/*
    * Copyright (C) 2005 by Arno Schumacher
    *
    * This file is part of net.sourceforge.servletspy
    *
    * net.sourceforge.servletspy is free software; you can redistribute
    * it and/or modify it under the terms of the GNU General Public 
    * License as published by the Free Software Foundation; either 
   * version 2, or (at your option) any later version.
   *
   * net.sourceforge.servletspy is distributed in the hope that it will
   * be useful, but WITHOUT ANY WARRANTY; without even the implied 
   * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
   * See the GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA 
   */
  
  package net.sourceforge.servletspy;
  
  import java.io.Serializable;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.List;
  
  /***
   * A <code>Node</code> represents the result of a serialization process.
   *
   * @author arno schumacher
   */
  public final class Node implements Comparable, Serializable {
  
      /*** The serial version id. */
      private static final long serialVersionUID = 3977867288743718964L;
  
      /*** The parent node. */
      private final Node parent;
  
      /***
       * In case a subject has already been serialized, this node represents the
       * subgraph for that subject.
       */
      private Node referenceNode;
  
      /*** The name of the node. */
      private final String name;
  
      /*** The result of the serialization process. */
      private String value;
  
      /*** The childs of this node. */
      private List childs = new ArrayList();
  
      /*** For debugging purpose... */
      private String hint = "";
  
      /***
       * Constructor.
       *
       * @param pName
       *            The node name
       * @param pValue
       *            The initial value of the node
       */
      public Node(final String pName, final String pValue) {
          this(null, pName, pValue);
      }
  
      /***
       * Constructor.
       *
       * @param pParent
       *            The parent node
       * @param pName
       *            The node name
       */
      public Node(final Node pParent, final String pName) {
          this(pParent, pName, null);
      }
  
      /***
       * Constructor.
       *
       * @param pParent
       *            The parent node
       * @param pName
       *            The node name
       * @param pValue
       *            The initial value of the node
       */
      public Node(final Node pParent, final String pName, final String pValue) {
          this.name = (pName == null) ? "<null>" : pName;
          this.value = (pValue == null) ? "" : pValue;
          this.parent = pParent;
      }
 
     /* (non-Javadoc)
      * @see java.lang.Comparable#compareTo(java.lang.Object)
      */
     public int compareTo(final Object pArg) {
         if (pArg == null || !(pArg instanceof Node)) {
             return 1;
         }
         final Node other = (Node) pArg;
 
         if (this.name == null) {
             return 1;
         }
 
         if (other.name == null) {
             return -1;
         }
 
         if (!this.hasChildNodes() && other.hasChildNodes()) {
             return -1;
         }
         if (this.hasChildNodes() && !other.hasChildNodes()) {
             return 1;
         }
 
         return this.name.compareTo(other.name);
     }
 
     /***
      * @return Returns the value.
      */
     public String getValue() {
         return value;
     }
 
     /***
      * @param pValue
      *            The value to set.
      */
     public void setValue(final String pValue) {
         this.value = pValue;
     }
 
     /***
      * @return Returns the name.
      */
     public String getName() {
         return name;
     }
 
     /***
      * @return Returns the parent.
      */
     public Node getParent() {
         return parent;
     }
 
     /***
      * @return Returns true if and only if the node has child nodes.
      */
     public boolean hasChildNodes() {
         return childs.size() > 0;
     }
 
     /***
      * Adds a child node.
      *
      * @param pChild
      *            The child.
      */
     public void addChildNode(final Node pChild) {
         if (pChild != null) {
             childs.add(pChild);
         }
     }
 
     /***
      * Returns the childs.
      *
      * @return The childs
      */
     public Iterator childNodes() {
         Collections.sort(childs);
         return Collections.unmodifiableList(childs).iterator();
     }
 
     /***
      * Returns the number of childs.
      *
      * @return The number of childs.
      */
     public int getNumberOfChild() {
         return childs.size();
     }
 
     /***
      * Sets the reference node.
      *
      * @param pReferenceNode
      *            The refernce node, a pointer to another node in the
      *            serialization graph representing an already processed subject.
      */
     public void setReference(final Node pReferenceNode) {
         if (hasChildNodes()) {
             throw new IllegalStateException("Childs already added.");
         }
         this.referenceNode = pReferenceNode;
     }
 
     /***
      * Returns the reference node.
      *
      * @return The refernce node, a pointer to another node in the serialization
      *         graph representing an already processed subject.
      */
     public Node getReference() {
         return referenceNode;
     }
 
     /***
      * Returns true if and only if this node does not hold a serialization
      * graph, but points to an other node representing an already performed
      * serialization.
      *
      * @return boolean value
      */
     public boolean hasReference() {
         return referenceNode != null;
     }
 
     /***
      * For debugging purpose only.
      *
      * @param pHint A hint
      */
     public void setDebugHint(final String pHint) {
         this.hint = pHint;
     }
 
     /***
      * For debugging purpose only.
      *
      * @return the debug hint
      */
     public String getDebugHint() {
         return hint;
     }
 }