/*
    * 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.tree;
   
  import java.io.IOException;
  import java.io.Serializable;
  import java.io.Writer;
  import java.util.List;
  
  import org.dom4j.Document;
  import org.dom4j.DocumentFactory;
  import org.dom4j.Element;
  import org.dom4j.Node;
  import org.dom4j.NodeFilter;
  import org.dom4j.XPath;
  import org.dom4j.rule.Pattern;
  
  /***
   * <p>
   * <code>AbstractNode</code> is an abstract base class for tree implementors
   * to use for implementation inheritence.
   * </p>
   * 
   * @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a>
   * @version $Revision: 1.31 $
   */
  public abstract class AbstractNode implements Node, Cloneable, Serializable {
      protected static final String[] NODE_TYPE_NAMES = {"Node", "Element",
              "Attribute", "Text", "CDATA", "Entity", "Entity",
              "ProcessingInstruction", "Comment", "Document", "DocumentType",
              "DocumentFragment", "Notation", "Namespace", "Unknown" };
  
      /*** The <code>DocumentFactory</code> instance used by default */
      private static final DocumentFactory DOCUMENT_FACTORY = DocumentFactory
              .getInstance();
  
      public AbstractNode() {
      }
  
      public short getNodeType() {
          return UNKNOWN_NODE;
      }
  
      public String getNodeTypeName() {
          int type = getNodeType();
  
          if ((type < 0) || (type >= NODE_TYPE_NAMES.length)) {
              return "Unknown";
          }
  
          return NODE_TYPE_NAMES[type];
      }
  
      public Document getDocument() {
          Element element = getParent();
  
          return (element != null) ? element.getDocument() : null;
      }
  
      public void setDocument(Document document) {
      }
  
      public Element getParent() {
          return null;
      }
  
      public void setParent(Element parent) {
      }
  
      public boolean supportsParent() {
          return false;
      }
  
      public boolean isReadOnly() {
          return true;
      }
  
      public boolean hasContent() {
          return false;
      }
  
      public String getPath() {
          return getPath(null);
      }
  
      public String getUniquePath() {
          return getUniquePath(null);
      }
  
      public Object clone() {
          if (isReadOnly()) {
              return this;
          } else {
              try {
                 Node answer = (Node) super.clone();
                 answer.setParent(null);
                 answer.setDocument(null);
 
                 return answer;
             } catch (CloneNotSupportedException e) {
                 // should never happen
                 throw new RuntimeException("This should never happen. Caught: "
                         + e);
             }
         }
     }
 
     public Node detach() {
         Element parent = getParent();
 
         if (parent != null) {
             parent.remove(this);
         } else {
             Document document = getDocument();
 
             if (document != null) {
                 document.remove(this);
             }
         }
 
         setParent(null);
         setDocument(null);
 
         return this;
     }
 
     public String getName() {
         return null;
     }
 
     public void setName(String name) {
         throw new UnsupportedOperationException("This node cannot be modified");
     }
 
     public String getText() {
         return null;
     }
 
     public String getStringValue() {
         return getText();
     }
 
     public void setText(String text) {
         throw new UnsupportedOperationException("This node cannot be modified");
     }
 
     public void write(Writer writer) throws IOException {
         writer.write(asXML());
     }
 
     // XPath methods
     public Object selectObject(String xpathExpression) {
         XPath xpath = createXPath(xpathExpression);
 
         return xpath.evaluate(this);
     }
 
     public List selectNodes(String xpathExpression) {
         XPath xpath = createXPath(xpathExpression);
 
         return xpath.selectNodes(this);
     }
 
     public List selectNodes(String xpathExpression,
             String comparisonXPathExpression) {
         return selectNodes(xpathExpression, comparisonXPathExpression, false);
     }
 
     public List selectNodes(String xpathExpression,
             String comparisonXPathExpression, boolean removeDuplicates) {
         XPath xpath = createXPath(xpathExpression);
         XPath sortBy = createXPath(comparisonXPathExpression);
 
         return xpath.selectNodes(this, sortBy, removeDuplicates);
     }
 
     public Node selectSingleNode(String xpathExpression) {
         XPath xpath = createXPath(xpathExpression);
 
         return xpath.selectSingleNode(this);
     }
 
     public String valueOf(String xpathExpression) {
         XPath xpath = createXPath(xpathExpression);
 
         return xpath.valueOf(this);
     }
 
     public Number numberValueOf(String xpathExpression) {
         XPath xpath = createXPath(xpathExpression);
 
         return xpath.numberValueOf(this);
     }
 
     public boolean matches(String patternText) {
         NodeFilter filter = createXPathFilter(patternText);
 
         return filter.matches(this);
     }
 
     public XPath createXPath(String xpathExpression) {
         return getDocumentFactory().createXPath(xpathExpression);
     }
 
     public NodeFilter createXPathFilter(String patternText) {
         return getDocumentFactory().createXPathFilter(patternText);
     }
 
     public Pattern createPattern(String patternText) {
         return getDocumentFactory().createPattern(patternText);
     }
 
     public Node asXPathResult(Element parent) {
         if (supportsParent()) {
             return this;
         }
 
         return createXPathResult(parent);
     }
 
     protected DocumentFactory getDocumentFactory() {
         return DOCUMENT_FACTORY;
     }
 
     protected Node createXPathResult(Element parent) {
         throw new RuntimeException("asXPathResult() not yet implemented fully "
                 + "for: " + this);
     }
 }
 
 /*
  * 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.
  */