Show first 100 photos on startup

This is to create an illusion that the app loads quickly when it's not ;)

app/lib/bloc/scan_account_dir.dart

@@ -186,6 +186,17 @@ class ScanAccountDirBloc
     final hasContent = state.files.isNotEmpty;
 
     final stopwatch = Stopwatch()..start();
+    if (!hasContent) {
+      try {
+        emit(ScanAccountDirBlocLoading(await _queryOfflineMini(ev)));
+      } catch (e, stackTrace) {
+        _log.shout(
+            "[_onEventQuery] Failed while _queryOfflineMini", e, stackTrace);
+      }
+      _log.info(
+          "[_onEventQuery] Elapsed time (_queryOfflineMini): ${stopwatch.elapsedMilliseconds}ms");
+      stopwatch.reset();
+    }
     final cacheFiles = await _queryOffline(ev);
     _log.info(
         "[_onEventQuery] Elapsed time (_queryOffline): ${stopwatch.elapsedMilliseconds}ms");
@@ -322,6 +333,16 @@ class ScanAccountDirBloc
     );
   }
 
+  /// Query a small amount of files to give an illusion of quick startup
+  Future<List<File>> _queryOfflineMini(ScanAccountDirBlocQueryBase ev) async {
+    return await ScanDirOfflineMini(_c)(
+      account,
+      account.roots.map((r) => File(path: file_util.unstripPath(account, r))),
+      100,
+      isOnlySupportedFormat: true,
+    );
+  }
+
   Future<List<File>> _queryOffline(ScanAccountDirBlocQueryBase ev) async {
     final files = <File>[];
     for (final r in account.roots) {

app/lib/entity/file/data_source.dart

@@ -308,15 +308,12 @@ class FileSqliteDbDataSource implements FileDataSource {
       Account account, int fromEpochMs, int toEpochMs) async {
     _log.info("[listByDate] [$fromEpochMs, $toEpochMs]");
     final dbFiles = await _c.sqliteDb.use((db) async {
-      final dateTime = sql.coalesce([
+      final query = db.queryFiles().run((q) {
-        db.accountFiles.overrideDateTime,
+        q.setQueryMode(sql.FilesQueryMode.completeFile);
-        db.images.dateTimeOriginal,
+        q.setAppAccount(account);
-        db.files.lastModified,
+        return q.build();
-      ]).secondsSinceEpoch;
+      });
-      final queryBuilder = db.queryFiles()
+      final dateTime = db.accountFiles.bestDateTime.secondsSinceEpoch;
-        ..setQueryMode(sql.FilesQueryMode.completeFile)
-        ..setAppAccount(account);
-      final query = queryBuilder.build();
       query
         ..where(dateTime.isBetweenValues(
             fromEpochMs ~/ 1000, (toEpochMs ~/ 1000) - 1))

app/lib/entity/sqlite_table.dart

@@ -58,6 +58,8 @@ class AccountFiles extends Table {
   BoolColumn get isArchived => boolean().nullable()();
   DateTimeColumn get overrideDateTime =>
       dateTime().map(const _DateTimeConverter()).nullable()();
+  DateTimeColumn get bestDateTime =>
+      dateTime().map(const _DateTimeConverter())();
 
   @override
   get uniqueKeys => [
@@ -186,6 +188,8 @@ class SqliteDb extends _$SqliteDb {
               "CREATE INDEX account_files_file_index ON account_files(file);"));
           await m.createIndex(Index("account_files_relative_path_index",
               "CREATE INDEX account_files_relative_path_index ON account_files(relative_path);"));
+          await m.createIndex(Index("account_files_best_date_time_index",
+              "CREATE INDEX account_files_best_date_time_index ON account_files(best_date_time);"));
 
           await m.createIndex(Index("dir_files_dir_index",
               "CREATE INDEX dir_files_dir_index ON dir_files(dir);"));

