perf(mobile): optimized album sorting (#25179)

* perf(mobile): optimized album sorting

* refactor: add index & sql query

* fix: migration

* refactor: enum, ordering & list

* test: update album service tests

* chore: fix enums

broken during merging main

* chore: remove unnecessary tests

* test: add tests for getSortedAlbumIds

* test: added back stubs in service test

mobile/lib/constants/enums.dart

@@ -18,3 +18,5 @@ enum ActionSource { timeline, viewer }
 enum CleanupStep { selectDate, scan, delete }
 
 enum AssetKeepType { none, photosOnly, videosOnly }
+
+enum AssetDateAggregation { start, end }

mobile/lib/domain/services/remote_album.service.dart

@@ -43,8 +43,8 @@ class RemoteAlbumService {
       AlbumSortMode.title => albums.sortedBy((album) => album.name),
       AlbumSortMode.lastModified => albums.sortedBy((album) => album.updatedAt),
       AlbumSortMode.assetCount => albums.sortedBy((album) => album.assetCount),
-      AlbumSortMode.mostRecent => await _sortByNewestAsset(albums),
-      AlbumSortMode.mostOldest => await _sortByOldestAsset(albums),
+      AlbumSortMode.mostRecent => await _sortByAssetDate(albums, aggregation: AssetDateAggregation.end),
+      AlbumSortMode.mostOldest => await _sortByAssetDate(albums, aggregation: AssetDateAggregation.start),
     };
     final effectiveOrder = isReverse ? sortMode.defaultOrder.reverse() : sortMode.defaultOrder;
 
@@ -172,46 +172,25 @@ class RemoteAlbumService {
     return _repository.getAlbumsContainingAsset(assetId);
   }
 
-  Future<List<RemoteAlbum>> _sortByNewestAsset(List<RemoteAlbum> albums) async {
-    // map album IDs to their newest asset dates
-    final Map<String, Future<DateTime?>> assetTimestampFutures = {};
-    for (final album in albums) {
-      assetTimestampFutures[album.id] = _repository.getNewestAssetTimestamp(album.id);
+  Future<List<RemoteAlbum>> _sortByAssetDate(
+    List<RemoteAlbum> albums, {
+    required AssetDateAggregation aggregation,
+  }) async {
+    if (albums.isEmpty) return [];
+
+    final albumIds = albums.map((e) => e.id).toList();
+    final sortedIds = await _repository.getSortedAlbumIds(albumIds, aggregation: aggregation);
+
+    final albumMap = Map<String, RemoteAlbum>.fromEntries(albums.map((a) => MapEntry(a.id, a)));
+
+    final sortedAlbums = sortedIds.map((id) => albumMap[id]).whereType<RemoteAlbum>().toList();
+
+    if (sortedAlbums.length < albums.length) {
+      final returnedIdSet = sortedIds.toSet();
+      final emptyAlbums = albums.where((a) => !returnedIdSet.contains(a.id));
+      sortedAlbums.addAll(emptyAlbums);
     }
 
-    // await all database queries
-    final entries = await Future.wait(
-      assetTimestampFutures.entries.map((entry) async => MapEntry(entry.key, await entry.value)),
-    );
-    final assetTimestamps = Map.fromEntries(entries);
-
-    final sorted = albums.sorted((a, b) {
-      final aDate = assetTimestamps[a.id] ?? DateTime.fromMillisecondsSinceEpoch(0);
-      final bDate = assetTimestamps[b.id] ?? DateTime.fromMillisecondsSinceEpoch(0);
-      return aDate.compareTo(bDate);
-    });
-
-    return sorted;
-  }
-
-  Future<List<RemoteAlbum>> _sortByOldestAsset(List<RemoteAlbum> albums) async {
-    // map album IDs to their oldest asset dates
-    final Map<String, Future<DateTime?>> assetTimestampFutures = {
-      for (final album in albums) album.id: _repository.getOldestAssetTimestamp(album.id),
-    };
-
-    // await all database queries
-    final entries = await Future.wait(
-      assetTimestampFutures.entries.map((entry) async => MapEntry(entry.key, await entry.value)),
-    );
-    final assetTimestamps = Map.fromEntries(entries);
-
-    final sorted = albums.sorted((a, b) {
-      final aDate = assetTimestamps[a.id] ?? DateTime.fromMillisecondsSinceEpoch(0);
-      final bDate = assetTimestamps[b.id] ?? DateTime.fromMillisecondsSinceEpoch(0);
-      return aDate.compareTo(bDate);
-    });
-
-    return sorted;
+    return sortedAlbums;
   }
 }

mobile/lib/infrastructure/repositories/remote_album.repository.dart

@@ -1,6 +1,8 @@
 import 'dart:async';
+import 'dart:convert';
 
 import 'package:drift/drift.dart';
+import 'package:immich_mobile/constants/enums.dart';
 import 'package:immich_mobile/domain/models/album/album.model.dart';
 import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
 import 'package:immich_mobile/domain/models/user.model.dart';
@@ -321,26 +323,32 @@ class DriftRemoteAlbumRepository extends DriftDatabaseRepository {
     }).watchSingleOrNull();
   }
 
-  Future<DateTime?> getNewestAssetTimestamp(String albumId) {
-    final query = _db.remoteAlbumAssetEntity.selectOnly()
-      ..where(_db.remoteAlbumAssetEntity.albumId.equals(albumId))
-      ..addColumns([_db.remoteAssetEntity.localDateTime.max()])
-      ..join([
-        innerJoin(_db.remoteAssetEntity, _db.remoteAssetEntity.id.equalsExp(_db.remoteAlbumAssetEntity.assetId)),
-      ]);
+  Future<List<String>> getSortedAlbumIds(List<String> albumIds, {required AssetDateAggregation aggregation}) async {
+    if (albumIds.isEmpty) return [];
 
-    return query.map((row) => row.read(_db.remoteAssetEntity.localDateTime.max())).getSingleOrNull();
-  }
+    final jsonIds = jsonEncode(albumIds);
+    final sqlAgg = aggregation == AssetDateAggregation.start ? 'MIN' : 'MAX';
 
-  Future<DateTime?> getOldestAssetTimestamp(String albumId) {
-    final query = _db.remoteAlbumAssetEntity.selectOnly()
-      ..where(_db.remoteAlbumAssetEntity.albumId.equals(albumId))
-      ..addColumns([_db.remoteAssetEntity.localDateTime.min()])
-      ..join([
-        innerJoin(_db.remoteAssetEntity, _db.remoteAssetEntity.id.equalsExp(_db.remoteAlbumAssetEntity.assetId)),
-      ]);
+    final rows = await _db
+        .customSelect(
+          '''
+          SELECT
+            raae.album_id,
+            $sqlAgg(rae.local_date_time) AS asset_date
+          FROM json_each(?) ids
+          INNER JOIN remote_album_asset_entity raae
+            ON raae.album_id = ids.value
+          INNER JOIN remote_asset_entity rae
+            ON rae.id = raae.asset_id
+          GROUP BY raae.album_id
+          ORDER BY asset_date ASC
+          ''',
+          variables: [Variable<String>(jsonIds)],
+          readsFrom: {_db.remoteAlbumAssetEntity, _db.remoteAssetEntity},
+        )
+        .get();
 
-    return query.map((row) => row.read(_db.remoteAssetEntity.localDateTime.min())).getSingleOrNull();
+    return rows.map((row) => row.read<String>('album_id')).toList();
   }
 
   Future<int> getCount() {