Fix no albums shown if any one of them erred

lib/bloc/list_album.dart

@@ -6,6 +6,7 @@ import 'package:nc_photos/entity/file.dart';
 import 'package:nc_photos/entity/file/data_source.dart';
 import 'package:nc_photos/event/event.dart';
 import 'package:nc_photos/use_case/list_album.dart';
+import 'package:tuple/tuple.dart';
 
 abstract class ListAlbumBlocEvent {
   const ListAlbumBlocEvent();
@@ -124,30 +125,19 @@ class ListAlbumBloc extends Bloc<ListAlbumBlocEvent, ListAlbumBlocState> {
 
     if (!hasContent) {
       // show something instantly on first load
-      ListAlbumBlocState cacheState = ListAlbumBlocInit();
-      await for (final s in _queryOffline(ev, () => cacheState)) {
-        cacheState = s;
-      }
+      final cacheState = await _queryOffline(ev);
       yield ListAlbumBlocLoading(ev.account, cacheState.albums);
       hasContent = cacheState.albums.isNotEmpty;
     }
 
-    ListAlbumBlocState newState = ListAlbumBlocInit();
-    if (!hasContent) {
-      await for (final s in _queryOnline(ev, () => newState)) {
-        newState = s;
-        yield s;
-      }
+    final newState = await _queryOnline(ev);
+    if (newState is ListAlbumBlocFailure) {
+      yield ListAlbumBlocFailure(
+          ev.account,
+          newState.albums?.isNotEmpty == true ? newState.albums : state.albums,
+          newState.exception);
     } else {
-      await for (final s in _queryOnline(ev, () => newState)) {
-        newState = s;
-      }
-      if (newState is ListAlbumBlocSuccess) {
-        yield newState;
-      } else if (newState is ListAlbumBlocFailure) {
-        yield ListAlbumBlocFailure(
-            ev.account, state.albums, newState.exception);
-      }
+      yield newState;
     }
   }
 
@@ -182,29 +172,37 @@ class ListAlbumBloc extends Bloc<ListAlbumBlocEvent, ListAlbumBlocState> {
     add(_ListAlbumBlocExternalEvent());
   }
 
-  Stream<ListAlbumBlocState> _queryOffline(
-          ListAlbumBlocQuery ev, ListAlbumBlocState Function() getState) =>
+  Future<ListAlbumBlocState> _queryOffline(ListAlbumBlocQuery ev) =>
       _queryWithAlbumDataSource(
-          ev, getState, FileAppDbDataSource(), AlbumAppDbDataSource());
+          ev, FileAppDbDataSource(), AlbumAppDbDataSource());
 
-  Stream<ListAlbumBlocState> _queryOnline(
-          ListAlbumBlocQuery ev, ListAlbumBlocState Function() getState) =>
+  Future<ListAlbumBlocState> _queryOnline(ListAlbumBlocQuery ev) =>
       _queryWithAlbumDataSource(
-          ev, getState, FileCachedDataSource(), AlbumCachedDataSource());
+          ev, FileCachedDataSource(), AlbumCachedDataSource());
 
-  Stream<ListAlbumBlocState> _queryWithAlbumDataSource(
-      ListAlbumBlocQuery ev,
-      ListAlbumBlocState Function() getState,
-      FileDataSource fileDataSource,
-      AlbumDataSource albumDataSrc) async* {
+  Future<ListAlbumBlocState> _queryWithAlbumDataSource(ListAlbumBlocQuery ev,
+      FileDataSource fileDataSource, AlbumDataSource albumDataSrc) async {
     try {
-      final results = await ListAlbum(
-          FileRepo(fileDataSource), AlbumRepo(albumDataSrc))(ev.account);
-      yield ListAlbumBlocSuccess(ev.account, results);
+      final albums = <Album>[];
+      final errors = <dynamic>[];
+      await for (final result in ListAlbum(
+          FileRepo(fileDataSource), AlbumRepo(albumDataSrc))(ev.account)) {
+        if (result is Tuple2) {
+          _log.severe("[_queryWithAlbumDataSource] Exception while ListAlbum",
+              result.item1, result.item2);
+          errors.add(result.item1);
+        } else if (result is Album) {
+          albums.add(result);
+        }
+      }
+      if (errors.isEmpty) {
+        return ListAlbumBlocSuccess(ev.account, albums);
+      } else {
+        return ListAlbumBlocFailure(ev.account, albums, errors.first);
+      }
     } catch (e, stacktrace) {
-      _log.severe(
-          "[_queryWithAlbumDataSource] Exception while request", e, stacktrace);
-      yield ListAlbumBlocFailure(ev.account, getState().albums, e);
+      _log.severe("[_queryWithAlbumDataSource] Exception", e, stacktrace);
+      return ListAlbumBlocFailure(ev.account, [], e);
     }
   }
 

