class AJAX {
    constructor() {
        this.baseUrl = config.checkBaseUrl();
        this.http = new XMLHttpRequest();
    }

    /**
     *
     * @param {*object} parmas
     */
    get(parmas) {
        return new Promise((success, error) => {
            // 将data 参数转化为 ?key=value&key=value
            var str = ""
            for (const key in parmas.data) {
                str += `&${key}=${parmas.data[key]}`
            }
            str = str.replace("&", "?")

            this.http.open("GET", `${this.baseUrl}${parmas.url}${str}`);
            this.http.send();

            this.readyState(success, error)
        })
    }

    post(parmas) {
        this.http.open("POST", `${this.baseUrl}${parmas.url}`);
        this.http.setRequestHeader('Content-type', 'application/json; charset="utf-8"');
        this.http.send(JSON.stringify(parmas.data));

        this.readyState(parmas.success, parmas.error)
    }


    put() { }
    delete() { }

    // 给 get post put delete 进行状态监听的封装
    readyState(success, error) {
        this.http.onreadystatechange = () => {
            if (this.http.readyState == 4) {
                if (this.http.status == 200) {
                    var data = JSON.parse(this.http.response);
                    switch (data.status) {
                        case 200:
                            success(data.result)
                            break;
                        case 404:
                            alert(data.message)
                            throw new Error(data.message)
                            break;
                    }
                    // success(data)
                } else {
                    error(this.http)
                }
            }
        }
    }
}

var http = new AJAX();