/*******************************************************************************
 * Copyright (c) 2003, 2009 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
 *******************************************************************************/
package org.eclipse.wst.web.ui.internal.wizards;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.SortedSet;

import org.eclipse.jface.dialogs.IDialogSettings;
import org.eclipse.jface.layout.GridDataFactory;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Group;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.IWorkingSet;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.dialogs.WorkingSetGroup;
import org.eclipse.wst.common.componentcore.datamodel.properties.IFacetProjectCreationDataModelProperties;
import org.eclipse.wst.common.frameworks.datamodel.DataModelEvent;
import org.eclipse.wst.common.frameworks.datamodel.DataModelPropertyDescriptor;
import org.eclipse.wst.common.frameworks.datamodel.IDataModel;
import org.eclipse.wst.common.frameworks.datamodel.IDataModelListener;
import org.eclipse.wst.common.frameworks.internal.datamodel.ui.DataModelWizardPage;
import org.eclipse.wst.common.frameworks.internal.operations.IProjectCreationPropertiesNew;
import org.eclipse.wst.common.frameworks.internal.ui.NewProjectGroup;
import org.eclipse.wst.common.project.facet.core.IFacetedProjectWorkingCopy;
import org.eclipse.wst.common.project.facet.core.IPreset;
import org.eclipse.wst.common.project.facet.core.IProjectFacet;
import org.eclipse.wst.common.project.facet.core.IProjectFacetVersion;
import org.eclipse.wst.common.project.facet.core.ProjectFacetsManager;
import org.eclipse.wst.common.project.facet.core.events.IFacetedProjectEvent;
import org.eclipse.wst.common.project.facet.core.events.IFacetedProjectListener;
import org.eclipse.wst.common.project.facet.core.events.IProjectFacetsChangedEvent;
import org.eclipse.wst.common.project.facet.core.runtime.IRuntime;
import org.eclipse.wst.common.project.facet.core.runtime.IRuntimeComponent;
import org.eclipse.wst.common.project.facet.core.runtime.RuntimeManager;
import org.eclipse.wst.common.project.facet.core.util.AbstractFilter;
import org.eclipse.wst.common.project.facet.core.util.FilterEvent;
import org.eclipse.wst.common.project.facet.core.util.IFilter;
import org.eclipse.wst.common.project.facet.ui.ModifyFacetedProjectWizard;
import org.eclipse.wst.common.project.facet.ui.PresetSelectionPanel;
import org.eclipse.wst.project.facet.ProductManager;
import org.eclipse.wst.server.ui.ServerUIUtil;
import org.eclipse.wst.web.internal.ResourceHandler;
import org.eclipse.wst.web.internal.facet.RuntimePresetMappingRegistry;

public class DataModelFacetCreationWizardPage extends DataModelWizardPage implements IFacetProjectCreationDataModelProperties {

	private static final String NULL_RUNTIME = "NULL_RUNTIME"; //$NON-NLS-1$
	private static final String MRU_RUNTIME_STORE = "MRU_RUNTIME_STORE"; //$NON-NLS-1$
	
	protected static final String RESOURCE_WORKING_SET = "org.eclipse.ui.resourceWorkingSetPage"; //$NON-NLS-1$
	protected static final String JAVA_WORKING_SET = "org.eclipse.jdt.ui.JavaWorkingSetPage"; //$NON-NLS-1$
	
	protected IProjectFacet primaryProjectFacet = null;
	protected Combo primaryVersionCombo = null;
	
	protected WorkingSetGroup workingSetGroup;
	
	protected Set<IProjectFacetVersion> getFacetConfiguration( final IProjectFacetVersion primaryFacetVersion )
	{
	    final Set<IProjectFacetVersion> config = new HashSet<IProjectFacetVersion>();
	    
	    for( IProjectFacet fixedFacet : this.fpjwc.getFixedProjectFacets() )
	    {
	        if( fixedFacet == primaryFacetVersion.getProjectFacet() )
	        {
	            config.add( primaryFacetVersion );
	        }
	        else
	        {
	            config.add( this.fpjwc.getHighestAvailableVersion( fixedFacet ) );
	        }
	    }
	    
	    return config;
	}
	
	private static final String[] VALIDATION_PROPERTIES = 
	{
	    IProjectCreationPropertiesNew.PROJECT_NAME, 
	    IProjectCreationPropertiesNew.PROJECT_LOCATION, 
	    FACET_RUNTIME,
	    FACETED_PROJECT_WORKING_COPY
	};
	
	protected static GridData gdhfill() {
		return new GridData(GridData.FILL_HORIZONTAL);
	}
    
    protected static GridData hspan( final GridData gd,
                                     final int span ) 
    {
        gd.horizontalSpan = span;
        return gd;
    }

