package com.jotuntech.sketcher.server.command;

import java.awt.image.ImageObserver;
import java.nio.ByteBuffer;
import java.util.HashSet;
import java.util.Set;

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

public class DeleteLayerCommand implements Command {
	int layerKey;

	public DeleteLayerCommand() {

	}

	public DeleteLayerCommand(int layerKey) {
		this.layerKey = layerKey;
	}

	public int perform(Server server, Connection connection) {
		User user = connection.getUser();

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

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

		/** Check access controller */
		AccessController controller = server.getAccessController();
		if(controller != null) {
			if(!controller.isLayerActionAllowed(server, user)) {
				connection.getSendQueue().offer(new CommandEntry(0, new ServerMessageCommand("You are not allowed to do that.")));
				return Connection.SEND_NONE;
			}
		}

		Canvas canvas = server.getCanvas();
		Layer layer = canvas.getLayerMap().remove(layerKey);

		if(layer == null) {
			return Connection.SEND_NONE;
		}
		
		if(canvas.getImageObserver() != null) {
			canvas.getImageObserver().imageUpdate(null, ImageObserver.ALLBITS, 0, 0, canvas.getWidth(), canvas.getHeight());
		}
		
		// Remove references to layer from undo deque
		for(Connection c: server.getConnectionMap().values()) {
			Set<UndoEntry> uers = new HashSet<UndoEntry>();
			if(c.getUser() == null) {
				continue;
			}
			for(UndoEntry ue : c.getUser().getUndoDeque()) {
				if(ue.getLayer() == layer) {
					uers.add(ue);
				}
			}
			for(UndoEntry ue : uers) {
				c.getUser().getUndoDeque().remove(ue);
			}
		}
		
		return Connection.SEND_ALL;
	}

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

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