import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Subject, of, BehaviorSubject } from 'rxjs';
import { map, catchError, tap } from 'rxjs/operators';
import { environment } from '../../../environments/environment';
import { IUser } from '../models/user';

@Injectable({
  providedIn: 'root',
})
export class AuthService {
  isLoggedIn = new BehaviorSubject(false);

  onLogin = new Subject<any>(); // deprecated
  onLogout = new Subject<any>(); // deprecated

  private token: string = null;
  private userData: IUser = null;

  constructor(private http: HttpClient) {
    // try and find out if there was a localstorage token was set
    this.resolveToken();
  }

  validateTokenOnServer() {
    return this.http
      .get(environment['apiBaseUrl'] + '/api/auth/validate-token')
      .pipe(
        map(data => {
          return data['user'] ? data['user'] : false;
        }),
        tap(status => {
          if (status) {
            this.userData = status['user'];
          }
        }),
        tap(status => {
          if (!status) {
            this.isLoggedIn.next(false);
          }
        }),
        catchError(err => {
          return of(false);
        })
      );
  }

  // check if localstorage token was set
  // if so, set the token in the service
  // and set the login status
  resolveToken(): boolean {
    this.token = localStorage.getItem('token');
    this.isLoggedIn.next(this.token ? true : false);
    return this.token ? true : false;
  }

  getToken(): string {
    return this.token;
  }

  hasToken(): boolean {
    return this.getToken() ? true : false;
  }

  async logout() {
    return this.http
      .get(environment['apiBaseUrl'] + '/api/auth/logout')
      .toPromise()
      .then(
        () => {
          // clear any current data
          this.clearData();

          // tell the rest of the application about the logout
          this.isLoggedIn.next(false);
          return true;
        },
        err => {
          return false;
        }
      );
  }

  async login({ email, password }): Promise<any> {
    // clear some data
    this.clearData();

    // create the payload data for the api request
    const loginData = {
      email: email,
      password: password,
    };

    const data = await this.http
      .post(environment['apiBaseUrl'] + '/api/login', loginData)
      .toPromise();

    // this part only gets executed when the promise is resolved
    if (data['token'] && data['user']) {
      this.setDataAfterLogin(data);
      this.isLoggedIn.next(true); // how do I unit test this?

      return data['user'];
    } else {
      return false;
    }
  }

  clearData() {
    this.userData = null;
    this.token = null;
    localStorage.clear();
  }

  getUserData(): IUser {
    return this.userData;
  }

  private setDataAfterLogin(data) {
    this.token = data['token'];

    // store some user data in the service
    this.userData = data['user'];

    // store some data in local storage (webbrowser)
    localStorage.setItem('token', this.token);
    localStorage.setItem('usermeta', JSON.stringify(this.userData));
  }
}