/*******************************************************************************
 * 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 fi.vtt.simantics.processeditor.common;

import java.util.ArrayList;
import java.util.Collection;

import org.simantics.db.Graph;
import org.simantics.db.Resource;
import org.simantics.layer0.utils.EntityFactory;
import org.simantics.layer0.utils.IEntity;
import org.simantics.layer0.utils.viewpoints.TraversalPath;
import org.simantics.proconf.browsing.GraphExplorer;
import org.simantics.utils.datastructures.Pair;





public class PathUtils {

	public static void createPath(java.util.List<Resource> samplePath, TraversalPath path, Resource sampleInstance, Resource sampleSource, GraphExplorer oe) {
//		while (tNode != null) {
//			long[] path = tNode.getPath();
//			for (int i = 0; i < path.length; i++) {
//				samplePath.add(i, path[i]);
//			}
//			samplePath.add(path.length,tNode.getCoreId());
//			tNode = oe.getTreeParent(tNode);
//		}
		while (path != null) {
			Resource predicate = path.getPredicate();
			Resource obj = path.getResource();
			if (predicate != null) {
				samplePath.add(0,predicate);
				path = path.getTail();
			} else {
				// there is no relation and so this has to be root
				path = null; 
			}
			samplePath.add(1,obj);
			
		}
		
		if (!sampleInstance.equals(samplePath.get(0)) || !sampleSource.equals(samplePath.get(samplePath.size()-1))) {
			String s = "";
			for (int i = 0; i < samplePath.size(); i++) {
				s += samplePath.get(i) + " ";
			}
			throw new RuntimeException("Path from " + sampleInstance + " to "
					+ sampleSource + " is broken: " + s);
		}

//		String s = "";
//		for (int i = 0; i < samplePath.size(); i++) {
//			s += samplePath.get(i) + " ";
//		}
//		System.out.println("Path from " + sampleInstance + " to " + sampleSource + " is: " + s);
		samplePath.remove(0);
	}
	
	
	
	/**
	 * Finds similar path in cloned resource
	 * TODO : this isn't correct way to do this;
	 * Rigth way would be finding mapping between two clones
	 * and then find the similar resource 
	 * (Viewpoint used to create clone is required)
	 * 
	 * @param path
	 * @param begin
	 * @return
	 */
	public static IEntity findSimilar(java.util.List<Resource> path,  IEntity begin) {
		if (path.size() == 0)
			return begin;
		if (path.size() == 1)
			return null;
		Graph g = begin.getGraph();
		java.util.List<Resource> tPath = new ArrayList<Resource>();
		tPath.addAll(path);
		
		Resource p = tPath.get(0); // predicate (relation)
		Resource o = tPath.get(1); // object 
		tPath.remove(0);
		tPath.remove(0);
		
		IEntity predicate = EntityFactory.create(g, p);

		
		Collection<IEntity> possibleObjects = begin.getRelatedObjects(predicate);
		if (possibleObjects.size() == 0)
			return null;
		if (possibleObjects.size() == 1) 
			return findSimilar(tPath, possibleObjects.iterator().next());
		else {
			IEntity object = EntityFactory.create(g, o);
			Collection<IEntity> objectTypes = object.getTypes();
			java.util.List<Pair<IEntity,IEntity>> list = new ArrayList<Pair<IEntity,IEntity>>();
			for (IEntity possible : possibleObjects) {
				boolean matchTypes = true;
				for (IEntity type : objectTypes) {
					if(!possible.isInstanceOf(type)) {
						matchTypes = false;
						break;
					}
						
				}
				if (matchTypes) {
					IEntity r = findSimilar(tPath,possible);
					if (r != null)
						list.add(new Pair<IEntity,IEntity>(possible,r));
						//return r;
				}
			}
			if (list.size() == 0)
				return null;
			if (list.size() == 1)
				return list.get(0).second;
			else {
				// uses names of objects to detect similarities
				String name = object.getName();
				if (name != null) {
					for (Pair<IEntity,IEntity> possible : list) {
						String otherName = possible.first.getName();
						//System.out.println(name + " : " + otherName);
						if (otherName != null && name.compareTo(otherName) == 0)
							return possible.second;
					}
				}
			}
		}
		
		return null;
	}
}