Remove metadata from album files

This help reduce the file size

lib/app_db.dart

@@ -140,6 +140,7 @@ class AppDbAlbumEntry {
         upgraderV1: AlbumUpgraderV1(),
         upgraderV2: AlbumUpgraderV2(),
         upgraderV3: AlbumUpgraderV3(),
+        upgraderV4: AlbumUpgraderV4(),
       )!,
     );
   }

lib/entity/album.dart

@@ -44,6 +44,7 @@ class Album with EquatableMixin {
     required AlbumUpgraderV1? upgraderV1,
     required AlbumUpgraderV2? upgraderV2,
     required AlbumUpgraderV3? upgraderV3,
+    required AlbumUpgraderV4? upgraderV4,
   }) {
     final jsonVersion = json["version"];
     JsonObj? result = json;
@@ -68,6 +69,13 @@ class Album with EquatableMixin {
         return null;
       }
     }
+    if (jsonVersion < 5) {
+      result = upgraderV4?.call(result);
+      if (result == null) {
+        _log.info("[fromJson] Version $jsonVersion not compatible");
+        return null;
+      }
+    }
     return Album(
       lastUpdated: result["lastUpdated"] == null
           ? null
@@ -168,7 +176,7 @@ class Album with EquatableMixin {
   final File? albumFile;
 
   /// versioning of this class, use to upgrade old persisted album
-  static const version = 4;
+  static const version = 5;
 }
 
 class AlbumRepo {
@@ -224,6 +232,7 @@ class AlbumRemoteDataSource implements AlbumDataSource {
         upgraderV1: AlbumUpgraderV1(),
         upgraderV2: AlbumUpgraderV2(),
         upgraderV3: AlbumUpgraderV3(),
+        upgraderV4: AlbumUpgraderV4(),
       )!
           .copyWith(
         lastUpdated: OrNull(null),

lib/entity/album/item.dart

@@ -4,6 +4,7 @@ import 'package:equatable/equatable.dart';
 import 'package:logging/logging.dart';
 import 'package:nc_photos/entity/file.dart';
 import 'package:nc_photos/list_extension.dart';
+import 'package:nc_photos/or_null.dart';
 import 'package:nc_photos/type.dart';
 
 List<AlbumItem> makeDistinctAlbumItems(List<AlbumItem> items) =>
@@ -95,6 +96,10 @@ class AlbumFileItem extends AlbumItem with EquatableMixin {
     };
   }
 
+  AlbumFileItem minimize() => AlbumFileItem(
+        file: file.copyWith(metadata: OrNull(null)),
+      );
+
   @override
   get props => [
         // file is handled separately, see [equals]

lib/entity/album/provider.dart

@@ -6,7 +6,6 @@ import 'package:logging/logging.dart';
 import 'package:nc_photos/entity/album.dart';
 import 'package:nc_photos/entity/album/item.dart';
 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/type.dart';
 
@@ -58,13 +57,54 @@ abstract class AlbumProvider with EquatableMixin {
   static final _log = Logger("entity.album.provider.AlbumProvider");
 }
 
-class AlbumStaticProvider extends AlbumProvider {
+abstract class AlbumProviderBase extends AlbumProvider {
+  const AlbumProviderBase({
+    this.latestItemTime,
+  });
+
+  @override
+  toString({bool isDeep = false}) {
+    return "$runtimeType {"
+        "latestItemTime: $latestItemTime, "
+        "}";
+  }
+
+  @override
+  toContentJson() {
+    return {
+      if (latestItemTime != null)
+        "latestItemTime": latestItemTime!.toUtc().toIso8601String(),
+    };
+  }
+
+  @override
+  AlbumProviderBase copyWith({
+    DateTime? latestItemTime,
+  });
+
+  @override
+  get props => [
+        latestItemTime,
+      ];
+
+  @override
+  final DateTime? latestItemTime;
+}
+
+class AlbumStaticProvider extends AlbumProviderBase {
   AlbumStaticProvider({
+    DateTime? latestItemTime,
     required List<AlbumItem> items,
-  }) : items = UnmodifiableListView(items);
+  })  : items = UnmodifiableListView(items),
+        super(
+          latestItemTime: latestItemTime,
+        );
 
   factory AlbumStaticProvider.fromJson(JsonObj json) {
     return AlbumStaticProvider(
+      latestItemTime: json["latestItemTime"] == null
+          ? null
+          : DateTime.parse(json["latestItemTime"]),
       items: (json["items"] as List)
           .map((e) => AlbumItem.fromJson(e.cast<String, dynamic>()))
           .toList(),
@@ -79,6 +119,7 @@ class AlbumStaticProvider extends AlbumProvider {
     final itemsStr =
         isDeep ? items.toReadableString() : "List {length: ${items.length}}";
     return "$runtimeType {"
+        "super: ${super.toString(isDeep: isDeep)}, "
         "items: $itemsStr, "
         "}";
   }
@@ -86,36 +127,25 @@ class AlbumStaticProvider extends AlbumProvider {
   @override
   toContentJson() {
     return {
+      ...super.toContentJson(),
       "items": items.map((e) => e.toJson()).toList(),
     };
   }
 
   @override
   AlbumStaticProvider copyWith({
+    DateTime? latestItemTime,
     List<AlbumItem>? items,
   }) {
     return AlbumStaticProvider(
+      latestItemTime: latestItemTime ?? this.latestItemTime,
       items: items ?? this.items,
     );
   }
 
-  @override
-  get latestItemTime {
-    try {
-      return items
-          .whereType<AlbumFileItem>()
-          .map((e) => e.file)
-          .where((element) => file_util.isSupportedFormat(element))
-          .sorted(compareFileDateTimeDescending)
-          .first
-          .bestDateTime;
-    } catch (_) {
-      return null;
-    }
-  }
-
   @override
   get props => [
+        ...super.props,
         items,
       ];
 
@@ -125,55 +155,28 @@ class AlbumStaticProvider extends AlbumProvider {
   static const _type = "static";
 }
 
