Module = {
  onRuntimeInitialized: function() {
    onWasmLoaded()
  },
}
importScripts('libffmpeg.js')

var MediaName = null
var IsStream = true
var FileLen = -1

var SocketObj //WebSocket
var CPointer_Buffer = null
var CPointer_Cap = 0

function onWasmLoaded() {
  DeliverVideo = Module.addFunction(function(Buf, BufLen, TimeStamp) {
    var CPointer_Array = Module.HEAPU8.subarray(Buf, Buf + BufLen)
    var message = {
      command: 'deliver_video',
      sample: { time_stamp: TimeStamp, buf: new Uint8Array(CPointer_Array) },
    }
    self.postMessage(message, [message.sample.buf.buffer])
  }, 'viii')

  DeliverAudio = Module.addFunction(function(Buf, BufLen, TimeStamp) {
    var CPointer_Array = Module.HEAPU8.subarray(Buf, Buf + BufLen)
    var message = {
      command: 'deliver_audio',
      sample: { time_stamp: TimeStamp, buf: new Uint8Array(CPointer_Array) },
    }
    self.postMessage(message, [message.sample.buf.buffer])
  }, 'viii')

  GetFileLength = Module.addFunction(function() {
    if (FileLen == -1) {
      var xhr = new XMLHttpRequest()
      xhr.open('get', MediaName, false) //false: syn mode
      xhr.send()
      FileLen = xhr.getResponseHeader('Content-Length')
      xhr.abort()
    }
    return FileLen
  }, 'i')

  ReadFile = Module.addFunction(function(Buf, Pos, Size) {
    var xhr = new XMLHttpRequest()
    xhr.open('get', MediaName, false)
    xhr.responseType = 'arraybuffer'
    xhr.setRequestHeader('Range', 'bytes=' + Pos + '-' + (Pos + Size - 1))
    xhr.send()
    Module.HEAPU8.set(new Uint8Array(xhr.response), Buf) //Uint8Array(xhr.response).length
    xhr.abort()
  }, 'viii')

  CreateVideo = Module.addFunction(function(Duration, Width, Height) {
    self.postMessage({
      command: 'create_video',
      param: { duration: Duration, width: Width, height: Height },
    })
  }, 'viii')

  CreateAudio = Module.addFunction(function(Channel, SampleRate) {
    self.postMessage({
      command: 'create_audio',
      param: { channel: Channel, sample_rate: SampleRate },
    })
  }, 'vii')

  Module._Initialize(
    DeliverVideo,
    DeliverAudio,
    GetFileLength,
    ReadFile,
    CreateVideo,
    CreateAudio
  )
  self.postMessage({ command: 'initialized' })
}

function OnTimer() {
  Module._Turbo0(null, 0)
}

function requestWebsocket(url, msg, cb_message) {
  SocketObj = new WebSocket(url)
  SocketObj.binaryType = 'arraybuffer'
  SocketObj.onopen = function(evt) {
    SocketObj.send(msg)
  }
  SocketObj.onerror = function(evt) {
    console.log('Ws connect error ' + evt.data)
  }
  SocketObj.onmessage = cb_message
  SocketObj.onclose = function() {
    console.log('Ws closed.')
  }
}

function downloadFileByWebsocket(ws, payload) {
  this.requestWebsocket(ws, payload, function(evt) {
    if (evt.data.byteLength > CPointer_Cap) {
      if (CPointer_Buffer != null) Module._free(CPointer_Buffer)
      CPointer_Cap = evt.data.byteLength
      CPointer_Buffer = Module._malloc(CPointer_Cap)
    }

    var typedArray = new Uint8Array(evt.data)
    Module.HEAPU8.set(typedArray, CPointer_Buffer)
    //console.log("websocket data: "+typedArray.length);
    Module._Turbo0(CPointer_Buffer, typedArray.length)
  })
}

self.onmessage = function(evt) {
  switch (evt.data.command) {
    case 'play': {
      MediaName = evt.data.media_name
      IsStream = evt.data.other
      if (IsStream) {
        downloadFileByWebsocket(MediaName, evt.data.payload)
      }

      Module._Play(null, !IsStream)
      TimerID = setInterval(OnTimer, 5) //此值越小,渲染精度越高,且可增强'双线程缓冲平滑机制'可靠性
      break
    }
    case 'pause': {
      Module._Pause()
      clearInterval(TimerID)
      break
    }
    case 'resume': {
      Module._Resume()
      TimerID = setInterval(OnTimer, 5)
      break
    }
    case 'stop': {
      Module._Stop()
      clearInterval(TimerID)
      if (IsStream) {
        SocketObj.close()
        if (CPointer_Buffer != null) {
          Module._free(CPointer_Buffer)
          CPointer_Buffer = null
          CPointer_Cap = 0
        }
      }
      close() //exit worker
      break
    }
    case 'seek': {
      Module._Seek(evt.data.pos)
      break
    }
    default:
      return
  }
}