import 'dart:async';

import 'package:flutter/widgets.dart';
import 'package:go_router/go_router.dart';

import 'session/session_cubit.dart';
import 'session/session_state.dart';
import '../features/auth/view/login_page.dart';
import '../features/auth/view/profile_page.dart';
import '../features/home/view/home_page.dart';
import '../features/splash/view/splash_page.dart';
import 'di.dart';

class Routes {
  const Routes._();
  static const splash = '/';
  static const login = '/login';
  static const profile = '/profile';
  static const home = '/home';
}

/// التوجيه يُشتقّ من `SessionCubit` وحده — لا `Navigator.push` بعد الدخول
/// موزّعة في الشاشات، فلا تتناقض حالتان.
final appRouter = GoRouter(
  initialLocation: Routes.splash,
  refreshListenable: _CubitListenable(sl<SessionCubit>().stream),
  redirect: (context, state) {
    final session = sl<SessionCubit>().state;
    final loc = state.matchedLocation;

    // قبل أن نعرف: نبقى على الإقلاع ولا نقرّر شيئاً.
    if (!session.isReady) return loc == Routes.splash ? null : Routes.splash;

    return switch (session.status) {
      SessionStatus.unauthenticated =>
        loc == Routes.login ? null : Routes.login,
      SessionStatus.needsProfile => loc == Routes.profile ? null : Routes.profile,
      SessionStatus.authenticated =>
        (loc == Routes.login || loc == Routes.profile || loc == Routes.splash)
            ? Routes.home
            : null,
      SessionStatus.unknown => Routes.splash,
    };
  },
  routes: [
    GoRoute(
      path: Routes.splash,
      builder: (context, state) => const SplashPage(),
    ),
    GoRoute(
      path: Routes.login,
      builder: (context, state) => const LoginPage(),
    ),
    GoRoute(
      path: Routes.profile,
      builder: (context, state) => const ProfilePage(),
    ),
    GoRoute(
      path: Routes.home,
      builder: (context, state) => const HomePage(),
    ),
  ],
);

/// جسر بين تيّار الـCubit و`refreshListenable` الذي يطلبه go_router.
class _CubitListenable extends ChangeNotifier {
  _CubitListenable(Stream<dynamic> stream) {
    _sub = stream.listen((_) => notifyListeners());
  }

  late final StreamSubscription<dynamic> _sub;

  @override
  void dispose() {
    _sub.cancel();
    super.dispose();
  }
}