mobile-app/lib/routing/app_router.dart

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:real_estate_mobile/core/constants/app_colors.dart';
import 'package:real_estate_mobile/core/widgets/app_shell.dart';
import 'package:real_estate_mobile/features/auth/presentation/providers/auth_provider.dart';
import 'package:real_estate_mobile/features/auth/presentation/screens/login_screen.dart';
import 'package:real_estate_mobile/features/auth/presentation/screens/signup_screen.dart';
import 'package:real_estate_mobile/features/agents/presentation/screens/agent_detail_screen.dart';
import 'package:real_estate_mobile/features/agents/presentation/screens/agent_search_screen.dart';
import 'package:real_estate_mobile/features/faq/presentation/screens/faq_screen.dart';
import 'package:real_estate_mobile/features/home/presentation/screens/home_screen.dart';
import 'package:real_estate_mobile/features/messaging/presentation/screens/conversations_screen.dart';
import 'package:real_estate_mobile/features/messaging/presentation/screens/chat_screen.dart';
import 'package:real_estate_mobile/features/agents/presentation/screens/agent_home_screen.dart';
import 'package:real_estate_mobile/features/contact/presentation/screens/contact_screen.dart';
import 'package:real_estate_mobile/features/about/presentation/screens/about_screen.dart';
import 'package:real_estate_mobile/features/agents/presentation/screens/agent_network_screen.dart';
import 'package:real_estate_mobile/features/profile/presentation/screens/profile_settings_screen.dart';

final routerProvider = Provider<GoRouter>((ref) {
  final authRefreshNotifier = _AuthRefreshNotifier();

  ref.listen(authProvider, (previous, next) {
    authRefreshNotifier.notify();
  });

  ref.onDispose(() {
    authRefreshNotifier.dispose();
  });

  // Public routes accessible without authentication (matching web middleware)
  const publicRoutes = ['/home', '/agents/search', '/agents/detail', '/faq', '/contact', '/about'];
  const authRoutes = ['/login', '/signup'];

  return GoRouter(
    initialLocation: '/home',
    refreshListenable: authRefreshNotifier,
    redirect: (context, state) {
      final authState = ref.read(authProvider);
      final isAuthenticated = authState.status == AuthStatus.authenticated;
      final isLoading = authState.status == AuthStatus.loading;

      final location = state.matchedLocation;
      final isAuthRoute = authRoutes.contains(location);
      final isPublicRoute = publicRoutes.any(
        (route) => location == route || location.startsWith('$route/'),
      );

      // While checking auth status, don't redirect
      if (isLoading) return null;

      // If authenticated and on auth page (login/signup), go to home
      if (isAuthenticated && isAuthRoute) return '/home';

      // Public routes are always accessible
      if (isPublicRoute || isAuthRoute) return null;

      // Protected routes require authentication — redirect to login
      if (!isAuthenticated) return '/login';

      return null;
    },
    routes: [
      // Auth routes (no shell — full screen)
      GoRoute(
        path: '/login',
        builder: (context, state) => const LoginScreen(),
      ),
      GoRoute(
        path: '/signup',
        builder: (context, state) => const SignupScreen(),
      ),

      // All main app routes wrapped in AppShell (shared header + bottom nav)
      ShellRoute(
        builder: (context, state, child) => AppShell(child: child),
        routes: [
          GoRoute(
            path: '/home',
            builder: (context, state) => const _HomeRouteWrapper(),
          ),
          GoRoute(
            path: '/agents/search',
            builder: (context, state) {
              final query = state.uri.queryParameters['q'];
              return AgentSearchScreen(initialQuery: query);
            },
          ),
          GoRoute(
            path: '/agents/detail/:id',
            builder: (context, state) {
              final id = state.pathParameters['id']!;
              return AgentDetailScreen(agentId: id);
            },
          ),
          GoRoute(
            path: '/messages',
            builder: (context, state) => const ConversationsScreen(),
          ),
          GoRoute(
            path: '/messages/chat/:id',
            builder: (context, state) {
              final id = state.pathParameters['id']!;
              return ChatScreen(conversationId: id);
            },
          ),
          GoRoute(
            path: '/faq',
            builder: (context, state) => const FaqScreen(),
          ),
          GoRoute(
            path: '/contact',
            builder: (context, state) => const ContactScreen(),
          ),
          GoRoute(
            path: '/about',
            builder: (context, state) => const AboutScreen(),
          ),
          GoRoute(
            path: '/agent/network',
            builder: (context, state) => const AgentNetworkScreen(),
          ),
          GoRoute(
            path: '/profile',
            builder: (context, state) => const ProfileSettingsScreen(),
          ),
        ],
      ),
    ],
  );
});

/// Reactively switches between HomeScreen and AgentHomeScreen based on auth.
/// Shows a loading indicator while auth status is being determined to prevent
/// flashing the wrong screen on refresh.
class _HomeRouteWrapper extends ConsumerWidget {
  const _HomeRouteWrapper();

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final authState = ref.watch(authProvider);

    // Show loader while auth is initializing or loading
    if (authState.status == AuthStatus.initial ||
        authState.status == AuthStatus.loading) {
      return const Center(
        child: CircularProgressIndicator(
          color: AppColors.accentOrange,
        ),
      );
    }

    if (authState.status == AuthStatus.authenticated &&
        authState.user?.role == 'AGENT') {
      return const AgentHomeScreen();
    }
    return const HomeScreen();
  }
}

/// Notifier that triggers GoRouter refresh when auth state changes.
class _AuthRefreshNotifier extends ChangeNotifier {
  void notify() {
    notifyListeners();
  }
}