flutter-rp-example/lib/router/router.dart

import 'package:flutter/material.dart';

import '../services/auth/auth.dart';
import '../pages/home.dart';
import '../pages/splash.dart';
import '../pages/login.dart';

class ReflexRouterDelegate extends RouterDelegate
    with ChangeNotifier, PopNavigatorRouterDelegateMixin {
  @override
  GlobalKey<NavigatorState> get navigatorKey => _navigatorKey;
  final GlobalKey<NavigatorState> _navigatorKey;

  bool? _loggedIn;
  bool? get loggedIn => _loggedIn;
  set loggedIn(value) {
    _loggedIn = value;
    notifyListeners();
  }

  final AuthService authService;

  ReflexRouterDelegate(this.authService)
      : _navigatorKey = GlobalKey<NavigatorState>() {
    _init();
  }

  _init() async {
    try {
      await authService.init();
      bool isAuthenticated = await authService.isLoggedIn();

      // If the access token check failed but we have a refresh token,
      // try to silently renew before forcing the user back to the login screen.
      if (!isAuthenticated &&
          authService.refreshToken != null &&
          authService.refreshToken!.isNotEmpty) {
        try {
          await authService.doRefreshToken();
          authService.tokenRefresher = TokenRefresher(authService,
              refreshInterval: const Duration(seconds: 60));
          authService.tokenRefresher!.start();
          isAuthenticated = await authService.isLoggedIn();
        } catch (_) {
          // Refresh token is expired or invalid — full re-login required.
        }
      }

      loggedIn = isAuthenticated;
    } catch (e) {
      loggedIn = false;
    }
  }

  @override
  Widget build(BuildContext context) {
    List<Page> stack;
    if (loggedIn == null) {
      stack = _splashStack;
    } else if (loggedIn!) {
      stack = _loggedInStack;
    } else {
      stack = _loggedOutStack;
    }
    return WillPopScope(
        onWillPop: () async => !await navigatorKey.currentState!.maybePop(),
        child: Navigator(
          key: navigatorKey,
          pages: stack,
          onPopPage: (route, result) {
            if (!route.didPop(result)) return false;
            return true;
          },
        ));
  }

  List<Page> get _splashStack => [const SplashPage()];

  List<Page> get _loggedOutStack => [
        LoginPage(onLogin: () {
          loggedIn = true;
        })
      ];

  List<Page> get _loggedInStack {
    return [
      HomePage(onLogout: () {
        loggedIn = false;
      }),
    ];
  }

  @override
  Future<void> setNewRoutePath(configuration) async {/* Do Nothing */}
}