Stuck with flutter auth architecture - flutter

Question

Okay, good day everyone, here comes a question:
I've started using flutter for mobile front, it's quite nice.
But I cannot understand an idea of handling a jwt token and redirecting if it is exists.
Consider small app, let me simplify:
final storage = FlutterSecureStorage(); # init storage here?
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData.dark(),
home: LoginPage(), # want home page actually, smth like if storage is empty, then call loginpage, if storage is not empty - try to make http request, if request is okay and data received - show homepage, if request is rejected - login to obtain new jwt
);
}
}
http request:
Future<User> userLogin(String login, String password) async {
Response response = await post('$_apiUrl' + '/' + '$_loginUrl',
headers: <String, String>{
'Content-Type': 'application/json; charset=UTF-8',
},
body: jsonEncode(<String, String>{
'login': login,
'password': password,
}));
if (response.statusCode == 200) {
return User.fromJson(json.decode(response.body));
} else {
throw HttpException(
'Error making login request. Status code: ${response.statusCode}');
}
}
User class:
class User {
final String token;
final String uuid;
final String login;
final String email;
final String firstName;
final String lastName;
User({this.token, this.uuid, this.login, this.email, this.firstName, this.lastName});
factory User.fromJson(Map<String, dynamic> json) {
return User(
token: json['token'],
uuid: json['user']['uuid'],
login: json['user']['login'],
email: json['user']['email'],
firstName: json['user']['firstName'],
lastName: json['user']['lastName'],
);
}
}
So how this works now:
In main file as for now I call login page, with a button:
FlatButton(
child: Text(
'Sign in',
style: TextStyle(
color: Colors.black,
),
),
color: Colors.white,
onPressed: () {
Future<User> user = ApiRequestController().userLogin('alex', 'alex123');
Navigator.push(context, MaterialPageRoute(builder: (context) {
return UserProfile(userData: user,);
}));
},
),
Then I get redirected to user profile, nothing interesting:
class UserProfile extends StatefulWidget {
UserProfile({this.userData});
final userData;
#override
_UserProfileState createState() => _UserProfileState();
}
class _UserProfileState extends State<UserProfile> {
#override
void initState() {
// TODO: implement initState
super.initState();
futureUser = widget.userData;
print(futureUser);
}
Future<User> futureUser;
#override
Widget build(BuildContext context) {
common stuff like scaffold etc
And then I build a profile:
FutureBuilder<User>(
future: futureUser,
builder: (context, snapshot) {
if (snapshot.hasData) {
dynamic userProfile = snapshot.data;
return Column(
children: [
Container(
child: ListTile(
title: Text(
'login: ' + '${userProfile.login}',
style: TextStyle(
color: Colors.black,
),
),
),
),
Container(
child: ListTile(
title: Text(
'uuid: ' + '${userProfile.uuid}',
style: TextStyle(
color: Colors.black,
),
),
),
),
Container(
child: ListTile(
title: Text(
'First name: ' + '${userProfile.firstName}',
style: TextStyle(
color: Colors.black,
),
),
),
),
Container(
child: ListTile(
title: Text(
'Last name: ' + '${userProfile.lastName}',
style: TextStyle(
color: Colors.black,
),
),
),
),
Container(
child: ListTile(
title: Text(
'Auth token: ' + '${userProfile.token}',
style: TextStyle(
color: Colors.black,
),
),
),
),
],
);
} else if (snapshot.hasError) {
return Text('${snapshot.error}');
}
return CircularProgressIndicator();
},
),
Interface is simplified for easier understanding.
So what I have now, I have main dart file, where I call login screen (not home screen, because I cannot get an idea how to use token), where I call async http request to an api, then I am redirected to the user profile.
Idea is very simple:
App opened -> send http request with existing auth header, if answer is 200, then show homepage
If answer was not 200 (token expired/corrupted/doesn't exist, checked on the server side), then navigate user to login screen to obtain new auth token
How to store damn jwt token correctly -_-? I've tried multiple times with futures, plain requests, I cannot get an idea of parsing token between multiple screens.
What should I do? Where to initialize a token? Where to store it? How can I call it from other widget?
I've read about InheritedWidget, okay. But i.e., my HomePage already extends StatefulWidget, and there is no multiple inheritance. Extend it to User class or what?
So I am stuck with this simple goal, and cannot move any further. Just need to check if token exists -> show home, if not - show login. After we've obtained correct token - we can use whole app, making each request with an auth token received at first login screen.
Where to initialize token? Where should I inherit InheritedWidget? Model? ViewPage? Where?
Architecture failure :(
Help is much appreciated! Thanks in advance