-abstract class AlbumDynamicProvider extends AlbumProvider {
-  AlbumDynamicProvider({
+abstract class AlbumDynamicProvider extends AlbumProviderBase {
+  const AlbumDynamicProvider({
     DateTime? latestItemTime,
-  }) : _latestItemTime = latestItemTime;
-
-  @override
-  toString({bool isDeep = false}) {
-    return "$runtimeType {"
-        "latestItemTime: $_latestItemTime, "
-        "}";
-  }
-
-  @override
-  toContentJson() {
-    return {
-      "latestItemTime": _latestItemTime?.toUtc().toIso8601String(),
-    };
-  }
-
-  @override
-  AlbumDynamicProvider copyWith({
-    DateTime? latestItemTime,
-  });
-
-  @override
-  get latestItemTime => _latestItemTime;
-
-  @override
-  get props => [
-        _latestItemTime,
-      ];
-
-  final DateTime? _latestItemTime;
+  }) : super(latestItemTime: latestItemTime);
 }
 
 class AlbumDirProvider extends AlbumDynamicProvider {
-  AlbumDirProvider({
+  const AlbumDirProvider({
     required this.dirs,
     DateTime? latestItemTime,
-  }) : super(latestItemTime: latestItemTime);
+  }) : super(
+          latestItemTime: latestItemTime,
+        );
 
   factory AlbumDirProvider.fromJson(JsonObj json) {
     return AlbumDirProvider(
-      dirs: (json["dirs"] as List)
-          .map((e) => File.fromJson(e.cast<String, dynamic>()))
-          .toList(),
       latestItemTime: json["latestItemTime"] == null
           ? null
           : DateTime.parse(json["latestItemTime"]),
+      dirs: (json["dirs"] as List)
+          .map((e) => File.fromJson(e.cast<String, dynamic>()))
+          .toList(),
     );
   }
 
@@ -195,12 +198,12 @@ class AlbumDirProvider extends AlbumDynamicProvider {
 
   @override
   AlbumDirProvider copyWith({
-    List<File>? dirs,
     DateTime? latestItemTime,
+    List<File>? dirs,
   }) {
     return AlbumDirProvider(
-      dirs: dirs ?? this.dirs,
       latestItemTime: latestItemTime ?? this.latestItemTime,
+      dirs: dirs ?? this.dirs,
     );
   }
 

lib/entity/album/upgrader.dart

@@ -1,5 +1,8 @@
 import 'package:logging/logging.dart';
+import 'package:nc_photos/entity/exif.dart';
+import 'package:nc_photos/iterable_extension.dart';
 import 'package:nc_photos/type.dart';
+import 'package:tuple/tuple.dart';
 
 abstract class AlbumUpgrader {
   JsonObj? call(JsonObj json);
@@ -85,3 +88,72 @@ class AlbumUpgraderV3 implements AlbumUpgrader {
 
   static final _log = Logger("entity.album.upgrader.AlbumUpgraderV3");
 }
+
+/// Upgrade v4 Album to v5
+class AlbumUpgraderV4 implements AlbumUpgrader {
+  AlbumUpgraderV4({
+    this.logFilePath,
+  });
+
+  @override
+  call(JsonObj json) {
+    _log.fine("[call] Upgrade v4 Album for file: $logFilePath");
+    final result = JsonObj.from(json);
+    try {
+      if (result["provider"]["type"] != "static") {
+        return result;
+      }
+      final latestItem = (result["provider"]["content"]["items"] as List)
+          .map((e) => e.cast<String, dynamic>())
+          .where((e) => e["type"] == "file")
+          .map((e) => e["content"]["file"] as JsonObj)
+          .map((e) {
+            final overrideDateTime = e["overrideDateTime"] == null
+                ? null
+                : DateTime.parse(e["overrideDateTime"]);
+            final String? dateTimeOriginalStr =
+                e["metadata"]?["exif"]?["DateTimeOriginal"];
+            final dateTimeOriginal =
+                dateTimeOriginalStr == null || dateTimeOriginalStr.isEmpty
+                    ? null
+                    : Exif.dateTimeFormat.parse(dateTimeOriginalStr).toUtc();
+            final lastModified = e["lastModified"] == null
+                ? null
+                : DateTime.parse(e["lastModified"]);
+            final latestItemTime =
+                overrideDateTime ?? dateTimeOriginal ?? lastModified;
+
+            // remove metadata
+            e.remove("metadata");
+            if (latestItemTime != null) {
+              return Tuple2(latestItemTime, e);
+            } else {
+              return null;
+            }
+          })
+          .whereType<Tuple2<DateTime, JsonObj>>()
+          .sorted((a, b) => a.item1.compareTo(b.item1))
+          .lastOrNull;
+      if (latestItem != null) {
+        // save the latest item time
+        result["provider"]["content"]["latestItemTime"] =
+            latestItem.item1.toIso8601String();
+        if (result["coverProvider"]["type"] == "auto") {
+          // save the cover
+          result["coverProvider"]["content"]["coverFile"] =
+              Map.of(latestItem.item2);
+        }
+      }
+    } 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);
+    }
+    return result;
+  }
+
+  /// File path for logging only
+  final String? logFilePath;
+
+  static final _log = Logger("entity.album.upgrader.AlbumUpgraderV4");
+}

lib/iterable_extension.dart

@@ -49,4 +49,12 @@ extension IterableExtension<T> on Iterable<T> {
       return null;
     }
   }
+
+  T? get lastOrNull {
+    try {
+      return last;
+    } on StateError catch (_) {
+      return null;
+    }
+  }
 }

lib/use_case/add_to_album.dart

@@ -1,24 +1,43 @@
+import 'package:logging/logging.dart';
 import 'package:nc_photos/account.dart';
 import 'package:nc_photos/entity/album.dart';
 import 'package:nc_photos/entity/album/item.dart';
 import 'package:nc_photos/entity/album/provider.dart';
+import 'package:nc_photos/use_case/resync_album.dart';
 import 'package:nc_photos/use_case/update_album.dart';
+import 'package:nc_photos/use_case/update_album_with_actual_items.dart';
 
 class AddToAlbum {
   AddToAlbum(this.albumRepo);
 
   /// Add a list of AlbumItems to [album]
-  Future<void> call(Account account, Album album, List<AlbumItem> items) =>
-      UpdateAlbum(albumRepo)(
-          account,
-          album.copyWith(
-            provider: AlbumStaticProvider.of(album).copyWith(
-              items: makeDistinctAlbumItems([
-                ...items,
-                ...AlbumStaticProvider.of(album).items,
-              ]),
-            ),
-          ));
+  Future<Album> call(
+      Account account, Album album, List<AlbumItem> items) async {
+    _log.info("[call] Add ${items.length} items to album '${album.name}'");
+    assert(album.provider is AlbumStaticProvider);
+    // resync is needed to work out album cover and latest item
+    final oldItems = await ResyncAlbum()(account, album);
+    final newItems = makeDistinctAlbumItems([
+      ...items,
+      ...oldItems,
+    ]);
+    var newAlbum = album.copyWith(
+      provider: AlbumStaticProvider.of(album).copyWith(
+        items: newItems,
+      ),
+    );
+    // UpdateAlbumWithActualItems only persists when there are changes to
+    // several properties, so we can't rely on it
+    newAlbum = await UpdateAlbumWithActualItems(null)(
+      account,
+      newAlbum,
+      newItems,
+    );
+    await UpdateAlbum(albumRepo)(account, newAlbum);
+    return newAlbum;
+  }
 
   final AlbumRepo albumRepo;
+
+  static final _log = Logger("use_case.add_to_album.AddToAlbum");
 }

