Introduce themebloc and persist theme

lib/food_entry_bloc.dart

@@ -4,7 +4,7 @@ import 'package:uuid/uuid.dart';
 
 class FoodEntryBloc extends Bloc<FoodEvent, FoodEntryState> {
   final FoodEntryState initialState;
-  final FoodStorage storage;
+  final AppStorage storage;
   final DateTime forDate;
 
   FoodEntryBloc(

lib/main.dart

@@ -1,3 +1,4 @@
+import 'package:calodiary/theme_bloc.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:flutter_localizations/flutter_localizations.dart';
@@ -9,24 +10,52 @@ import 'package:calodiary/storage/storage.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
-  var storage = await FoodStorage.create();
+  var storage = await AppStorage.create();
   var kcalLimit = await storage.readLimit();
+  var brightness = await storage.readBrightness();
 
-  runApp(MainApp(storage: storage, kcalLimit: kcalLimit));
+  runApp(
+    MainApp(
+      storage: storage,
+      kcalLimit: kcalLimit,
+      brightness: brightness,
+    ),
+  );
 }
 
 class MainApp extends StatelessWidget {
-  final FoodStorage storage;
+  final AppStorage storage;
   final double kcalLimit;
+  final String brightness;
 
-  const MainApp({required this.storage, required this.kcalLimit, super.key});
+  const MainApp(
+      {required this.storage,
+      required this.kcalLimit,
+      required this.brightness,
+      super.key});
 
   @override
   Widget build(BuildContext context) {
-    return BlocProvider(
-      create: (context) => SettingsDataBloc(SettingsState(kcalLimit: kcalLimit),
+    return MultiBlocProvider(
+      providers: [
+        BlocProvider(
+          create: (context) => SettingsDataBloc(
+              SettingsState(kcalLimit: kcalLimit),
               storage: storage),
-      child: MaterialApp.router(
+        ),
+        BlocProvider(
+          create: (context) => ThemeDataBloc(ThemeState(brightness: brightness),
+              storage: storage),
+        ),
+      ],
+      child: BlocBuilder<ThemeDataBloc, ThemeState>(
+        builder: (context, state) {
+          var switchToTheme = ThemeData.light();
+          if (state.brightness == 'dark') {
+            switchToTheme = ThemeData.dark();
+          }
+
+          return MaterialApp.router(
             localizationsDelegates: const [
               GlobalMaterialLocalizations.delegate,
               GlobalWidgetsLocalizations.delegate,
@@ -35,8 +64,10 @@ class MainApp extends StatelessWidget {
             supportedLocales: const [
               Locale('de'),
             ],
-        theme: ThemeData.dark(),
+            theme: switchToTheme,
             routerConfig: router,
+          );
+        },
       ),
     );
   }

lib/perdate_widget.dart

@@ -1,3 +1,4 @@
+import 'package:calodiary/theme_bloc.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:intl/intl.dart';
@@ -18,7 +19,7 @@ class PerDateWidget extends StatefulWidget {
 }
 
 class _PerDateWidgetState extends State<PerDateWidget> {
-  late FoodStorage storage;
+  late AppStorage storage;
   late Future<List<FoodEntry>> entriesFuture;
   late List<FoodEntry> entries;
 
@@ -26,7 +27,7 @@ class _PerDateWidgetState extends State<PerDateWidget> {
   void initState() {
     super.initState();
 
-    storage = FoodStorage.getInstance();
+    storage = AppStorage.getInstance();
     entriesFuture = storage.getEntriesForDate(widget.date);
     entriesFuture.then((val) {
       entries = val;
@@ -39,6 +40,14 @@ class _PerDateWidgetState extends State<PerDateWidget> {
     return Scaffold(
         appBar: AppBar(
           title: Text(formattedDate),
+          actions: [
+            IconButton(
+              icon: const Icon(Icons.lightbulb),
+              onPressed: () {
+                context.read<ThemeDataBloc>().add(ThemeToggleEvent());
+              },
+            ),
+          ],
         ),
         drawer: const AppDrawer(),
         body: FutureBuilder(

lib/settings_bloc.dart

@@ -2,7 +2,7 @@ import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:calodiary/storage/storage.dart';
 
 class SettingsDataBloc extends Bloc<SettingsEvent, SettingsState> {
-  final FoodStorage storage;
+  final AppStorage storage;
 
