Link between front-end and back-end

lib/providers/local_provider.dart

@@ -0,0 +1,54 @@
+import 'package:flutter/material.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+class LocaleProvider extends ChangeNotifier {
+  Locale? _locale;
+
+  Locale? get locale => _locale;
+
+
+  LocaleProvider() {
+    _loadLocale();
+  }
+
+
+  void _loadLocale() async {
+    final prefs = await SharedPreferences.getInstance();
+    final languageCode = prefs.getString('languageCode');
+    final countryCode = prefs.getString('countryCode');
+
+    if (languageCode != null) {
+      _locale = Locale(languageCode, countryCode);
+    } else {
+      _locale = null;
+    }
+    notifyListeners();
+  }
+
+
+  void setLocale(Locale newLocale) async {
+    if (_locale == newLocale) return;
+
+    _locale = newLocale;
+    notifyListeners();
+
+
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setString('languageCode', newLocale.languageCode);
+    if (newLocale.countryCode != null) {
+      await prefs.setString('countryCode', newLocale.countryCode!);
+    } else {
+      await prefs.remove('countryCode');
+    }
+  }
+
+
+  void clearLocale() async {
+    _locale = null;
+    notifyListeners();
+
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.remove('languageCode');
+    await prefs.remove('countryCode');
+  }
+}

lib/providers/theme_provider.dart

@@ -0,0 +1,28 @@
+import 'package:flutter/material.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+class ThemeProvider extends ChangeNotifier {
+  ThemeMode _themeMode = ThemeMode.system;
+
+  ThemeMode get themeMode => _themeMode;
+
+  ThemeProvider() {
+    _loadThemeMode();
+  }
+
+  void _loadThemeMode() async {
+    final prefs = await SharedPreferences.getInstance();
+    final themeIndex = prefs.getInt('themeMode') ?? 0;
+    _themeMode = ThemeMode.values[themeIndex];
+    notifyListeners();
+  }
+
+  void setThemeMode(ThemeMode mode) async {
+    if (_themeMode != mode) {
+      _themeMode = mode;
+      notifyListeners();
+      final prefs = await SharedPreferences.getInstance();
+      await prefs.setInt('themeMode', mode.index);
+    }
+  }
+}