Flutter Push Notification - Navigation Failure

main.dart

import 'package:flutter/material.dart';

import 'package:MyTesttv/backend/users.context.dart';
import 'dart:async';
import './ui/contactusPage.dart';
import './ui/calendarPage.dart';
import './ui/videosPage.dart';
import './ui/faqPage.dart';
import './ui/interestsPage.dart';
import './ui/profilePage.dart';
import './ui/alternate_sign_up_with_country_codePage.dart';
import './ui/sign_upPage.dart';
import './ui/splashPage.dart';
import 'package:firebase_messaging/firebase_messaging.dart';

final GlobalKey<NavigatorState> navigatorKey =
    GlobalKey(debugLabel: "Main Navigator");

void main() {
  runApp(new MaterialApp(
    navigatorKey: navigatorKey,
    home: MyTestApp(),
    title: 'MyTesttv',
    // Start the app with the "/" named route. In our case, the app will start
    // on the FirstScreen Widget
    // initialRoute: '/',
    routes: {
      // When we navigate to the "/" route, build the FirstScreen Widget
      // '/': (context) => splashPage(),

      '/contactus': (context) => contactusPage(),

      '/calendar': (context) => calendarPage(),

      '/video': (context) => videosPage(),

      '/faq': (context) => faqPage(),

      '/interests': (context) => interestsPage(),

      '/profile': (context) => profilePage(),

      '/alternate_sign_up_with_country_code': (context) =>
          alternate_sign_up_with_country_codePage(),

      '/sign_up': (context) => sign_upPage(),

      '/splash': (context) => splashPage(),
    },
  ));
}

class MyTestApp extends StatefulWidget {
  MyTestApp({Key key}) : super(key: key);

  @override
  MyTestAppState createState() => new MyTestAppState();
}

class MyTestAppState extends State<MyTestApp> {
  // final GlobalKey<NavigatorState> navigatorKey = new GlobalKey();
  static const loading = const Duration(seconds: 3);
  final FirebaseMessaging _firebaseMessaging = new FirebaseMessaging();

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    _firebaseMessaging.configure(
      onMessage: (Map<String, dynamic> message) async {
        print("onMessage:1 $message");
        // Navigator.push(navigatorKey.currentContext,
        //  MaterialPageRoute(builder: (_) => new videosPage()));
//        Navigator.push(context, MaterialPageRoute(builder: (context) => new videosPage()));
//        if (Navigator.canPop(context)) {
//          Navigator.popUntil(
//              context, (Route<dynamic> route) => route is PageRoute);
//        }
//
//        Navigator.of(context).pushReplacementNamed('/video');
      },
      onLaunch: (Map<String, dynamic> message) async {
        print("onLaunch: $message");
        //Navigator.of(navigatorKey.currentContext)
        //  .pushReplacementNamed('/video');
      },
      onResume: (Map<String, dynamic> message) async {
        print("onResume: $message");
//        Navigator.of(navigatorKey.currentContext)
//            .pushReplacementNamed('/video');
      },
    );
    _firebaseMessaging.requestNotificationPermissions();
    _firebaseMessaging.getToken().then((String token) {
      assert(token != null);

      print(token);
    });
    //startLoading(3);
  }

  Future<Timer> startLoading(int seconds) async {
    var duration = seconds == null ? loading : new Duration(seconds: seconds);
    return new Timer(duration, doesUserFileExist);
  }

  void doesUserFileExist() {
    Users.doesUserFileExist().then((exists) {
      if (exists == true) {
        Navigator.of(context).pushReplacementNamed('/video');
      } else {
        // Navigator.pushReplacementNamed()
        Navigator.of(context).pushReplacementNamed('/sign_up');
      }
    });
  }



  @override
  Widget build(BuildContext context) {
    return Scaffold(
      //key: navigatorKey,
      body: new GestureDetector(
          onTap: () {
            print("Clicked");
          },
          child: Stack(
            fit: StackFit.expand,
            children: <Widget>[
              new Positioned(
                  child: new Image.asset("images/SplashBackground.png",
                      fit: BoxFit.fill)),
              new Container(
                child: new Image.asset("images/MyTestLogo.png"),
                alignment: Alignment(0.0, 0.0),
              )
            ],
          )),
    );
  }
}