   SettingsDataBloc(super.initialState, {required this.storage}) {
     on<DailyKcalLimitUpdated>(persistDailyLimit);

lib/storage/storage.dart

@@ -2,22 +2,31 @@ import 'dart:io';
 
 import 'package:calodiary/food_entry_bloc.dart';
 import 'package:path_provider/path_provider.dart';
+import 'package:universal_platform/universal_platform.dart';
 
-class FoodStorage {
-  static late FoodStorage _instance;
+class AppStorage {
+  static late AppStorage _instance;
   late String path;
-  FoodStorage._create();
+  AppStorage._create();
 
-  static Future<FoodStorage> create() async {
-    var storage = FoodStorage._create();
-    var directory = await getApplicationCacheDirectory();
-    storage.path = directory.path;
+  static Future<AppStorage> create() async {
+    var storage = AppStorage._create();
+
+    Directory dir = Directory('');
+
+    if (UniversalPlatform.isDesktop) {
+      dir = await getApplicationCacheDirectory();
+    } else if (UniversalPlatform.isAndroid) {
+      dir = await getApplicationDocumentsDirectory();
+    }
+
+    storage.path = dir.path;
     _instance = storage;
 
     return _instance;
   }
 
-  static FoodStorage getInstance() => _instance;
+  static AppStorage getInstance() => _instance;
 
   Future<List<FoodEntry>> getEntriesForDate(DateTime date) async {
     List<FoodEntry> entries = [];
@@ -93,4 +102,34 @@ class FoodStorage {
 
     return limit;
   }
+
+  Future<String> readBrightness() async {
+    var filePath = '$path/brightness';
+    var file = File(filePath);
+    var exists = await file.exists();
+
+    if (!exists) {
+      return 'dark';
+    }
+
+    var line = await file.readAsLines();
+
+    if (line.isEmpty || (line[0] != 'dark' && line[0] != 'light')) {
+      return 'dark';
+    }
+
+    return line[0];
+  }
+
+  Future<void> writeBrightness(String brightness) async {
+    var filePath = '$path/brightness';
+    var file = File(filePath);
+    var exists = await file.exists();
+
+    if (!exists) {
+      file.create();
+    }
+
+    await file.writeAsString(brightness);
+  }
 }

lib/theme_bloc.dart

@@ -0,0 +1,37 @@
+import 'package:calodiary/storage/storage.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+
+class ThemeDataBloc extends Bloc<ThemeToggleEvent, ThemeState> {
+  final AppStorage storage;
+
+  ThemeDataBloc(super.initialState, {required this.storage}) {
+    on<ThemeToggleEvent>(switchTheme);
+  }
+
+  void switchTheme(ThemeToggleEvent event, Emitter<ThemeState> emit) async {
+    String newBrightness = 'light';
+    if (state.brightness == 'light') newBrightness = 'dark';
+
+    persistTheme(newBrightness);
+
+    emit(ThemeState(brightness: newBrightness));
+  }
+
+  void persistTheme(String brightness) async {
+    storage.writeBrightness(brightness);
+  }
+
+  Future<String> getPersistedTheme() async {
+    return storage.readBrightness();
+  }
+}
+
+class ThemeToggleEvent {
+  ThemeToggleEvent();
+}
+
+class ThemeState {
+  final String brightness;
+
+  ThemeState({required this.brightness});
+}

pubspec.lock

@@ -442,6 +442,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.3.2"
+  universal_platform:
+    dependency: "direct main"
+    description:
+      name: universal_platform
+      sha256: "64e16458a0ea9b99260ceb5467a214c1f298d647c659af1bff6d3bf82536b1ec"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.0"
   uuid:
     dependency: "direct main"
     description:

pubspec.yaml

@@ -18,6 +18,7 @@ dependencies:
   path_provider: ^2.1.3
   quiver: ^3.2.1
   settings_ui: ^2.0.2
+  universal_platform: ^1.1.0
   uuid: ^4.4.0
 
 dev_dependencies: