// Push a new screen
Navigator.push(
  context,
  MaterialPageRoute(builder: (_) => const DetailScreen()),
);

// Pop back
Navigator.pop(context);

// Push with a result
final result = await Navigator.push(
  context,
  MaterialPageRoute(builder: (_) => const PickerScreen()),
);
// Handle result
if (result != null) { /* use result */ }

MaterialApp(
  routes: {
    '/': (context) => const HomeScreen(),
    '/details': (context) => const DetailScreen(),
    '/settings': (context) => const SettingsScreen(),
  },
);

// Navigate by name
Navigator.pushNamed(context, '/details');

// With arguments
Navigator.pushNamed(context, '/details', arguments: {'id': 42});

class MyRouterDelegate extends RouterDelegate<RoutePath>
    with ChangeNotifier, PopNavigatorRouterDelegateMixin {
  @override
  Widget build(BuildContext context) {
    return Navigator(
      pages: [
        MaterialPage(child: HomeScreen()),
        if (selectedItem != null)
          MaterialPage(child: DetailScreen(item: selectedItem!)),
      ],
      onPopPage: (route, result) {
        selectedItem = null;
        notifyListeners();
        return route.didPop(result);
      },
    );
  }
}

final router = GoRouter(
  routes: [
    GoRoute(
      path: '/',
      builder: (context, state) => const HomeScreen(),
    ),
    GoRoute(
      path: '/details',
      builder: (context, state) => const DetailScreen(),
    ),
    GoRoute(
      path: '/profile/:userId',
      builder: (context, state) {
        final userId = state.pathParameters['userId']!;
        return ProfileScreen(userId: userId);
      },
    ),
  ],
);
// Use in MaterialApp
MaterialApp.router(routerConfig: router);

// Navigate to a route
context.go('/details');           // Replaces entire stack
context.goNamed('details');       // By name

// Push onto stack (preserves back navigation)
context.push('/details');
context.pushNamed('details');

// Go back
context.pop();

// With query parameters
context.go('/search?q=flutter&page=1');
// Access in builder:
final query = state.uri.queryParameters['q']; // 'flutter'

// With extra data
context.go('/details', extra: myObject);
// Access:
final data = state.extra as MyObject;

// Navigate by name with params
context.goNamed('profile', pathParameters: {'userId': '42'});
context.goNamed('search', queryParameters: {'q': 'flutter'});

GoRouter(
  routes: [
    ShellRoute(
      builder: (context, state, child) => ScaffoldWithNavBar(child: child),
      routes: [
        GoRoute(path: '/', builder: (_, __) => const HomeTab()),
        GoRoute(path: '/search', builder: (_, __) => const SearchTab()),
        GoRoute(path: '/profile', builder: (_, __) => const ProfileTab()),
      ],
    ),
    GoRoute(path: '/login', builder: (_, __) => const LoginScreen()),
  ],
)

final router = GoRouter(
  redirect: (context, state) {
    final isLoggedIn = AuthService.instance.isLoggedIn;
    final isLoginRoute = state.matchedLocation == '/login';

    if (!isLoggedIn && !isLoginRoute) return '/login';
    if (isLoggedIn && isLoginRoute) return '/';
    return null; // No redirect needed
  },
  routes: [
    GoRoute(path: '/', builder: (_, __) => const HomeScreen()),
    GoRoute(path: '/login', builder: (_, __) => const LoginScreen()),
    GoRoute(
      path: '/admin',
      builder: (_, __) => const AdminScreen(),
      // Per-route guard
      redirect: (context, state) {
        if (!AuthService.instance.isAdmin) return '/';
        return null;
      },
    ),
  ],
);

final router = GoRouter(
  redirect: (context, state) {
    final auth = AuthService.instance;
    final isLogin = state.matchedLocation == '/login';
    if (!auth.isLoggedIn && !isLogin) return '/login';
    if (auth.isLoggedIn && isLogin) return '/';
    return null;
  },
  routes: [
    GoRoute(path: '/login', builder: (_, __) => const LoginScreen()),
    ShellRoute(
      builder: (_, __, child) => MainScaffold(child: child),
      routes: [
        GoRoute(path: '/', builder: (_, __) => const HomeTab()),
        GoRoute(path: '/explore', builder: (_, __) => const ExploreTab()),
        GoRoute(path: '/profile', builder: (_, __) => const ProfileTab()),
      ],
    ),
    GoRoute(
      path: '/details/:id',
      builder: (_, state) {
        final id = state.pathParameters['id']!;
        return DetailScreen(id: id);
      },
    ),
  ],
);