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/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_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';

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

  ref.listen(authProvider, (_, __) {
    authRefreshNotifier.notify();
  });

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

  // Public routes accessible without authentication (matching web middleware)
  const publicRoutes = ['/home', '/agents/search', '/faq'];
  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: [
      GoRoute(
        path: '/login',
        builder: (context, state) => const LoginScreen(),
      ),
      GoRoute(
        path: '/signup',
        builder: (context, state) => const SignupScreen(),
      ),
      GoRoute(
        path: '/home',
        builder: (context, state) => const HomeScreen(),
      ),
      GoRoute(
        path: '/agents/search',
        builder: (context, state) {
          final query = state.uri.queryParameters['q'];
          return AgentSearchScreen(initialQuery: query);
        },
      ),
      GoRoute(
        path: '/faq',
        builder: (context, state) => const FaqScreen(),
      ),
    ],
  );
});

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