package com.aurea.maven.plugins.sonic.utils.xmlsorter;

 import java.io.File;

 import java.io.FileWriter;

 import java.io.IOException;

 import java.util.ArrayList;

 import java.util.Collections;

 import java.util.Comparator;

 import java.util.List;

 import org.codehaus.plexus.util.xml.XmlStreamReader;

 import org.codehaus.plexus.util.xml.Xpp3Dom;

 import org.codehaus.plexus.util.xml.Xpp3DomBuilder;

 import org.codehaus.plexus.util.xml.Xpp3DomWriter;

 import org.codehaus.plexus.util.xml.pull.XmlPullParserException;

 import org.w3c.dom.Text;

 public class XMLSort {

   public static void sortXMLFile(final File file) throws IOException {

     try {

       XmlStreamReader inputReader = new XmlStreamReader(file);

       Xpp3Dom fileDom;

       fileDom = Xpp3DomBuilder.build(inputReader);

       XMLSort.sortChildNodes(fileDom, 2, new AttributeNameComparator());

       FileWriter writer = new FileWriter(file);

       Xpp3DomWriter.write(writer, fileDom);

       writer.close();

     } catch (XmlPullParserException e) {

       throw new IOException("Could not parse XML file " + file.getAbsolutePath());

     }

   }

   /**

    * sorts the children of the given node up to the specified depth if available.

    * 

    * @param dom

    *          node whose children will be sorted

    * @param depth

    *          number of levels down in the DOM to sort

    * @param comparator

    *          comparator used to sort, if null a default NodeName comparator is used.

    */

   public static void sortChildNodes(final Xpp3Dom dom, final int depth, final Comparator<Xpp3Dom> comparator) {

     Comparator<Xpp3Dom> comp = (comparator != null) ? comparator : new DefaultNodeNameComparator();

     List<Xpp3Dom> xpp3Doms = new ArrayList<Xpp3Dom>();

     for (int i = 0; i < dom.getChildCount(); i++) {

       Xpp3Dom child = dom.getChild(i);

       if (depth > 1) {

         sortChildNodes(child, depth - 1, comparator);

       }

       // ignore empty text nodes

       if ((!(child instanceof Text)) || (child instanceof Text && ((Text) child).getTextContent().trim().length() > 1)) {

         xpp3Doms.add(child);

       }

     }

     Collections.sort(xpp3Doms, comp);

     while (dom.getChildCount() > 0) {

       dom.removeChild(0);

     }

     for (Xpp3Dom xpp3Dom : xpp3Doms) {

       dom.addChild(xpp3Dom);

     }

   }

 }

 class DefaultNodeNameComparator implements Comparator<Xpp3Dom> {

   public int compare(final Xpp3Dom arg0, final Xpp3Dom arg1) {

     return arg0.getName().compareTo(arg1.getName());

   }

 }