import { v4 } from 'uuid'
import { Package40, Package50 } from '../package';
import { Package, ConnectionState, SendMessage, AsyncTask } from './types';
import moment from 'moment'

/**
 * MTP2.0 长链通信类
 */
export class MTP2WebSocket<T extends Package40 | Package50>{
    /** 报文协议 */
    private readonly Package: Package<T>;
    /** 当前实例标识 */
    private uuid = '';
    /** 服务端地址 */
    private host;
    /** WebSocket 对象 */
    private ws?: WebSocket;
    /** 心跳定时器 */
    private beatTimer = 0;
    /** 心跳发送时间 */
    private beatTimerId = '';
    /** 重连定时器 */
    private reconnectTimer = 0;
    /** 超时定时器 */
    private timeoutTimer = 0;
    /** 当前流水号 */
    private currentSerial = 1;
    /** 信息发送异步建值对 */
    private asyncTaskMap = new Map<number, AsyncTask<T>>();
    /** 连接准备完成 */
    private onReady?: Promise<MTP2WebSocket<T>>;

    /** 连接成功的回调 */
    onOpen?: (socket: MTP2WebSocket<T>) => void;
    /** 连接断开的回调 */
    onClose?: () => void;
    /** 连接发生错误的回调 */
    onError?: (e: Event) => void;
    /** 接收到推送类报文的回调 */
    onPush?: (data: T) => void;
    /** 在重连之前回调 */
    onBeforeReconnect?: (count: number) => void;
    /** 在重连成功之后回调 */
    onReconnect?: () => void;

    /** 当前连接状态 */
    connState: keyof typeof ConnectionState = 'Unconnected';
    /** 重连次数 */
    reconnectCount = 0;
    /** 心跳间隔时长，默认为30秒 */
    beatInterval = 30 * 1000;
    /** 消息超时时长，默认为15秒 */
    timeoutInterval = 15 * 1000;

    constructor(pkg: Package<T>, host = '') {
        this.Package = pkg;
        this.host = host;
    }

    /**
     * 连接服务器
     */
    async connect(host?: string, protocols?: string | string[]): Promise<MTP2WebSocket<T>> {
        if (!this.onReady) {
            clearTimeout(this.reconnectTimer);
            this.stopHeartBeat();
            this.host = host || this.host;
            this.connState = 'Connecting';
            console.log(this.host, '正在连接');

            this.onReady = new Promise((resolve, reject) => {
                const errMsg = this.host + ' 连接发生错误';
                const uuid = v4();
                this.uuid = uuid;

                try {
                    this.ws = new WebSocket(this.host, protocols);
                    // 连接成功
                    this.ws.onopen = () => {
                        console.log(this.host, '连接成功');
                        this.connState = 'Connected';
                        this.startHeartBeat();
                        this.onOpen && this.onOpen(this);
                        resolve(this);
                    }
                    // 连接断开(CLOSING有可能延迟)
                    this.ws.onclose = () => {
                        // 判断是否当前实例
                        // 如果连接断开后不等待 onclose 响应，由于 onclose 延迟的原因可能会在创建新的 ws 实例后触发，导致刚创建的实例被断开进入重连机制
                        if (this.uuid === uuid) {
                            console.warn(this.host, '连接已断开');
                            this.reset();
                            this.reconnect(); // 重连失败会不断尝试，直到成功为止
                        }
                    }
                    // 连接发生错误
                    this.ws.onerror = (e) => {
                        this.onError && this.onError(e);
                        reject(errMsg);
                    }
                    // 接收数据
                    this.ws.onmessage = (e) => {
                        // 接收数据
                        new Response(e.data).arrayBuffer().then((res) => {
                            this.disposeReceiveDatas(new Uint8Array(res));
                        })
                    }
                } catch {
                    reject(errMsg);
                }
            })
        }
        return this.onReady
    }