	@Override
	protected Composite createTopLevelComposite(Composite parent) {
		Composite top = new Composite(parent, SWT.NONE);
		PlatformUI.getWorkbench().getHelpSystem().setHelp(top, getInfopopID());
		top.setLayout(new GridLayout());
		top.setLayoutData(new GridData(GridData.FILL_BOTH));
		createProjectGroup(top);
		createServerTargetComposite(top);
		createPrimaryFacetComposite(top);
        createPresetPanel(top);
        return top;
	}
	
	private String getPrimaryFacetCompositeLabel()
	{
	    final StringBuilder buf = new StringBuilder();
	    boolean firstWord = true;
	    
	    for( String word : primaryProjectFacet.getLabel().split( " " ) ) //$NON-NLS-1$
	    {
	        if( firstWord )
	        {
	            buf.append( word );
	            firstWord = false;
	        }
	        else
	        {
	            buf.append( ' ' );
	            
    	        if( word.length() == 1 || ! Character.isUpperCase( word.charAt( 1 ) ) )
    	        {
    	            buf.append( Character.toLowerCase( word.charAt( 0 ) ) );
    	            buf.append( word.substring( 1 ) );
    	        }
    	        else
    	        {
    	            buf.append( word );
    	        }
	        }
	    }
	    
	    buf.append( ' ' );
	    buf.append( Messages.FACET_VERSION );
	    
	    return buf.toString();
	}

	protected void createPrimaryFacetComposite(Composite top) {
		primaryProjectFacet = ProjectFacetsManager.getProjectFacet( getModuleTypeID() );
		if (primaryProjectFacet.getVersions().size()  <= 1){
			//there is no need to create this section if there is only one
			//facet version to choose from (e.g. utility and static web)
			return;
		}
		
		final Group group = new Group( top, SWT.NONE );
        group.setLayoutData( gdhfill() );
        group.setLayout( new GridLayout( 1, false ) );
        group.setText( getPrimaryFacetCompositeLabel() );
		
        primaryVersionCombo = new Combo( group, SWT.BORDER | SWT.READ_ONLY );
        primaryVersionCombo.setLayoutData( gdhfill() );
        updatePrimaryVersions();
        
        primaryVersionCombo.addSelectionListener
        (
            new SelectionAdapter()
            {
                @Override
                public void widgetSelected( final SelectionEvent e )
                {
                    handlePrimaryFacetVersionSelectedEvent();
                }
            }
        );
        
        fpjwc.addListener(new IFacetedProjectListener() {
			public void handleEvent(IFacetedProjectEvent event) {
				if(event.getType() == IFacetedProjectEvent.Type.PROJECT_FACETS_CHANGED){
					//this block is to update the combo when the underlying facet version changes
					IProjectFacetsChangedEvent actionEvent = (IProjectFacetsChangedEvent)event;
					Set<IProjectFacetVersion> changedVersions = actionEvent.getFacetsWithChangedVersions();
					
					boolean foundComboVersion = false;
					for(Iterator <IProjectFacetVersion> iterator = changedVersions.iterator(); iterator.hasNext() && !foundComboVersion;){
						IProjectFacetVersion next = iterator.next();
						if(next.getProjectFacet().equals(primaryProjectFacet)){
							foundComboVersion = true;
							final IProjectFacetVersion selectedVersion = next;
							Display.getDefault().asyncExec(new Runnable(){
								public void run() {
									String selectedText = primaryVersionCombo.getItem(primaryVersionCombo.getSelectionIndex());
									if(!selectedText.equals(selectedVersion.getVersionString())){
										String [] items = primaryVersionCombo.getItems();
										int selectedVersionIndex = -1;
										for(int i=0;i<items.length && selectedVersionIndex == -1; i++){
											if(items[i].equals(selectedVersion.getVersionString())){
												selectedVersionIndex = i;
												primaryVersionCombo.select(selectedVersionIndex);
											}
										}
									}	
								}
							});
						}
					}
				} else if(event.getType() == IFacetedProjectEvent.Type.PRIMARY_RUNTIME_CHANGED){
					//this block updates the items in the combo when the runtime changes
					Display.getDefault().asyncExec(new Runnable(){
						public void run() {
							updatePrimaryVersions();
						}
					});
				}
			}
        	
