/************************************************************************************
 * FileName: HttpProto.ts
 * Description:
 *
 * Version: v1.0.0
 * Creator: Jacky(jackylvm@foxmail.com)
 * CreationTime: 2024-04-22 15:09:20
 * Copyright: 2021 - 2024
 * ==============================================================
 * History update record:
 *
 * ==============================================================
 *************************************************************************************/

export type ParamsType = Record<string, string | number | boolean>;
export type HeadersType = Record<string, string | number | boolean>;
export type BodiesType = Record<string, any>;
export type RequestCallback = (err: Error | null, response: { type: XMLHttpRequestResponseType, data: any }) => void;

export enum HttpMethod {
    GET = "GET",
    POST = "POST",
}

export class HttpProto {
    private _requests: string[] = [];

    /**
     * GET请求
     * @param {string} url 请求地址,不带参数
     * @param {RequestCallback} callback 请求回调
     * @param {ParamsType} params 请求查询参数,附加到url后面的查询参数
     * @param {HeadersType} headers 请求头
     */
    public get(url: string, callback: RequestCallback, params: ParamsType = null, headers: HeadersType = null): void {
        this.request(url, HttpMethod.GET, params, headers, {}, callback);
    }

    /**
     * POST请求
     * @param {string} url 请求地址,不带参数
     * @param {RequestCallback} callback 请求回调
     * @param {BodiesType} bodies 请求体,post请求用到
     * @param {ParamsType} params 请求查询参数,附加到url后面的查询参数
     * @param {HeadersType} headers 请求头
     * @param urlEncode
     */
    public post(url: string, callback: RequestCallback, bodies: BodiesType | { req: BodiesType } = null, params: ParamsType = null, headers: HeadersType = null, urlEncode: boolean = true): void {
        this.request(url, HttpMethod.POST, params, headers, bodies, callback, urlEncode);
    }

    private request(
        url: string, method: HttpMethod, params: ParamsType, headers: HeadersType,
        bodies: BodiesType | { req: BodiesType }, callback: RequestCallback, urlEncode: boolean = true
    ): void {
        if (!url) {
            console.error("url is null");
            return;
        }

        let urlParams: string = this.makeURLParams(url, params);

        let bodiesStr: string;
        let urlBodies: any;
        if (urlEncode) {
            urlBodies = this.makeURLBodies(headers, bodies);
            bodiesStr = urlBodies;
        } else {
            urlBodies = bodies;
            bodiesStr = JSON.stringify(urlBodies);
        }

        let key: string = `${method} ${urlParams} ${bodiesStr}`;

        if (this._requests.indexOf(key) > -1) {
            console.warn(`${key} is in requests`);
            return;
        }
        this._requests.push(key);

        let xhr: XMLHttpRequest = new XMLHttpRequest();
        xhr.timeout = 10000;

        xhr.onreadystatechange = (): void => {
            // readyState的状态值
            // 0，表示 XMLHttpRequest 实例已经生成，但是实例的open()方法还没有被调用。
            // 1，表示open()方法已经调用，但是实例的send()方法还没有调用，仍然可以使用实例的setRequestHeader()方法，设定 HTTP 请求的头信息。
            // 2，表示实例的send()方法已经调用，并且服务器返回的头信息和状态码已经收到。
            // 3，表示正在接收服务器传来的数据体（body 部分）。这时，如果实例的responseType属性等于text或者空字符串，responseText属性就会包含已经收到的部分信息。
            // 4，表示服务器返回的数据已经完全接收，或者本次接收已经失败。
            if (xhr.readyState === 1) {
                // 必须open方法调用后才能设置请求头
                if (headers) {
                    for (let key in headers) {
                        if (key.indexOf("Content-Type") > -1 || key.indexOf("content-type") > -1) {
                            continue;
                        }
                        xhr.setRequestHeader(key, headers[key].toString());
                    }
                    xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
                } else {
                    xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
                }
            }
            if (xhr.readyState === 4) {
                this._requests.splice(this._requests.indexOf(key), 1);

                    console.log(`[HttpProto>onreadystatechange:96]>>${xhr.status} ${xhr.statusText} ${xhr.responseType}`, xhr.response);

                if (callback) {
                    if (xhr.status === 200) {
                        callback(null, {type: xhr.responseType, data: xhr.response});
                    } else {
                        callback(new Error(`${xhr.status} ${xhr.statusText}`), null);
                    }
                }
            }
        };
        xhr.ontimeout = (): void => {
            this._requests.splice(this._requests.indexOf(key), 1);
            if (callback) {
                callback(new Error(`${xhr.status} ${xhr.statusText}`), null);
            }
        }
        xhr.onerror = (): void => {
            this._requests.splice(this._requests.indexOf(key), 1);
            if (callback) {
                callback(new Error(`${xhr.status} ${xhr.statusText}`), null);
            }
        }
        xhr.onabort = (): void => {
            this._requests.splice(this._requests.indexOf(key), 1);
            if (callback) {
                callback(new Error(`${xhr.status} ${xhr.statusText}`), null);
            }
        }

        if (method === HttpMethod.GET) {
            xhr.open(method, urlParams, true);
            xhr.send();
        } else {
            xhr.open(method, urlParams, true);
            console.log("xhr ============ ",xhr)
            console.log(typeof urlBodies)
            // xhr.send(urlBodies);
            let b =  JSON.parse(urlBodies)
            console.log(typeof b)
            xhr.send(b);
        }
    }

    private makeURLParams(url: string, params: ParamsType): string {
        if (params) {
            let lst: string[] = [];
            for (let key in params) {
                lst.push(`${key}=${params[key]}`);
            }
            let paramsStr: string = lst.join("&");
            if (url.indexOf("?") > -1) {
                url += `&${paramsStr}`;
            } else {
                if (paramsStr.length > 0) {
                    if (!url.endsWith("/")) {
                        url += "/";
                    }
                    url += `?${paramsStr}`;
                }
            }
        }
        return url;
    }

    private makeURLBodies(headers: HeadersType, bodies: BodiesType): string {
        let contentType: string = "application/json";
        if (headers) {
            contentType = headers["Content-Type"] as string;
        }
        let body: string = "";
        if (bodies) {
            if (contentType === "application/json") {
                body = JSON.stringify(bodies);
            } else if (contentType === "application/x-www-form-urlencoded") {
                let lst: string[] = [];
                for (let key in bodies) {
                    lst.push(`${key}=${bodies[key]}`);
                }
                body = lst.join("&");
            }
        }
        return body;
    }
}