class Ajax {

  constructor () {
    this.http = new XMLHttpRequest();
  }

  get(option) {
    Tips.loading()
    var params = ""
    for (const key in option.data) {
      params+= `&${key}=${option.data[key]}`
    }
    params = params.replace("&", "?")
    option.url = this.url() + option.url + params

    return new Promise( (resolve, reject) => {

      this.http.open("GET", option.url);
      this.http.send()
      return this.onreadystatechange(resolve, reject)
    })
  }

  post(option) {
    this.http.open("POST", option.url);
    this.http.setRequestHeader('Content-Type', 'application/josn');
    this.http.send(JSON.stringify(option.data))
    this.onreadystatechange(option)
  }


  onreadystatechange(resolve, reject) {
    this.http.onreadystatechange = () => {
      if (this.http.readyState == 4) {
        Tips.close()
        if (this.http.status == 200) {
          var res = JSON.parse(this.http.response);
          switch (res.status) {
            case 200:
              resolve(res.result);
              break;

            case 404:
              Tips.dialog({
                title: '程序出错啦',
                message: res.msg
              });
              throw new Error(res.msg);
              break;

          }
          resolve()
        }  else {
          reject(this.http)
        }
      }
    }
  }

  url() {
    switch (config.stage) {
      case "dev":
        return config.devUrl;
        break;
      case "test":
        return config.testUrl;
        break;
      case "prod":
        return config.prodUrl;
        break;
    }
  }
}

var ajax = new Ajax()