/*******************************************************************************
 * Copyright (c) 2005 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:
 *    Gerry Kessler - initial API and implementation
 *******************************************************************************/ 
package org.eclipse.jst.jsf.core.internal.project.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.jst.j2ee.common.ParamValue;
import org.eclipse.jst.j2ee.internal.J2EEVersionConstants;
import org.eclipse.jst.j2ee.web.componentcore.util.WebArtifactEdit;
import org.eclipse.jst.j2ee.webapplication.ContextParam;
import org.eclipse.jst.j2ee.webapplication.Servlet;
import org.eclipse.jst.j2ee.webapplication.WebApp;
import org.eclipse.wst.common.project.facet.core.IDelegate;
import org.eclipse.wst.common.project.facet.core.IProjectFacetVersion;

/**
 * JSF Facet Uninstall Delegate for WTP faceted projects.
 *	
 *	<li> removes JSF servlet, servlet-mappings and context-params
 *	<li> leaves JSF configuration files on disk
 *  <li> removes JSF classpath containers
 *  
 * @author Gerry Kessler - Oracle
 * @since M1
 */
public class JSFFacetUninstallDelegate implements IDelegate {

	public void execute(IProject project, IProjectFacetVersion fv,
			Object config, IProgressMonitor monitor) throws CoreException {
		{

			if (monitor != null) {
				monitor.beginTask("", 1); //$NON-NLS-1$
			}

			try {

				// Remove JSF App Model

				// Rempoe JSF Impl Class Container
				// Add JSF Impl Class Container
				// final IJavaProject jproj = JavaCore.create(project);
				// final IPath cont = new
				// Path(JSFImplContainer.CONTAINER_ID).append(project.getName());
				// removeClasspathContainer(jproj, cont);

				// remove servlet stuff from web.xml
				uninstallJSFReferencesFromWebApp(project, monitor);

				if (monitor != null) {
					monitor.worked(1);
				}
			} finally {
				if (monitor != null) {
					monitor.done();
				}
			}
		}
	}

	private void uninstallJSFReferencesFromWebApp(IProject project,
			IProgressMonitor monitor) {
		WebArtifactEdit artifactEdit = JSFUtils
				.getWebArtifactEditForWrite(project);
		WebApp webApp = artifactEdit.getWebApp();

		try {
			Servlet servlet = JSFUtils.findJSFServlet(webApp);
			if (servlet == null)
				return;

			// remove faces url mappings
			removeJSFURLMappings(webApp, servlet);
			// remove context params
			removeJSFContextParams(webApp, servlet);
			// remove servlet
			removeJSFServlet(webApp, servlet);

		} finally {
			if (artifactEdit != null) {
				artifactEdit.saveIfNecessary(monitor);
				artifactEdit.dispose();
			}
		}

	}

	private void removeJSFURLMappings(WebApp webApp, Servlet servlet) {
		while (webApp.getServletMapping(servlet) != null) {
			webApp.getServletMappings().remove(
					webApp.getServletMapping(servlet));
		}
	}

	private void removeJSFContextParams(WebApp webApp, Servlet servlet) {
		if (webApp.getVersionID() == J2EEVersionConstants.WEB_2_3_ID){
			Iterator it = webApp.getContexts().iterator();
			while (it.hasNext()) {
				ContextParam cp = (ContextParam) it.next();
				if (cp.getParamName().equals(JSFUtils.JSF_CONFIG_CONTEXT_PARAM)) {
					webApp.getContexts().remove(cp);
					break;
				}
			}
		}
		else {//could check for 2_4 version here.   
			//hoping that the API gets fixed so I don't need to do any of this version checking
			Iterator it = webApp.getContextParams().iterator();
			while (it.hasNext()) {
				ParamValue cp = (ParamValue) it.next();
				if (cp.getName().equals(JSFUtils.JSF_CONFIG_CONTEXT_PARAM)) {
					webApp.getContextParams().remove(cp);
					break;
				}
			}
		}
	}

	private void removeJSFServlet(WebApp webApp, Servlet servlet) {
		webApp.getServlets().remove(servlet);
	}

}