/*******************************************************************************
 * Copyright (c) 2005, 2006 IBM Corporation 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
/*
 * Created on Feb 17, 2005
 */
package org.eclipse.jst.j2ee.navigator.internal;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IResourceChangeEvent;
import org.eclipse.core.resources.IResourceChangeListener;
import org.eclipse.core.resources.IResourceDelta;
import org.eclipse.core.resources.IResourceDeltaVisitor;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.jem.util.logger.proxy.Logger;
import org.eclipse.swt.SWTError;
import org.eclipse.swt.SWTException;

public class EMFRootObjectProvider implements  IResourceChangeListener, IResourceDeltaVisitor{
	private final HashMap emfModelCache = new HashMap();
	private final List listeners = new ArrayList();
	
	public interface IRefreshHandlerListener {
		void onRefresh(Object element);
	}
	
	/**
	 *  
	 */
	public EMFRootObjectProvider() {
		super();
		ResourcesPlugin.getWorkspace().addResourceChangeListener(this);
	}
	
	public Object[] getModels(IProject project){
		try {
			EMFModelManager modelManager = null;
			synchronized (emfModelCache) {
				modelManager = (EMFModelManager) emfModelCache.get(project);
				if (modelManager == null) {
					modelManager= EMFModelManagerFactory.createEMFModelManager(project,this) ;
					emfModelCache.put(project,modelManager);
				}
			}
		return modelManager.getModels();
		} catch (Exception ex) {
			return null;
		}
	}
	
	public boolean hasLoadedModels(IProject project) {
		synchronized (emfModelCache) {
			return emfModelCache.get(project) != null;
		}
	}

	/* (non-Javadoc)
	 * @see org.eclipse.core.resources.IResourceChangeListener#resourceChanged(org.eclipse.core.resources.IResourceChangeEvent)
	 */
	public void resourceChanged(IResourceChangeEvent event) {
		final IResourceDelta delta = event.getDelta();

		if (delta != null) {
			try {
				delta.accept(EMFRootObjectProvider.this);
			} catch (CoreException e) {
				Logger.getLogger().logError(e);
			} catch (SWTException swte) {
				Logger.getLogger().logError(swte);
			} catch (SWTError swte) {
				Logger.getLogger().logError(swte);
			}
		}
		
	}

	/* (non-Javadoc)
	 * @see org.eclipse.core.resources.IResourceDeltaVisitor#visit(org.eclipse.core.resources.IResourceDelta)
	 */
	public boolean visit(IResourceDelta delta) throws CoreException {
		IResource resource = delta.getResource();
		if (resource != null) {
			switch (resource.getType()) {
				case IResource.ROOT :
					return true;
				case IResource.PROJECT :
					boolean projectOpenStateChanged = ((delta.getFlags() & IResourceDelta.OPEN) != 0);
					if (delta.getKind() == IResourceDelta.REMOVED || projectOpenStateChanged) {
						IProject project = (IProject) resource;
						dispose(project);
					}
					return false;
			}
		}
		return false;
	}
	
	private void dispose(IProject project) {
		if (project == null) return;
		EMFModelManager modelManager = (EMFModelManager) emfModelCache.remove(project);
		if (modelManager != null) {
			modelManager.dispose();
			modelManager = null;
		}
	}
	public void dispose() {
		ResourcesPlugin.getWorkspace().removeResourceChangeListener(this);
		EMFModelManager modelManager = null;
		Object[] keys = emfModelCache.keySet().toArray();
		for (int i = 0; i < keys.length; i++) {
			modelManager = (EMFModelManager) emfModelCache.remove(keys[i]);
			if (modelManager != null) {
				modelManager.dispose();
			}
		}
	}
	

	/**
	 * @param aProject
	 */
	public void notifyListeners(IProject aProject) {
		for (int x = 0; x < listeners.size(); ++x) {
			IRefreshHandlerListener refreshHandler = (IRefreshHandlerListener) listeners.get(x);
			refreshHandler.onRefresh(aProject);
		}

	}
	
	public void addRefreshHandlerListener(IRefreshHandlerListener aListener) {
		synchronized (getListeners()) {
			if (aListener != null && !getListeners().contains(aListener))
				getListeners().add(aListener);
		}
	}

	public void removeRefreshHandlerListener(IRefreshHandlerListener aListener) {
		synchronized (listeners) {
			listeners.remove(aListener);
		}
	}

	/**
	 * Insert the method's description here. Creation date: (4/11/2001 4:42:58 PM)
	 * 
	 * @return java.util.List
	 */
	protected java.util.List getListeners() {
		return listeners;
	}
	

}