Lawo.IO.TelnetStream.ReadByte C# (CSharp) Method

        private byte[] ReadByte(ReadBuffer readBuffer, byte[] buffer, ref int index)
        {
            var currentByte = readBuffer[readBuffer.Index++];

            switch (this.readState)
            {
                case ReadState.Data:
                    if (currentByte == Command.InterpretAsCommand)
                    {
                        this.readState = ReadState.Command;
                    }
                    else
                    {
                        buffer[index++] = currentByte;
                    }

                    return null;
                case ReadState.Command:
                    switch (currentByte)
                    {
                        case Command.Will:
                        case Command.Wont:
                        case Command.Do:
                        case Command.Dont:
                            this.readState = ReadState.OptionCode;
                            this.readCommand = currentByte;
                            break;
                        case Command.InterpretAsCommand:
                            this.readState = ReadState.Data;
                            buffer[index++] = currentByte;
                            break;
                        default:
                            this.readState = ReadState.Data;
                            break;
                    }

                    return null;
                default:
                    this.readState = ReadState.Data;
                    byte response;

                    if (currentByte == Option.SuppressGoAhead)
                    {
                        response = this.readCommand == Command.Do ? Command.Will : Command.Do;
                    }
                    else
                    {
                        response = this.readCommand == Command.Do ? Command.Wont : Command.Dont;
                    }

                    return new[] { Command.InterpretAsCommand, response, currentByte };
            }
        }