Login with facebook Angular 5

UserService.ts

import { Injectable } from "@angular/core";
import { Component } from "@angular/core";
import { Http } from "@angular/http";
import { facebookVariables } from "../../getFBSDK";
import { Router } from "@angular/router";
import { LocalStorage, JSONSchema } from "@ngx-pwa/local-storage";
import { User } from "../models/User";

import {GoogleAuthService} from "ng-gapi/lib/GoogleAuthService";
import GoogleUser = gapi.auth2.GoogleUser;
import GoogleAuth = gapi.auth2.GoogleAuth;

declare var window: any;
declare var FB: any;

@Injectable()
export class UserService {

  public static SESSION_STORAGE_KEY: string = 'accessToken';

  private userData: User = {
    name: "",
    token: ""
  };

  constructor(private router: Router, protected localStorage: LocalStorage, private googleAuth: GoogleAuthService) {
    (function(d, s, id) {
      var js,
        fjs = d.getElementsByTagName(s)[0];
      if (d.getElementById(id)) {
        return;
      }
      js = d.createElement(s);
      js.id = id;
      js.src = "//connect.facebook.net/en_US/sdk.js";
      fjs.parentNode.insertBefore(js, fjs);
    })(document, "script", "facebook-jssdk");

    window.fbAsyncInit = () => {
      FB.init(facebookVariables);
      FB.AppEvents.logPageView();
      FB.Event.subscribe("auth.statusChange", response => {
        if (response.status === "connected") {
          // use the response variable to get any information about the user and to see the tokens about the users session
        }
      });
    };
  }

  public getToken(): string {
    let token: string = sessionStorage.getItem(UserService.SESSION_STORAGE_KEY);
    if (!token) {
        throw new Error("no token set , authentication required");
    }
    return sessionStorage.getItem(UserService.SESSION_STORAGE_KEY);
  }

  public signIn(): void {
    this.googleAuth.getAuth()
        .subscribe((auth) => {
            auth.signIn().then(res => this.signInSuccessHandler(res));
        });
}

private signInSuccessHandler(res: User) {
        this.userData = res;
        // sessionStorage.setItem(
        //     UserService.SESSION_STORAGE_KEY, res.getAuthResponse().access_token
        // );
    }

  private getUserData(): Promise<any> {
    console.log("Welcome!  Fetching your information.... ");
    return new Promise(resolve => {
      FB.api("/me", (response) => {
        this.userData.name = response.name;
        this.localStorage.setItem('user', this.userData).subscribe(() => {});
        resolve(this.userData);
      });
    });
  }

  public loginWithFacebook() {
    return new Promise(resolve => {
      FB.getLoginStatus(async response => {
        if (response.status == "connected") {
          this.userData.token = response.authResponse.accessToken;
          const data = await this.getUserData();
          resolve(this.userData);
          // this.getUserData().then(data => resolve(this.facebookData));
        } else {
          FB.login(
            async loginResponse => {
              this.userData.token = loginResponse.authResponse.accessToken;
              const data = await this.getUserData();
              resolve(this.userData);
              // this.getUserData().then(data => resolve(this.facebookData));
            },
            { scope: "public_profile,email" }
          );
        }
      });
    });
  }

public getFacebookData() {
  const schema: JSONSchema = {
    properties: {
      name: { type: 'string' },
      token: { type: 'string' }
    },
    required: ['name', 'token']
  };
  return new Promise(resolve => {
    this.localStorage.getItem<User>('user', { schema }).subscribe((user) => {
      // Called if data is valid or null
      console.log(user);
      resolve(user);
    }, (error) => {
      console.log(error);
      resolve(error);
      // Called if data is invalid
    });
  });
}

  public logoutFromFacebook() {
    FB.logout((response) => {
      console.log('Logged Out');
      console.log(response);
      this.router.navigate([''])
    });
  }

  public parseFBToSDK() {
    if (window.FB) {
      window.FB.XFBML.parse();
    }
  }
}