package com.jotuntech.sketcher.server.command;

import java.nio.ByteBuffer;

import com.jotuntech.sketcher.common.Canvas;
import com.jotuntech.sketcher.common.Layer;
import com.jotuntech.sketcher.common.User;
import com.jotuntech.sketcher.server.Command;
import com.jotuntech.sketcher.server.Connection;
import com.jotuntech.sketcher.server.Server;

public class SetLayerCommand implements Command {
	Integer layerKey;

	public SetLayerCommand() {
	}

	public SetLayerCommand(Integer layerKey) {
		this.layerKey = layerKey;
	}

	public int perform(Server server, Connection connection) {
		return perform(server.getCanvas(), connection.getUser());
	}

	private int perform(Canvas canvas, User user) {
		if(user == null) {
			return Connection.SEND_NONE;
		}

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

		if(canvas == null) {
			return Connection.SEND_NONE;
		}

		Layer layer = canvas.getLayerMap().get(layerKey);

		if(layer == null) {
			return Connection.SEND_NONE;
		}

		if(user.getLayer() == layer) {
			return Connection.SEND_NONE;
		}

		user.setLayer(layer);

		return Connection.SEND_OTHERS;
	}

	public void decode(ByteBuffer in) {
		layerKey = in.getInt();
	}

	public void encode(ByteBuffer out) {
		out.putInt(layerKey);
	}
}