/*
    *   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.directory.server.core.jndi;
  
  
  import java.util.NoSuchElementException;
  
  import javax.naming.NamingEnumeration;
  import javax.naming.NamingException;
  import javax.naming.directory.SearchResult;
  
  import org.apache.directory.api.ldap.model.entry.Entry;
  import org.apache.directory.api.ldap.util.JndiUtils;
  import org.apache.directory.server.core.api.entry.ServerEntryUtils;
  import org.apache.directory.server.core.api.filtering.EntryFilteringCursor;
  
  
  /**
   * Adapts a Cursor over entries into a NamingEnumeration.
   *
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class NamingEnumerationAdapter implements NamingEnumeration<SearchResult>
  {
      private final EntryFilteringCursor cursor;
      private boolean available = false;
  
  
      public NamingEnumerationAdapter( EntryFilteringCursor cursor ) throws NamingException
      {
          this.cursor = cursor;
          try
          {
              if ( !cursor.first() )
              {
                  cursor.close();
                  available = false;
              }
              else
              {
                  available = true;
              }
          }
          catch ( Exception e )
          {
              JndiUtils.wrap( e );
          }
      }
  
  
      /* 
       * @see NamingEnumeration#close()
       */
      public void close() throws NamingException
      {
          try
          {
              cursor.close();
              available = false;
          }
          catch ( Exception e )
          {
              JndiUtils.wrap( e );
          }
      }
  
  
      /* 
       * @see NamingEnumeration#hasMore()
       */
      public boolean hasMore() throws NamingException
      {
          return available;
      }
  
  
      /* 
       * @see NamingEnumeration#next()
       */
      public SearchResult next() throws NamingException
      {
          Entry entry = null;
 
         try
         {
             entry = cursor.get();
 
             if ( cursor.next() )
             {
                 available = true;
             }
             else
             {
                 available = false;
                 cursor.close();
             }
         }
         catch ( Exception e )
         {
             JndiUtils.wrap( e );
         }
 
         SearchResult result = new SearchResult( entry.getDn().getName(), null,
             ServerEntryUtils.toBasicAttributes( entry ) );
         result.setRelative( false );
 
         return result;
     }
 
 
     /* 
      * @see Enumeration#hasMoreElements()
      */
     public boolean hasMoreElements()
     {
         return available;
     }
 
 
     /* 
      * @see Enumeration#nextElement()
      */
     public SearchResult nextElement()
     {
         try
         {
             return next();
         }
         catch ( NamingException e )
         {
             throw new NoSuchElementException( e.getLocalizedMessage() );
         }
     }
 }