recipe-app/flutter/lib/core/router/app_router.dart

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

import '../../core/ui/app_shell.dart';
import '../../features/auth/data/auth_providers.dart';
import '../../features/recipes/presentation/recipes_screen.dart';
import '../../features/auth/presentation/login_screen.dart';
import '../../features/profile/presentation/profile_screen.dart';

final appRouterProvider = Provider<GoRouter>((ref) {
  final authState = ref.watch(authStateProvider);

  return GoRouter(
    initialLocation: '/',
    redirect: (context, state) {
      final isLoading = authState.isLoading;
      final token = authState.valueOrNull;
      final isLoggedIn = token != null && token.isNotEmpty;
      final isLoginRoute = state.matchedLocation == '/login';
      final isRootRoute = state.matchedLocation == '/';

      if (isLoading) {
        return null;
      }

      if (isRootRoute) {
        return isLoggedIn ? '/recipes' : '/login';
      }

      if (!isLoggedIn && !isLoginRoute) {
        return '/login';
      }

      if (isLoggedIn && isLoginRoute) {
        return '/recipes';
      }

      return null;
    },
    routes: [
      GoRoute(path: '/', builder: (context, state) => const SizedBox.shrink()),
      GoRoute(
        path: '/login',
        builder: (context, state) => const LoginScreen(),
      ),
      ShellRoute(
        builder: (context, state, child) {
          return AppShell(location: state.uri.path, child: child);
        },
        routes: [
          GoRoute(
            path: '/recipes',
            builder: (context, state) => const RecipesScreen(),
          ),
          GoRoute(
            path: '/profile',
            builder: (context, state) => const ProfileScreen(),
          ),
        ],
      ),
    ],
  );
});