app/lib/entity/sqlite_table.g.dart

@@ -1000,6 +1000,7 @@ class AccountFile extends DataClass implements Insertable<AccountFile> {
   final bool? isFavorite;
   final bool? isArchived;
   final DateTime? overrideDateTime;
+  final DateTime bestDateTime;
   AccountFile(
       {required this.rowId,
       required this.account,
@@ -1007,7 +1008,8 @@ class AccountFile extends DataClass implements Insertable<AccountFile> {
       required this.relativePath,
       this.isFavorite,
       this.isArchived,
-      this.overrideDateTime});
+      this.overrideDateTime,
+      required this.bestDateTime});
   factory AccountFile.fromData(Map<String, dynamic> data, {String? prefix}) {
     final effectivePrefix = prefix ?? '';
     return AccountFile(
@@ -1026,6 +1028,9 @@ class AccountFile extends DataClass implements Insertable<AccountFile> {
       overrideDateTime: $AccountFilesTable.$converter0.mapToDart(
           const DateTimeType().mapFromDatabaseResponse(
               data['${effectivePrefix}override_date_time'])),
+      bestDateTime: $AccountFilesTable.$converter1.mapToDart(
+          const DateTimeType().mapFromDatabaseResponse(
+              data['${effectivePrefix}best_date_time']))!,
     );
   }
   @override
@@ -1046,6 +1051,11 @@ class AccountFile extends DataClass implements Insertable<AccountFile> {
       map['override_date_time'] =
           Variable<DateTime?>(converter.mapToSql(overrideDateTime));
     }
+    {
+      final converter = $AccountFilesTable.$converter1;
+      map['best_date_time'] =
+          Variable<DateTime>(converter.mapToSql(bestDateTime)!);
+    }
     return map;
   }
 
@@ -1064,6 +1074,7 @@ class AccountFile extends DataClass implements Insertable<AccountFile> {
       overrideDateTime: overrideDateTime == null && nullToAbsent
           ? const Value.absent()
           : Value(overrideDateTime),
+      bestDateTime: Value(bestDateTime),
     );
   }
 
@@ -1079,6 +1090,7 @@ class AccountFile extends DataClass implements Insertable<AccountFile> {
       isArchived: serializer.fromJson<bool?>(json['isArchived']),
       overrideDateTime:
           serializer.fromJson<DateTime?>(json['overrideDateTime']),
+      bestDateTime: serializer.fromJson<DateTime>(json['bestDateTime']),
     );
   }
   @override
@@ -1092,6 +1104,7 @@ class AccountFile extends DataClass implements Insertable<AccountFile> {
       'isFavorite': serializer.toJson<bool?>(isFavorite),
       'isArchived': serializer.toJson<bool?>(isArchived),
       'overrideDateTime': serializer.toJson<DateTime?>(overrideDateTime),
+      'bestDateTime': serializer.toJson<DateTime>(bestDateTime),
     };
   }
 
@@ -1102,7 +1115,8 @@ class AccountFile extends DataClass implements Insertable<AccountFile> {
           String? relativePath,
           Value<bool?> isFavorite = const Value.absent(),
           Value<bool?> isArchived = const Value.absent(),
-          Value<DateTime?> overrideDateTime = const Value.absent()}) =>
+          Value<DateTime?> overrideDateTime = const Value.absent(),
+          DateTime? bestDateTime}) =>
       AccountFile(
         rowId: rowId ?? this.rowId,
         account: account ?? this.account,
@@ -1113,6 +1127,7 @@ class AccountFile extends DataClass implements Insertable<AccountFile> {
         overrideDateTime: overrideDateTime.present
             ? overrideDateTime.value
             : this.overrideDateTime,
+        bestDateTime: bestDateTime ?? this.bestDateTime,
       );
   @override
   String toString() {
@@ -1123,14 +1138,15 @@ class AccountFile extends DataClass implements Insertable<AccountFile> {
           ..write('relativePath: $relativePath, ')
           ..write('isFavorite: $isFavorite, ')
           ..write('isArchived: $isArchived, ')
-          ..write('overrideDateTime: $overrideDateTime')
+          ..write('overrideDateTime: $overrideDateTime, ')
+          ..write('bestDateTime: $bestDateTime')
           ..write(')'))
         .toString();
   }
 
   @override
   int get hashCode => Object.hash(rowId, account, file, relativePath,
-      isFavorite, isArchived, overrideDateTime);
+      isFavorite, isArchived, overrideDateTime, bestDateTime);
   @override
   bool operator ==(Object other) =>
       identical(this, other) ||
@@ -1141,7 +1157,8 @@ class AccountFile extends DataClass implements Insertable<AccountFile> {
           other.relativePath == this.relativePath &&
           other.isFavorite == this.isFavorite &&
           other.isArchived == this.isArchived &&
-          other.overrideDateTime == this.overrideDateTime);
+          other.overrideDateTime == this.overrideDateTime &&
+          other.bestDateTime == this.bestDateTime);
 }
 
