import {HTTP_INTERCEPTORS, HttpErrorResponse, HttpEvent} from '@angular/common/http';
import { Injectable } from '@angular/core';
import { HttpInterceptor, HttpHandler, HttpRequest } from '@angular/common/http';

import { TokenStorageService } from '../services/token-storage.service';
import {catchError, Observable, switchMap, throwError} from 'rxjs';
import {EventBusService} from '../_shared/event-bus.service';
import {EventData} from '../_shared/event.class';
import {environment} from '../../environments/environment';
import {AuthService} from '../services/auth.service';

const TOKEN_HEADER_KEY = 'Authorization';       // for Spring Boot back-end

@Injectable()
export class AuthInterceptor implements HttpInterceptor {
  private isRefreshing = false;
  enviorment = environment;

  constructor(
    private tokenStorageService: TokenStorageService,
    private eventBusService: EventBusService,
    private authService:AuthService
  ) { }

  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {

      // req = req.clone({
      //   withCredentials: true,
      // });

      return next.handle(req).pipe(
        catchError((error) => {
          if (
            error instanceof HttpErrorResponse &&
            !req.url.includes('auth/signin') &&
            (error.status === 401)  /// must be only 401 without 500 and 0
          ) {
            return this.handle401Error(req, next);
          }

          return throwError(() => error);
        })
      );
  }

  private handle401Error(request: HttpRequest<any>, next: HttpHandler) {
    if (!this.isRefreshing) {
      this.isRefreshing = true;

      if (this.tokenStorageService.isLoggedIn()) {
        return this.authService.refreshToken().pipe(
          switchMap(() => {
            this.isRefreshing = false;
            console.log("refresh token");
            return next.handle(request);
          }),
          catchError((error) => {
            this.isRefreshing = false;

            if (error.status == '403') {
              this.eventBusService.emit(new EventData('logout', null));
            }

            return throwError(() => error);
          })
        );
      }
    }

    return next.handle(request);
  }
}

export const authInterceptorProviders = [
  { provide: HTTP_INTERCEPTORS, useClass: AuthInterceptor, multi: true }
];