Improved json auto save & budget mobile UI

lib/domains/settings/settings_bloc.dart

@@ -0,0 +1,36 @@
+import 'dart:async';
+
+import 'package:equatable/equatable.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:tunas/repositories/metadata/metadata_repository.dart';
+import 'package:tunas/repositories/metadata/models/settings.dart';
+
+part 'settings_event.dart';
+part 'settings_state.dart';
+
+class SettingsBloc extends Bloc<SettingsEvent, SettingsState> {
+  final MetadataRepository _metadataRepository;
+
+  SettingsBloc({required MetadataRepository metadataRepository}) : _metadataRepository = metadataRepository, super(const SettingsState()) {
+    on<SettingsLoad>(_onSettingsLoad);
+    on<SetThemeMode>(_onSetThemeMode);
+
+    _metadataRepository
+      .getSettingsStream()
+      .listen((settings) => add(SettingsLoad(settings)));
+  }
+
+  FutureOr<void> _onSettingsLoad(SettingsLoad event, Emitter<SettingsState> emit) {
+    emit(state.copyWith(
+      themeMode: event.settings.themeMode,
+    ));
+  }
+
+  FutureOr<void> _onSetThemeMode(SetThemeMode event, Emitter<SettingsState> emit) {
+    _metadataRepository.saveSettings(Settings(themeMode: event.themeMode));
+    emit(state.copyWith(
+      themeMode: event.themeMode,
+    ));
+  }
+}