        }, IFacetedProjectEvent.Type.PROJECT_FACETS_CHANGED, IFacetedProjectEvent.Type.PRIMARY_RUNTIME_CHANGED);
	}
	
	protected IProjectFacet getPrimaryFacet()
	{
	    return this.primaryProjectFacet;
	}
	
	public IProjectFacetVersion getPrimaryFacetVersion()
	{
	    IProjectFacetVersion fv = null;
	    
	    if( this.primaryProjectFacet.getVersions().size() > 1 )
	    {
            final int selectedIndex = this.primaryVersionCombo.getSelectionIndex();
    
            if( selectedIndex != -1 )
            {
                final String fvstr = this.primaryVersionCombo.getItem( selectedIndex );
                fv = this.primaryProjectFacet.getVersion( fvstr );
            }
	    }
	    else
	    {
	        fv = this.primaryProjectFacet.getDefaultVersion();
	    }
        
        return fv;
	}
	
	protected void handlePrimaryFacetVersionSelectedEvent()
	{
	    final IProjectFacetVersion fv = getPrimaryFacetVersion();
        if( fv != null )
        {
        	String presetID = null;
        	IRuntime runtime = (IRuntime)model.getProperty(IFacetProjectCreationDataModelProperties.FACET_RUNTIME);
        	if(runtime != null){
        		if(runtime.getRuntimeComponents().size() > 0){
        			IRuntimeComponent runtimeComponent = runtime.getRuntimeComponents().get(0);
        			String facetRuntimeTypeID = runtimeComponent.getRuntimeComponentType().getId();
        			String facetRuntimeVersion = runtimeComponent.getRuntimeComponentVersion().getVersionString();
        			String facetID = fv.getProjectFacet().getId();
		    	    String facetVersion = fv.getVersionString();
		    	    presetID = RuntimePresetMappingRegistry.INSTANCE.getPresetID(facetRuntimeTypeID, facetRuntimeVersion, facetID, facetVersion);	
        		}
        	}
        	
        	if( presetID == null )
        	{
                final Set<IProjectFacetVersion> facets = getFacetConfiguration( fv );
                this.fpjwc.setProjectFacets( facets );
        	}
        	else
        	{  // setting the facets prior to setting the preset is to let the dynamic presets adjust
        		final Set<IProjectFacetVersion> facets = getFacetConfiguration( fv );
                this.fpjwc.setProjectFacets( facets );
        		this.fpjwc.setSelectedPreset(presetID);
        		
        	}
        }
	}

	protected void updatePrimaryVersions(){
		IProjectFacetVersion selectedVersion = fpjwc.getProjectFacetVersion(primaryProjectFacet);
		SortedSet<IProjectFacetVersion> initialVersions = fpjwc.getAvailableVersions(primaryProjectFacet);
        String [] items = new String[initialVersions.size()];
        int i=0;
        int selectedVersionIndex = -1;
        for(Iterator <IProjectFacetVersion> iterator = initialVersions.iterator(); iterator.hasNext(); i++){
        	items[i] = iterator.next().getVersionString();
        	if(selectedVersionIndex == -1 && items[i].equals(selectedVersion.getVersionString())){
        		selectedVersionIndex = i;
        	}
        }
        primaryVersionCombo.clearSelection();
        primaryVersionCombo.setItems(items);
        primaryVersionCombo.select(selectedVersionIndex);
	}
	
	public static class Messages extends NLS {
		private static final String BUNDLE_NAME = "org.eclipse.wst.web.ui.internal.wizards.facetcreationpagemessages"; //$NON-NLS-1$

		public static String FACET_VERSION;
		
		static {
			// initialize resource bundle
			NLS.initializeMessages(BUNDLE_NAME, Messages.class);
		}

		private Messages() {
		}
	}
	
	protected void createPresetPanel(Composite top) {
		final IFacetedProjectWorkingCopy fpjwc
            = ( (ModifyFacetedProjectWizard) getWizard() ).getFacetedProjectWorkingCopy();
		
