barker/bookie/src/app/core/http-auth-interceptor.ts

import { Observable, throwError } from 'rxjs';
import { catchError } from 'rxjs/operators';
import { Injectable } from '@angular/core';
import { HttpRequest, HttpHandler, HttpEvent, HttpInterceptor } from '@angular/common/http';
import { Router } from '@angular/router';
import { MatDialog } from '@angular/material/dialog';
import { AuthService } from '../auth/auth.service';
import { ToasterService } from './toaster.service';
import { ConfirmDialogComponent } from '../shared/confirm-dialog/confirm-dialog.component';

@Injectable()
export class ErrorInterceptor implements HttpInterceptor {
  constructor(private authService: AuthService, private router: Router, private dialog: MatDialog, private toaster: ToasterService) {
  }

  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(request).pipe(catchError(err => {
      // We don't want to refresh token for some requests like login or refresh token itself
      // So we verify url and we throw an error if it's the case
      if (request.url.includes('/refresh') || request.url.includes('/token')) {
        // We do another check to see if refresh token failed
        // In this case we want to logout user and to redirect it to login page
        if (request.url.includes('/refresh')) {
          this.authService.logout();
        }
        return throwError(err);
      }
      // If error status is different than 401 we want to skip refresh token
      // So we check that and throw the error if it's the case
      if (err.status !== 401) {
        const error = err.error.message || err.error.detail || err.statusText;
        return throwError(error);
      }
      // auto logout if 401 response returned from api
      this.authService.logout();
      this.toaster.show('Danger', 'User has been logged out');
      const dialogRef = this.dialog.open(ConfirmDialogComponent, {
        width: '250px',
        data: {
          title: 'Logged out!',
          content: 'You have been logged out.\nYou can press Cancel to stay on page and login in another tab to resume here, or you can press Ok to navigate to the login page.'
        }
      });
      dialogRef.afterClosed().subscribe((result: boolean) => {
        if (result) {
          this.router.navigate(['login']);
        }
      });
    }));
  }
}