 class AccountFilesCompanion extends UpdateCompanion<AccountFile> {
@@ -1152,6 +1169,7 @@ class AccountFilesCompanion extends UpdateCompanion<AccountFile> {
   final Value<bool?> isFavorite;
   final Value<bool?> isArchived;
   final Value<DateTime?> overrideDateTime;
+  final Value<DateTime> bestDateTime;
   const AccountFilesCompanion({
     this.rowId = const Value.absent(),
     this.account = const Value.absent(),
@@ -1160,6 +1178,7 @@ class AccountFilesCompanion extends UpdateCompanion<AccountFile> {
     this.isFavorite = const Value.absent(),
     this.isArchived = const Value.absent(),
     this.overrideDateTime = const Value.absent(),
+    this.bestDateTime = const Value.absent(),
   });
   AccountFilesCompanion.insert({
     this.rowId = const Value.absent(),
@@ -1169,9 +1188,11 @@ class AccountFilesCompanion extends UpdateCompanion<AccountFile> {
     this.isFavorite = const Value.absent(),
     this.isArchived = const Value.absent(),
     this.overrideDateTime = const Value.absent(),
+    required DateTime bestDateTime,
   })  : account = Value(account),
         file = Value(file),
-        relativePath = Value(relativePath);
+        relativePath = Value(relativePath),
+        bestDateTime = Value(bestDateTime);
   static Insertable<AccountFile> custom({
     Expression<int>? rowId,
     Expression<int>? account,
@@ -1180,6 +1201,7 @@ class AccountFilesCompanion extends UpdateCompanion<AccountFile> {
     Expression<bool?>? isFavorite,
     Expression<bool?>? isArchived,
     Expression<DateTime?>? overrideDateTime,
+    Expression<DateTime>? bestDateTime,
   }) {
     return RawValuesInsertable({
       if (rowId != null) 'row_id': rowId,
@@ -1189,6 +1211,7 @@ class AccountFilesCompanion extends UpdateCompanion<AccountFile> {
       if (isFavorite != null) 'is_favorite': isFavorite,
       if (isArchived != null) 'is_archived': isArchived,
       if (overrideDateTime != null) 'override_date_time': overrideDateTime,
+      if (bestDateTime != null) 'best_date_time': bestDateTime,
     });
   }
 
@@ -1199,7 +1222,8 @@ class AccountFilesCompanion extends UpdateCompanion<AccountFile> {
       Value<String>? relativePath,
       Value<bool?>? isFavorite,
       Value<bool?>? isArchived,
-      Value<DateTime?>? overrideDateTime}) {
+      Value<DateTime?>? overrideDateTime,
+      Value<DateTime>? bestDateTime}) {
     return AccountFilesCompanion(
       rowId: rowId ?? this.rowId,
       account: account ?? this.account,
@@ -1208,6 +1232,7 @@ class AccountFilesCompanion extends UpdateCompanion<AccountFile> {
       isFavorite: isFavorite ?? this.isFavorite,
       isArchived: isArchived ?? this.isArchived,
       overrideDateTime: overrideDateTime ?? this.overrideDateTime,
+      bestDateTime: bestDateTime ?? this.bestDateTime,
     );
   }
 
@@ -1237,6 +1262,11 @@ class AccountFilesCompanion extends UpdateCompanion<AccountFile> {
       map['override_date_time'] =
           Variable<DateTime?>(converter.mapToSql(overrideDateTime.value));
     }
+    if (bestDateTime.present) {
+      final converter = $AccountFilesTable.$converter1;
+      map['best_date_time'] =
+          Variable<DateTime>(converter.mapToSql(bestDateTime.value)!);
+    }
     return map;
   }
 
@@ -1249,7 +1279,8 @@ class AccountFilesCompanion extends UpdateCompanion<AccountFile> {
           ..write('relativePath: $relativePath, ')
           ..write('isFavorite: $isFavorite, ')
           ..write('isArchived: $isArchived, ')
-          ..write('overrideDateTime: $overrideDateTime')
+          ..write('overrideDateTime: $overrideDateTime, ')
+          ..write('bestDateTime: $bestDateTime')
           ..write(')'))
         .toString();
   }
@@ -1310,6 +1341,14 @@ class $AccountFilesTable extends AccountFiles
               'override_date_time', aliasedName, true,
               type: const IntType(), requiredDuringInsert: false)
           .withConverter<DateTime>($AccountFilesTable.$converter0);
+  final VerificationMeta _bestDateTimeMeta =
+      const VerificationMeta('bestDateTime');
+  @override
+  late final GeneratedColumnWithTypeConverter<DateTime, DateTime?>
+      bestDateTime = GeneratedColumn<DateTime?>(
+              'best_date_time', aliasedName, false,
+              type: const IntType(), requiredDuringInsert: true)
+          .withConverter<DateTime>($AccountFilesTable.$converter1);
   @override
   List<GeneratedColumn> get $columns => [
         rowId,
@@ -1318,7 +1357,8 @@ class $AccountFilesTable extends AccountFiles
         relativePath,
         isFavorite,
         isArchived,
-        overrideDateTime
+        overrideDateTime,
+        bestDateTime
       ];
   @override
   String get aliasedName => _alias ?? 'account_files';
@@ -1366,6 +1406,7 @@ class $AccountFilesTable extends AccountFiles
               data['is_archived']!, _isArchivedMeta));
     }
     context.handle(_overrideDateTimeMeta, const VerificationResult.success());
+    context.handle(_bestDateTimeMeta, const VerificationResult.success());
     return context;
   }
 
