// === DOMAIN: kontrak ===
abstract class UserRepository {
  Future<User> getUser(String id);
}

// === DATA: implementasi nyata ===
class UserRepositoryImpl implements UserRepository {
  final ApiClient api;
  UserRepositoryImpl(this.api);

  @override
  Future<User> getUser(String id) async {
    final json = await api.get('/users/$id');
    return UserModel.fromJson(json).toEntity();
  }
}

// === Mock untuk testing / offline ===
class UserRepositoryMock implements UserRepository {
  @override
  Future<User> getUser(String id) async {
    await Future.delayed(
        Duration(milliseconds: 300));
    return User(id, 'Budi Dummy',
                'budi@test.com');
  }
}

// Saat dipakai: tinggal swap satu baris!
UserRepository repo = UserRepositoryMock();
// atau ⇩ tanpa ubah kode lain
UserRepository repo = UserRepositoryImpl(api);

import 'package:get_it/get_it.dart';

final sl = GetIt.instance;

void setupLocator() {
  // 1. Service & client dasar
  sl.registerLazySingleton(() => ApiClient());

  // 2. Repository (butuh ApiClient)
  sl.registerLazySingleton<UserRepository>(
    () => UserRepositoryImpl(sl()),
  );

  // 3. UseCase (butuh Repository)
  sl.registerFactory(
    () => GetUserUseCase(sl()),
  );
}

// ❌ TANPA DI — buat manual, berantai
final api  = ApiClient();
final repo = UserRepositoryImpl(api);
final uc   = GetUserUseCase(repo);
// diulang di setiap file... 😫

// ✅ DENGAN DI — tinggal ambil
final uc = sl<GetUserUseCase>();
final user = await uc('42');

// Riverpod versi DI:
final userRepoProvider = Provider(
  (ref) => UserRepositoryImpl(ref.read(apiProvider)),
);

// === entities/todo.dart ===
class Todo {
  final String id;
  final String title;
  final bool done;
  const Todo({required this.id, required this.title, this.done = false});
}

// === repositories/todo_repository.dart (KONTRAK) ===
abstract class TodoRepository {
  Future<List<Todo>> getTodos();
  Future<void> addTodo(Todo todo);
}

// === usecases/get_todos.dart ===
class GetTodos {
  final TodoRepository repo;
  GetTodos(this.repo);
  Future<List<Todo>> call() => repo.getTodos();
}

// === usecases/add_todo.dart ===
class AddTodo {
  final TodoRepository repo;
  AddTodo(this.repo);
  Future<void> call(Todo t) => repo.addTodo(t);
}

// === models/todo_model.dart ===
class TodoModel extends Todo {
  const TodoModel({required String id, required String title, bool done = false})
      : super(id: id, title: title, done: done);

  factory TodoModel.fromJson(Map<String, dynamic> j) => TodoModel(
        id: j['id'], title: j['title'], done: j['done'] ?? false);
}

// === datasources/todo_remote_ds.dart ===
class TodoRemoteDataSource {
  final ApiClient api;
  TodoRemoteDataSource(this.api);
  Future<List<TodoModel>> fetch() async {
    final list = await api.get('/todos') as List;
    return list.map((e) => TodoModel.fromJson(e)).toList();
  }
}

// === repositories/todo_repository_impl.dart ===
class TodoRepositoryImpl implements TodoRepository {
  final TodoRemoteDataSource ds;
  TodoRepositoryImpl(this.ds);
  @override
  Future<List<Todo>> getTodos() => ds.fetch();
  @override
  Future<void> addTodo(Todo t) async {/* api.post */}
}

// === core/di/locator.dart ===
void setupTodo() {
  sl.registerLazySingleton(() => TodoRemoteDataSource(sl()));
  sl.registerLazySingleton<TodoRepository>(() => TodoRepositoryImpl(sl()));
  sl.registerFactory(() => GetTodos(sl()));
  sl.registerFactory(() => AddTodo(sl()));
}

// === presentation/state/todo_notifier.dart ===
class TodoNotifier extends ChangeNotifier {
  final GetTodos getTodos;
  TodoNotifier(this.getTodos);

  List<Todo> todos = [];
  bool loading = false;

  Future<void> load() async {
    loading = true; notifyListeners();
    todos = await getTodos();       // panggil UseCase
    loading = false; notifyListeners();
  }
}

// === presentation/pages/todo_page.dart ===
class TodoPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final n = context.watch<TodoNotifier>();
    if (n.loading) return const CircularProgressIndicator();
    return ListView(
      children: n.todos.map((t) => CheckboxListTile(
        title: Text(t.title),
        value: t.done,
        onChanged: (_) {},
      )).toList(),
    );
  }
}

// === main.dart — rangkai semua ===
void main() {
  setupLocator(); setupTodo();
  runApp(ChangeNotifierProvider(
    create: (_) => TodoNotifier(sl())..load(),
    child: const MyApp(),
  ));
}