import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import '../../features/auth/providers/auth_provider.dart';
import '../../features/auth/screens/login_screen.dart';
import '../../features/iptv/screens/playlist_selection_screen.dart';
import '../../features/iptv/screens/dashboard_screen.dart';
import '../../features/admin/screens/admin_panel.dart';
import '../../mobile/features/iptv/screens/mobile_playlist_selection_screen.dart';
import '../../mobile/features/iptv/screens/mobile_dashboard_screen.dart';
import '../../mobile/features/auth/screens/mobile_login_screen.dart';
import '../widgets/themed_loading_screen.dart';
import '../../features/iptv/providers/xtream_provider.dart';

final routerProvider = Provider<GoRouter>((ref) {
  return GoRouter(
    initialLocation: '/login',
    refreshListenable: RouterRefreshNotifier(ref),
    redirect: (context, state) {
      final authState = ref.read(authProvider);
      final isLoggedIn = authState.isAuthenticated;
      final isLoginRoute = state.matchedLocation == '/login';

      // Wait for initial auth check to complete
      if (!authState.isInitialized) {
        return null;
      }

      // Redirect to login if not authenticated
      if (!isLoggedIn && !isLoginRoute) {
        return '/login';
      }

      // Redirect to playlists if already logged in and trying to access login
      if (isLoggedIn && isLoginRoute) {
        return '/playlists';
      }

      // Admin guard for /admin route
      if (state.matchedLocation == '/admin' && !authState.isAdmin) {
        return '/playlists';
      }

      // If we are on dashboard but have no playlist selected, try to restore it
      if (state.matchedLocation == '/dashboard') {
        final playlist = ref.read(selectedPlaylistProvider);
        if (playlist == null) {
          return '/playlists';
        }
      }

      return null;
    },
    routes: [
      GoRoute(
        path: '/login',
        builder: (context, state) {
          if (MediaQuery.of(context).size.width < 768) {
            return const MobileLoginScreen();
          }
          return const LoginScreen();
        },
      ),
      GoRoute(
        path: '/playlists',
        builder: (context, state) {
          if (MediaQuery.of(context).size.width < 768) {
            return const MobilePlaylistSelectionScreen();
          }
          return const PlaylistSelectionScreen();
        },
      ),
      GoRoute(
        path: '/dashboard',
        builder: (context, state) {
          final playlist = ref.watch(selectedPlaylistProvider);
          if (playlist == null) {
            return const Scaffold(
              body: ThemedLoading(),
            );
          }

          // Adaptive layout without forcing a router rebuild on every pixel change
          final isMobile = MediaQuery.sizeOf(context).width < 768;
          if (isMobile) {
            return MobileDashboardScreen(playlist: playlist);
          }
          return DashboardScreen(playlist: playlist);
        },
      ),
      GoRoute(
        path: '/admin',
        builder: (context, state) => const AdminPanel(),
      ),
    ],
  );
});

/// Notifier that triggers router refresh when auth state or selected playlist changes
class RouterRefreshNotifier extends ChangeNotifier {
  RouterRefreshNotifier(this._ref) {
    _ref.listen(authProvider, (_, __) {
      notifyListeners();
    });
    _ref.listen(selectedPlaylistProvider, (_, __) {
      notifyListeners();
    });
  }

  final Ref _ref;
}