(function (){

  class Ajax {

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

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

      this.ajax.open("GET", option.url)
      this.ajax.send()
      this.readystatechange(option.success, option.error && option.error)
    }

    post(option) {
      this.ajax.open("POST", option.url)
      this.ajax.setRequestHeader("Content-Type","application/json")
      this.ajax.send(JSON.stringify(option.data))
      this.readystatechange(option.success, option.error && option.error)
    }

    readystatechange(success,error) {
      this.ajax.onreadystatechange =  () => {
        if (this.ajax.readyState == 4) {
          if (this.ajax.status == 200) {

            var result = typeof this.ajax.responseText == "string"
                        ? JSON.parse(this.ajax.responseText)
                        : this.ajax.responseText;


            switch (result.status) {
              case 200:
                success(result.data)
                break;
              case 500:
                error(result.msg)
                break;
              default:
            }


          } else {
            error("请求出错")
          }
        }
      }
    }
  }

  window.$ajax = new Ajax()


})()