupportedVideoFormat(FileDescriptor file) =>
-    isSupportedFormat(file) && file.fdMime?.startsWith("video/") == true;
+    isSupportedVideoMime(file.fdMime ?? "");
 
 bool isMetadataSupportedMime(String mime) =>
     _metadataSupportedFormatMimes.contains(mime);
@@ -32,21 +36,25 @@ bool isMetadataSupportedFormat(FileDescriptor file) =>
 bool isTrash(Account account, FileDescriptor file) =>
     file.fdPath.startsWith(api_util.getTrashbinPath(account));
 
-bool isAlbumFile(Account account, File file) =>
-    file.path.startsWith(remote_storage_util.getRemoteAlbumsDir(account));
+bool isAlbumFile(Account account, FileDescriptor file) =>
+    file.fdPath.startsWith(remote_storage_util.getRemoteAlbumsDir(account));
+
+bool isNcAlbumFile(Account account, FileDescriptor file) =>
+    file.fdPath.startsWith("${api.ApiPhotos.path}/");
 
 /// Return if [file] is located under [dir]
 ///
 /// Return false if [file] is [dir] itself (since it's not "under")
 ///
 /// See [isOrUnderDir]
-bool isUnderDir(File file, File dir) => file.path.startsWith("${dir.path}/");
+bool isUnderDir(FileDescriptor file, FileDescriptor dir) =>
+    file.fdPath.startsWith("${dir.fdPath}/");
 
 /// Return if [file] is [dir] or located under [dir]
 ///
 /// See [isUnderDir]
-bool isOrUnderDir(File file, File dir) =>
-    file.path == dir.path || isUnderDir(file, dir);
+bool isOrUnderDir(FileDescriptor file, FileDescriptor dir) =>
+    file.fdPath == dir.fdPath || isUnderDir(file, dir);
 
 /// Convert a stripped path to a full path
 ///
@@ -118,6 +126,9 @@ final supportedFormatMimes = [
 final supportedImageFormatMimes =
     supportedFormatMimes.where((f) => f.startsWith("image/")).toList();
 
+final supportedVideoFormatMimes =
+    supportedFormatMimes.where((f) => f.startsWith("video/")).toList();
+
 const _metadataSupportedFormatMimes = [
   "image/jpeg",
   "image/heic",

app/lib/entity/nc_album.dart

@@ -0,0 +1,142 @@
+import 'package:copy_with/copy_with.dart';
+import 'package:equatable/equatable.dart';
+import 'package:nc_photos/account.dart';
+import 'package:np_api/np_api.dart' as api;
+import 'package:np_common/ci_string.dart';
+import 'package:np_common/string_extension.dart';
+import 'package:np_common/type.dart';
+import 'package:to_string/to_string.dart';
+
+part 'nc_album.g.dart';
+
+/// Server-side album since Nextcloud 25
+@toString
+@genCopyWith
+class NcAlbum with EquatableMixin {
+  NcAlbum({
+    required String path,
+    required this.lastPhoto,
+    required this.nbItems,
+    required this.location,
+    required this.dateStart,
+    required this.dateEnd,
+    required this.collaborators,
+  }) : path = path.trimAny("/");
+
+  static NcAlbum createNew({
+    required Account account,
+    required String name,
+  }) {
+    return NcAlbum(
+      path: "${api.ApiPhotos.path}/${account.userId}/albums/$name",
+      lastPhoto: null,
+      nbItems: 0,
+      location: null,
+      dateStart: null,
+      dateEnd: null,
+      collaborators: const [],
+    );
+  }
+
+  @override
+  String toString() => _$toString();
+
+  @override
+  List<Object?> get props => [
+        path,
+        lastPhoto,
+        nbItems,
+        location,
+        dateStart,
+        dateEnd,
+        collaborators,
+      ];
+
+  final String path;
+
+  /// File ID of the last photo
+  ///
+  /// The API will return -1 if there's no photos in the album. It's mapped to
+  /// null here instead
+  final int? lastPhoto;
+
+  /// Items count
+  final int nbItems;
+  final String? location;
+  final DateTime? dateStart;
+  final DateTime? dateEnd;
+  final List<NcAlbumCollaborator> collaborators;
+}
+
+extension NcAlbumExtension on NcAlbum {
+  /// Return the path of this file with the DAV part stripped
+  ///
+  /// WebDAV file path: remote.php/dav/photos/{userId}/albums/{strippedPath}.
+  /// If this path points to the user's root album path, return "."
+  String get strippedPath {
+    if (!path.startsWith("remote.php/dav/photos/")) {
+      return path;
+    }
+    var begin = "remote.php/dav/photos/".length;
+    begin = path.indexOf("/", begin);
+    if (begin == -1) {
+      return path;
+    }
+    if (path.slice(begin, begin + 7) != "/albums") {
+      return path;
+    }
+    // /albums/
+    begin += 8;
+    final stripped = path.slice(begin);
+    if (stripped.isEmpty) {
+      return ".";
+    } else {
+      return stripped;
+    }
+  }
+
+  String getRenamedPath(String newName) {
+    final i = path.indexOf("albums/");
+    if (i == -1) {
+      throw StateError("Invalid path: $path");
+    }
+    return "${path.substring(0, i + "albums/".length)}$newName";
+  }
+
+  int get count => nbItems;
+
+  bool compareIdentity(NcAlbum other) {
+    return path == other.path;
+  }
+
+  int get identityHashCode => path.hashCode;
+}
+
+@toString
+class NcAlbumCollaborator {
+  const NcAlbumCollaborator({
+    required this.id,
+    required this.label,
+    required this.type,
+  });
+
+  factory NcAlbumCollaborator.fromJson(JsonObj json) => NcAlbumCollaborator(
+        id: CiString(json["id"]),
+        label: json["label"],
+        type: json["type"],
+      );
+
+  JsonObj toJson() => {
+        "id": id.raw,
+        "label": label,
+        "type": type,
+      };
+
+  @override
+  String toString() => _$toString();
+
+  final CiString id;
+  final String label;
+  // right now it's unclear what this variable represents
+  final int type;
+}