/**

  * Copyright 2005-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  * http://www.opensource.org/licenses/ecl2.php

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.kuali.rice.edl.impl;

 import org.apache.commons.lang.StringUtils;

 import org.apache.log4j.Logger;

 import org.kuali.rice.core.api.util.xml.XmlJotter;

 import org.kuali.rice.kim.api.identity.Person;

 import org.kuali.rice.krad.util.GlobalVariables;

 import org.w3c.dom.Document;

 import javax.servlet.http.HttpServletResponse;

 import javax.xml.transform.OutputKeys;

 import javax.xml.transform.Transformer;

 import javax.xml.transform.dom.DOMSource;

 import javax.xml.transform.stream.StreamResult;

 import java.util.Stack;

 /**

  * Contains a stack of EDLControllers.  Allows EDL components to add new controllers to the chain runtime.  The idea

  * being that this is how you would page between edls.  Uses the template associated with the last edl controller

  * to render the dom of the last edl controller.

  *

  * @author Kuali Rice Team (rice.collab@kuali.org)

  *

  */

 public class EDLControllerChain {

         private static final Logger LOG = Logger.getLogger(EDLControllerChain.class);

         private Stack<EDLController> edlControllers = new Stack<EDLController>();

         public void renderEDL(RequestParser requestParser, HttpServletResponse response) throws Exception {

                 EDLController edlController = edlControllers.pop();

                 edlController.setEdlContext(getInitialEDLContext(edlController, requestParser, edlController.getStyle().newTransformer()));

                 Document dom = edlController.notifyComponents();

                 if (edlControllers.isEmpty()) {

                         transform(edlController.getEdlContext(), dom, response);

                 } else {

                         renderEDL(requestParser, response);

                 }

         }

         public void addEdlController(EDLController edlController) {

                 edlControllers.add(edlController);

         }

         private void transform(EDLContext edlContext, Document dom, HttpServletResponse response) throws Exception {

                 if (StringUtils.isNotBlank(edlContext.getRedirectUrl())) {

                         response.sendRedirect(edlContext.getRedirectUrl());

                         return;

                 }

             response.setContentType("text/html; charset=UTF-8");

                 Transformer transformer = edlContext.getTransformer();

         transformer.setOutputProperty("indent", "yes");

         transformer.setOutputProperty(OutputKeys.INDENT, "yes");

         String user = null;

         String loggedInUser = null;

         if (edlContext.getUserSession() != null) {

             Person wu = edlContext.getUserSession().getPerson();

             if (wu != null) user = wu.getPrincipalId();

             wu = edlContext.getUserSession().getPerson();

             if (wu != null) loggedInUser = wu.getPrincipalId();

         }

         transformer.setParameter("user", user);

         transformer.setParameter("loggedInUser", loggedInUser);

         if (LOG.isDebugEnabled()) {

                 LOG.debug("Transforming dom " + XmlJotter.jotNode(dom, true));

         }

         transformer.transform(new DOMSource(dom), new StreamResult(response.getOutputStream()));

         }

         private EDLContext getInitialEDLContext(EDLController edlController, RequestParser requestParser, Transformer transformer) {

                 EDLContext edlContext = new EDLContext();

                 edlContext.setEdlControllerChain(this);

                 edlContext.setEdocLiteAssociation(edlController.getEdocLiteAssociation());

                 edlContext.setUserSession(GlobalVariables.getUserSession());

                 edlContext.setTransformer(transformer);

                 edlContext.setRequestParser(requestParser);

                 return edlContext;

         }

 }