public static CoapOption Decode(byte[] buffer, int index, int previousDelta, out int newIndex)
{
int deltaPart = buffer[index] >> 0x04;
int deltaExtendedLength = deltaPart <= 12 ? 0 : deltaPart == 13 ? 1 : 2;
int valuePart = buffer[index] & 0x0F;
int valueExtendedLength = valuePart <= 12 ? 0 : valuePart == 13 ? 1 : 2;
index++;
int optionTypeValue = deltaExtendedLength == 0 ? deltaPart + previousDelta : deltaExtendedLength == 1 ? (deltaPart + previousDelta) + (int)buffer[index++] : (deltaPart + 255 + previousDelta) + (int)(buffer[index++] | buffer[index++]);
OptionType option = (OptionType)optionTypeValue;
int valueLength = valueExtendedLength == 0 ? valuePart : valueExtendedLength == 1 ? valuePart + (int)buffer[index++] : (valuePart + 255) + (int)(buffer[index++] | buffer[index++]);
byte[] encodedValue = new byte[valueLength];
Buffer.BlockCopy(buffer, index, encodedValue, 0, valueLength);
newIndex = index + valueLength;
object value = option.DecodeOptionValue(encodedValue);
return(new CoapOption(option, value));
}
