/*
    * 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.beans;
  
  import java.util.Locale;
  
  import org.apache.commons.jxpath.JXPathInvalidAccessException;
  import org.apache.commons.jxpath.ri.Compiler;
  import org.apache.commons.jxpath.ri.QName;
  import org.apache.commons.jxpath.ri.compiler.NodeNameTest;
  import org.apache.commons.jxpath.ri.compiler.NodeTest;
  import org.apache.commons.jxpath.ri.compiler.NodeTypeTest;
  import org.apache.commons.jxpath.ri.model.NodeIterator;
  import org.apache.commons.jxpath.ri.model.NodePointer;
  import org.apache.commons.jxpath.util.ValueUtils;
  
  /**
   * A pointer describing a node that has properties, each of which could be
   * a collection.
   *
   * @author Dmitri Plotnikov
   * @version $Revision: 652845 $ $Date: 2008-05-02 19:46:46 +0200 (Fr, 02 Mai 2008) $
   */
  public abstract class PropertyOwnerPointer extends NodePointer {
      private static final Object UNINITIALIZED = new Object();
  
      private Object value = UNINITIALIZED;
  
      public NodeIterator childIterator(NodeTest test, boolean reverse,
              NodePointer startWith) {
          if (test == null) {
              return createNodeIterator(null, reverse, startWith);
          }
          if (test instanceof NodeNameTest) {
              NodeNameTest nodeNameTest = (NodeNameTest) test;
              QName testName = nodeNameTest.getNodeName();
              if (isValidProperty(testName)) {
                  return createNodeIterator(nodeNameTest.isWildcard() ? null
                          : testName.toString(), reverse, startWith);
              }
              return null;
          }
          return test instanceof NodeTypeTest && ((NodeTypeTest) test).getNodeType() == Compiler.NODE_TYPE_NODE
                  ? createNodeIterator(null, reverse, startWith) : null;
      }
  
      /**
       * Create a NodeIterator.
       * @param property property name
       * @param reverse whether to iterate in reverse
       * @param startWith first pointer to return
       * @return NodeIterator
       */
      public NodeIterator createNodeIterator(String property, boolean reverse,
              NodePointer startWith) {
          return new PropertyIterator(this, property, reverse, startWith);
      }
  
      public NodeIterator attributeIterator(QName name) {
          return new BeanAttributeIterator(this, name);
      }
  
      /**
       * Create a new PropertyOwnerPointer.
       * @param parent parent pointer
       * @param locale Locale
       */
      protected PropertyOwnerPointer(NodePointer parent, Locale locale) {
          super(parent, locale);
      }
  
      /**
       * Create a new PropertyOwnerPointer.
       * @param parent pointer
       */
      protected PropertyOwnerPointer(NodePointer parent) {
          super(parent);
      }
  
      public void setIndex(int index) {
          if (this.index != index) {
              super.setIndex(index);
              value = UNINITIALIZED;
          }
      }
 
     public Object getImmediateNode() {
         if (value == UNINITIALIZED) {
             value = index == WHOLE_COLLECTION ? ValueUtils.getValue(getBaseValue())
                     : ValueUtils.getValue(getBaseValue(), index);
         }
         return value;
     }
 
     public abstract QName getName();
 
     /**
      * Learn whether <code>name</code> is a valid child name for this PropertyOwnerPointer.
      * @param name the QName to test
      * @return <code>true</code> if <code>QName</code> is a valid property name.
      * @since JXPath 1.3
      */
     public boolean isValidProperty(QName name) {
         return isDefaultNamespace(name.getPrefix());
     }
 
     /**
      * Throws an exception if you try to change the root element, otherwise
      * forwards the call to the parent pointer.
      * @param value to set
      */
     public void setValue(Object value) {
         this.value = value;
         if (parent != null) {
             if (parent.isContainer()) {
                 parent.setValue(value);
             }
             else {
                 if (index == WHOLE_COLLECTION) {
                     throw new UnsupportedOperationException(
                         "Cannot setValue of an object that is not "
                             + "some other object's property");
                 }
                 throw new JXPathInvalidAccessException(
                     "The specified collection element does not exist: " + this);
             }
         }
         else {
             throw new UnsupportedOperationException(
                 "Cannot replace the root object");
         }
     }
 
     /**
      * If this is a root node pointer, throws an exception; otherwise
      * forwards the call to the parent node.
      */
     public void remove() {
         this.value = null;
         if (parent != null) {
             parent.remove();
         }
         else {
             throw new UnsupportedOperationException(
                 "Cannot remove an object that is not "
                     + "some other object's property or a collection element");
         }
     }
 
     /**
      * Get a PropertyPointer for this PropertyOwnerPointer.
      * @return PropertyPointer
      */
     public abstract PropertyPointer getPropertyPointer();
 
     /**
      * Learn whether dynamic property declaration is supported.
      * @return true if the property owner can set a property "does not exist".
      *         A good example is a Map. You can always assign a value to any
      *         key even if it has never been "declared".
      */
     public boolean isDynamicPropertyDeclarationSupported() {
         return false;
     }
 
     public int compareChildNodePointers(NodePointer pointer1,
             NodePointer pointer2) {
         int r = pointer1.getName().toString().compareTo(pointer2.getName().toString());
         return r == 0 ? pointer1.getIndex() - pointer2.getIndex() : r;
     }
 }