lib/use_case/remove_from_album.dart

@@ -3,8 +3,11 @@ import 'package:nc_photos/account.dart';
 import 'package:nc_photos/entity/album.dart';
 import 'package:nc_photos/entity/album/item.dart';
 import 'package:nc_photos/entity/album/provider.dart';
+import 'package:nc_photos/entity/file.dart';
 import 'package:nc_photos/iterable_extension.dart';
+import 'package:nc_photos/use_case/resync_album.dart';
 import 'package:nc_photos/use_case/update_album.dart';
+import 'package:nc_photos/use_case/update_album_with_actual_items.dart';
 
 class RemoveFromAlbum {
   RemoveFromAlbum(this.albumRepo);
@@ -26,6 +29,18 @@ class RemoveFromAlbum {
         items: newItems,
       ),
     );
+    // check if any of the removed items was the latest item
+    if (items.whereType<AlbumFileItem>().any((element) =>
+        element.file.bestDateTime == album.provider.latestItemTime)) {
+      _log.info("[call] Resync as latest item is being removed");
+      // need to update the album properties
+      final newItemsSynced = await ResyncAlbum()(account, newAlbum);
+      newAlbum = await UpdateAlbumWithActualItems(null)(
+        account,
+        newAlbum,
+        newItemsSynced,
+      );
+    }
     await UpdateAlbum(albumRepo)(account, newAlbum);
     return newAlbum;
   }

lib/use_case/resync_album.dart

@@ -10,11 +10,11 @@ import 'package:nc_photos/entity/file_util.dart' as file_util;
 
 /// Resync files inside an album with the file db
 class ResyncAlbum {
-  Future<Album> call(Account account, Album album) async {
+  Future<List<AlbumItem>> call(Account account, Album album) async {
+    _log.info("[call] Resync album: ${album.name}");
     if (album.provider is! AlbumStaticProvider) {
-      _log.warning(
-          "[call] Resync only make sense for static albums: ${album.name}");
-      return album;
+      throw ArgumentError(
+          "Resync only make sense for static albums: ${album.name}");
     }
     return await AppDb.use((db) async {
       final transaction =
@@ -38,7 +38,7 @@ class ResyncAlbum {
           newItems.add(item);
         }
       }
-      return album.copyWith(provider: AlbumStaticProvider(items: newItems));
+      return newItems;
     });
   }
 

lib/use_case/update_album.dart

@@ -2,15 +2,33 @@ import 'package:event_bus/event_bus.dart';
 import 'package:kiwi/kiwi.dart';
 import 'package:nc_photos/account.dart';
 import 'package:nc_photos/entity/album.dart';
+import 'package:nc_photos/entity/album/item.dart';
+import 'package:nc_photos/entity/album/provider.dart';
 import 'package:nc_photos/event/event.dart';
 
 class UpdateAlbum {
   UpdateAlbum(this.albumRepo);
 
   Future<void> call(Account account, Album album) async {
-    await albumRepo.update(account, album);
+    final provider = album.provider;
+    if (provider is AlbumStaticProvider) {
+      await albumRepo.update(
+        account,
+        album.copyWith(
+          provider: provider.copyWith(
+            items: _minimizeItems(provider.items),
+          ),
+        ),
+      );
+    } else {
+      await albumRepo.update(account, album);
+    }
     KiwiContainer().resolve<EventBus>().fire(AlbumUpdatedEvent(account, album));
   }
 
+  List<AlbumItem> _minimizeItems(List<AlbumItem> items) {
+    return items.map((e) => e is AlbumFileItem ? e.minimize() : e).toList();
+  }
+
   final AlbumRepo albumRepo;
 }

lib/use_case/update_album_time.dart

@@ -0,0 +1,56 @@
+import 'package:nc_photos/entity/album.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/file.dart';
+import 'package:nc_photos/entity/file_util.dart' as file_util;
+
+class UpdateAlbumTime {
+  /// Update the latest item time of an album with unsorted items
+  ///
+  /// If no updates are needed, return the same object
+  Album call(Album album, List<AlbumItem> items) {
+    if (album.provider is! AlbumProviderBase) {
+      return album;
+    } else {
+      final sortedItems =
+          const AlbumTimeSortProvider(isAscending: false).sort(items);
+      return _updateWithSortedItems(album, sortedItems);
+    }
+  }
+
+  /// Update the latest item time of an album with pre-sorted files
+  ///
+  /// The album items are expected to be sorted by [AlbumTimeSortProvider] with
+  /// isAscending = false, otherwise please call the unsorted version. If no
+  /// updates are needed, return the same object
+  Album updateWithSortedItems(Album album, List<AlbumItem> sortedItems) {
+    if (album.provider is! AlbumProviderBase) {
+      return album;
+    } else {
+      return _updateWithSortedItems(album, sortedItems);
+    }
+  }
+
+  Album _updateWithSortedItems(Album album, List<AlbumItem> sortedItems) {
+    DateTime? latestItemTime;
+    try {
+      final latestFile = sortedItems
+          .whereType<AlbumFileItem>()
+          .map((e) => e.file)
+          .where((element) => file_util.isSupportedFormat(element))
+          .first;
+      latestItemTime = latestFile.bestDateTime;
+    } catch (_) {
+      latestItemTime = null;
+    }
+    if (latestItemTime != album.provider.latestItemTime) {
+      return album.copyWith(
+        provider: (album.provider as AlbumProviderBase).copyWith(
+          latestItemTime: latestItemTime,
+        ),
+      );
+    }
+    return album;
+  }
+}

lib/use_case/update_album_with_actual_items.dart

@@ -0,0 +1,50 @@
+import 'package:logging/logging.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/entity/album.dart';
+import 'package:nc_photos/entity/album/item.dart';
+import 'package:nc_photos/entity/album/sort_provider.dart';
+import 'package:nc_photos/use_case/update_album.dart';
+import 'package:nc_photos/use_case/update_album_time.dart';
+import 'package:nc_photos/use_case/update_auto_album_cover.dart';
+
+class UpdateAlbumWithActualItems {
+  UpdateAlbumWithActualItems(this.albumRepo);
+
+  /// Update, if necessary, [album] after resynced/populated with actual items
+  ///
+  /// If [albumRepo] is null, the modified album will not be saved
+  Future<Album> call(
+      Account account, Album album, List<AlbumItem> items) async {
+    final sortedItems =
+        const AlbumTimeSortProvider(isAscending: false).sort(items);
+
+    bool shouldUpdate = false;
+    final albumUpdatedCover =
+        UpdateAutoAlbumCover().updateWithSortedItems(album, sortedItems);
+    if (!identical(albumUpdatedCover, album)) {
+      _log.info("[call] Update album cover");
+      shouldUpdate = true;
+    }
+    album = albumUpdatedCover;
+
+    final albumUpdatedTime =
+        UpdateAlbumTime().updateWithSortedItems(album, sortedItems);
+    if (!identical(albumUpdatedTime, album)) {
+      _log.info(
+          "[call] Update album time: ${album.provider.latestItemTime} -> ${albumUpdatedTime.provider.latestItemTime}");
+      shouldUpdate = true;
+    }
+    album = albumUpdatedTime;
+
+    if (albumRepo != null && shouldUpdate) {
+      _log.info("[call] Persist album");
+      await UpdateAlbum(albumRepo!)(account, album);
+    }
+    return album;
+  }
+
+  final AlbumRepo? albumRepo;
+
+  static final _log = Logger(
+      "use_case.update_album_with_actual_items.UpdateAlbumWithActualItems");
+}

