import useStore from '@/store'
/**
 * WebRTC服务
 */
export default class WebRtcService {
  private ICE = [
    { urls: [ 'stun:caner.top:3478' ] },
    {
      urls: 'turn:caner.top:3478',
      username: 'admin',
      credential: '123456'
    },
    { urls: 'stun:stun.l.google.com:19302' }
  ]

  public Peer: RTCPeerConnection | null = null

  private audioTack: MediaStreamTrack | null = null

  private store = useStore()

  private lastStats: RTCStatsReport | null = null

  private sleep = (ms: number) => new Promise((resolve) => { setTimeout(resolve, ms) })

  /**
   * 初始化
   * @param DOM HTMLVideoElement
   */
  initRTC(DOM: HTMLVideoElement) {
    try {
      if (this.Peer) this.distory()
      if (!DOM) { this.store.setMqttMessage({ type: 'WebRtcIntError' }); return }
      console.log('start initRTC')

      // create Peer
      this.Peer = new RTCPeerConnection({
        iceServers: this.ICE,
        bundlePolicy: 'max-bundle'
      })

      // listen state
      this.Peer.onicegatheringstatechange = () => {
        console.log('GatheringState: ', this.Peer?.iceGatheringState)
        if (this.Peer?.iceGatheringState === 'complete') {
          const answer = this.Peer?.localDescription
          this.store.setMqttMessage({ type: 'answer', data: answer?.toJSON() })
        }
      }

      // listen track
      this.Peer.ontrack = (evt) => {
        console.log('track', evt)
        // TODO safari 不支持opus ogg 音频编码
        DOM.srcObject = evt.streams[0]
      }

      // listen changestate·
      this.Peer.oniceconnectionstatechange = () => {
        const state = this.Peer?.iceConnectionState
        console.log('StateChange', state)
        // P2P 连接失败
        if (state === 'failed' || state === 'closed') {
          console.log('P2P通信失败')
          this.store.setMqttMessage({ type: 'WebRtcFailed' })
        }
        // ICE连接成功
        if (state === 'connected') {
          this.store.setMqttMessage({ type: 'WebRtcConnected', data: null })
        }
      }

      // get stats
      this.getStats()

      console.log('RTC success')
    } catch (error) {
      console.log('RTC 初始化失败', error)
      this.store.setMqttMessage({ type: 'WebRtcIntError' })
    }
  }

  /**
   * 远程静音
   * @param mute boolean
   */
  muteRemoteAudio(mute: boolean) {
    console.log('远程静音', mute)
    if (!this.audioTack) return
    this.audioTack!.enabled = mute
  }

  /**
   * 比特率｜丢包率
   * @returns
   */
  async getStats() {
    if (this.Peer) {
      const stats = await this.Peer.getStats()
      let packetLoss = 0
      let bitrate = 0
      if (this.lastStats) {
        stats.forEach((report) => {
          if (report.type === 'inbound-rtp' && report.kind === 'video') {
            if (this.lastStats && this.lastStats.has(report.id)) {
              const lastReport = this.lastStats.get(report.id)
              const duration = (report.timestamp - lastReport.timestamp) / 1000
              bitrate = (report.bytesReceived - lastReport.bytesReceived) / duration / 1000
              const lostPackets = (report.packetsLost - lastReport.packetsLost)
              if ((report.packetsReceived - lastReport.packetsReceived + lostPackets) === 0) {
                packetLoss = 0
              } else {
                packetLoss = (lostPackets / (report.packetsReceived - lastReport.packetsReceived + lostPackets)) * 100
              }
            }
          }
        })
      }
      this.lastStats = stats
      this.store.setMqttMessage({ type: 'WebRtcStats', data: { packetLoss: Math.floor(packetLoss * 100) / 100, bitrate: Math.floor(bitrate * 100) / 100 } })
    } else {
      this.store.setMqttMessage({ type: 'WebRtcStats', data: { packetLoss: 0, bitrate: 0 } })
    }
    await this.sleep(1000)
    this.getStats()
  }

  distory() {
    this.Peer?.close()
    this.Peer = null
    this.audioTack = null
  }
}