AuthService

import { Router } from '@angular/router';
import { Observable } from 'rxjs';
import { Injectable } from '@angular/core';
import { AngularFireAuth } from '@angular/fire/auth';
import { AngularFirestore } from '@angular/fire/firestore';
import firebase from 'firebase/app';

@Injectable({
  providedIn: 'root'
})
export class AuthService {
  user$: Observable<any>;

  constructor(private afAuth: AngularFireAuth, public db: AngularFirestore, private router: Router) {
    this.user$ = afAuth.authState;
    this.db = db;

    afAuth.onAuthStateChanged((user) => {
      if (user && user.emailVerified) {
        console.log("Logged in");

        db.collection('user').doc(user.uid).valueChanges().subscribe((data) => {
          console.log("User Data loaded: " + JSON.stringify(data));
        });
      } else {
        this.router.navigate(['/login']);

      }
    });
   }

   async login() {
    await this.afAuth.setPersistence(firebase.auth.Auth.Persistence.SESSION)
     .then(() => {
        const credential = this.afAuth.signInWithPopup(new firebase.auth.GoogleAuthProvider());
     });
    return this.router.navigate(['/dashboard']);
  }

  async logout() {
    await this.afAuth.signOut();
    return this.router.navigate(['/login']);
  }
}