lib/use_case/update_auto_album_cover.dart

@@ -0,0 +1,55 @@
+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/sort_provider.dart';
+import 'package:nc_photos/entity/file_util.dart' as file_util;
+
+class UpdateAutoAlbumCover {
+  /// Update the AlbumAutoCoverProvider of an album with unsorted items
+  ///
+  /// If no updates are needed, return the same object
+  Album call(Album album, List<AlbumItem> items) {
+    if (album.coverProvider is! AlbumAutoCoverProvider) {
+      return album;
+    } else {
+      final sortedItems =
+          const AlbumTimeSortProvider(isAscending: false).sort(items);
+      return _updateWithSortedItems(album, sortedItems);
+    }
+  }
+
+  /// Update the AlbumAutoCoverProvider of an album with pre-sorted files
+  ///
+  /// The album items are expected to be sorted by [AlbumTimeSortProvider] with
+  /// isAscending = false, otherwise please call the unsorted version. If no
+  /// updates are needed, return the same object
+  Album updateWithSortedItems(Album album, List<AlbumItem> sortedItems) {
+    if (album.coverProvider is! AlbumAutoCoverProvider) {
+      return album;
+    } else {
+      return _updateWithSortedItems(album, sortedItems);
+    }
+  }
+
+  Album _updateWithSortedItems(Album album, List<AlbumItem> sortedItems) {
+    try {
+      final coverFile = sortedItems
+          .whereType<AlbumFileItem>()
+          .map((e) => e.file)
+          .where((element) => file_util.isSupportedFormat(element))
+          .firstWhere((element) => element.hasPreview ?? false);
+      // cache the result for later use
+      if (coverFile.path !=
+          (album.coverProvider as AlbumAutoCoverProvider).coverFile?.path) {
+        return album.copyWith(
+          coverProvider: AlbumAutoCoverProvider(
+            coverFile: coverFile,
+          ),
+        );
+      }
+    } on StateError catch (_) {
+      // no files
+    }
+    return album;
+  }
+}

lib/use_case/update_dynamic_album_cover.dart

@@ -1,60 +0,0 @@
-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/file.dart';
-import 'package:nc_photos/entity/file_util.dart' as file_util;
-import 'package:nc_photos/iterable_extension.dart';
-
-class UpdateDynamicAlbumCover {
-  /// Update the cover of a dynamic album with unsorted items
-  ///
-  /// If no updates are needed, return the same object
-  Album call(Album album, List<AlbumItem> populatedItems) {
-    if (album.provider is! AlbumDynamicProvider ||
-        album.coverProvider is! AlbumAutoCoverProvider) {
-      return album;
-    } else {
-      return _updateWithSortedFiles(
-          album,
-          populatedItems
-              .whereType<AlbumFileItem>()
-              .map((e) => e.file)
-              .where((element) => file_util.isSupportedFormat(element))
-              .sorted(compareFileDateTimeDescending));
-    }
-  }
-
-  /// Update the cover of a dynamic album with pre-sorted files
-  ///
-  /// The album items are expected to be sorted by
-  /// [compareFileDateTimeDescending], otherwise please call the unsorted
-  /// version. If no updates are needed, return the same object
-  Album updateWithSortedFiles(Album album, List<File> sortedFiles) {
-    if (album.provider is! AlbumDynamicProvider ||
-        album.coverProvider is! AlbumAutoCoverProvider) {
-      return album;
-    } else {
-      return _updateWithSortedFiles(album, sortedFiles);
-    }
-  }
-
-  Album _updateWithSortedFiles(Album album, List<File> sortedFiles) {
-    try {
-      final coverFile =
-          sortedFiles.firstWhere((element) => element.hasPreview ?? false);
-      // cache the result for later use
-      if (coverFile.path !=
-          (album.coverProvider as AlbumAutoCoverProvider).coverFile?.path) {
-        return album.copyWith(
-          coverProvider: AlbumAutoCoverProvider(
-            coverFile: coverFile,
-          ),
-        );
-      }
-    } on StateError catch (_) {
-      // no files
-    }
-    return album;
-  }
-}

lib/use_case/update_dynamic_album_time.dart

@@ -1,55 +0,0 @@
-import 'package:nc_photos/entity/album.dart';
-import 'package:nc_photos/entity/album/item.dart';
-import 'package:nc_photos/entity/album/provider.dart';
-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';
-
-class UpdateDynamicAlbumTime {
-  /// Update the latest item time of a dynamic album with unsorted items
-  ///
-  /// If no updates are needed, return the same object
-  Album call(Album album, List<AlbumItem> populatedItems) {
-    if (album.provider is! AlbumDynamicProvider) {
-      return album;
-    } else {
-      return _updateWithSortedFiles(
-          album,
-          populatedItems
-              .whereType<AlbumFileItem>()
-              .map((e) => e.file)
-              .where((element) => file_util.isSupportedFormat(element))
-              .sorted(compareFileDateTimeDescending));
-    }
-  }
-
-  /// Update the latest item time of a dynamic album with pre-sorted files
-  ///
-  /// The album items are expected to be sorted by
-  /// [compareFileDateTimeDescending], otherwise please call the unsorted
-  /// version. If no updates are needed, return the same object
-  Album updateWithSortedFiles(Album album, List<File> sortedFiles) {
-    if (album.provider is! AlbumDynamicProvider) {
-      return album;
-    } else {
-      return _updateWithSortedFiles(album, sortedFiles);
-    }
-  }
-
-  Album _updateWithSortedFiles(Album album, List<File> sortedFiles) {
-    DateTime? latestItemTime;
-    try {
-      latestItemTime = sortedFiles.first.bestDateTime;
-    } catch (_) {
-      latestItemTime = null;
-    }
-    if (latestItemTime != album.provider.latestItemTime) {
-      return album.copyWith(
-        provider: (album.provider as AlbumDynamicProvider).copyWith(
-          latestItemTime: latestItemTime,
-        ),
-      );
-    }
-    return album;
-  }
-}