    /**
     * 主动断开连接，断开后不会自动重连
     */
    close() {
        clearTimeout(this.reconnectTimer);
        this.stopHeartBeat();
        this.uuid = v4(); // 改变实例标识，取消重连状态
        this.reconnectCount = 0;

        if (this.ws) {
            this.ws.close();
            console.warn(this.host, '主动断开');
        }

        this.reset(); // 不等待 ws.onclose 响应强制重置实例
    }

    /**
     * 重置实例
     */
    private reset() {
        this.ws = undefined;
        this.onReady = undefined;
        this.connState = 'Unconnected';
        this.onClose && this.onClose();
    }

    /**
    * 启动心跳请求包发送Timer
    */
    private startHeartBeat() {
        this.beatTimer = window.setTimeout(() => {
            this.beatTimerId = moment(new Date()).format('HH:mm:ss');
            //console.log(this.host, '发送心跳', this.beatTimerId);
            // 发送心跳
            switch (this.Package) {
                case Package40: {
                    // 4.0
                    this.send({
                        data: { rspCode: -1, payload: new this.Package(0x12) }
                    })
                    break;
                }
                case Package50: {
                    // 5.0
                    this.send({
                        data: { rspCode: 0, payload: new this.Package(0) }
                    })
                    break;
                }
            }
            // 如果已经超过或心跳超时时长没有收到心跳回复，则认为网络已经异常，进行断网重连
            // WARNING: - 注意在正常断网时停止心跳逻辑
            this.timeoutTimer = window.setTimeout(() => {
                console.warn(this.host, '心跳超时', this.beatTimerId);
                this.reconnect();
            }, this.timeoutInterval)
        }, this.beatInterval)
    }

    /**
     * 停止心跳请求包发送Timer
     */
    private stopHeartBeat() {
        clearTimeout(this.timeoutTimer);
        clearTimeout(this.beatTimer);
    }

    /**
     * 断网重连方法，在重连尝试失败时会再次重试
     */
    private reconnect() {
        this.stopHeartBeat();
        if (this.connState !== 'Connecting') {
            this.reconnectCount++;
            this.onBeforeReconnect && this.onBeforeReconnect(this.reconnectCount);

            // 自动计算每次重试的延时，重试次数越多，延时越大
            const delay = this.reconnectCount * 5000
            console.log(this.host, `${delay / 1000}秒后将进行第${this.reconnectCount}次重连`);

            this.reconnectTimer = window.setTimeout(() => {
                this.onReady = undefined;
                this.connect().then(() => {
                    console.log(this.host, '重连成功，可开始进行业务操作');
                    this.reconnectCount = 0;
                    this.onReconnect && this.onReconnect();
                }).catch(() => {
                    // 重连失败会进入 ws.onclose 再次发起重连
                    if (this.reconnectCount) {
                        console.warn(this.host, `第${this.reconnectCount}次重连失败`);
                    }
                })
            }, delay);
        }
    }

    /**
     * 发送报文
     * @param data 目标报文
     * @param fncode 回复号。P为Package40对象时为回复大类号，同时必传；P为Package50对象为回复功能码，可不传。
     * @param success 成功回调
     * @param fail 失败回调
     */
    send(msg: SendMessage<T>) {
        const { data, success, fail } = msg;
        const { payload } = data;

        if (this.onReady) {
            this.onReady.then(() => {
                const mapKey = this.currentSerial;
                payload.serialNumber = mapKey; // 设置流水号

                // 判断是否需要异步回调
                if (success || fail) {
                    // 保存发送任务，为任务设置一个自动超时定时器
                    this.asyncTaskMap.set(mapKey, {
                        sendMessage: msg,
                        timeoutId: window.setTimeout(() => this.asyncTimeout(mapKey), this.timeoutInterval),
                    })
                }

                // 发送信息
                this.ws?.send(payload.data());
                this.currentSerial++;
            })
        } else {
            fail && fail('服务未连接');
        }
    }

