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

// RxJs
import { Observable, throwError } from 'rxjs';
import { catchError } from "rxjs/operators";

@Injectable()
export class ErrorCatchingInterceptor implements HttpInterceptor {

  constructor() {}

  intercept(request: HttpRequest<unknown>, next: HttpHandler): Observable<HttpEvent<unknown>> {
    return next.handle(request)
    .pipe(
      catchError((error: HttpErrorResponse) => {
          let errorMsg = '';
          if (error.error instanceof ErrorEvent) {
              errorMsg = `Error: ${error.error.message}`;
          } else {
              errorMsg = `Error Code: ${error.status},  Message: ${error.message}`;
          }
          return throwError(error);
      })
    );
  }
}