/*******************************************************************************
 * Copyright (c) 2007 VTT Technical Research Centre of Finland and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.processeditor.monitors;

import java.util.Collection;
import java.util.List;

import org.simantics.db.Resource;
import org.simantics.layer0.utils.IEntity;
import org.simantics.utils.datastructures.MapList;


/**
 * Container for Paths
 * FIXME : singleton
 * TODO : removing paths
 * TODO : prevent adding same path multiple times
 * TODO : how to handle multi-instances?
 * 
 * 
 * @author Marko Luukkainen
 *
 */
public class PathContainer {
	
	private static PathContainer instance = new PathContainer();
	
	MapList<Resource, List<Resource>> paths;
	//List<Pair<List<Resource>,List<Resource>>> multiInstancePaths;
	
	private PathContainer() {
		paths = new MapList<Resource, List<Resource>>();
		//multiInstancePaths = new ArrayList<Pair<List<Resource>,List<Resource>>>();
	}
	
	public List<List<Resource>> getPaths(IEntity instance) {
		Collection<IEntity> types = instance.getTypes();
		if (types.size() != 1) {
			// for multi-instances we check if any of the types have paths
			// no we return paths for a single type (it is possible to combine paths for all types)
			for (IEntity type : types) {
				Resource r = type.getResource();
				List<List<Resource>> path = paths.getValues(r);
				if (path != null)
					return path;
			}
			return null;
		} else {
			Resource type = types.iterator().next().getResource();
			return paths.getValues(type);
		}
	}
	
	public void addPath(Resource type, List<Resource> path) {
		paths.add(type, path);
	}
	
	public void clearPaths(Resource type) {
		paths.remove(type);
	}
	
	public static PathContainer getInstance() {
		return instance;
	}

}