package com.jotuntech.sketcher.client.command;

import java.nio.ByteBuffer;
import java.util.Deque;

import com.jotuntech.sketcher.client.Client;
import com.jotuntech.sketcher.client.Command;
import com.jotuntech.sketcher.client.Connection;
import com.jotuntech.sketcher.common.BitmapUndoData;
import com.jotuntech.sketcher.common.UndoEntry;
import com.jotuntech.sketcher.common.User;

public class UndoDataCommand implements Command {
	byte[] data;

	public int perform(Client client, User user) {
		if(user == null) {
			return Connection.SEND_NONE;
		}

		if(user.isViewer()) {
			return Connection.SEND_NONE;
		}

		Deque<UndoEntry> undoDeque = user.getUndoDeque();

		if(undoDeque.size() == 0) {
			return Connection.SEND_NONE;
		}

		BitmapUndoData bud = (BitmapUndoData) undoDeque.getLast().getUndoData();
		bud.decode(data);

		return Connection.SEND_NONE;
	}

	public void decode(ByteBuffer in) {
		data = new byte[in.remaining()];
		in.get(data);
	}

	public void encode(ByteBuffer out) {
		out.put(data);
	}
}