		final IFilter<IPreset> filter = new AbstractFilter<IPreset>()
		{
		    {
		        fpjwc.addListener
		        (
		            new IFacetedProjectListener()
		            {
                        public void handleEvent( final IFacetedProjectEvent event )
                        {
                            handleProjectFacetsChangedEvent( (IProjectFacetsChangedEvent) event );
                        }
		            }, 
		            IFacetedProjectEvent.Type.PROJECT_FACETS_CHANGED 
		        );
		    }
		    
            public boolean check( final IPreset preset )
            {
                final IProjectFacetVersion primaryFacetVersion = getPrimaryFacetVersion();
                return preset.getProjectFacets().contains( primaryFacetVersion );
            }
            
            private void handleProjectFacetsChangedEvent( final IProjectFacetsChangedEvent event )
            {
                for( IProjectFacetVersion fv : event.getFacetsWithChangedVersions() )
                {
                    if( fv.getProjectFacet() == getPrimaryFacet() )
                    {
                        final IFilterEvent<IPreset> filterEvent
                            = new FilterEvent<IPreset>( this, IFilterEvent.Type.FILTER_CHANGED );
                        
                        notifyListeners( filterEvent );
                    }
                }
            }
		};

        final PresetSelectionPanel ppanel = new PresetSelectionPanel( top, fpjwc, filter );
        
        ppanel.setLayoutData( gdhfill() );
	}
	
	public static boolean launchNewRuntimeWizard(Shell shell, IDataModel model) {
		return launchNewRuntimeWizard(shell, model, null);
	}
	
	public static boolean launchNewRuntimeWizard(Shell shell, final IDataModel model, String serverTypeID) 
	{
	    if( model == null )
	    {
	        return false;
	    }
	    
		final DataModelPropertyDescriptor[] preAdditionDescriptors = model.getValidPropertyDescriptors(FACET_RUNTIME);
		
		final boolean[] keepWaiting = { true };
		
		final IDataModelListener listener = new IDataModelListener()
		{
            public void propertyChanged( final DataModelEvent event )
            {
                if( event.getPropertyName().equals( FACET_RUNTIME ) &&
                    event.getFlag() == DataModelEvent.VALID_VALUES_CHG )
                {
                    synchronized( keepWaiting )
                    {
                        keepWaiting[ 0 ] = false;
                        keepWaiting.notify();
                    }
                    
                    model.removeListener( this );
                }
            }
		};
		
		model.addListener( listener );
		
		boolean isOK = ServerUIUtil.showNewRuntimeWizard(shell, serverTypeID, null);
		
		if( isOK ) 
		{
		    // Do the rest of the processing in a separate thread. Since we are going to block
		    // and wait, doing this on the UI thread can cause hangs.
		    
		    final Thread newRuntimeSelectionThread = new Thread()
		    {
		        @Override
				public void run()
		        {
        		    // Causes the list of runtimes held by the RuntimeManager to be refreshed and 
        		    // triggers events to listeners on that list.
        		    
        		    RuntimeManager.getRuntimes();
        		    
        		    // Wait until the list of valid values has updated to include the new runtime.
        		    
        		    synchronized( keepWaiting )
        		    {
        		        while( keepWaiting[ 0 ] == true )
        		        {
        		            try
        		            {
        		                keepWaiting.wait();
        		            }
        		            catch( InterruptedException e ) {}
        		        }
        		    }
        		    
        		    // Select the new runtime.
        		    
        			DataModelPropertyDescriptor[] postAdditionDescriptors = model.getValidPropertyDescriptors(FACET_RUNTIME);
        			Object[] preAddition = new Object[preAdditionDescriptors.length];
        			for (int i = 0; i < preAddition.length; i++) {
        				preAddition[i] = preAdditionDescriptors[i].getPropertyValue();
        			}
        			Object[] postAddition = new Object[postAdditionDescriptors.length];
        			for (int i = 0; i < postAddition.length; i++) {
        				postAddition[i] = postAdditionDescriptors[i].getPropertyValue();
        			}
        			Object newAddition = getNewObject(preAddition, postAddition);
        
        			if (newAddition != null) // can this ever be null?
        				model.setProperty(FACET_RUNTIME, newAddition);
		        }
		    };
		    
		    newRuntimeSelectionThread.start();
		    
		    return true;
		}
	    model.removeListener( listener );
	    return false;
	}
	
	public boolean internalLaunchNewRuntimeWizard(Shell shell, IDataModel model) {
		return launchNewRuntimeWizard(shell, model, getModuleTypeID());
	}
	
