import {Injectable} from '@angular/core';
import {HttpClient} from '@angular/common/http';
import {BehaviorSubject, Observable} from 'rxjs';
import {map} from 'rxjs/operators';

import {environment} from '@environments/environment';
import {User} from '@app/_models';

@Injectable({providedIn: 'root'})
export class AuthenticationService {
  public currentUser: Observable<User>;
  private currentUserSubject: BehaviorSubject<User>;

  constructor(private http: HttpClient) {
    if (localStorage.getItem('currentUser')) {
      this.currentUserSubject = new BehaviorSubject<User>(JSON.parse(localStorage.getItem('currentUser')));
    } else {
      this.currentUserSubject = new BehaviorSubject<User>(null);
    }
    this.currentUser = this.currentUserSubject.asObservable();
  }
  public get currentUserValue(): User {
    return this.currentUserSubject.value;
  }

  login(mail: string, password: string) {
    return this.http.post<any>(`${environment.apiUrl}/auth/login`, {mail, password})
      .pipe(map(user => {
        // login successful if there's a jwt token in the response
        if (user && user.jwtToken) {
          // store user details and jwt token in local storage to keep user logged in between page refreshes
          localStorage.setItem('currentUser', JSON.stringify(user));
          this.currentUserSubject.next(user);
          this.currentUserSubject = new BehaviorSubject<User>(JSON.parse(localStorage.getItem('currentUser')));
          this.currentUser = this.currentUserSubject.asObservable();
        }

        return user;
      }));
  }

  logout() {
    // remove user from local storage to log user out
    localStorage.removeItem('currentUser');
    this.currentUserSubject.next(null);
    location.reload();
  }
}