/*******************************************************************************
 * Copyright (c) 2008 Oracle Corporation.
 * 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:
 *    Cameron Bateman - initial API and implementation
 *******************************************************************************/
package org.eclipse.jst.jsf.facelet.core.internal.facet;

import java.util.Iterator;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.emf.common.util.EList;
import org.eclipse.jst.jsf.facelet.core.internal.FaceletCoreTraceOptions;
import org.eclipse.jst.jsf.facesconfig.emf.ApplicationType;
import org.eclipse.jst.jsf.facesconfig.emf.FacesConfigType;
import org.eclipse.jst.jsf.facesconfig.emf.ViewHandlerType;
import org.eclipse.ui.PlatformUI;
import org.eclipse.wst.common.project.facet.core.IDelegate;
import org.eclipse.wst.common.project.facet.core.IProjectFacetVersion;

/**
 * The super-class of all Facelet facet change delegates.  The only expected 
 * delegates at this time are install and uninstall.  Each super-class must
 * decide the meaning of "change" and implement the abstract members 
 * appropriately.
 * 
 * @author cbateman
 *
 */
public abstract class FaceletChangeDelegate implements IDelegate
{
    /**
     * The default name of the Facelet runtime view handler
     */
    protected static final String RUNTIME_VIEWHANDLER_CLASS_NAME = "com.sun.facelets.FaceletViewHandler"; //$NON-NLS-1$

    public void execute(final IProject project, final IProjectFacetVersion fv,
            final Object config, final IProgressMonitor monitor)
            throws CoreException
    {
        PlatformUI.getWorkbench().getDisplay().syncExec(new Runnable()
        {
            public void run()
            {
                final FacetChangeModel model = (FacetChangeModel) config;

                // XXX: look at glassfish changes
                handleDesignTimeViewHandler(project);

                if (model.isChgViewHandler())
                {
                    maybeChangeFaceletViewHandler(project, monitor);
				}
				
				final WebAppConfigurator configurator = WebAppConfigurator
                        .getConfigurator(project);

                if (configurator != null)
                {
                    maybeChangeDefaultSuffix(model, configurator);
                    maybeChangeConfigureListener(model, configurator);
                    maybeChangeWebLifecycleListener(model, configurator);
                }
                else if (FaceletCoreTraceOptions.TRACE_FACETCHANGEDELEGATE)
                {
                    FaceletCoreTraceOptions
                            .log("FaceletChangeDelegate: No web configurator"); //$NON-NLS-1$
                }
            }
        });
    }

    /**
     * Performs the change to the web lifecycle listener configuration of of the
     * web.xml model using configurator, if applicable.
     * 
     * @param model
     * @param configurator
     */
    protected abstract void maybeChangeWebLifecycleListener(
            FacetChangeModel model, WebAppConfigurator configurator);

    /**
     * Performs the change to the configure listener configuration of the
     * web.xml model using configurator, if applicable.
     * 
     * @param model
     * @param configurator
     */
    protected abstract void maybeChangeConfigureListener(
            FacetChangeModel model, WebAppConfigurator configurator);

    /**
     * Performs the change to the DEFAULT_SUFFIX configuration of the web.xml
     * model using configurator, if applicable.
     * 
     * @param model
     * @param configurator
     */
    protected abstract void maybeChangeDefaultSuffix(FacetChangeModel model,
            WebAppConfigurator configurator);

    /**
     * Changes the runtime view handler settings on project if applicable.
     * 
     * @param project
     * @param monitor
     * 
     */
    protected abstract void maybeChangeFaceletViewHandler(IProject project,
            IProgressMonitor monitor);

    /**
     * Change the designtime view handler if applicable.
     * 
     * @param project
     */
    protected abstract void handleDesignTimeViewHandler(final IProject project);

    /**
     * @return a user displayable name of the sub-classing change delegate.
     */
    protected abstract String getDisplayName();

    /**
     * @param root
     * @return true if the Facelet view handler is already present in the
     *         WEB-INF/faces-config.xml file.
     */
    protected final boolean isViewHandlerPresent(final FacesConfigType root)
    {
        final EList<?> applications = root.getApplication();
        for (final Object name : applications)
        {
            final ApplicationType app = (ApplicationType) name;
            if (app != null)
            {
                for (final Iterator<?> viewIt = app.getViewHandler().iterator(); viewIt
                        .hasNext();)
                {
                    final ViewHandlerType viewHandler = (ViewHandlerType) viewIt
                            .next();
                    if (viewHandler != null && viewHandler.getTextContent() != null
                            && RUNTIME_VIEWHANDLER_CLASS_NAME
                                    .equals(viewHandler.getTextContent().trim()))
                    {
                        return true;
                    }
                }
            }
        }
        return false;
    }
}