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 = null
  private events: Array<Function> = []

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

  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();
    this.bindTcp()
  }

  bindTcp(): Promise<void> {
    return this.tcp.bind({
      address: this.localIp, port: parseInt(this.localIpPort), family: 1
    }).then(() => {
      return this.tcp.connect({
        address: {
          address: this.oppositeIp, port: parseInt(this.oppositeIpPort)
        },
        timeout: 6000
      })
    }).then(() => {
      try {
        this.tcp.on("message", value => {
          let data = new DataView(value.message)
          this.events.forEach(cb => {
            cb(value.message.slice(5, data.byteLength))
          })
        })
        return Promise.resolve()
      } catch (e) {
        return Promise.reject(e)
      }
    })
  }

  async reBind() {
    await this.close()
    this.tcp = socket.constructTCPSocketInstance();
    await this.bindTcp()
  }

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

  onMsg(callback: Function) {
    this.events.push(callback)
  }

  sendMsg(data: string): Promise<void> {
    return this.tcp?.send({
      data
    }).catch(async (err: BusinessError) => {
      this.tcpSendNum++
      if (this.tcpSendNum > 10) {
        this.tcpSendNum = 0
        await this.reBind()
      }
      return Promise.reject(err)
    })
  }

  offMsg(callback: Function) {
    this.events = this.events.filter(cb => cb !== callback)
  }
}