	protected String getModuleTypeID() {
		return null;
	}
	
	protected Combo serverTargetCombo;
	protected NewProjectGroup projectNameGroup;
	private final IFacetedProjectWorkingCopy fpjwc;
	private final IFacetedProjectListener fpjwcListener;

	public DataModelFacetCreationWizardPage(IDataModel dataModel, String pageName) 
	{
		super(dataModel, pageName);
		
        this.fpjwc = (IFacetedProjectWorkingCopy) this.model.getProperty( FACETED_PROJECT_WORKING_COPY );
        
        this.fpjwcListener = new IFacetedProjectListener()
        {
            public void handleEvent( final IFacetedProjectEvent event )
            {
                final Runnable runnable = new Runnable()
                {
                    public void run()
                    {
                        validatePage();
                    }
                };
                
                getContainer().getShell().getDisplay().asyncExec( runnable );
            }
        };
        
        this.fpjwc.addListener( this.fpjwcListener, IFacetedProjectEvent.Type.VALIDATION_PROBLEMS_CHANGED );
	}

	protected void createServerTargetComposite(Composite parent) {
        Group group = new Group(parent, SWT.NONE);
        group.setText(ResourceHandler.TargetRuntime);
        group.setLayoutData(gdhfill());
        group.setLayout(new GridLayout(2, false));
		serverTargetCombo = new Combo(group, SWT.BORDER | SWT.READ_ONLY);
		serverTargetCombo.setLayoutData(gdhfill());
		Button newServerTargetButton = new Button(group, SWT.NONE);
		newServerTargetButton.setText(Resources.newRuntimeButton);
		GridDataFactory.defaultsFor(newServerTargetButton).applyTo(newServerTargetButton);		
		newServerTargetButton.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				if (!internalLaunchNewRuntimeWizard(getShell(), model)) {
					//Bugzilla 135288
					//setErrorMessage(ResourceHandler.InvalidServerTarget);
				}
			}
		});
		Control[] deps = new Control[]{newServerTargetButton};
		synchHelper.synchCombo(serverTargetCombo, FACET_RUNTIME, deps);
		if (serverTargetCombo.getSelectionIndex() == -1 && serverTargetCombo.getVisibleItemCount() != 0)
			serverTargetCombo.select(0);
	}

	protected void createProjectGroup(Composite parent) {
		IDataModel nestedProjectDM = model.getNestedModel(NESTED_PROJECT_DM);
		nestedProjectDM.addListener(this);
		projectNameGroup = new NewProjectGroup(parent, nestedProjectDM);
	}

	@Override
	protected String[] getValidationPropertyNames() 
	{
	    return VALIDATION_PROPERTIES;
	}

	@Override
	public void dispose() {
		super.dispose();
		if (projectNameGroup != null)
			projectNameGroup.dispose();
		
		this.fpjwc.removeListener( this.fpjwcListener );
	}

	@Override
	public void storeDefaultSettings() {
		IDialogSettings settings = getDialogSettings();
		DataModelFacetCreationWizardPage.saveRuntimeSettings(settings, model);
	}

	@Override
	public void restoreDefaultSettings() {
		IDialogSettings settings = getDialogSettings();
		DataModelFacetCreationWizardPage.restoreRuntimeSettings(settings, model);
	}
	
	public static void saveRuntimeSettings(IDialogSettings settings, IDataModel model){
		if (settings != null) {
			String[] mruRuntimeArray = settings.getArray(MRU_RUNTIME_STORE);
			List mruRuntimes = new ArrayList();
			if(mruRuntimeArray != null)
				mruRuntimes.addAll(Arrays.asList(mruRuntimeArray));
			
