/*
    * 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.
   */
  package org.apache.commons.jxpath.ri.model.dom;
  
  import org.apache.commons.jxpath.ri.Compiler;
  import org.apache.commons.jxpath.ri.QName;
  import org.apache.commons.jxpath.ri.compiler.NodeTest;
  import org.apache.commons.jxpath.ri.compiler.NodeTypeTest;
  import org.apache.commons.jxpath.ri.model.NodePointer;
  
  /**
   * Represents a namespace node.
   *
   * @author Dmitri Plotnikov
   * @version $Revision: 652884 $ $Date: 2008-05-02 22:02:00 +0200 (Fr, 02 Mai 2008) $
   */
  public class NamespacePointer extends NodePointer {
      private String prefix;
      private String namespaceURI;
  
      private static final long serialVersionUID = -7622456151550131709L;
  
      /**
       * Create a new NamespacePointer.
       * @param parent parent pointer
       * @param prefix associated ns prefix.
       */
      public NamespacePointer(NodePointer parent, String prefix) {
          super(parent);
          this.prefix = prefix;
      }
  
      /**
       * Create a new NamespacePointer.
       * @param parent parent pointer
       * @param prefix associated ns prefix.
       * @param namespaceURI associated ns URI.
       */
      public NamespacePointer(
          NodePointer parent,
          String prefix,
          String namespaceURI) {
          super(parent);
          this.prefix = prefix;
          this.namespaceURI = namespaceURI;
      }
  
      public QName getName() {
          return new QName(prefix);
      }
  
      public Object getBaseValue() {
          return null;
      }
  
      public boolean isCollection() {
          return false;
      }
  
      public int getLength() {
          return 1;
      }
  
      public Object getImmediateNode() {
          return getNamespaceURI();
      }
  
      public String getNamespaceURI() {
          if (namespaceURI == null) {
              namespaceURI = parent.getNamespaceURI(prefix);
          }
          return namespaceURI;
      }
  
      public boolean isLeaf() {
          return true;
      }
  
      /**
       * Throws UnsupportedOperationException.
       * @param value Object
       */
      public void setValue(Object value) {
          throw new UnsupportedOperationException("Cannot modify DOM trees");
      }
 
     public boolean testNode(NodeTest nodeTest) {
         return nodeTest == null
             || ((nodeTest instanceof NodeTypeTest)
                 && ((NodeTypeTest) nodeTest).getNodeType()
                     == Compiler.NODE_TYPE_NODE);
     }
 
     public String asPath() {
         StringBuffer buffer = new StringBuffer();
         if (parent != null) {
             buffer.append(parent.asPath());
             if (buffer.length() == 0
                 || buffer.charAt(buffer.length() - 1) != '/') {
                 buffer.append('/');
             }
         }
         buffer.append("namespace::");
         buffer.append(prefix);
         return buffer.toString();
     }
 
     public int hashCode() {
         return prefix.hashCode();
     }
 
     public boolean equals(Object object) {
         if (object == this) {
             return true;
         }
 
         if (!(object instanceof NamespacePointer)) {
             return false;
         }
 
         NamespacePointer other = (NamespacePointer) object;
         return prefix.equals(other.prefix);
     }
 
     public int compareChildNodePointers(
         NodePointer pointer1,
         NodePointer pointer2) {
         // Won't happen - namespaces don't have children
         return 0;
     }
 }