package protocolP2P;
import protocolP2P.Payload;
import protocolP2P.RequestResponseCode;
import exception.ProtocolError;

public class FilePart extends Payload {
	private static final RequestResponseCode requestResponseCode = RequestResponseCode.LOAD_RESPONSE;
	private String filename;
	private int totalSize;
	private int offset;
	private byte[] partialContent;

	public FilePart(String filename, int totalSize, int offset, byte[] partialContent) {
		this.filename = filename;
		this.totalSize = totalSize;
		this.offset = offset;
		this.partialContent = partialContent;
	}

	public FilePart(byte[] datagram) throws ProtocolError {
		//TODO
		assert RequestResponseCode.fromCode(datagram[RequestResponseCode.RRCODE_POSITION]) == RequestResponseCode.LOAD_RESPONSE : "FilePart subclass is incompatible with this datagram, request/response code must be checked before using this constructor";
		int size = (datagram[PAYLOAD_SIZE_POSITON] << (8*3)) | (datagram[PAYLOAD_SIZE_POSITON+1] << (8*2)) | (datagram[PAYLOAD_SIZE_POSITON+2] << 8) | datagram[PAYLOAD_SIZE_POSITON+3];
	}

	/** To datagram with padding */
	public byte[] toDatagram() {
		byte[] datagram; // java initialize all to zero
		// size is keep blank (ProtocolP2PDatagram will handle it)
		// set request/response code
		datagram[RequestResponseCode.RRCODE_POSITION] = requestResponseCode.codeValue;
		// bits 16-31 are reserved for future use
		//TODO size
		int size = ;
		for(i=0;i<4;i++) {
			datagram[Payload.PAYLOAD_SIZE_POSITON + i] = (byte) (size >> (8 * (3 - i)) & 0xFF);
		}
		//TODO content
	}

}