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

import socket from '@ohos.net.socket'
import { BusinessError } from '@ohos.base'
import { TCPTag } from '../config'


export default class TcpClient {
  private static instance: TcpClient
  private localIp: string = ''
  private localIpPort: string = ''
  private oppositeIp: string = ''
  private oppositeIpPort: string = ''
  private tcpSendNum: number = 0
  private tcp: socket.TCPSocket = socket.constructTCPSocketInstance()
  private events: Array<Function> = []
  // 连接状态是否成功
  private linkStatus: boolean = false

  constructor() {
    if (!TcpClient.instance) {
      TcpClient.instance = this
    }
    return TcpClient.instance
  }

  // 初始化tcp连接
  async init(tcpLocalIp: string, tcpLocalIpPort: string, tcpOppositeIp: string, tcpOppositePort: string) {
    this.localIp = tcpLocalIp
    this.oppositeIp = tcpOppositeIp
    this.localIpPort = tcpLocalIpPort
    this.oppositeIpPort = tcpOppositePort
    console.log(TCPTag, 'new Tcp', this.localIp, this.localIpPort, this.oppositeIp, this.oppositeIpPort)
    this.tcp = socket.constructTCPSocketInstance();
    await this.bindTcp()
    await this.connectTcp()
  }

  // 绑定tcp
  bindTcp(): Promise<Boolean> {
    return new Promise((resolve, reject) => {
      this.tcp.bind({
        address: this.localIp,
        port: Number(this.localIpPort),
        family: 1
      }).then(() => {
        console.log(TCPTag, 'bindTcp success:', this.localIp, this.localIpPort, this.oppositeIp, this.oppositeIpPort)
        resolve(true)
      }).catch((err: BusinessError) => {
        console.log(TCPTag, 'bindTcp error:', JSON.stringify(err), this.localIp, this.localIpPort, this.oppositeIp, this.oppositeIpPort)
        reject(err)
      })
    })
  }

  // 连接tcp
  connectTcp(): Promise<Boolean> {
    return new Promise((resolve, reject) => {
      this.tcp.connect({
        address: {
          address: this.oppositeIp, port: Number(this.oppositeIpPort), family: 1
        }, timeout: 1000 * 15
      })
        .then(() => {
          this.linkStatus = true
          this.getMessage()
          console.log(TCPTag, "tcp connect success")
          return this.tcp.setExtraOptions({
            keepAlive: true
          })
        })
        .then(() => {
          resolve(true)
        })
        .catch((err: BusinessError) => {
          this.linkStatus = false
          console.log(TCPTag, "tcp connect or keepAlive error: ", JSON.stringify(err))
          console.log(TCPTag, "tcp 重启服务")
          reject(err)
        })
    })
  }

  getMessage() {
    if (!this.linkStatus) {
      console.log(TCPTag, '不允许获取消息: TCP未连接');
      return;
    }
    this.tcp.on("message", value => {
      let data = new DataView(value.message)
      this.events.forEach(cb => {
        // TODO
        // 一体机不需要截取
        cb(value.message.slice(5, data.byteLength))
      })
    })
  }

  // 重新绑定tcp
  async reBind() {
    console.log(TCPTag, 'tcp rebind')
    await this.close()
    this.tcp = socket.constructTCPSocketInstance();
    await this.bindTcp()
    await this.connectTcp()
  }

  // 监听tcp错误
  onError(callback: Function) {
    this.tcp.on('error', err => {
      console.log(TCPTag, 'tcp on error: ', JSON.stringify(err))
      callback?.()
    });
  }

  // 关闭tcp连接
  close(): Promise<void> {
    return this.tcp?.close()
  }

  // 监听tcp消息
  onMsg(callback: Function) {
    if (this.events.includes(callback)) {
      console.log(TCPTag, '已经存在这个获取消息方法了');
      return;
    }
    this.events.push(callback);
  }

  // 接收tcp消息
  sendMsg(data: string): Promise<void> {
    if (!this.linkStatus) {
      console.log(TCPTag, '不允许发送: TCP未连接');
      return Promise.reject(new Error('TCP connection is not established'));
    }
    return this.tcp?.send({
      data
    }).catch(async (err: BusinessError) => {
      console.log(TCPTag, 'sendMsg error:', JSON.stringify(err), this.oppositeIp, this.oppositeIpPort)
      this.tcpSendNum++
      if (this.tcpSendNum > 10) {
        this.tcpSendNum = 0
        await this.reBind()
      }
      return Promise.reject(err)
    })
  }

  // 取消监听tcp消息
  offMsg(callback: Function) {
    this.events = this.events.filter(cb => cb !== callback)
  }
}