/*
    * 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.myfaces.trinidad.menu;
  
  import java.lang.reflect.Array;
  
  import java.util.Iterator;
  import java.util.List;
  
  import org.apache.myfaces.trinidad.logging.TrinidadLogger;
  
  /**
   * Code specific to a Menu Model's GroupNode.
   *
   */
  
  public class GroupNode extends MenuNode
  {
    /**
      * Constructs a GroupNode
      */
    public GroupNode()
    {
      super();
    }
  
    /**
      * Called by the Default ActionListener
      * when a menu node is clicked/selected.
      *
      * @return String outcome or viewId used
      *         during a POST for navigation.
      */
    @Override
    public String doAction()
    {
      // Call the doAction method of my idref node
      return getRefNode().doAction();
    }
  
    /**
      * Get the Destination URL of a page for a
      * GET.
      *
      * @return String URL of a page.
      */
    @Override
    public String getDestination()
    {
      // Call the getDestination method of my idref node
      return getRefNode().getDestination();
    }
  
    /**
      * Sets the idref of the node.
      *
      * The value of this attribute is an "id" of another node
      * This tells the pointing node where to obtain its viewId and
      * takes precedence (and will replace) the pointing nodes viewId,
      * if one exists.  This should point to a node of the same style,
      * e.g. actionNode points to actionNode.
      *
      * @param idref - String name pointing to the "id" of another node
      */
    public void setIdRef(String idref)
    {
      _idref = idref;
  
      // Create a list of idref's for easier access
      if (_idref != null)
        _makeIdRefList (idref);
    }
  
    /**
      * Get the node whose id matches this node's
      * idref attribute value.
      *
      * @return the MenuNode whose id matches this
      *         node's idref attribute value.
      */
    @Override
    public MenuNode getRefNode()
    {
     MenuNode refNode = null;
 
     // create one if it does not exist
     // should not happen, but can't hurt
     if (_idrefList == null)
     {
       String idref = getIdRef();
       _makeIdRefList(idref);
     }
 
     // Get idrefList
     String[] idrefList = _getIdRefList();
 
     // get group node's children
     List<MenuNode> children = getChildren();
 
     // Traverse the list. Do the following:
     //    o get Node from Model's hashMap of nodes and ids
     //    o check attributes (rendered, disabled, readOnly)
     //    o if they are ok, return the node
     for (int i=0; i < Array.getLength(idrefList); i++)
     {
       Iterator<MenuNode> childIter = children.iterator();
 
       // All node "id" attribute values had the node's
       // system hashcode id appended to the id when
       // placed in the model's idNodeMap.
       //
       // Each id in the idreflist of a group node does
       // NOT have this node sys id appended it to it
       // and needs to or we won't find the group's
       // ref node.
       //
       // Since group nodes can only point to one of
       // its children, we iterate through them, get
       // their sys id and append it to idref until
       // we find a match (or not).
       while (childIter.hasNext())
       {
         MenuNode childNode = childIter.next();
         String modelId = childNode.getModelId();
 
         // Need to append mode's sys id here to create a
         // unique id.
         String refNodeId = idrefList[i] + modelId;
 
         refNode = (MenuNode) getRootModel().getNode(refNodeId);
 
         // if nothing found, move on to the next child
         if (refNode != null)
          break;
       }
 
       if (refNode == null)
         continue;
 
       // Check the attributes of the found node
       if (   !refNode.getRendered()
           ||  refNode.getDisabled()
           ||  refNode.getReadOnly()
           || !refNode.getVisible()
          )
       {
         refNode = null;
         continue;
       }
 
       // Ok, we have a valid RefNode
       break;
     }
 
     // If no valid node is found,
     // log an error
     if (refNode == null)
     {
         _LOG.severe("GroupNode " + getLabel() + " refers to no valid node.\n");
         return null;
     }
 
     return refNode;
   }
 
   /**
     * Get the id of the node referred to by
     * the idref attribute of this node.
     *
     * @return String id of the node referred
     *         to by the idref attribure of
     *         this node.
     */
   public String getIdRef()
   {
     return _idref;
   }
   
   public String[] getIdRefListProperty()
   {
     return _idrefList;
   }
 
   @Override
   public MenuNode getThreadSafeCopy()
   {
     return new ImmutableGroupNode(this);
   }
   
   /* =============================================================
    * Private methods
    * =============================================================*/
 
   /**
     * _getIdRefList. gets the list of idrefs for this node.
     *
     * @return String[] list of idrefs for this node.
     */
   private String[] _getIdRefList()
   {
     return _idrefList;
   }
 
   /**
     * Make a list of idref entries from the nodes String
     * of idref's.
     *
     * This should only be called from the node's setIdRef
     * method.  So if it is called more than once (highly
     * unlikely), simply empty out the previous contents.
     *
     * @param entries - String of String entries
     *
     */
   private void _makeIdRefList (String entries)
   {
     _idrefList = entries.trim().split("\\s+");
   }
 
   private String   _idref     = null;
   private String[] _idrefList = null;
 
   private final static TrinidadLogger _LOG =
        TrinidadLogger.createTrinidadLogger(GroupNode.class);
 }