lib/widget/album_browser.dart

@@ -14,8 +14,8 @@ 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/exception_util.dart' as exception_util;
-import 'package:nc_photos/iterable_extension.dart';
 import 'package:nc_photos/k.dart' as k;
+import 'package:nc_photos/list_extension.dart';
 import 'package:nc_photos/or_null.dart';
 import 'package:nc_photos/platform/k.dart' as platform_k;
 import 'package:nc_photos/session_storage.dart';
@@ -25,6 +25,7 @@ import 'package:nc_photos/theme.dart';
 import 'package:nc_photos/use_case/remove_from_album.dart';
 import 'package:nc_photos/use_case/resync_album.dart';
 import 'package:nc_photos/use_case/update_album.dart';
+import 'package:nc_photos/use_case/update_album_with_actual_items.dart';
 import 'package:nc_photos/widget/album_browser_mixin.dart';
 import 'package:nc_photos/widget/draggable_item_list_mixin.dart';
 import 'package:nc_photos/widget/fancy_option_picker.dart';
@@ -32,7 +33,6 @@ import 'package:nc_photos/widget/photo_list_item.dart';
 import 'package:nc_photos/widget/selectable_item_stream_list_mixin.dart';
 import 'package:nc_photos/widget/simple_input_dialog.dart';
 import 'package:nc_photos/widget/viewer.dart';
-import 'package:quiver/iterables.dart';
 
 class AlbumBrowserArguments {
   AlbumBrowserArguments(this.account, this.album);
@@ -169,20 +169,10 @@ class _AlbumBrowserState extends State<AlbumBrowser>
     }
   }
 
-  void _initAlbum() {
-    assert(widget.album.provider is AlbumStaticProvider);
-    ResyncAlbum()(widget.account, widget.album).then((album) {
-      if (_shouldPropagateResyncedAlbum(album)) {
-        _propagateResyncedAlbum(album);
-      }
-      if (mounted) {
-        setState(() {
-          _album = album;
-          _transformItems();
-          initCover(widget.account, album);
-        });
-      }
-    });
+  Future<void> _initAlbum() async {
+    final albumRepo = AlbumRepo(AlbumCachedDataSource());
+    final album = await albumRepo.get(widget.account, widget.album.albumFile!);
+    await _setAlbum(album);
   }
 
   Widget _buildContent(BuildContext context) {
@@ -495,13 +485,9 @@ class _AlbumBrowserState extends State<AlbumBrowser>
     });
   }
 
-  void _onAlbumUpdatedEvent(AlbumUpdatedEvent ev) {
+  Future<void> _onAlbumUpdatedEvent(AlbumUpdatedEvent ev) async {
     if (ev.album.albumFile!.path == _album?.albumFile?.path) {
-      setState(() {
-        _album = ev.album;
-        _transformItems();
-        initCover(widget.account, ev.album);
-      });
+      await _setAlbum(ev.album);
     }
   }
 
@@ -600,64 +586,29 @@ class _AlbumBrowserState extends State<AlbumBrowser>
     draggableItemList = items;
   }
 
-  void _propagateResyncedAlbum(Album album) {
-    final propagateItems =
-        zip([_getAlbumItemsOf(album), _getAlbumItemsOf(widget.album)]).map((e) {
-      if (e[0] is AlbumFileItem) {
-        final item = e[0] as AlbumFileItem;
-        if (!item.file.isOwned(widget.account.username)) {
-          // don't propagate shared file not owned by this user, this is to
-          // prevent multiple user having different properties to keep
-          // overriding each others
-          _log.info(
-              "[_propagateResyncedAlbum] Skip shared file: ${item.file.path}");
-          return e[1];
-        }
-      }
-      return e[0];
-    }).toList();
-    final propagateAlbum = album.copyWith(
+  Future<void> _setAlbum(Album album) async {
+    assert(album.provider is AlbumStaticProvider);
+    final items = await ResyncAlbum()(widget.account, album);
+    album = album.copyWith(
       provider: AlbumStaticProvider.of(album).copyWith(
-        items: propagateItems,
+        items: items,
       ),
     );
-    UpdateAlbum(AlbumRepo(AlbumCachedDataSource()))(
-            widget.account, propagateAlbum)
-        .catchError((e, stacktrace) {
-      _log.shout("[_propagateResyncedAlbum] Failed while updating album", e,
-          stacktrace);
-    });
+    album = await _updateAlbumPostResync(album, items);
+    if (mounted) {
+      setState(() {
+        _album = album;
+        _transformItems();
+        initCover(widget.account, album);
+      });
+    }
   }
 
-  bool _shouldPropagateResyncedAlbum(Album album) {
-    final origItems = _getAlbumItemsOf(widget.album);
-    final resyncItems = _getAlbumItemsOf(album);
-    if (origItems.length != resyncItems.length) {
-      _log.info(
-          "[_shouldPropagateResyncedAlbum] Item length differ: ${origItems.length}, ${resyncItems.length}");
-      return true;
-    }
-    for (final z in zip([origItems, resyncItems])) {
-      final a = z[0], b = z[1];
-      bool isEqual;
-      if (a is AlbumFileItem && b is AlbumFileItem) {
-        if (!a.file.isOwned(widget.account.username)) {
-          // ignore shared files
-          continue;
-        }
-        // faster compare
-        isEqual = a.equals(b, isDeep: false);
-      } else {
-        isEqual = a == b;
-      }
-      if (!isEqual) {
-        _log.info(
-            "[_shouldPropagateResyncedAlbum] Item differ:\nOriginal: ${z[0]}\nResynced: ${z[1]}");
-        return true;
-      }
-    }
-    _log.info("[_shouldPropagateResyncedAlbum] false");
-    return false;
+  Future<Album> _updateAlbumPostResync(
+      Album album, List<AlbumItem> items) async {
+    final albumRepo = AlbumRepo(AlbumCachedDataSource());
+    return await UpdateAlbumWithActualItems(albumRepo)(
+        widget.account, album, items);
   }
 
   static List<AlbumItem> _getAlbumItemsOf(Album a) =>

lib/widget/album_importer.dart

@@ -8,11 +8,9 @@ import 'package:nc_photos/app_localizations.dart';
 import 'package:nc_photos/bloc/list_importable_album.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/file.dart';
-import 'package:nc_photos/entity/file_util.dart' as file_util;
 import 'package:nc_photos/exception_util.dart' as exception_util;
 import 'package:nc_photos/iterable_extension.dart';
 import 'package:nc_photos/k.dart' as k;
@@ -20,8 +18,7 @@ import 'package:nc_photos/snack_bar_manager.dart';
 import 'package:nc_photos/theme.dart';
 import 'package:nc_photos/use_case/create_album.dart';
 import 'package:nc_photos/use_case/populate_album.dart';
-import 'package:nc_photos/use_case/update_dynamic_album_cover.dart';
-import 'package:nc_photos/use_case/update_dynamic_album_time.dart';
+import 'package:nc_photos/use_case/update_album_with_actual_items.dart';
 import 'package:nc_photos/widget/processing_dialog.dart';
 import 'package:path/path.dart' as path;
 
