/// <summary>
/// Decode AVL udp data packet
/// </summary>
/// <returns></returns>
public UdpDataPacket DecodeUdpData()
{
var length = _reader.ReadInt16();
var packetId = _reader.ReadInt16();
var packetType = _reader.ReadByte();
var avlPacketId = _reader.ReadByte();
var imeiLength = _reader.ReadInt16();
var imei = _reader.ReadBytes(imeiLength - 1);
var avlData = new AvlDataCollection();
_reader.BaseStream.Position = _reader.BaseStream.Position + 1;
var codecId = _reader.ReadByte();
_reader.BaseStream.Position = _reader.BaseStream.Position - 1;
if (codecId == 7)
{
avlData = new Codec7(_reader).DecodeAvlDataCollection();
}
if (codecId == 8)
{
avlData = new Codec8(_reader).DecodeAvlDataCollection();
}
return(UdpDataPacket.Create(length, packetId, packetType, avlPacketId, imeiLength, imei, avlData));
}
/// <summary>
/// Decode AVL Tcp data packet
/// </summary>
/// <returns></returns>
public TcpDataPacket DecodeTcpData()
{
var preamble = _reader.ReadInt32();
var length = _reader.ReadInt32();
var codecId = _reader.ReadByte();
_reader.BaseStream.Position = 8;
var data = _reader.ReadBytes(length);
var crc = _reader.ReadInt32();
_reader.BaseStream.Position = 8;
if (preamble != 0)
{
throw new NotSupportedException("Unable to decode. Missing package prefix.");
}
if (crc != CRC.Default.CalcCrc16(data))
{
throw new InvalidOperationException("CRC does not match the expected.");
}
var avlDataCollection = new AvlDataCollection();
if (codecId == 7)
{
avlDataCollection = new Codec7(_reader).DecodeAvlDataCollection();
}
if (codecId == 8)
{
avlDataCollection = new Codec8(_reader).DecodeAvlDataCollection();
}
return(TcpDataPacket.Create(preamble, length, crc, avlDataCollection));
}
