Sage/lib/core/router/app_router.dart

import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:supabase_flutter/supabase_flutter.dart';

import '../../features/authentication/presentation/pages/login_page.dart';
import '../../features/authentication/presentation/pages/signup_page.dart';
import '../../features/home/presentation/pages/home_page.dart';
import '../../features/authentication/presentation/pages/splash_page.dart';

/// Application router configuration
/// 
/// Handles navigation with authentication state awareness and protected routes
class AppRouter {
  static final GoRouter _router = GoRouter(
    initialLocation: '/',
    debugLogDiagnostics: true,
    redirect: (context, state) {
      // Use Supabase directly for auth state checking
      final currentUser = Supabase.instance.client.auth.currentUser;
      
      // Allow splash page regardless of auth state
      if (state.uri.toString() == '/splash') {
        return null;
      }
      
      // If not authenticated and trying to access protected route, redirect to login
      if (currentUser == null && !state.uri.toString().startsWith('/login') && !state.uri.toString().startsWith('/signup')) {
        return '/login';
      }
      
      // If authenticated and on auth pages, redirect to home
      if (currentUser != null && (state.uri.toString().startsWith('/login') || state.uri.toString().startsWith('/signup'))) {
        return '/home';
      }
      
      return null;
    },
    routes: [
      // Splash route - initial loading screen
      GoRoute(
        path: '/splash',
        builder: (context, state) => const SplashPage(),
      ),
      
      // Authentication routes (public)
      GoRoute(
        path: '/login',
        builder: (context, state) => const LoginPage(),
      ),
      
      GoRoute(
        path: '/signup',
        builder: (context, state) => const SignupPage(),
      ),
      
      // Protected routes (require authentication)
      GoRoute(
        path: '/home',
        builder: (context, state) => const HomePage(),
      ),
      
      // Root route - redirects based on auth state
      GoRoute(
        path: '/',
        redirect: (context, state) {
          final currentUser = Supabase.instance.client.auth.currentUser;
          return currentUser != null ? '/home' : '/splash';
        },
      ),
    ],
errorBuilder: (context, state) => Scaffold(
        appBar: AppBar(
          title: const Text('Error'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              const Icon(
                Icons.error_outline,
                size: 64,
                color: Colors.red,
              ),
              const SizedBox(height: 16),
              Text(
                'Page not found',
                style: Theme.of(context).textTheme.headlineSmall,
              ),
              const SizedBox(height: 8),
              Text(
                'Could not find: ${state.uri.toString()}',
                style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                  color: Colors.grey[600],
                ),
              ),
              const SizedBox(height: 24),
              ElevatedButton(
                onPressed: () {
                  // Navigate to home or login based on auth state
                  final currentUser = Supabase.instance.client.auth.currentUser;
                  if (currentUser != null) {
                    GoRouter.of(context).go('/home');
                  } else {
                    GoRouter.of(context).go('/login');
                  }
                },
                child: const Text('Go Home'),
              ),
            ],
          ),
        ),
      ),
  );

  /// Get the router instance
  static GoRouter get router => _router;
}