@@ -239,15 +236,8 @@ class _AlbumImporterState extends State<AlbumImporter> {
         _log.info("[_createAllAlbums] Creating dir album: $album");
 
         final items = await PopulateAlbum()(widget.account, album);
-        final sortedFiles = items
-            .whereType<AlbumFileItem>()
-            .map((e) => e.file)
-            .where((element) => file_util.isSupportedFormat(element))
-            .sorted(compareFileDateTimeDescending);
-        album =
-            UpdateDynamicAlbumCover().updateWithSortedFiles(album, sortedFiles);
-        album =
-            UpdateDynamicAlbumTime().updateWithSortedFiles(album, sortedFiles);
+        album = await UpdateAlbumWithActualItems(null)(
+            widget.account, album, items);
 
         final albumRepo = AlbumRepo(AlbumCachedDataSource());
         await CreateAlbum(albumRepo)(widget.account, album);

lib/widget/dynamic_album_browser.dart

@@ -27,8 +27,7 @@ import 'package:nc_photos/theme.dart';
 import 'package:nc_photos/use_case/populate_album.dart';
 import 'package:nc_photos/use_case/remove.dart';
 import 'package:nc_photos/use_case/update_album.dart';
-import 'package:nc_photos/use_case/update_dynamic_album_cover.dart';
-import 'package:nc_photos/use_case/update_dynamic_album_time.dart';
+import 'package:nc_photos/use_case/update_album_with_actual_items.dart';
 import 'package:nc_photos/widget/album_browser_mixin.dart';
 import 'package:nc_photos/widget/fancy_option_picker.dart';
 import 'package:nc_photos/widget/photo_list_item.dart';
@@ -159,58 +158,16 @@ class _DynamicAlbumBrowserState extends State<DynamicAlbumBrowser>
     }
   }
 
-  void _initAlbum() {
+  Future<void> _initAlbum() async {
     assert(widget.album.provider is AlbumDynamicProvider);
-    PopulateAlbum()(widget.account, widget.album).then((items) {
-      if (mounted) {
-        setState(() {
-          _album = widget.album;
-          _transformItems(items);
-          initCover(widget.account, widget.album);
-          _updateAlbumPostPopulate(items);
-        });
-      }
-    });
-  }
-
-  Future<void> _updateAlbumPostPopulate(List<AlbumItem> items) async {
-    final List<File> timeDescSortedFiles;
-    if (widget.album.sortProvider is AlbumTimeSortProvider) {
-      if ((widget.album.sortProvider as AlbumTimeSortProvider).isAscending) {
-        timeDescSortedFiles = _backingFiles.reversed.toList();
-      } else {
-        timeDescSortedFiles = _backingFiles;
-      }
-    } else {
-      timeDescSortedFiles = const AlbumTimeSortProvider(isAscending: false)
-          .sort(items)
-          .whereType<AlbumFileItem>()
-          .map((e) => e.file)
-          .where((element) => file_util.isSupportedFormat(element))
-          .toList();
-    }
-
-    bool shouldUpdate = false;
-    final albumUpdatedCover = UpdateDynamicAlbumCover()
-        .updateWithSortedFiles(_album!, timeDescSortedFiles);
-    if (!identical(albumUpdatedCover, _album)) {
-      _log.info("[_updateAlbumPostPopulate] Update album cover");
-      shouldUpdate = true;
-    }
-    _album = albumUpdatedCover;
-
-    final albumUpdatedTime = UpdateDynamicAlbumTime()
-        .updateWithSortedFiles(_album!, timeDescSortedFiles);
-    if (!identical(albumUpdatedTime, _album)) {
-      _log.info(
-          "[_updateAlbumPostPopulate] Update album time: ${albumUpdatedTime.provider.latestItemTime}");
-      shouldUpdate = true;
-    }
-    _album = albumUpdatedTime;
-
-    if (shouldUpdate) {
-      await UpdateAlbum(AlbumRepo(AlbumCachedDataSource()))(
-          widget.account, _album!);
+    final items = await PopulateAlbum()(widget.account, widget.album);
+    final album = await _updateAlbumPostPopulate(widget.album, items);
+    if (mounted) {
+      setState(() {
+        _album = album;
+        _transformItems(items);
+        initCover(widget.account, widget.album);
+      });
     }
   }
 
@@ -376,6 +333,7 @@ class _DynamicAlbumBrowserState extends State<DynamicAlbumBrowser>
           widget.account,
           _album!.copyWith(
             provider: AlbumStaticProvider(
+              latestItemTime: _album!.provider.latestItemTime,
               items: _sortedItems,
             ),
             coverProvider: AlbumAutoCoverProvider(),
@@ -513,12 +471,12 @@ class _DynamicAlbumBrowserState extends State<DynamicAlbumBrowser>
     });
   }
 
-  void _onAlbumUpdatedEvent(AlbumUpdatedEvent ev) {
+  Future<void> _onAlbumUpdatedEvent(AlbumUpdatedEvent ev) async {
     if (ev.album.albumFile!.path == _album?.albumFile?.path) {
+      final album = await _updateAlbumPostPopulate(ev.album, _sortedItems);
       setState(() {
-        _album = ev.album;
-        initCover(widget.account, ev.album);
-        _updateAlbumPostPopulate(_sortedItems);
+        _album = album;
+        initCover(widget.account, album);
       });
     }
   }
@@ -572,6 +530,13 @@ class _DynamicAlbumBrowserState extends State<DynamicAlbumBrowser>
         .toList();
   }
 
+  Future<Album> _updateAlbumPostPopulate(
+      Album album, List<AlbumItem> items) async {
+    final albumRepo = AlbumRepo(AlbumCachedDataSource());
+    return await UpdateAlbumWithActualItems(albumRepo)(
+        widget.account, album, items);
+  }
+
   Album? _album;
   var _sortedItems = <AlbumItem>[];
   var _backingFiles = <File>[];

