import { Inject, Injectable, InjectionToken } from '@angular/core';
import { HttpEvent, HttpHandler, HttpInterceptor, HttpRequest } from '@angular/common/http';
import { Observable, from, TimeoutError } from 'rxjs';
import { timeout, tap } from 'rxjs/operators';
import { HttpErrorResponse, HttpResponse } from '@angular/common/http';
@Injectable({
  providedIn: 'root'
})
export class TimeoutInterceptorService implements HttpInterceptor{
  constructor() {
  }
  /**
   * 拦截器拦截请求
   */
  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
      // 处理请求
      return next.handle(req).pipe(
        // 处理请求的响应
        tap(
            event => {
              if (event instanceof HttpResponse) {
                // console.log(event);
                if (event.status >= 500) {
                  // 服务器错误
                }
              }
            },
            error => {
              // console.log(error);
              if (error instanceof TimeoutError) {
                console.log('服务器连接超时');
              }
              else if (error instanceof HttpErrorResponse) {
                console.log('网络连接异常');
              }
              // console.log(error.message);
              // console.log(error.name);
            }
        )
    );
  }
}