/**

  * 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.kew.routeheader;

 import java.io.BufferedReader;

 import java.io.IOException;

 import java.io.ObjectInputStream;

 import java.io.Serializable;

 import java.io.StringReader;

 import javax.xml.parsers.DocumentBuilder;

 import javax.xml.parsers.DocumentBuilderFactory;

 import javax.xml.parsers.ParserConfigurationException;

 import org.kuali.rice.core.api.exception.RiceRuntimeException;

 import org.kuali.rice.kew.api.document.InvalidDocumentContentException;

 import org.kuali.rice.kew.engine.RouteContext;

 import org.kuali.rice.kew.api.KewApiConstants;

 import org.w3c.dom.Document;

 import org.w3c.dom.Element;

 import org.w3c.dom.Node;

 import org.w3c.dom.NodeList;

 import org.xml.sax.InputSource;

 import org.xml.sax.SAXException;

 /**

  * Standard implementation of {@link DocumentContent} which nows hows to parse a

  * String that it's constructed with into content with the application,

  * attribute, and searchable content sections.

  *

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

  */

 public class StandardDocumentContent implements DocumentContent, Serializable {

         private static final long serialVersionUID = -3189330007364191220L;

         private static final String LEGACY_FLEXDOC_ELEMENT = "flexdoc";

         private String docContent;

         private transient Document document;

         private transient Element applicationContent;

         private transient Element attributeContent;

         private transient Element searchableContent;

         private RouteContext routeContext;

         public StandardDocumentContent(String docContent) {

                 this(docContent, null);

         }

         public StandardDocumentContent(String docContent, RouteContext routeContext) {

                 this.routeContext = routeContext;

                 initialize(docContent, routeContext);

         }

         private void initialize(String docContent, RouteContext routeContext) {

                 if (org.apache.commons.lang.StringUtils.isEmpty(docContent)) {

                         this.docContent = "";

                         this.document = null;

                 } else {

                         try {

                                 this.docContent = docContent;

                                 this.document = parseDocContent(docContent);

                                 extractElements(this.document);

                         } catch (IOException e) {

                                 throw new InvalidDocumentContentException("I/O Error when attempting to parse document content.", e);

                         } catch (SAXException e) {

                                 throw new InvalidDocumentContentException("XML parse error when attempting to parse document content.", e);

                         } catch (ParserConfigurationException e) {

                                 throw new RiceRuntimeException("XML parser configuration error when attempting to parse document content.", e);

                         }

                 }

         }

         private Document parseDocContent(String docContent) throws IOException, SAXException, ParserConfigurationException {

                 DocumentBuilder documentBuilder = DocumentBuilderFactory.newInstance().newDocumentBuilder();

                 return documentBuilder.parse(new InputSource(new BufferedReader(new StringReader(docContent))));

         }

         private void extractElements(Document document) {

                 // this handles backward compatibility in document content

                 if (!document.getDocumentElement().getNodeName().equals(KewApiConstants.DOCUMENT_CONTENT_ELEMENT)) {

                         // if the root element is the flexdoc element (pre Workflow 2.0)

                         // then designate that as attribute content

                         if (document.getDocumentElement().getNodeName().equals(LEGACY_FLEXDOC_ELEMENT)) {

                                 attributeContent = document.getDocumentElement();

                         } else {

                                 applicationContent = document.getDocumentElement();

                         }

                 } else {

                         NodeList nodes = document.getDocumentElement().getChildNodes();

                         for (int index = 0; index < nodes.getLength(); index++) {

                                 Node node = nodes.item(index);

                                 if (node.getNodeType() == Node.ELEMENT_NODE && node.getNodeName().equals(KewApiConstants.APPLICATION_CONTENT_ELEMENT)) {

                                         int numChildElements = 0;

                                         for (int childIndex = 0; childIndex < node.getChildNodes().getLength(); childIndex++) {

                                                 Node child = (Node) node.getChildNodes().item(childIndex);

                                                 if (child.getNodeType() == Node.ELEMENT_NODE) {

                                                         applicationContent = (Element) child;

                                                         numChildElements++;

                                                 }

                                         }

                                         // TODO can we have application content without a root node?

                                         if (numChildElements > 1) {

                                                 applicationContent = (Element) node;

                                         }

                                 } else if (node.getNodeType() == Node.ELEMENT_NODE && node.getNodeName().equals(KewApiConstants.ATTRIBUTE_CONTENT_ELEMENT)) {

                                         attributeContent = (Element) node;

                                 } else if (node.getNodeType() == Node.ELEMENT_NODE && node.getNodeName().equals(KewApiConstants.SEARCHABLE_CONTENT_ELEMENT)) {

                                         searchableContent = (Element) node;

                                 }

                         }

                 }

         }

         public Element getApplicationContent() {

                 return applicationContent;

         }

         public Element getAttributeContent() {

                 return attributeContent;

         }

         public String getDocContent() {

                 return docContent;

         }

         public Document getDocument() {

                 return document;

         }

         public Element getSearchableContent() {

                 return searchableContent;

         }

         public RouteContext getRouteContext() {

                 return this.routeContext;

         }

         private void readObject(ObjectInputStream ais) throws IOException, ClassNotFoundException {

                 ais.defaultReadObject();

                 initialize(this.docContent, this.routeContext);

         }

 }