test/entity/album_test.dart

@@ -1,3 +1,4 @@
+import 'package:intl/intl.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';
@@ -31,8 +32,13 @@ void main() {
           },
         };
         expect(
-            Album.fromJson(json,
-                upgraderV1: null, upgraderV2: null, upgraderV3: null),
+            Album.fromJson(
+              json,
+              upgraderV1: null,
+              upgraderV2: null,
+              upgraderV3: null,
+              upgraderV4: null,
+            ),
             Album(
               lastUpdated: DateTime.utc(2020, 1, 2, 3, 4, 5, 678, 901),
               name: "",
@@ -65,8 +71,13 @@ void main() {
           },
         };
         expect(
-            Album.fromJson(json,
-                upgraderV1: null, upgraderV2: null, upgraderV3: null),
+            Album.fromJson(
+              json,
+              upgraderV1: null,
+              upgraderV2: null,
+              upgraderV3: null,
+              upgraderV4: null,
+            ),
             Album(
               lastUpdated: DateTime.utc(2020, 1, 2, 3, 4, 5, 678, 901),
               name: "album",
@@ -117,8 +128,13 @@ void main() {
             },
           };
           expect(
-              Album.fromJson(json,
-                  upgraderV1: null, upgraderV2: null, upgraderV3: null),
+              Album.fromJson(
+                json,
+                upgraderV1: null,
+                upgraderV2: null,
+                upgraderV3: null,
+                upgraderV4: null,
+              ),
               Album(
                 lastUpdated: DateTime.utc(2020, 1, 2, 3, 4, 5, 678, 901),
                 name: "",
@@ -165,8 +181,13 @@ void main() {
             },
           };
           expect(
-              Album.fromJson(json,
-                  upgraderV1: null, upgraderV2: null, upgraderV3: null),
+              Album.fromJson(
+                json,
+                upgraderV1: null,
+                upgraderV2: null,
+                upgraderV3: null,
+                upgraderV4: null,
+              ),
               Album(
                 lastUpdated: DateTime.utc(2020, 1, 2, 3, 4, 5, 678, 901),
                 name: "",
@@ -208,8 +229,13 @@ void main() {
           },
         };
         expect(
-            Album.fromJson(json,
-                upgraderV1: null, upgraderV2: null, upgraderV3: null),
+            Album.fromJson(
+              json,
+              upgraderV1: null,
+              upgraderV2: null,
+              upgraderV3: null,
+              upgraderV4: null,
+            ),
             Album(
               lastUpdated: DateTime.utc(2020, 1, 2, 3, 4, 5, 678, 901),
               name: "",
@@ -248,8 +274,13 @@ void main() {
           },
         };
         expect(
-            Album.fromJson(json,
-                upgraderV1: null, upgraderV2: null, upgraderV3: null),
+            Album.fromJson(
+              json,
+              upgraderV1: null,
+              upgraderV2: null,
+              upgraderV3: null,
+              upgraderV4: null,
+            ),
             Album(
               lastUpdated: DateTime.utc(2020, 1, 2, 3, 4, 5, 678, 901),
               name: "",
@@ -287,8 +318,13 @@ void main() {
           },
         };
         expect(
-            Album.fromJson(json,
-                upgraderV1: null, upgraderV2: null, upgraderV3: null),
+            Album.fromJson(
+              json,
+              upgraderV1: null,
+              upgraderV2: null,
+              upgraderV3: null,
+              upgraderV4: null,
+            ),
             Album(
               lastUpdated: DateTime.utc(2020, 1, 2, 3, 4, 5, 678, 901),
               name: "",
@@ -942,5 +978,374 @@ void main() {
         },
       });
     });
+
+    group("AlbumUpgraderV4", () {
+      test("Non AlbumFileItem", () {
+        final json = <String, dynamic>{
+          "version": 4,
+          "lastUpdated": "2020-01-02T03:04:05.678901Z",
+          "provider": <String, dynamic>{
+            "type": "static",
+            "content": <String, dynamic>{
+              "items": [
+                <String, dynamic>{
+                  "type": "label",
+                  "content": <String, dynamic>{
+                    "text": "123",
+                  },
+                },
+              ],
+            },
+          },
+          "coverProvider": <String, dynamic>{
+            "type": "auto",
+            "content": <String, dynamic>{},
+          },
+          "sortProvider": <String, dynamic>{
+            "type": "time",
+            "content": <String, dynamic>{
+              "isAscending": false,
+            },
+          },
+          "albumFile": <String, dynamic>{
+            "path": "remote.php/dav/files/admin/test1.json",
+          },
+        };
+        expect(AlbumUpgraderV4()(json), <String, dynamic>{
+          "version": 4,
+          "lastUpdated": "2020-01-02T03:04:05.678901Z",
+          "provider": <String, dynamic>{
+            "type": "static",
+            "content": <String, dynamic>{
+              "items": [
+                <String, dynamic>{
+                  "type": "label",
+                  "content": <String, dynamic>{
+                    "text": "123",
+                  },
+                },
+              ],
+            },
+          },
+          "coverProvider": <String, dynamic>{
+            "type": "auto",
+            "content": <String, dynamic>{},
+          },
+          "sortProvider": <String, dynamic>{
+            "type": "time",
+            "content": <String, dynamic>{
+              "isAscending": false,
+            },
+          },
+          "albumFile": <String, dynamic>{
+            "path": "remote.php/dav/files/admin/test1.json",
+          },
+        });
+      });
+
+      group("AlbumFileItem", () {
+        test("drop metadata", () {
+          final json = <String, dynamic>{
+            "version": 4,
+            "lastUpdated": "2020-01-02T03:04:05.678901Z",
+            "provider": <String, dynamic>{
+              "type": "static",
+              "content": <String, dynamic>{
+                "items": [
+                  <String, dynamic>{
+                    "type": "file",
+                    "content": <String, dynamic>{
+                      "file": <String, dynamic>{
+                        "path": "remote.php/dav/files/admin/test1.jpg",
+                        "metadata": <String, dynamic>{
+                          "Make": "Super",
+                          "Model": "A123",
+                        },
+                      },
+                    },
+                  },
+                ],
+              },
+            },
+            "coverProvider": <String, dynamic>{
+              "type": "auto",
+              "content": <String, dynamic>{},
+            },
+            "sortProvider": <String, dynamic>{
+              "type": "time",
+              "content": <String, dynamic>{
+                "isAscending": false,
+              },
+            },
+            "albumFile": <String, dynamic>{
+              "path": "remote.php/dav/files/admin/test1.json",
+            },
+          };
+          expect(AlbumUpgraderV4()(json), <String, dynamic>{
+            "version": 4,
+            "lastUpdated": "2020-01-02T03:04:05.678901Z",
+            "provider": <String, dynamic>{
+              "type": "static",
+              "content": <String, dynamic>{
+                "items": [
+                  <String, dynamic>{
+                    "type": "file",
+                    "content": <String, dynamic>{
+                      "file": <String, dynamic>{
+                        "path": "remote.php/dav/files/admin/test1.jpg",
+                      },
+                    },
+                  },
+                ],
+              },
+            },
+            "coverProvider": <String, dynamic>{
+              "type": "auto",
+              "content": <String, dynamic>{},
+            },
+            "sortProvider": <String, dynamic>{
+              "type": "time",
+              "content": <String, dynamic>{
+                "isAscending": false,
+              },
+            },
+            "albumFile": <String, dynamic>{
+              "path": "remote.php/dav/files/admin/test1.json",
+            },
+          });
+        });
+
+        test("lastModified as latestItemTime", () {
+          final json = <String, dynamic>{
+            "version": 4,
+            "lastUpdated": "2020-01-02T03:04:05.678901Z",
