import { Injectable } from '@angular/core';
import {ApiService} from './api.service';
import {ActivatedRouteSnapshot, CanActivate, RouterStateSnapshot} from '@angular/router';
import {LocalStorageService} from 'angular-2-local-storage';
import {Observable} from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class LoginService implements CanActivate {

  private loggedIn;

  constructor(
    private api: ApiService,
    private storage: LocalStorageService
  ) {

  }

  login(username = '', password = '') {
    return new Promise(resolve => {
      if (username !== '') {
        this.storage.set('basicAuth', btoa(username + ':' + password));
      }
      this.api.get('/authorized', (data: any, error) => {
        if (!error) {
          if (data.status === 'Authorization successful') {
            this.loggedIn = true;
            resolve(true);
          } else {
            this.loggedIn = false;
            this.storage.remove('basicAuth');
            resolve(false);
          }
        } else {
          this.loggedIn = false;
          this.storage.remove('basicAuth');
          resolve(false);
        }
      });
    });
  }

  canActivate(route: ActivatedRouteSnapshot = null, state: RouterStateSnapshot = null): Observable<boolean> {
    return new Observable<boolean>(observer => {
      if (this.loggedIn === undefined) {
        this.login().then(res => {
          observer.next(res as any);
          observer.complete();
        });
      }
      else {
        observer.next(this.loggedIn);
        observer.complete();
      }
    });
  }

  get isLoggedIn() {
    return this.loggedIn;
  }
}