/*******************************************************************************
 * 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.proconf.g3d.base;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import org.simantics.db.Resource;
import org.simantics.layer0.utils.IEntity;
import org.simantics.utils.ui.plugin.Extension;
import org.simantics.utils.ui.plugin.ExtensionLoader;

import com.jme.scene.Geometry;

public class GeometryProviderRegistry {
    private static GeometryProviderRegistry instance;
    public final static String ELEMENT_NAME = "Geometry";
    public final static String NAME_SPACE = "org.simantics.proconf.g3d";
    public final static String EP_NAME = "geometry";
    
    private ExtensionLoader<GeometryProvider> loader;
    private Map<Resource,GeometryProvider> providers;
    
    private GeometryProviderRegistry() {
        loader = new ExtensionLoader<GeometryProvider>(ELEMENT_NAME, NAME_SPACE, EP_NAME);
        providers = new HashMap<Resource,GeometryProvider>();
    }
    
    public static GeometryProviderRegistry getInstance() {
        if (instance==null) instance = new GeometryProviderRegistry();
        return instance;
    }

    public Extension<GeometryProvider>[] getExtensions() {
        return loader.getExtensions();
    }
    
    private Map<Resource,GeometryProvider> getProviderMap() {
        return providers;
    }
    
    public static Geometry[] getGeometry(IEntity thing, boolean transform) {
        GeometryProvider provider = getGeometryProvider(thing);
        return provider.getGeometryFromResource(thing, transform);
    }
    
    public static GeometryProvider getGeometryProvider(IEntity thing) {
    	Collection<IEntity> types = thing.getRelatedObjects(thing.getGraph().getBuiltins().InstanceOf);
        
    	//Resource types[] = OntologyUtils.getTypes(resource);
    	for (IEntity t : types) {
    		GeometryProvider provider = getInstance().getProviderMap().get(t.getResource());
        	if (provider == null) {
                for (Extension<GeometryProvider> e : getInstance().getExtensions()) {
                    if (e.getInstance().canHandle(thing)) {
                        getInstance().getProviderMap().put(t.getResource(), e.getInstance());
                        return e.getInstance();
                    }
                }
                
            } else {
            	return provider;
            }
    	}
    	
    	throw new UnsupportedOperationException("Cannot handle resource " + thing);
    }
}