/*

  * 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.kew.plugin;

 import java.io.File;

 import java.net.MalformedURLException;

 import java.net.URL;

 import java.util.HashMap;

 import java.util.Iterator;

 import java.util.Map;

 /**

  * Tracks modifications to a set of files and directories.

  * 

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

  */

 public class ModificationTracker implements Modifiable {

         protected final org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(getClass());

         // Maintains a map of root directories that we are watching to sub directories  

     private final Map dirTree = new HashMap();

     public synchronized void addURL(URL url) {

         addURL(dirTree, url);

     }

     private void addURL(Map parentMap, URL url)  {

         Node node = new Node(url);

         if (!parentMap.keySet().contains(node)) {

             Map subDir = new HashMap();

             parentMap.put(node, subDir);

             if (node.getFile().isDirectory()) {

                 File[] files = node.getFile().listFiles();

                 for (int index = 0; index < files.length; index++) {

                     try {

                         addURL(subDir, files[index].toURL());

                     } catch (MalformedURLException e) {

                         // TODO fix up this error handling

                         throw new RuntimeException(e);

                     }

                 }

             }

         }

     }

     public boolean isModified() {

             return isModified(dirTree);

     }

     private boolean isModified(Map dirTree) {

             for (Iterator iterator = dirTree.keySet().iterator(); iterator.hasNext();) {

                         Node node = (Node) iterator.next();

                         if (node.isModified() || isModified((Map)dirTree.get(node))) {

                                 return true;

                         }

                 }

             return false;

     }

     private class Node implements Modifiable {

         private URL url;

         private File file;

         private long lastModified;

         public Node(URL url) {

             this.url = url;

             this.file = new File(url.getFile());

             this.lastModified = file.lastModified();

         }

         public URL getURL() {

             return url;

         }

         public File getFile() {

             return file;

         }

         public long getLastModified() {

             return lastModified;

         }

         public boolean isModified() {

             return lastModified != file.lastModified();

         }

         public boolean equals(Object object) {

             if (object instanceof Node) {

                 return ((Node)object).getURL().equals(getURL());

             }

             return false;

         }

         public int hashCode() {

             return url.hashCode();

         }

     }

 }