/*

  * Copyright 2005-2008 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 java.io.InputStream;

 import java.util.LinkedHashMap;

 import java.util.Map;

 import javax.xml.parsers.DocumentBuilderFactory;

 import javax.xml.xpath.XPath;

 import javax.xml.xpath.XPathConstants;

 import javax.xml.xpath.XPathFactory;

 import org.kuali.rice.core.util.RiceUtilities;

 import org.w3c.dom.Document;

 import org.w3c.dom.Element;

 import org.w3c.dom.NodeList;

 /**

  * Builds a EDLGlobalConfig.

  *

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

  */

 public class EDLGlobalConfigFactory {

         private static final String CONFIG_PROCESSOR_XPATH_XPRSN = "xpathExp";

         private static final String CONFIG_PROCESSOR_CLASS_NAME = "className";

         public static EDLGlobalConfig createEDLGlobalConfig(String edlConfigLocation) throws Exception {

                 EDLGlobalConfig edlConfig = new EDLGlobalConfig();

                 InputStream configStream = RiceUtilities.getResourceAsStream(edlConfigLocation);

                 Document configXml = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(configStream);

                 edlConfig.setPreProcessors(createProcessorMap("//preProcessors/preProcessor", configXml));

                 edlConfig.setPostProcessors(createProcessorMap("//postProcessors/postProcessor", configXml));

                 edlConfig.setStateComponents(createProcessorMap("//stateComponents/stateComponent", configXml));

                 edlConfig.setConfigProcessors(createConfigProcessorMap("//configProcessors/configProcessor", configXml));

                 return edlConfig;

         }

         private static Map createProcessorMap(String xpathExpression, Document doc) throws Exception {

                 Map processors = new LinkedHashMap();//preserve parsing order

                 XPath xpath = XPathFactory.newInstance().newXPath();

                 NodeList globalProcessorDeclarations = (NodeList)xpath.evaluate(xpathExpression, doc, XPathConstants.NODESET);

                 for (int i = 0; i < globalProcessorDeclarations.getLength(); i++) {

                         Element globalProcessorDeclaraion = (Element)globalProcessorDeclarations.item(i);

                         processors.put(globalProcessorDeclaraion, Class.forName(globalProcessorDeclaraion.getFirstChild().getNodeValue()));

                 }

                 return processors;

         }

         private static Map createConfigProcessorMap(String xpathExpression, Document doc) throws Exception {

                 Map configProcessors = new LinkedHashMap();//preserve parsing order

                 XPath xpath = XPathFactory.newInstance().newXPath();

                 NodeList globalConfigProcessorDeclarations = (NodeList)xpath.evaluate(xpathExpression, doc, XPathConstants.NODESET);

                 for (int i = 0; i < globalConfigProcessorDeclarations.getLength(); i++) {

                         Element globalProcessorDeclaraion = (Element)globalConfigProcessorDeclarations.item(i);

                         String xpathEx = (String)xpath.evaluate(CONFIG_PROCESSOR_XPATH_XPRSN, globalProcessorDeclaraion, XPathConstants.STRING);

                         String className = (String)xpath.evaluate(CONFIG_PROCESSOR_CLASS_NAME, globalProcessorDeclaraion, XPathConstants.STRING);

                         configProcessors.put(xpathEx, Class.forName(className));

                 }

                 return configProcessors;

         }

 }