set album cover from asset

mobile/lib/presentation/widgets/action_buttons/set_album_cover.widget.dart

@@ -0,0 +1,62 @@
+import 'package:flutter/material.dart';
+import 'package:fluttertoast/fluttertoast.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:immich_mobile/constants/enums.dart';
+import 'package:immich_mobile/domain/models/events.model.dart';
+import 'package:immich_mobile/domain/utils/event_stream.dart';
+import 'package:immich_mobile/extensions/translate_extensions.dart';
+import 'package:immich_mobile/presentation/widgets/action_buttons/base_action_button.widget.dart';
+import 'package:immich_mobile/providers/infrastructure/action.provider.dart';
+import 'package:immich_mobile/providers/timeline/multiselect.provider.dart';
+import 'package:immich_mobile/widgets/common/immich_toast.dart';
+
+class SetAlbumCoverActionButton extends ConsumerWidget {
+  final String albumId;
+  final ActionSource source;
+  final bool iconOnly;
+  final bool menuItem;
+
+  const SetAlbumCoverActionButton({
+    super.key,
+    required this.albumId,
+    required this.source,
+    this.iconOnly = false,
+    this.menuItem = false,
+  });
+
+  void _onTap(BuildContext context, WidgetRef ref) async {
+    if (!context.mounted) {
+      return;
+    }
+
+    final result = await ref.read(actionProvider.notifier).setAlbumCover(source, albumId);
+    ref.read(multiSelectProvider.notifier).reset();
+
+    if (source == ActionSource.viewer) {
+      EventStream.shared.emit(const ViewerReloadAssetEvent());
+    }
+
+    final successMessage = 'album_cover_updated'.t(context: context);
+
+    if (context.mounted) {
+      ImmichToast.show(
+        context: context,
+        msg: result.success ? successMessage : 'scaffold_body_error_occurred'.t(context: context),
+        gravity: ToastGravity.BOTTOM,
+        toastType: result.success ? ToastType.success : ToastType.error,
+      );
+    }
+  }
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    return BaseActionButton(
+      iconData: Icons.image_outlined,
+      label: 'set_as_album_cover'.t(context: context),
+      iconOnly: iconOnly,
+      menuItem: menuItem,
+      onPressed: () => _onTap(context, ref),
+      maxWidth: 100,
+    );
+  }
+}

mobile/lib/providers/infrastructure/action.provider.dart

@@ -343,6 +343,26 @@ class ActionNotifier extends Notifier<void> {
     }
   }
 
+  Future<ActionResult> setAlbumCover(ActionSource source, String albumId) async {
+    final assets = _getAssets(source);
+    if (assets.length != 1) {
+      return ActionResult(count: assets.length, success: false, error: 'Expected single asset for album cover');
+    }
+
+    final asset = assets.first;
+    if (asset is! RemoteAsset) {
+      return ActionResult(count: 1, success: false, error: 'Asset must be remote');
+    }
+
+    try {
+      await _service.setAlbumCover(albumId, asset.id);
+      return ActionResult(count: 1, success: true);
+    } catch (error, stack) {
+      _logger.severe('Failed to set album cover', error, stack);
+      return ActionResult(count: 1, success: false, error: error.toString());
+    }
+  }
+
   Future<ActionResult> updateDescription(ActionSource source, String description) async {
     final ids = _getRemoteIdsForSource(source);
     if (ids.length != 1) {

mobile/lib/services/action.service.dart

@@ -240,6 +240,12 @@ class ActionService {
     return _downloadRepository.downloadAllAssets(assets);
   }
 
+  Future<bool> setAlbumCover(String albumId, String assetId) async {
+    final updatedAlbum = await _albumApiRepository.updateAlbum(albumId, thumbnailAssetId: assetId);
+    await _remoteAlbumRepository.update(updatedAlbum);
+    return true;
+  }
+
   Future<int> _deleteLocalAssets(List<String> localIds) async {
     final deletedIds = await _assetMediaRepository.deleteAll(localIds);
     if (deletedIds.isEmpty) {

mobile/lib/utils/action_button.utils.dart

@@ -20,6 +20,7 @@ import 'package:immich_mobile/presentation/widgets/action_buttons/like_activity_
 import 'package:immich_mobile/presentation/widgets/action_buttons/move_to_lock_folder_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/remove_from_album_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/remove_from_lock_folder_action_button.widget.dart';
+import 'package:immich_mobile/presentation/widgets/action_buttons/set_album_cover.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/share_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/share_link_action_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/similar_photos_action_button.widget.dart';
@@ -42,6 +43,7 @@ class ActionButtonContext {
   final bool isCasting;
   final TimelineOrigin timelineOrigin;
   final ThemeData? originalTheme;
+  final int selectedCount;
 
   const ActionButtonContext({
     required this.asset,
@@ -56,6 +58,7 @@ class ActionButtonContext {
     this.isCasting = false,
     this.timelineOrigin = TimelineOrigin.main,
     this.originalTheme,
+    this.selectedCount = 1,
   });
 }
 
@@ -75,6 +78,7 @@ enum ActionButtonType {
   moveToLockFolder,
   removeFromLockFolder,
   removeFromAlbum,
+  setAlbumCover,
   trash,
   deleteLocal,
   deletePermanent,
@@ -134,6 +138,11 @@ enum ActionButtonType {
         context.isOwner && //
             !context.isInLockedView && //
             context.currentAlbum != null,
+      ActionButtonType.setAlbumCover =>
+        context.isOwner && //
+            !context.isInLockedView && //
+            context.currentAlbum != null && //
+            context.selectedCount == 1,
       ActionButtonType.unstack =>
         context.isOwner && //
             !context.isInLockedView && //
@@ -213,6 +222,12 @@ enum ActionButtonType {
         iconOnly: iconOnly,
         menuItem: menuItem,
       ),
+      ActionButtonType.setAlbumCover => SetAlbumCoverActionButton(
+        albumId: context.currentAlbum!.id,
+        source: context.source,
+        iconOnly: iconOnly,
+        menuItem: menuItem,
+      ),
       ActionButtonType.likeActivity => LikeActivityActionButton(iconOnly: iconOnly, menuItem: menuItem),
       ActionButtonType.unstack => UnStackActionButton(source: context.source, iconOnly: iconOnly, menuItem: menuItem),
       ActionButtonType.similarPhotos => SimilarPhotosActionButton(