package org.kne.cloud.network.srv6;

import java.io.EOFException;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;

import org.kne.cloud.network.NetworkPacket;
import org.kne.cloud.network.klalb.KLALBPacket;

public class IPv6SegmentRoutingTLV extends NetworkPacket {
	public static final int PAD1=0;
	public static final int PADN=4;
	public static final int HMAC=5;
	public static final int SEQS=7;
	public static final int ACKSEQS=8;
	
	private int headerLength=2;
	
	public int getHeaderLength() {
		return headerLength;
	}

	private boolean isDefault;
	
	protected volatile ByteBuffer header;
	
	private ByteBuffer data;
	
	public IPv6SegmentRoutingTLV(ByteBuffer header ) {
		this(header,true);
	}
	
	public ByteBuffer getData() {
		return data;
	}

	public IPv6SegmentRoutingTLV(ByteBuffer header ,boolean isDefault ) {
		super();
		this.header = header;
		this.isDefault=isDefault;
		if(getType()==PAD1)
			headerLength=1;
		if(isDefault&&(headerLength>1)) {
			data=ByteBuffer.allocate(512);
		}
	}
	public IPv6SegmentRoutingTLV(int type) {
		this(type,true);
	}
	public IPv6SegmentRoutingTLV(int type,boolean isDefault) {
		super();
		this.header=ByteBuffer.allocate(2);
		this.isDefault=isDefault;
		header.put((byte) type);
		if(type==PAD1) {
			headerLength=1;
		}
		if(isDefault&&(headerLength>1)) {
			data=ByteBuffer.allocate(512);
		}
	}

	@Override
	public long getLength() {
		return headerLength+(isDefault?data.limit():0);
	}
	
	public static IPv6SegmentRoutingTLV readIPv6SegmentRoutingTLVFromChannel(ReadableByteChannel din) throws IOException {
		ByteBuffer bbf= ByteBuffer.allocate(2);
		bbf.limit(1);
		while (bbf.hasRemaining()) {
			if (din.read(bbf) == -1) {
				return null;
			}
		}
		int type=bbf.get(0)&0xff;
		IPv6SegmentRoutingTLV rtlv;
		switch(type) {
		case PAD1:
			rtlv=new PAD1SegmentRoutingTLV(bbf);
			rtlv.readFromChannel(din);
			return rtlv;
		case PADN:
			rtlv=new PADNSegmentRoutingTLV(bbf);
			rtlv.readFromChannel(din);
			return rtlv;
		case SEQS:
			rtlv=new SEQSSegmentRoutingTLV(bbf);
			rtlv.readFromChannel(din);
			return rtlv;
		case ACKSEQS:
			rtlv=new ACKSEQSSegmentRoutingTLV(bbf);
			rtlv.readFromChannel(din);
			return rtlv;
		default:
			rtlv=new IPv6SegmentRoutingTLV(bbf);
			rtlv.readFromChannel(din);
			return rtlv;
		}
	}
	public static void writeIPv6SegmentRoutingTLVToChannel(WritableByteChannel dto,IPv6SegmentRoutingTLV tlv) throws IOException {
		tlv.writeToChannel(dto);
	}
	@Override
	public void writeToChannel(WritableByteChannel dto) throws IOException {
		if(isDefault&&(headerLength>1)) {
		setDataLength(data.limit());
		}
		header.limit(headerLength);
		dto.write(header.slice(0,header.limit()));
		if(isDefault&&(headerLength>1)) {
			dto.write(data.slice(0, data.limit()));
		}
	}

	@Override
	public void readFromChannel(ReadableByteChannel din, long length) throws IOException {
		header.limit(1);
		while (header.hasRemaining()) {
			if (din.read(header) == -1) {
				throw new EOFException();
			}
		}
		if(headerLength>1) {
			header.limit(2);
			while (header.hasRemaining()) {
				if (din.read(header) == -1) {
					throw new EOFException();
				}
			}
		}
		header.flip();
		
		if(isDefault&&(headerLength>1)) {
		data.clear();
		data.limit(getDataLength());
		 while(data.hasRemaining()){
				if(din.read(data)==-1) {
					throw new EOFException();
				}
				}
		 data.flip();
		}
	}

	@Override
	protected boolean needEndPosition() {
		return false;
	}

	public int getType() {
		return header.get(0)&0xff;
	}
	public void setType(int type) {
		header.put(0,(byte) type);
	}
	
	public int getDataLength() {
		return header.get(1)&0xff;
	}
	
	public void setDataLength(int dataLength) {
		header.put(1,(byte) dataLength);
	}
}