import {HttpEvent, HttpHandler, HttpInterceptor, HttpRequest} from '@angular/common/http';
import {Injectable} from '@angular/core';
import {Observable} from 'rxjs';
import {NGXLogger} from 'ngx-logger';
import {AuthService} from './auth.service';
import {Router} from '@angular/router';

@Injectable({
  providedIn: 'root'
})
/**
 * The InterceptorService intercepts EVERY http event.
 */
export class InterceptorService implements HttpInterceptor {

  constructor(private logger: NGXLogger,
              private authService: AuthService,
              private router: Router
              ) {
  }

  /**
   * Intercepts every HTTP request.
   * If the token is invalid (expired) the user is redirected to logout (always).
   * @param req   http request
   * @param next  http response handler
   */
  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    // FOR TESTING ONLY - sets an expired token
    // sessionStorage.setItem('loginToken', 'eyJhbGciOiJIUzI1NiJ9.eyJleHAiOjE2MTk4ODYzNTF9.e83okQ1NHjeO-AxaB3SQP9P5UjOYy-e5DFissDdf2Mo');

    const authenticated = this.authService.isAuthenticated();
    this.logger.debug('isAuthenticated?', authenticated);
    if (!this.authService.isAuthenticated()) {
      this.logger.debug('token invalid, route to login');
      this.router.navigate(['login']).then(() => {});
    }
    return next.handle(req);
  }
}