    /**
     * 异步任务超时
     * @param key key
     */
    private asyncTimeout(key: number) {
        // 获取对应异步任务对象
        const asyncTask = this.asyncTaskMap.get(key);
        const onFail = asyncTask?.sendMessage.fail;
        onFail && onFail('业务超时');
        this.asyncTaskMap.delete(key);
    }

    /**
     * 处理接收数据
     * @param bytes 接收的数据
     */
    private disposeReceiveDatas(bytes: Uint8Array) {
        const cache: number[] = [];
        let cachePackageLength = 0;

        for (let i = 0; i < bytes.length; i++) {
            const byte = bytes[i];
            cache.push(byte);

            if (i === 0 && byte !== 0xff) {
                console.error('接收到首字节不是0xFF');
                return;
            } else {
                // 取报文长度
                if (cache.length === 5) {
                    switch (this.Package) {
                        // 4.0报文
                        case Package40: {
                            cachePackageLength = new DataView(new Uint8Array(new Uint8Array(cache).subarray(1, 5)).buffer).getUint32(0, false);
                            if (cachePackageLength > 65535) {
                                console.error('接收到长度超过65535的行情包');
                                return;
                            }
                            break;
                        }
                        // 5.0报文
                        case Package50: {
                            const sub = new Uint8Array(cache).subarray(1, 5);
                            const dataView = new DataView(new Uint8Array(sub).buffer); // 注意这里要new一个新的Uint8Array，直接buffer取到的还是原数组的buffer
                            cachePackageLength = dataView.getUint32(0, true);
                            break;
                        }
                    }
                }
                // 判断是否已经到包尾
                if (cache.length === cachePackageLength) {
                    if (byte !== 0x0) {
                        console.error('接收到尾字节不是0x0的错误数据包');
                        return;
                    }

                    const content = new Uint8Array(cache);
                    const result = new this.Package(content);

                    if (result.packageLength === 0) {
                        console.error('报文装箱失败');
                        return;
                    }
                    this.disposePackageResult(result);
                }
            }
        }
    }

    /**
     * 处理完整的报文
     */
    private disposePackageResult(p: T) {
        const asyncTask = this.asyncTaskMap.get(p.serialNumber);
        const sendMessage = asyncTask?.sendMessage;

        // 4.0报文
        if (p instanceof Package40) {
            // 推送类报文, 0x12 - 心跳, 0x41 - 实时行情推送, 0x42 - 控制信号
            switch (p.mainClassNumber) {
                case 0x12: {
                    // 接收到心跳回复
                    //console.log(this.host, '收到心跳回复', this.beatTimerId);
                    this.stopHeartBeat();
                    this.startHeartBeat();
                    break;
                }
                case 0x41:
                case 0x42: {
                    // 推送类报文
                    this.onPush && this.onPush(p);
                    break;
                }
                default: {
                    // 非推送类报文
                    sendMessage?.success && sendMessage.success(p);
                }
            }
        }

        // 5.0报文
        if (p instanceof Package50) {
            if (p.funCode === 0) {
                // 接收到心跳回复
                //console.log(this.host, '收到心跳回复', this.beatTimerId);
                this.stopHeartBeat();
                this.startHeartBeat();
            } else if (p.serialNumber === 0) {
                // 推送类报文
                this.onPush && this.onPush(p);
            } else if (sendMessage) {
                // 非推送类报文
                const { data, success } = sendMessage;

                // 可能会收到多个流水号相同的数据包，需判断是否正确的回复码
                if (data.rspCode === p.funCode) {
                    success && success(p);
                } else {
                    // 跳过当前收到的数据包，继续等待直到asyncTask超时
                    //console.log('无效的回复码', p.funCode)
                    return
                }
            }
        }

        // 移除当前发送的任务请求
        if (asyncTask) {
            clearTimeout(asyncTask.timeoutId);
            this.asyncTaskMap.delete(p.serialNumber);
        }
    }
}