/*******************************************************************************
 * 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.launch;

import java.util.Iterator;

import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.jst.j2ee.internal.web.jfaces.extension.FileURL;
import org.eclipse.jst.j2ee.model.IModelProvider;
import org.eclipse.jst.j2ee.model.ModelProviderManager;
import org.eclipse.jst.j2ee.webapplication.Servlet;
import org.eclipse.jst.j2ee.webapplication.ServletMapping;
import org.eclipse.jst.j2ee.webapplication.WebApp;
import org.eclipse.jst.jsf.core.internal.project.facet.JSFUtils11;
import org.eclipse.jst.jsf.core.internal.project.facet.JSFUtils12;

/**
 * Extends the FileURL extension-point so that a JSF JSP page
 * can have it's URL mapped to the Faces Servlet using the servlet-mapping 
 * specified in the web.xml file
 * 
 * @author Gerry Kessler - Oracle
 *
 */
public class JSFFileURL implements FileURL {

	/**
	 * If this is a JSP page, this will return a URL using the first valid servlet-mapping to the Faces Servlet
	 * if found.   If the faces servlet is not defined in the web.xml or there is no servlet-mapping, this will return null.
	 * 
	 * The resource's file extension is compared with the javax.faces.DEFAULT_SUFFIX context-param if set.   If the same, then 
	 * extension mapping will be used if found in the web.xml.  If not set, "jsp" default is assumed.   If resource does not have the default
	 * file extension, then it must have either: jsp,jspx, or jsf file extensions in order to be considered for launch.
	 * 
	 * This will not guarentee a page to be run.  The user will still need a properly configured server with valid URL mappings and
	 * context-params.
	 * 
	 * TODO: We could detect and insert or just warn for context-params and url mappings to run.  However, this would better detected during a JSF App validation step.
	 * 
	 * @see org.eclipse.jst.j2ee.internal.web.jfaces.extension.FileURL#getFileURL(org.eclipse.core.resources.IResource, org.eclipse.core.runtime.IPath)
	 */
	public IPath getFileURL(IResource resource, IPath existingURL) {
		
		//is this is a Faces Project with a Faces Servlet?
		//we will not check to see if facet is installed.  
		// check to see if this resource is a JSF page (currently always true) and then,
		//if servlet is present, we will change the url based on first mapping found 
		IModelProvider provider = ModelProviderManager.getModelProvider(resource.getProject());
		Object webAppObj = provider.getModelObject();
		if (webAppObj != null){
			//methods below returning the path are identical except for the APIs required
			if (JSFUtils12.isWebApp25(webAppObj)){
				return getJavaEEFileURLPath(webAppObj, resource, existingURL);
			} 
			else if (JSFUtils11.isWebApp24(webAppObj) || JSFUtils11.isWebApp23(webAppObj)) {
				return getJ2EEFileURLPath(webAppObj, resource, existingURL);
			}
		}
		return null;			
	}
	
	private IPath getJ2EEFileURLPath(Object webAppObj, IResource resource,
			IPath existingURL) {
		WebApp webApp = (WebApp)webAppObj;
		if (webApp != null){
			Servlet servlet = JSFUtils11.findJSFServlet(webApp);
			if (servlet == null)//if no faces servlet, do nothing
				return null;
			
			//if not a JSF page, do nothing
			if (!isJSFPage(resource))
				return null;
			
			String defaultSuffix = JSFUtils11.getDefaultSuffix(webApp);
			//is the resource using default_suffix
			boolean canUseExtensionMapping = resource.getFileExtension().equalsIgnoreCase(defaultSuffix);
			
			//if not using default extension and is not a known file extension, then we will abort
			if (! canUseExtensionMapping && ! isValidKnownExtension(resource.getFileExtension()))
				return null;
			
			Iterator mappings = servlet.getMappings().iterator();
			ServletMapping map = null;
			String foundFileExtension = null;
			while (mappings.hasNext()){
				map = (ServletMapping)mappings.next();
				
				foundFileExtension = JSFUtils11.getFileExtensionFromMap(map);
				if (foundFileExtension != null && canUseExtensionMapping) {
					return existingURL.removeFileExtension().addFileExtension(foundFileExtension);
				}
					
				String foundPrefixMapping = JSFUtils11.getPrefixMapping(map);
				if (foundPrefixMapping != null){						
					return new Path(foundPrefixMapping).append(existingURL); 
				}
				
			}
			
			if (! canUseExtensionMapping && foundFileExtension != null){
				//we could prompt user that this may not work...
				//for now we will return the extension mapping
				return existingURL.removeFileExtension().addFileExtension(foundFileExtension);
			}
			
			//we could, at this point, add a url mapping to the faces servlet, or prompt user that it may be a good idea to add one... ;-
		}
		return null;
	}

	private IPath getJavaEEFileURLPath(Object webAppObj, IResource resource,
			IPath existingURL) {
		org.eclipse.jst.javaee.web.WebApp webApp = (org.eclipse.jst.javaee.web.WebApp )webAppObj;
		if (webApp != null){
			org.eclipse.jst.javaee.web.Servlet servlet = JSFUtils12.findJSFServlet(webApp);
			if (servlet == null)//if no faces servlet, do nothing
				return null;
			
			//if not a JSF page, do nothing
			if (!isJSFPage(resource))
				return null;
			
			String defaultSuffix = JSFUtils12.getDefaultSuffix(webApp);
			//is the resource using default_suffix
			boolean canUseExtensionMapping = resource.getFileExtension().equalsIgnoreCase(defaultSuffix);
			
			//if not using default extension and is not a known file extension, then we will abort
			if (! canUseExtensionMapping && ! isValidKnownExtension(resource.getFileExtension()))
				return null;
			
			Iterator mappings = webApp.getServletMappings().iterator();
			org.eclipse.jst.javaee.web.ServletMapping map = null;
			String foundFileExtension = null;
			while (mappings.hasNext()){
				map = (org.eclipse.jst.javaee.web.ServletMapping)mappings.next();
				if (map.getServletName().equals(servlet.getServletName())){
					foundFileExtension = JSFUtils12.getFileExtensionFromMap(map);
					if (foundFileExtension != null && canUseExtensionMapping) {
						return existingURL.removeFileExtension().addFileExtension(foundFileExtension);
					}
						
					String foundPrefixMapping = JSFUtils12.getPrefixMapping(map);
					if (foundPrefixMapping != null){						
						return new Path(foundPrefixMapping).append(existingURL); 
					}
				}
			}
			
			if (! canUseExtensionMapping && foundFileExtension != null){
				//we could prompt user that this may not work...
				//for now we will return the extension mapping
				return existingURL.removeFileExtension().addFileExtension(foundFileExtension);
			}
			
			//we could, at this point, add a url mapping to the faces servlet, or prompt user that it may be a good idea to add one... ;-
		}

		return null;
	}

	private boolean isValidKnownExtension(String fileExtension) {
		if ((	fileExtension.equalsIgnoreCase("jsp") ||  //$NON-NLS-1$
				fileExtension.equalsIgnoreCase("jspx") ||  //$NON-NLS-1$
				fileExtension.equalsIgnoreCase("jsf"))) //$NON-NLS-1$
			return true;

		return false;
	}

	
	private boolean isJSFPage(IResource resource) {
		// currently always return true.
		// need to find quick way of determining whether this is a JSF JSP Page
		return true;
	}
}