lib/bloc/list_importable_album.dart

@@ -102,7 +102,9 @@ class ListImportableAlbumBloc
     try {
       final fileRepo = FileRepo(FileCachedDataSource());
       final albumRepo = AlbumRepo(AlbumCachedDataSource());
-      final albums = await ListAlbum(fileRepo, albumRepo)(ev.account);
+      final albums = (await ListAlbum(fileRepo, albumRepo)(ev.account)
+          .where((event) => event is Album)
+          .toList()).cast<Album>();
       final importedDirs = albums.map((a) {
         if (a.provider is! AlbumDirProvider) {
           return <File>[];

lib/use_case/list_album.dart

@@ -6,54 +6,59 @@ import 'package:nc_photos/exception.dart';
 import 'package:nc_photos/remote_storage_util.dart' as remote_storage_util;
 import 'package:nc_photos/use_case/compat/v15.dart';
 import 'package:nc_photos/use_case/ls.dart';
+import 'package:tuple/tuple.dart';
 
 class ListAlbum {
   ListAlbum(this.fileRepo, this.albumRepo);
 
   /// List all albums associated with [account]
-  Future<List<Album>> call(Account account) async {
-    final results = await _call(account);
-    if (results.isEmpty) {
+  ///
+  /// The returned stream would emit either Album data or a tuple of exception
+  /// and stacktrace
+  Stream<dynamic> call(Account account) async* {
+    bool hasAlbum = false;
+    await for (final result in _call(account)) {
+      hasAlbum = true;
+      yield result;
+    }
+    if (!hasAlbum) {
       if (await CompatV15.migrateAlbumFiles(account, fileRepo)) {
-        // migrated
-        return await _call(account);
-      } else {
-        // no need to migrate
-        return [];
+        // migrated, try again
+        yield* _call(account);
       }
-    } else {
-      return results;
     }
   }
 
-  Future<List<Album>> _call(Account account) async {
+  Stream<dynamic> _call(Account account) async* {
+    List<File> ls;
     try {
-      final ls = await Ls(fileRepo)(
+      ls = await Ls(fileRepo)(
           account,
           File(
             path: remote_storage_util.getRemoteAlbumsDir(account),
           ));
-      final albumFiles =
-          ls.where((element) => element.isCollection != true).toList();
-      final albums = <Album>[];
-      for (final f in albumFiles) {
-        final album = await albumRepo.get(account, f);
-        albums.add(album);
-      }
-      try {
-        albumRepo.cleanUp(account, albumFiles);
-      } catch (e, stacktrace) {
-        // not important, log and ignore
-        _log.shout("[_call] Failed while cleanUp", e, stacktrace);
-      }
-      return albums;
     } catch (e) {
       if (e is ApiException && e.response.statusCode == 404) {
         // no albums
-        return [];
+        return;
       }
       rethrow;
     }
+    final albumFiles =
+        ls.where((element) => element.isCollection != true).toList();
+    for (final f in albumFiles) {
+      try {
+        yield await albumRepo.get(account, f);
+      } catch (e, stacktrace) {
+        yield Tuple2(e, stacktrace);
+      }
+    }
+    try {
+      albumRepo.cleanUp(account, albumFiles);
+    } catch (e, stacktrace) {
+      // not important, log and ignore
+      _log.shout("[_call] Failed while cleanUp", e, stacktrace);
+    }
   }
 
   final FileRepo fileRepo;

lib/use_case/remove.dart

@@ -24,7 +24,9 @@ class Remove {
   }
 
   Future<void> _cleanUpAlbums(Account account, File file) async {
-    final albums = await ListAlbum(fileRepo, albumRepo)(account);
+    final albums = (await ListAlbum(fileRepo, albumRepo)(account)
+        .where((event) => event is Album)
+        .toList()).cast<Album>();
     // clean up only make sense for static albums
     for (final a
         in albums.where((element) => element.provider is AlbumStaticProvider)) {