/*
    * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
    *
    * This software is open source.
    * See the bottom of this file for the licence.
    */
   
   package org.dom4j.util;
   
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  import org.dom4j.Attribute;
  import org.dom4j.Element;
  import org.dom4j.Node;
  import org.dom4j.QName;
  import org.dom4j.tree.BackedList;
  import org.dom4j.tree.DefaultElement;
  
  /***
   * <p>
   * <code>IndexedElement</code> is an implementation of {@link Element}which
   * maintains an index of the attributes and elements it contains to optimise
   * lookups via name.
   * </p>
   * 
   * @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a>
   * @version $Revision: 1.10 $
   */
  public class IndexedElement extends DefaultElement {
      /*** Lazily constructed index for elements */
      private Map elementIndex;
  
      /*** Lazily constructed index for attributes */
      private Map attributeIndex;
  
      public IndexedElement(String name) {
          super(name);
      }
  
      public IndexedElement(QName qname) {
          super(qname);
      }
  
      public IndexedElement(QName qname, int attributeCount) {
          super(qname, attributeCount);
      }
  
      public Attribute attribute(String name) {
          return (Attribute) attributeIndex().get(name);
      }
  
      public Attribute attribute(QName qName) {
          return (Attribute) attributeIndex().get(qName);
      }
  
      public Element element(String name) {
          return asElement(elementIndex().get(name));
      }
  
      public Element element(QName qName) {
          return asElement(elementIndex().get(qName));
      }
  
      public List elements(String name) {
          return asElementList(elementIndex().get(name));
      }
  
      public List elements(QName qName) {
          return asElementList(elementIndex().get(qName));
      }
  
      // Implementation methods
      // -------------------------------------------------------------------------
      protected Element asElement(Object object) {
          if (object instanceof Element) {
              return (Element) object;
          } else if (object != null) {
              List list = (List) object;
  
              if (list.size() >= 1) {
                  return (Element) list.get(0);
              }
          }
  
          return null;
      }
  
      protected List asElementList(Object object) {
          if (object instanceof Element) {
              return createSingleResultList(object);
          } else if (object != null) {
              List list = (List) object;
              BackedList answer = createResultList();
  
              for (int i = 0, size = list.size(); i < size; i++) {
                 answer.addLocal(list.get(i));
             }
 
             return answer;
         }
 
         return createEmptyList();
     }
 
     /***
      * DOCUMENT ME!
      * 
      * @param object
      *            DOCUMENT ME!
      * 
      * @return DOCUMENT ME!
      * 
      * @deprecated WILL BE REMOVED IN dom4j-1.6 !!
      */
     protected Iterator asElementIterator(Object object) {
         return asElementList(object).iterator();
     }
 
     // #### could we override the add(Element) remove(Element methods?
     protected void addNode(Node node) {
         super.addNode(node);
 
         if ((elementIndex != null) && node instanceof Element) {
             addToElementIndex((Element) node);
         } else if ((attributeIndex != null) && node instanceof Attribute) {
             addToAttributeIndex((Attribute) node);
         }
     }
 
     protected boolean removeNode(Node node) {
         if (super.removeNode(node)) {
             if ((elementIndex != null) && node instanceof Element) {
                 removeFromElementIndex((Element) node);
             } else if ((attributeIndex != null) && node instanceof Attribute) {
                 removeFromAttributeIndex((Attribute) node);
             }
 
             return true;
         }
 
         return false;
     }
 
     protected Map attributeIndex() {
         if (attributeIndex == null) {
             attributeIndex = createAttributeIndex();
 
             for (Iterator iter = attributeIterator(); iter.hasNext();) {
                 addToAttributeIndex((Attribute) iter.next());
             }
         }
 
         return attributeIndex;
     }
 
     protected Map elementIndex() {
         if (elementIndex == null) {
             elementIndex = createElementIndex();
 
             for (Iterator iter = elementIterator(); iter.hasNext();) {
                 addToElementIndex((Element) iter.next());
             }
         }
 
         return elementIndex;
     }
 
     /***
      * A Factory Method to create the index for attributes
      * 
      * @return DOCUMENT ME!
      */
     protected Map createAttributeIndex() {
         Map answer = createIndex();
 
         return answer;
     }
 
     /***
      * A Factory Method to create the index for elements
      * 
      * @return DOCUMENT ME!
      */
     protected Map createElementIndex() {
         Map answer = createIndex();
 
         return answer;
     }
 
     protected void addToElementIndex(Element element) {
         QName qName = element.getQName();
         String name = qName.getName();
         addToElementIndex(qName, element);
         addToElementIndex(name, element);
     }
 
     protected void addToElementIndex(Object key, Element value) {
         Object oldValue = elementIndex.get(key);
 
         if (oldValue == null) {
             elementIndex.put(key, value);
         } else {
             if (oldValue instanceof List) {
                 List list = (List) oldValue;
                 list.add(value);
             } else {
                 List list = createList();
                 list.add(oldValue);
                 list.add(value);
                 elementIndex.put(key, list);
             }
         }
     }
 
     protected void removeFromElementIndex(Element element) {
         QName qName = element.getQName();
         String name = qName.getName();
         removeFromElementIndex(qName, element);
         removeFromElementIndex(name, element);
     }
 
     protected void removeFromElementIndex(Object key, Element value) {
         Object oldValue = elementIndex.get(key);
 
         if (oldValue instanceof List) {
             List list = (List) oldValue;
             list.remove(value);
         } else {
             elementIndex.remove(key);
         }
     }
 
     protected void addToAttributeIndex(Attribute attribute) {
         QName qName = attribute.getQName();
         String name = qName.getName();
         addToAttributeIndex(qName, attribute);
         addToAttributeIndex(name, attribute);
     }
 
     protected void addToAttributeIndex(Object key, Attribute value) {
         Object oldValue = attributeIndex.get(key);
 
         if (oldValue != null) {
             attributeIndex.put(key, value);
         }
     }
 
     protected void removeFromAttributeIndex(Attribute attribute) {
         QName qName = attribute.getQName();
         String name = qName.getName();
         removeFromAttributeIndex(qName, attribute);
         removeFromAttributeIndex(name, attribute);
     }
 
     protected void removeFromAttributeIndex(Object key, Attribute value) {
         Object oldValue = attributeIndex.get(key);
 
         if ((oldValue != null) && oldValue.equals(value)) {
             attributeIndex.remove(key);
         }
     }
 
     /***
      * Factory method to return a new map implementation for indices
      * 
      * @return DOCUMENT ME!
      */
     protected Map createIndex() {
         return new HashMap();
     }
 
     /***
      * Factory method to return a list implementation for indices
      * 
      * @return DOCUMENT ME!
      */
     protected List createList() {
         return new ArrayList();
     }
 }
 
 /*
  * Redistribution and use of this software and associated documentation
  * ("Software"), with or without modification, are permitted provided that the
  * following conditions are met:
  * 
  * 1. Redistributions of source code must retain copyright statements and
  * notices. Redistributions must also contain a copy of this document.
  * 
  * 2. Redistributions in binary form must reproduce the above copyright notice,
  * this list of conditions and the following disclaimer in the documentation
  * and/or other materials provided with the distribution.
  * 
  * 3. The name "DOM4J" must not be used to endorse or promote products derived
  * from this Software without prior written permission of MetaStuff, Ltd. For
  * written permission, please contact dom4j-info@metastuff.com.
  * 
  * 4. Products derived from this Software may not be called "DOM4J" nor may
  * "DOM4J" appear in their names without prior written permission of MetaStuff,
  * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
  * 
  * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
  * 
  * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  * 
  * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
  */