harmony_vehicle_terminal/entry/src/main/ets/utils/UdpUtils.ets

import socket from '@ohos.net.socket'
import { UDPTag } from '../config'
import { FillZero, StringToASCII } from './Common'
import { BusinessError } from '@ohos.base'
import { dConsole } from './LogWorker'

interface MsgExt {
  id: number,
  list: number[],
  carNo: string,
  placeId: string,
}

function generateHead(param: MsgExt): number[] {
  let lshNo = AppStorage.get<string>("lsh")
  let a = new Uint16Array(StringToASCII(`${param.id}${FillZero(param.placeId, 3)}`))
  let b = new Uint32Array(StringToASCII(`${FillZero(param.carNo, 4)}${lshNo}`))
  let c = new Uint16Array(param.list.length)
  return [...a, ...b, ...c];
}

function exclusive(target: number[]): number[] {
  let result = target[0]
  for (let i = 1; i < target.length; i++) {
    result = result ^ target[i]
  }
  return [result];
}

type DealMethod<T extends Object> = (value: ArrayBuffer) => T


export default class UdpClient {
  protected udp: socket.UDPSocket | null = null
  private localIp: string = ''
  private localIpPort: string = ''
  private oppositeIp: string = ''
  private oppositeIpPort: string = ''
  private messageEvents: Array<Function> = []
  private errorEvents: Array<Function> = []
  private dealMethod?: DealMethod<object>
  // 连接状态
  private linkStatus: boolean = false

  // 绑定udp连接
  bindUdp(): Promise<void> | undefined {
    console.log(UDPTag, "绑定udp", this.localIp, this.localIpPort)
    return this.udp?.bind({
      address: this.localIp, port: parseInt(this.localIpPort), family: 1
    }).then(res => {
      console.log(UDPTag, "udp 绑定成功!", JSON.stringify(res))
    })
  }

  // 重新绑定udp连接
  async reBind() {
    await this.close()
    this.udp = socket.constructUDPSocketInstance();
    this.bindEvent()
    await this.bindUdp()
  }

  // 关闭udp连接
  close(): Promise<void> | undefined {
    this.messageEvents = []
    this.errorEvents = []
    this.dealMethod = undefined
    this.udp?.off("message")
    this.udp?.off("error")
    return this.udp?.close()
  }

  // 设置处理消息的函数
  setDealMethod<T extends Object>(fun: DealMethod<T>) {
    this.dealMethod = fun
  }

  // 发送消息
  sendMsg(data: ArrayBuffer | string): Promise<void> | undefined {
    return this.udp?.send({
      data,
      address: {
        address: this.oppositeIp, port: parseInt(this.oppositeIpPort), family: 1
      }
    }).then(res => {
      // console.log(UDPTag, "udp发送成功", JSON.stringify(res))
    }).catch((e: BusinessError) => {
      console.error(UDPTag, "udp发送失败", JSON.stringify(e))
    })
  }

  // 组装消息
  setWholeMsg(params: MsgExt): ArrayBuffer {
    let head = generateHead(params);
    let headJudge = exclusive(head);
    let body = params.list;
    let bodyJudge = exclusive(body);
    let end = [13, 10];
    const arr = [...head, ...headJudge, ...body, ...bodyJudge, ...end]
    return new Uint8Array(arr).buffer
  }

  // 发送消息
  sendMsgExt(param: MsgExt) {
    dConsole.info(UDPTag, "小红球数据", param)
    const msgData = this.setWholeMsg(param)
    this.sendMsg(msgData)
  }

  // 创建udp实例
  async create(udpLocalIp: string, udpLocalIpPort: string, udpOppositeIp: string, udpOppositeIpPort: string) {
    console.log(UDPTag, "udp 初始化参数", udpLocalIp, udpLocalIpPort, udpOppositeIp, udpOppositeIpPort)
    await this.close()
    this.localIp = udpLocalIp
    this.oppositeIp = udpOppositeIp
    this.localIpPort = udpLocalIpPort
    this.oppositeIpPort = udpOppositeIpPort
    try {
      this.udp = socket.constructUDPSocketInstance();
      this.bindUdp()
      this.bindEvent()
    } catch (e) {
      console.log(UDPTag, "udp错误", JSON.stringify(e))
    }
  }

  // 绑定消息事件
  onMsg(callback: Function) {
    if (this.messageEvents.findIndex(cb => cb === callback) !== -1) {
      return
    }
    this.messageEvents.push(callback)
  }

  // 绑定错误事件
  onError(callback: Function) {
    this.errorEvents.push(callback)
  }

  // 取消绑定事件
  offMsg(callback: Function) {
    this.messageEvents = this.messageEvents.filter(cb => cb !== callback)
  }

  // 绑定事件
  private bindEvent() {
    this.udp?.on("message", value => {
      let result = this.dealMethod?.(value.message)
      // console.log(UDPTag, "udp获取消息", result)
      this.messageEvents.forEach(cb => {
        cb(result)
      })
    })
    this.udp?.on("error", (err) => {
      console.log(UDPTag, 'udp error', JSON.stringify(err))
      this.errorEvents.forEach(cb => {
        cb(err)
      })
    })
  }
}