shared preference + firebase auth not working properly - flutter

Question

Firebase Auth is working properly, I'm able to log in, Sign in but I want to preserve the state of the application. For state persistence, I'm using Share preferences.
I'm using sharedpreferences. I made a class and defined some keys and methods to fetch and set the data in the keys at the time of login and use it later in the app.
Please help me out with an easy approch how to do this.
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
class CurrentUser {
static SharedPreferences? mypreferences;
static const emailKey = 'emailKey';
static const passwordKey = 'paswordKey';
static const loginStatusKey = 'loginStatusKey';
static Future init() async {
mypreferences = await SharedPreferences.getInstance();
}
static Future setUserEmail(String? emailValue) async {
return await mypreferences?.setString(emailKey, emailValue!);
}
static Future setUserPassword(String? passwordValue) async {
return await mypreferences?.setString(passwordKey, passwordValue!);
}
static Future setLoginStatus(bool status) async {
return await mypreferences?.setBool(loginStatusKey, status);
}
static String? getUserEmail() {
return mypreferences?.getString(emailKey);
}
static String? getUserPassword() {
return mypreferences?.getString(passwordKey);
}
static bool? getUserLoginStatus(){
if(loginStatusKey==null){
mypreferences?.setBool(loginStatusKey, false);
}
return mypreferences?.getBool(loginStatusKey);
}
}```
// storing the value during login //
``` myLogIn() async {
try {
UserCredential myuser= await FirebaseAuth.instance
.signInWithEmailAndPassword(email: email, password: password);
// print(myuser);
// print(myuser.user?.email);
CurrentUser.setUserEmail(myuser.user?.email);
CurrentUser.setUserPassword(password);
CurrentUser.setLoginStatus(true);
Navigator.pushReplacementNamed(context, MyRoutes.homeRoute);
} on FirebaseAuthException catch (e) {
if (e.code == 'user-not-found') {
print('user is not registered');
ScaffoldMessenger.of(context).showSnackBar(
MySnackBar.showcustomSnackbar('user is not registered'));
} else if (e.code == 'wrong-password') {
print('wrong password');
ScaffoldMessenger.of(context)
.showSnackBar(MySnackBar.showcustomSnackbar('wrong password'));
}
}
}```
// using the store login status in main file to show login page and home page accordingly.
```import 'package:flutter/material.dart';
import 'package:firebase_core/firebase_core.dart';
// import 'firebase_options.dart';
import './pages/login.dart';
import './pages/signup.dart';
import './pages/homepage.dart';
import './utils/my_theme.dart';
import './utils/my_routes.dart';
import './pages/forgot_password.dart';
import './utils/my_user.dart';
void main() {
WidgetsFlutterBinding.ensureInitialized();
CurrentUser.init();
runApp(MyApp());
}
class MyApp extends StatefulWidget {
#override
State<MyApp> createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
// const MyApp({ Key? key }) : super(key: key);
final Future<FirebaseApp> initializeMyFirebaseApp = Firebase.initializeApp();
bool? isLogin = CurrentUser.getUserLoginStatus();
#override
void initState() {
// TODO: implement initState
isLogin = CurrentUser.getUserLoginStatus();
super.initState();
}
#override
Widget build(BuildContext context) {
return FutureBuilder(
future: initializeMyFirebaseApp,
builder: (context, snaphot) {
//Error checking
if (snaphot.hasError) {
print("Something went wrong!");
}
//If snapshot state is in waiting or so
if (snaphot.connectionState == ConnectionState.waiting) {
return Center(
child: CircularProgressIndicator(),
);
}
//else we will show the normal login page.
return MaterialApp(
theme: MyTheme.lightTheme(context),
//isUserLoggedIn !=null ? isUserLoggedIn ? Home() : SignUp() : SignIn(),
home:isLogin!=null ?
isLogin! ? HomePage() : Login() : Login(),
// Login(),
routes: {
// "/":(context) => Login(),
MyRoutes.loginRoute: (context) => Login(),
MyRoutes.signupRoute: (context) => SignUp(),
MyRoutes.homeRoute: (context) => HomePage(),
MyRoutes.forgotpasswordRoute: (context) => ForgotPassword(),
},
);
});
}
}
```