import 'dart:async';

import 'package:flutter/material.dart';
import 'package:myapp/HomePage.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:google_sign_in/google_sign_in.dart';
import 'package:flutter_auth_buttons/flutter_auth_buttons.dart';
import 'HomePage.dart';

final FirebaseAuth _auth = FirebaseAuth.instance;
final GoogleSignIn _googleSignIn = new GoogleSignIn();

class UserDetails {
final String providerId;

final String uid;

final String displayName;

final String photoUrl;

final String email;

final bool isAnonymous;

final bool isEmailVerified;

final List<UserInfoDetails> providerData;

UserDetails(this.providerId, this.uid, this.displayName, this.photoUrl,
  this.email, this.isAnonymous, this.isEmailVerified, this.providerData);
}

class UserInfoDetails {
UserInfoDetails(
  this.providerId, this.displayName, this.email, this.photoUrl, this.uid);

/// The provider identifier.
final String providerId;

/// The provider’s user ID for the user.
final String uid;

/// The name of the user.
final String displayName;

/// The URL of the user’s profile photo.
final String photoUrl;

/// The user’s email address.
final String email;
}

class LoginPage extends StatefulWidget {
static String tag = 'login-page';
@override
_LoginPageState createState() => new _LoginPageState();
}

class _LoginPageState extends State<LoginPage> {
Future<FirebaseUser> _signIn() async {
final GoogleSignInAccount googleUser = await _googleSignIn.signIn();
final GoogleSignInAuthentication googleAuth =
    await googleUser.authentication;

final FirebaseUser user = await FirebaseAuth.instance.signInWithGoogle(
    idToken: googleAuth.idToken, accessToken: googleAuth.accessToken);

assert(user.email != null);
assert(user.displayName != null);
assert(!user.isAnonymous);
assert(await user.getIdToken() != null);

final FirebaseUser currentUser = await _auth.currentUser();
assert(user.uid == currentUser.uid);

UserInfoDetails userInfo = new UserInfoDetails(
    user.providerId, user.displayName, user.email, user.photoUrl, user.uid);

List<UserInfoDetails> providerData = new List<UserInfoDetails>();
providerData.add(userInfo);

UserDetails details = new UserDetails(
    user.providerId,
    user.uid,
    user.displayName,
    user.photoUrl,
    user.email,
    user.isAnonymous,
    user.isEmailVerified,
    providerData);

print("signed in : ${user.displayName}");
Navigator.pushReplacement(
  context,
  new MaterialPageRoute(
    builder: (context) => new HomePage(detailsUser: details),
  ),
);
return user;
}
// other codes....
}