/*
    * 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;
  import org.apache.commons.jxpath.util.TypeUtils;
  import org.w3c.dom.Attr;
  
  /**
   * A Pointer that points to a DOM {@link Attr} node. Because the underlying DOM Attr is not Serializable, neither is this pointer class truly so.
   */
  public class DOMAttributePointer extends NodePointer {
  
      private static final long serialVersionUID = 1115085175427555951L;
  
      /**
       * A DOM {@link Attr} node.
       */
      private final Attr attr;
  
      /**
       * Constructs a new DOMAttributePointer.
       *
       * @param parent pointer
       * @param attr   pointed
       */
      public DOMAttributePointer(final NodePointer parent, final Attr attr) {
          super(parent);
          this.attr = attr;
      }
  
      @Override
      public String asPath() {
          final StringBuilder buffer = new StringBuilder();
          if (parent != null) {
              buffer.append(parent.asPath());
              if (buffer.length() == 0 || buffer.charAt(buffer.length() - 1) != '/') {
                  buffer.append('/');
              }
          }
          buffer.append('@');
          buffer.append(getName());
          return buffer.toString();
      }
  
      @Override
      public int compareChildNodePointers(final NodePointer pointer1, final NodePointer pointer2) {
          // Won't happen - attributes don't have children
          return 0;
      }
  
      @Override
      public boolean equals(final Object object) {
          return object == this || object instanceof DOMAttributePointer && attr == ((DOMAttributePointer) object).attr;
      }
  
      @Override
      public Object getBaseValue() {
          return attr;
      }
  
      @Override
      public Object getImmediateNode() {
          return attr;
      }
  
      @Override
      public int getLength() {
          return 1;
      }
  
      @Override
      public QName getName() {
          return new QName(DOMNodePointer.getPrefix(attr), DOMNodePointer.getLocalName(attr));
      }
  
      @Override
      public String getNamespaceURI() {
          final String prefix = DOMNodePointer.getPrefix(attr);
          return prefix == null ? null : parent.getNamespaceURI(prefix);
     }
 
     @Override
     public Object getValue() {
         final String value = attr.getValue();
         if (value == null || value.isEmpty() && !attr.getSpecified()) {
             return null;
         }
         return value;
     }
 
     @Override
     public int hashCode() {
         return System.identityHashCode(attr);
     }
 
     @Override
     public boolean isActual() {
         return true;
     }
 
     @Override
     public boolean isCollection() {
         return false;
     }
 
     @Override
     public boolean isLeaf() {
         return true;
     }
 
     @Override
     public void remove() {
         attr.getOwnerElement().removeAttributeNode(attr);
     }
 
     /**
      * Sets the value of this attribute.
      *
      * @param value to set
      */
     @Override
     public void setValue(final Object value) {
         attr.setValue((String) TypeUtils.convert(value, String.class));
     }
 
     @Override
     public boolean testNode(final NodeTest nodeTest) {
         return nodeTest == null || nodeTest instanceof NodeTypeTest && ((NodeTypeTest) nodeTest).getNodeType() == Compiler.NODE_TYPE_NODE;
     }
 }