			IRuntime runtime = (IRuntime) model.getProperty(IFacetProjectCreationDataModelProperties.FACET_RUNTIME);
			String runtimeName = runtime == null ? NULL_RUNTIME : runtime.getName();
			
			if (mruRuntimes.contains(runtimeName)) {
				mruRuntimes.remove(runtimeName);
			}
			mruRuntimes.add(0, runtimeName);
			while (mruRuntimes.size() > 5) {
				mruRuntimes.remove(5);
			}
			mruRuntimeArray = new String[mruRuntimes.size()];
			for (int i = 0; i < mruRuntimeArray.length; i++) {
				mruRuntimeArray[i] = (String) mruRuntimes.get(i);
			}
			settings.put(MRU_RUNTIME_STORE, mruRuntimeArray);
		}
	}
	
	public static void restoreRuntimeSettings(IDialogSettings settings, IDataModel model){
		if (settings != null) {
			if (!model.isPropertySet(IFacetProjectCreationDataModelProperties.FACET_RUNTIME)) {
				boolean runtimeSet = false;
				String[] mruRuntimeArray = settings.getArray(MRU_RUNTIME_STORE);
				DataModelPropertyDescriptor[] descriptors = model.getValidPropertyDescriptors(IFacetProjectCreationDataModelProperties.FACET_RUNTIME);
				List mruRuntimes = new ArrayList();
				if (mruRuntimeArray == null) {
					List defRuntimes = ProductManager.getDefaultRuntimes();
					for (Iterator iter = defRuntimes.iterator(); iter.hasNext();)
						mruRuntimes.add(((IRuntime) iter.next()).getName());
				} else {
					mruRuntimes.addAll(Arrays.asList(mruRuntimeArray));
				}
				if (!mruRuntimes.isEmpty()) {
					for (int i = 0; i < mruRuntimes.size() && !runtimeSet; i++) {
						for (int j = 0; j < descriptors.length-1 && !runtimeSet; j++) {
							if (mruRuntimes.get(i).equals(((IRuntime)descriptors[j].getPropertyValue()).getName())) {
								model.setProperty(IFacetProjectCreationDataModelProperties.FACET_RUNTIME, descriptors[j].getPropertyValue());
								runtimeSet = true;
							}
						}
						if(!runtimeSet && mruRuntimes.get(i).equals(NULL_RUNTIME)){
							model.setProperty(IFacetProjectCreationDataModelProperties.FACET_RUNTIME, descriptors[descriptors.length -1].getPropertyValue());
							runtimeSet = true;
						}
					}
				}
				if (!runtimeSet && descriptors.length > 0) {
					model.setProperty(IFacetProjectCreationDataModelProperties.FACET_RUNTIME, descriptors[0].getPropertyValue());
				}
			}
		}
	}
	

	/**
	 * Find first newObject that is not in the oldObjects array (using "==").
	 * 
	 * @param oldObjects
	 * @param newObjects
	 * @return first newObject not found in oldObjects, or <code>null</code> if all found.
	 * 
	 * @since 1.0.0
	 */
	private static Object getNewObject(Object[] oldObjects, Object[] newObjects) {
		if (oldObjects != null && newObjects != null && oldObjects.length < newObjects.length) {
			for (int i = 0; i < newObjects.length; i++) {
				boolean found = false;
				Object object = newObjects[i];
				for (int j = 0; j < oldObjects.length; j++) {
					if (oldObjects[j] == object) {
						found = true;
						break;
					}
				}
				if (!found)
					return object;
			}
		}
		if (oldObjects == null && newObjects != null && newObjects.length == 1)
			return newObjects[0];
		return null;
	}
	
	protected WorkingSetGroup createWorkingSetGroup(Composite composite,
			IStructuredSelection selection, String[] supportedWorkingSetTypes) {
		if (workingSetGroup != null)
			return workingSetGroup;
		workingSetGroup = new WorkingSetGroup(composite, selection,
				supportedWorkingSetTypes);
		return workingSetGroup;
	}
	
	protected WorkingSetGroup createWorkingSetGroupPanel(Composite composite, String[] workingSetTypes) {
		IStructuredSelection structuredSelection = null;
		ISelection currentSelection = PlatformUI.getWorkbench()
				.getActiveWorkbenchWindow().getSelectionService()
				.getSelection();
		if (currentSelection instanceof IStructuredSelection) {
			structuredSelection = (IStructuredSelection) currentSelection;
		}
		WorkingSetGroup group = createWorkingSetGroup(composite, structuredSelection, workingSetTypes);
		return group;
	} 
	
	public IWorkingSet[] getSelectedWorkingSets() {
		return workingSetGroup == null ? new IWorkingSet[0] : workingSetGroup
				.getSelectedWorkingSets();
	}
	
    private static final class Resources extends NLS
    {
        public static String newRuntimeButton;
        
        static
        {
            initializeMessages( DataModelFacetCreationWizardPage.class.getName(), Resources.class );
        }
    }
	
}