class Ajax {

  constructor() {
    this.ajax = new XMLHttpRequest()
  }

  // { url: '请求地址', data: {} //请求参数 }
  get (params) {
    Tips.loading()
    var str = ""
    for (const key in params.data) {
      str += `&${key}=${params.data[key]}`
    }
    str = str.replace("&", "?")
    this.ajax.open("GET",  this.baseUrl() + params.url + str);

    return new Promise((resolve, reject) => {
      this.ajax.send();
      this.statechange(resolve, reject)
    })
  }


  post () {
    this.open("POST", "http://127.0.0.1/index.php")
  }


  statechange (resolve, reject) {
    this.ajax.onreadystatechange = () => {
      if (this.ajax.readyState == 4) {
        Tips.close()
        if (this.ajax.status == 200) {
          var data = JSON.parse(this.ajax.responseText)
          switch (data.status) {
            case 200:
              resolve(data.result)
              break;

            case 404:
              alert(data.msg)
              reject(data)
              throw new Error(data.msg)
              break;
          }
        } else {
          reject(this.ajax)
        }
      }
    }
  }

  baseUrl() {
    switch (config.stage) {
      case "dev":
        return config.devBaseUrl;
        break;

      case "test":
        return config.testBaseUrl;
        break;

      case "prod":
        return config.prodBaseUrl;
        break;
    }
  }
}