package org.apache.maven.shared.utils.xml;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache 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.apache.org/licenses/LICENSE-2.0
   *
   * 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.
   */
  
  import java.io.StringWriter;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  import javax.annotation.Nonnull;
  
  /**
   * A reimplementation of plexys xpp3dom based on the public interface of plexus xpp3dom.
   *
   * @author Kristian Rosenvold
   */
  public class Xpp3Dom implements Iterable<Xpp3Dom> {
      @SuppressWarnings( "UnusedDeclaration" )
      private static final long serialVersionUID = 2567894443061173996L;
  
      private String name; // plexus: protected
  
      private String value; // plexus: protected
  
      private Map<String, String> attributes; // plexus: protected
  
      private final List<Xpp3Dom> childList; // plexus: protected
  
      private final Map<String, Xpp3Dom> childMap; // plexus: protected
  
      private Xpp3Dom parent; // plexus: protected
  
      public static final String CHILDREN_COMBINATION_MODE_ATTRIBUTE = "combine.children";
  
      private static final String CHILDREN_COMBINATION_MERGE = "merge";
  
      public static final String CHILDREN_COMBINATION_APPEND = "append";
  
      @SuppressWarnings("UnusedDeclaration")
      private static final String DEFAULT_CHILDREN_COMBINATION_MODE = CHILDREN_COMBINATION_MERGE; // plexus: public
  
      public static final String SELF_COMBINATION_MODE_ATTRIBUTE = "combine.self";
  
      public static final String SELF_COMBINATION_OVERRIDE = "override";  // plexus: public
  
      public static final String SELF_COMBINATION_MERGE = "merge";
  
      @SuppressWarnings("UnusedDeclaration")
      private static final String DEFAULT_SELF_COMBINATION_MODE = SELF_COMBINATION_MERGE;  // plexus: public
  
      private static final String[] EMPTY_STRING_ARRAY = new String[0];
      private static final Xpp3Dom[] EMPTY_DOM_ARRAY = new Xpp3Dom[0];
  
      public Xpp3Dom( String name )
      {
          this.name = name;
          childList = new ArrayList<Xpp3Dom>();
          childMap = new HashMap<String, Xpp3Dom>();
      }
  
      public Xpp3Dom( Xpp3Dom source)
      {
          this(source, source.getName() );
      }
  
      public Xpp3Dom( @Nonnull Xpp3Dom src, String name )
      {
          this.name = name;
  
          int size = src.getChildCount();
          childList = new ArrayList<Xpp3Dom>( size );
          childMap = new HashMap<String, Xpp3Dom>( );
  
          setValue( src.getValue() );
  
          for (String attributeName : src.getAttributeNames()) {
              setAttribute(attributeName, src.getAttribute(attributeName));
          }
  
         for (Xpp3Dom xpp3Dom : src.getChildren()) {
             addChild( new Xpp3Dom( xpp3Dom ));
         }
     }
 
     public String getName()
     {
         return name;
     }
 
     public @Nonnull String getValue()
     {
         return value;
     }
 
     public void setValue( @Nonnull String value )
     {
         this.value = value;
     }
 
 
     public String[] getAttributeNames()
     {
         boolean isNothing = attributes == null || attributes.isEmpty();
         return isNothing ? EMPTY_STRING_ARRAY :  attributes.keySet().toArray( new String[attributes.size()] );
     }
 
 
     public String getAttribute( String name )
     {
         return attributes != null ? attributes.get( name ) : null;
     }
 
     @SuppressWarnings( "ConstantConditions" )
     public void setAttribute( @Nonnull String name, @Nonnull String value )
     {
         if ( value == null) {
             throw new NullPointerException( "value can not be null" );
         }
         if ( name == null) {
             throw new NullPointerException( "name can not be null" );
         }
         if ( attributes == null)
         {
             attributes = new HashMap<String, String>();
         }
 
         attributes.put( name, value );
     }
 
     public Xpp3Dom getChild( int i )
     {
         return childList.get( i );
     }
 
     public Xpp3Dom getChild( String name )
     {
         return childMap.get( name );
     }
 
     public void addChild( Xpp3Dom child )
     {
         child.setParent( this );
         childList.add( child );
         childMap.put( child.getName(), child );
     }
 
     public Xpp3Dom[] getChildren()
     {
         boolean isNothing = childList == null || childList.isEmpty();
         return isNothing ? EMPTY_DOM_ARRAY : childList.toArray( new Xpp3Dom[childList.size()] );
     }
 
     private List<Xpp3Dom> getChildrenList()
     {
         boolean isNothing = childList == null || childList.isEmpty();
         return isNothing ? Collections.<Xpp3Dom>emptyList() : childList;
     }
 
     public Xpp3Dom[] getChildren( String name )
     {
         List<Xpp3Dom> children = getChildrenList(name);
         return children.toArray(new Xpp3Dom[children.size()]);
     }
 
     private List<Xpp3Dom> getChildrenList( String name )
     {
         if ( childList== null )
         {
             return Collections.emptyList();
         }
         else
         {
             ArrayList<Xpp3Dom> children = new ArrayList<Xpp3Dom>();
             for (Xpp3Dom aChildList : childList) {
                 if (name.equals(aChildList.getName())) {
                     children.add(aChildList);
                 }
             }
             return children;
         }
     }
 
     public int getChildCount()
     {
         if ( childList == null )
         {
             return 0;
         }
 
         return childList.size();
     }
 
     public void removeChild( int i )
     {
         Xpp3Dom child = childList.remove( i );
         childMap.values().remove( child );
         child.setParent( null );
     }
 
     public Xpp3Dom getParent()
     {
         return parent;
     }
 
     public void setParent( Xpp3Dom parent )
     {
        this.parent = parent;
     }
 