+            "provider": <String, dynamic>{
+              "type": "static",
+              "content": <String, dynamic>{
+                "items": [
+                  <String, dynamic>{
+                    "type": "file",
+                    "content": <String, dynamic>{
+                      "file": <String, dynamic>{
+                        "path": "remote.php/dav/files/admin/test1.jpg",
+                        "lastModified": "2020-01-02T03:04:05.678901Z",
+                      },
+                    },
+                  },
+                ],
+              },
+            },
+            "coverProvider": <String, dynamic>{
+              "type": "auto",
+              "content": <String, dynamic>{},
+            },
+            "sortProvider": <String, dynamic>{
+              "type": "time",
+              "content": <String, dynamic>{
+                "isAscending": false,
+              },
+            },
+            "albumFile": <String, dynamic>{
+              "path": "remote.php/dav/files/admin/test1.json",
+            },
+          };
+          expect(AlbumUpgraderV4()(json), <String, dynamic>{
+            "version": 4,
+            "lastUpdated": "2020-01-02T03:04:05.678901Z",
+            "provider": <String, dynamic>{
+              "type": "static",
+              "content": <String, dynamic>{
+                "latestItemTime": "2020-01-02T03:04:05.678901Z",
+                "items": [
+                  <String, dynamic>{
+                    "type": "file",
+                    "content": <String, dynamic>{
+                      "file": <String, dynamic>{
+                        "path": "remote.php/dav/files/admin/test1.jpg",
+                        "lastModified": "2020-01-02T03:04:05.678901Z",
+                      },
+                    },
+                  },
+                ],
+              },
+            },
+            "coverProvider": <String, dynamic>{
+              "type": "auto",
+              "content": <String, dynamic>{
+                "coverFile": <String, dynamic>{
+                  "path": "remote.php/dav/files/admin/test1.jpg",
+                  "lastModified": "2020-01-02T03:04:05.678901Z",
+                },
+              },
+            },
+            "sortProvider": <String, dynamic>{
+              "type": "time",
+              "content": <String, dynamic>{
+                "isAscending": false,
+              },
+            },
+            "albumFile": <String, dynamic>{
+              "path": "remote.php/dav/files/admin/test1.json",
+            },
+          });
+        });
+
+        test("dateTimeOriginal as latestItemTime", () {
+          final json = <String, dynamic>{
+            "version": 4,
+            "lastUpdated": "2020-01-02T03:04:05.678901Z",
+            "provider": <String, dynamic>{
+              "type": "static",
+              "content": <String, dynamic>{
+                "items": [
+                  <String, dynamic>{
+                    "type": "file",
+                    "content": <String, dynamic>{
+                      "file": <String, dynamic>{
+                        "path": "remote.php/dav/files/admin/test1.jpg",
+                        "metadata": <String, dynamic>{
+                          "exif": <String, dynamic>{
+                            // convert 2020-01-02T03:04:05Z to local time
+                            "DateTimeOriginal":
+                                DateFormat("yyyy:MM:dd HH:mm:ss").format(
+                                    DateTime.utc(2020, 1, 2, 3, 4, 5)
+                                        .toLocal()),
+                          },
+                        },
+                      },
+                    },
+                  },
+                ],
+              },
+            },
+            "coverProvider": <String, dynamic>{
+              "type": "auto",
+              "content": <String, dynamic>{},
+            },
+            "sortProvider": <String, dynamic>{
+              "type": "time",
+              "content": <String, dynamic>{
+                "isAscending": false,
+              },
+            },
+            "albumFile": <String, dynamic>{
+              "path": "remote.php/dav/files/admin/test1.json",
+            },
+          };
+          expect(AlbumUpgraderV4()(json), <String, dynamic>{
+            "version": 4,
+            "lastUpdated": "2020-01-02T03:04:05.678901Z",
+            "provider": <String, dynamic>{
+              "type": "static",
+              "content": <String, dynamic>{
+                "latestItemTime": "2020-01-02T03:04:05.000Z",
+                "items": [
+                  <String, dynamic>{
+                    "type": "file",
+                    "content": <String, dynamic>{
+                      "file": <String, dynamic>{
+                        "path": "remote.php/dav/files/admin/test1.jpg",
+                      },
+                    },
+                  },
+                ],
+              },
+            },
+            "coverProvider": <String, dynamic>{
+              "type": "auto",
+              "content": <String, dynamic>{
+                "coverFile": <String, dynamic>{
+                  "path": "remote.php/dav/files/admin/test1.jpg",
+                },
+              },
+            },
+            "sortProvider": <String, dynamic>{
+              "type": "time",
+              "content": <String, dynamic>{
+                "isAscending": false,
+              },
+            },
+            "albumFile": <String, dynamic>{
+              "path": "remote.php/dav/files/admin/test1.json",
+            },
+          });
+        });
+
+        test("overrideDateTime as latestItemTime", () {
+          final json = <String, dynamic>{
+            "version": 4,
+            "lastUpdated": "2020-01-02T03:04:05.678901Z",
+            "provider": <String, dynamic>{
+              "type": "static",
+              "content": <String, dynamic>{
+                "items": [
+                  <String, dynamic>{
+                    "type": "file",
+                    "content": <String, dynamic>{
+                      "file": <String, dynamic>{
+                        "path": "remote.php/dav/files/admin/test1.jpg",
+                        "overrideDateTime": "2020-01-02T03:04:05.678901Z",
+                      },
+                    },
+                  },
+                ],
+              },
+            },
+            "coverProvider": <String, dynamic>{
+              "type": "auto",
+              "content": <String, dynamic>{},
+            },
+            "sortProvider": <String, dynamic>{
+              "type": "time",
+              "content": <String, dynamic>{
+                "isAscending": false,
+              },
+            },
+            "albumFile": <String, dynamic>{
+              "path": "remote.php/dav/files/admin/test1.json",
+            },
+          };
+          expect(AlbumUpgraderV4()(json), <String, dynamic>{
+            "version": 4,
+            "lastUpdated": "2020-01-02T03:04:05.678901Z",
+            "provider": <String, dynamic>{
+              "type": "static",
+              "content": <String, dynamic>{
+                "latestItemTime": "2020-01-02T03:04:05.678901Z",
+                "items": [
+                  <String, dynamic>{
+                    "type": "file",
+                    "content": <String, dynamic>{
+                      "file": <String, dynamic>{
+                        "path": "remote.php/dav/files/admin/test1.jpg",
+                        "overrideDateTime": "2020-01-02T03:04:05.678901Z",
+                      },
+                    },
+                  },
+                ],
+              },
+            },
+            "coverProvider": <String, dynamic>{
+              "type": "auto",
+              "content": <String, dynamic>{
+                "coverFile": <String, dynamic>{
+                  "path": "remote.php/dav/files/admin/test1.jpg",
+                  "overrideDateTime": "2020-01-02T03:04:05.678901Z",
+                },
+              },
+            },
+            "sortProvider": <String, dynamic>{
+              "type": "time",
+              "content": <String, dynamic>{
+                "isAscending": false,
+              },
+            },
+            "albumFile": <String, dynamic>{
+              "path": "remote.php/dav/files/admin/test1.json",
+            },
+          });
+        });
+      });
+    });
   });
 }