PeerCastStation.FLV.RTMP.RTMPPlayConnection.OnCommandPlay C# (CSharp) Method

    protected override async Task OnCommandPlay(CommandMessage msg, CancellationToken cancel_token)
    {
      var stream_name = StreamName.Parse((string)msg.Arguments[0]);
      var start       = msg.Arguments.Count>1 ? (int)msg.Arguments[1] : -2;
      var duration    = msg.Arguments.Count>2 ? (int)msg.Arguments[2] : -1;
      var reset       = msg.Arguments.Count>3 ? (bool)msg.Arguments[3] : false;
      logger.Debug("Play: {0}, {1}, {2}, {3}", stream_name.ToString(), start, duration, reset);
      if (owner.CheckAuthotization(stream_name.GetParameter("auth"))) {
        this.Channel = await RequestChannel(stream_name, cancel_token);
        this.StreamId = msg.StreamId;
        await SendMessage(2, new UserControlMessage.StreamBeginMessage(this.Now, 0, msg.StreamId), cancel_token);
        if (this.Channel!=null) {
          await SendOnStatus(
            this.StreamId,
            msg.TransactionId+1,
            "status",
            "NetStream.Play.Start",
            stream_name.ToString(),
            cancel_token);
          if (reset) {
            await SendOnStatus(
              this.StreamId,
              msg.TransactionId+1,
              "status",
              "NetStream.Play.Reset",
              stream_name.ToString(),
              cancel_token);
          }
        }
        else {
          await SendOnStatus(
            this.StreamId,
            msg.TransactionId+1,
            "error",
            "NetStream.Play.FileNotFound",
            stream_name.ToString(),
            cancel_token);
        }
      }
      else {
        await SendOnStatus(
          this.StreamId,
          msg.TransactionId+1,
          "error",
          "NetStream.Play.Failed",
          "auth failed",
          cancel_token);
      }
      if (msg.TransactionId!=0) {
        var result = CommandMessage.Create(
          this.ObjectEncoding,
          this.Now,
          msg.StreamId,
          "_result",
          msg.TransactionId,
          null
        );
        await SendMessage(3, result, cancel_token);
      }
      if (this.Channel!=null) {
        await base.OnCommandPlay(msg, cancel_token);
        this.Channel.ContentChanged += OnContentChanged;
        OnContentChanged(this, new EventArgs());
      }
      else {
        Close();
      }
    }