     // Todo: Support writing to serializer (>1.0)
   //  public void writeToSerializer( String namespace, XmlSerializer serializer )
     //        throws IOException
 
     private static Xpp3Dom merge(Xpp3Dom dominant, Xpp3Dom recessive, Boolean childMergeOverride)
     {
         if ( recessive == null || isCombineSelfOverride(dominant))
         {
             return dominant;
         }
 
         if (isEmpty(dominant.getValue())) {
             dominant.setValue(recessive.getValue());
         }
 
         for (String attr : recessive.getAttributeNames()) {
             if (isEmpty(dominant.getAttribute(attr))) {
                 dominant.setAttribute(attr, recessive.getAttribute(attr));
             }
         }
 
         if ( recessive.getChildCount() > 0 )
         {
             boolean mergeChildren = isMergeChildren(dominant, childMergeOverride);
 
             if (mergeChildren) {
                 Map<String, Iterator<Xpp3Dom>> commonChildren = getCommonChildren(dominant, recessive);
                 for (Xpp3Dom recessiveChild : recessive) {
                     Iterator<Xpp3Dom> it = commonChildren.get( recessiveChild.getName() );
                     if ( it == null )
                     {
                         dominant.addChild( new Xpp3Dom( recessiveChild ) );
                     }
                     else if ( it.hasNext() )
                     {
                         Xpp3Dom dominantChild = it.next();
                         merge(dominantChild, recessiveChild, childMergeOverride);
                     }
                 }
             } else {
                 Xpp3Dom[] dominantChildren = dominant.getChildren();
                 dominant.childList.clear();
                 for (Xpp3Dom child: recessive) {
                     dominant.addChild( new Xpp3Dom( child ) );
                 }
 
                 for (Xpp3Dom aDominantChildren : dominantChildren) {
                     dominant.addChild(aDominantChildren);
                 }
             }
         }
         return dominant;
     }
 
     private static Map<String, Iterator<Xpp3Dom>> getCommonChildren(Xpp3Dom dominant, Xpp3Dom recessive) {
         Map<String, Iterator<Xpp3Dom>> commonChildren = new HashMap<String, Iterator<Xpp3Dom>>();
 
         for ( String childName : recessive.childMap.keySet() )
         {
             List<Xpp3Dom> dominantChildren = dominant.getChildrenList(childName);
             if ( dominantChildren.size() > 0 )
             {
                 commonChildren.put(childName, dominantChildren.iterator());
             }
         }
         return commonChildren;
     }
 
     private static boolean isMergeChildren(Xpp3Dom dominant, Boolean override) {
         return override != null ? override : !isMergeChildren(dominant);
     }
 
     private static boolean isMergeChildren(Xpp3Dom dominant) {
         return CHILDREN_COMBINATION_APPEND.equals(dominant.getAttribute( CHILDREN_COMBINATION_MODE_ATTRIBUTE ));
     }
 
     private static boolean isCombineSelfOverride(Xpp3Dom xpp3Dom){
         String selfMergeMode = xpp3Dom.getAttribute( SELF_COMBINATION_MODE_ATTRIBUTE );
         return SELF_COMBINATION_OVERRIDE.equals( selfMergeMode );
     }
 
     public static Xpp3Dom mergeXpp3Dom( Xpp3Dom dominant, Xpp3Dom recessive, Boolean childMergeOverride )
     {
          return dominant != null ? merge(dominant, recessive, childMergeOverride) : recessive;
     }
 
     public static Xpp3Dom mergeXpp3Dom( Xpp3Dom dominant, Xpp3Dom recessive )
     {
             return dominant != null ? merge(dominant, recessive, null) : recessive;
     }
 
     public boolean equals( Object obj )
     {
         if ( obj == this )
         {
             return true;
         }
 
         if ( !( obj instanceof Xpp3Dom ) )
         {
             return false;
         }
 
         Xpp3Dom dom = (Xpp3Dom) obj;
 
         return !(name == null ? dom.name != null : !name.equals(dom.name)) &&
                !(value == null ? dom.value != null : !value.equals(dom.value)) &&
                !(attributes == null ? dom.attributes != null : !attributes.equals(dom.attributes)) &&
                !(childList == null ? dom.childList != null : !childList.equals(dom.childList));
     }
 
     public int hashCode()
     {
         int result = 17;
         result = 37 * result + ( name != null ? name.hashCode() : 0 );
         result = 37 * result + ( value != null ? value.hashCode() : 0 );
         result = 37 * result + ( attributes != null ? attributes.hashCode() : 0 );
         result = 37 * result + ( childList != null ? childList.hashCode() : 0 );
         return result;
     }
 
     public String toString()
     {
         StringWriter writer = new StringWriter();
         Xpp3DomWriter.write(getPrettyPrintXMLWriter(writer), this );
         return writer.toString();
 
     }
 
     public String toUnescapedString()
     {
         StringWriter writer = new StringWriter();
         Xpp3DomWriter.write(getPrettyPrintXMLWriter(writer), this, false );
         return writer.toString();
     }
 
     private PrettyPrintXMLWriter getPrettyPrintXMLWriter(StringWriter writer) {
         return new PrettyPrintXMLWriter( writer, "UTF-8", null );
     }
 
     public static boolean isNotEmpty( String str )
     {
         return str != null && str.length() > 0;
     }
 
     public static boolean isEmpty( String str )
     {
         return str == null || str.trim().length() == 0;
     }
 
     public Iterator<Xpp3Dom> iterator()
     {
         return getChildrenList().iterator();
     }
 }