package ch.ethz.ssh2.packets;

import java.io.IOException;

/**
 * PacketChannelWindowAdjust.
 * 
 * @author Christian Plattner
 * @version 2.50, 03/15/10
 */
public class PacketChannelWindowAdjust
{
	byte[] payload;

	public int recipientChannelID;
	public int windowChange;

	public PacketChannelWindowAdjust(int recipientChannelID, int windowChange)
	{
		this.recipientChannelID = recipientChannelID;
		this.windowChange = windowChange;
	}

	public PacketChannelWindowAdjust(byte payload[], int off, int len) throws IOException
	{
		this.payload = new byte[len];
		System.arraycopy(payload, off, this.payload, 0, len);

		TypesReader tr = new TypesReader(payload, off, len);

		int packet_type = tr.readByte();

		if (packet_type != Packets.SSH_MSG_CHANNEL_WINDOW_ADJUST)
			throw new IOException(
					"This is not a SSH_MSG_CHANNEL_WINDOW_ADJUST! ("
							+ packet_type + ")");

		recipientChannelID = tr.readUINT32();
		windowChange = tr.readUINT32();
		
		if (tr.remain() != 0)
			throw new IOException("Padding in SSH_MSG_CHANNEL_WINDOW_ADJUST packet!");
	}

	public byte[] getPayload()
	{
		if (payload == null)
		{
			TypesWriter tw = new TypesWriter();
			tw.writeByte(Packets.SSH_MSG_CHANNEL_WINDOW_ADJUST);
			tw.writeUINT32(recipientChannelID);
			tw.writeUINT32(windowChange);
			payload = tw.getBytes();
		}
		return payload;
	}
}
