auth.dart file for Chat App Tutorial

auth_chat_app.dart

import 'package:chatapp/models/user.dart';
import 'package:chatapp/views/chat.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/material.dart';
import 'package:google_sign_in/google_sign_in.dart';

class AuthService {
  final FirebaseAuth _auth = FirebaseAuth.instance;

  User _userFromFirebaseUser(FirebaseUser user) {
    return user != null ? User(uid: user.uid) : null;
  }

  Future signInWithEmailAndPassword(String email, String password) async {
    try {
      AuthResult result = await _auth.signInWithEmailAndPassword(
          email: email, password: password);
      FirebaseUser user = result.user;
      return _userFromFirebaseUser(user);
    } catch (e) {
      print(e.toString());
      return null;
    }
  }

  Future signUpWithEmailAndPassword(String email, String password) async {
    try {
      AuthResult result = await _auth.createUserWithEmailAndPassword(
          email: email, password: password);
      FirebaseUser user = result.user;
      return _userFromFirebaseUser(user);
    } catch (e) {
      print(e.toString());
      return null;
    }
  }

  Future resetPass(String email) async {
    try {
      return await _auth.sendPasswordResetEmail(email: email);
    } catch (e) {
      print(e.toString());
      return null;
    }
  }

  Future<FirebaseUser> signInWithGoogle(BuildContext context) async {
    final GoogleSignIn _googleSignIn = new GoogleSignIn();

    final GoogleSignInAccount googleSignInAccount =
        await _googleSignIn.signIn();
    final GoogleSignInAuthentication googleSignInAuthentication =
        await googleSignInAccount.authentication;

    final AuthCredential credential = GoogleAuthProvider.getCredential(
        idToken: googleSignInAuthentication.idToken,
        accessToken: googleSignInAuthentication.accessToken);

    AuthResult result = await _auth.signInWithCredential(credential);
    FirebaseUser userDetails = result.user;

    if (result == null) {
    } else {
      Navigator.push(context, MaterialPageRoute(builder: (context) => Chat()));
    }
  }

  Future signOut() async {
    try {
      return await _auth.signOut();
    } catch (e) {
      print(e.toString());
      return null;
    }
  }
}