@@ -1388,6 +1429,8 @@ class $AccountFilesTable extends AccountFiles
 
   static TypeConverter<DateTime, DateTime> $converter0 =
       const _DateTimeConverter();
+  static TypeConverter<DateTime, DateTime> $converter1 =
+      const _DateTimeConverter();
 }
 
 class Image extends DataClass implements Insertable<Image> {

app/lib/entity/sqlite_table_converter.dart

@@ -122,6 +122,7 @@ class SqliteFileConverter {
       isFavorite: Value(file.isFavorite),
       isArchived: Value(file.isArchived),
       overrideDateTime: Value(file.overrideDateTime),
+      bestDateTime: Value(file.bestDateTime),
     );
     final dbImage = file.metadata?.run((m) => sql.ImagesCompanion.insert(
           lastUpdated: m.lastUpdated,

app/lib/entity/sqlite_table_extension.dart

@@ -466,7 +466,7 @@ class FilesQueryBuilder {
   }
 
   void byRelativePathPattern(String pattern) {
-    _byRelativePathPattern = pattern;
+    (_byRelativePathPatterns ??= []).add(pattern);
   }
 
   void byMimePattern(String pattern) {
@@ -536,8 +536,14 @@ class FilesQueryBuilder {
     if (_byRelativePath != null) {
       query.where(db.accountFiles.relativePath.equals(_byRelativePath));
     }
-    if (_byRelativePathPattern != null) {
+    if (_byRelativePathPatterns?.isNotEmpty == true) {
-      query.where(db.accountFiles.relativePath.like(_byRelativePathPattern!));
+      final expression = _byRelativePathPatterns!
+          .sublist(1)
+          .fold<Expression<bool?>>(
+              db.accountFiles.relativePath.like(_byRelativePathPatterns![0]),
+              (previousValue, element) =>
+                  previousValue | db.accountFiles.relativePath.like(element));
+      query.where(expression);
     }
     if (_byMimePatterns?.isNotEmpty == true) {
       final expression = _byMimePatterns!.sublist(1).fold<Expression<bool?>>(
@@ -576,7 +582,7 @@ class FilesQueryBuilder {
   int? _byFileId;
   Iterable<int>? _byFileIds;
   String? _byRelativePath;
-  String? _byRelativePathPattern;
+  List<String>? _byRelativePathPatterns;
   List<String>? _byMimePatterns;
   bool? _byFavorite;
   int? _byDirRowId;

app/lib/use_case/scan_dir_offline.dart

@@ -1,3 +1,4 @@
+import 'package:drift/drift.dart' as sql;
 import 'package:nc_photos/account.dart';
 import 'package:nc_photos/di_container.dart';
 import 'package:nc_photos/entity/file.dart';
@@ -57,3 +58,53 @@ class ScanDirOffline {
 
   final DiContainer _c;
 }
+
+class ScanDirOfflineMini {
+  ScanDirOfflineMini(this._c) : assert(require(_c));
+
+  static bool require(DiContainer c) => DiContainer.has(c, DiType.sqliteDb);
+
+  Future<List<File>> call(
+    Account account,
+    Iterable<File> roots,
+    int limit, {
+    bool isOnlySupportedFormat = true,
+  }) async {
+    final dbFiles = await _c.sqliteDb.use((db) async {
+      final query = db.queryFiles().run((q) {
+        q
+          ..setQueryMode(sql.FilesQueryMode.completeFile)
+          ..setAppAccount(account);
+        for (final r in roots) {
+          final path = r.strippedPathWithEmpty;
+          if (path.isEmpty) {
+            break;
+          }
+          q.byRelativePathPattern("$path/%");
+        }
+        if (isOnlySupportedFormat) {
+          q
+            ..byMimePattern("image/%")
+            ..byMimePattern("video/%");
+        }
+        return q.build();
+      });
+      query
+        ..orderBy([sql.OrderingTerm.desc(db.accountFiles.bestDateTime)])
+        ..limit(limit);
+      return await query
+          .map((r) => sql.CompleteFile(
+                r.readTable(db.files),
+                r.readTable(db.accountFiles),
+                r.readTableOrNull(db.images),
+                r.readTableOrNull(db.trashes),
+              ))
+          .get();
+    });
+    return dbFiles
+        .map((f) => SqliteFileConverter.fromSql(account.userId.toString(), f))
+        .toList();
+  }
+
+  final DiContainer _c;
+}