/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE
 * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
 * add the following below this CDDL HEADER, with the fields enclosed
 * by brackets "[]" replaced with your own identifying * information:
 *      Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 *
 *      Portions Copyright 2007 Sun Microsystems, Inc.
 */
package org.opends.server.extensions;



import java.util.Iterator;
import java.util.LinkedList;
import java.util.Set;

import org.opends.server.types.DirectoryConfig;
import org.opends.server.types.DirectoryException;
import org.opends.server.types.DN;
import org.opends.server.types.Entry;
import org.opends.server.types.MemberList;
import org.opends.server.types.MembershipException;

import static org.opends.server.loggers.Debug.*;
import static org.opends.server.messages.ExtensionsMessages.*;
import static org.opends.server.messages.MessageHandler.*;
import static org.opends.server.util.Validator.*;



/**
 * This class provides an implementation of the {@code MemberList} class that
 * may be used in conjunction when static groups when no additional criteria is
 * to be used to select a subset of the group members.
 */
public class SimpleStaticGroupMemberList
       extends MemberList
{
  /**
   * The fully-qualified name of this class for debugging purposes.
   */
  private static final String CLASS_NAME =
       "org.opends.server.extensions.SimpleStaticGroupMemberList";



  // The DN of the static group with which this member list is associated.
  private DN groupDN;

  // The iterator used to traverse the set of member DNs.
  private Iterator<DN> memberDNIterator;

  // The set of DNs for the users that are members of the associated static
  // group.
  private LinkedList<DN> memberDNs;



  /**
   * Creates a new simple static group member list with the provided set of
   * member DNs.
   *
   * @param  groupDN    The DN of the static group with which this member list
   *                    is associated.
   * @param  memberDNs  The set of DNs for the users that are members of the
   *                    associated static group.
   */
  public SimpleStaticGroupMemberList(DN groupDN, Set<DN> memberDNs)
  {
    assert debugConstructor(CLASS_NAME, String.valueOf(memberDNs));

    ensureNotNull(groupDN, memberDNs);

    this.groupDN   = groupDN;
    this.memberDNs = new LinkedList<DN>(memberDNs);
    memberDNIterator = memberDNs.iterator();
  }



  /**
   * {@inheritDoc}
   */
  @Override()
  public boolean hasMoreMembers()
  {
    assert debugEnter(CLASS_NAME, "hasMoreMembers");

    return memberDNIterator.hasNext();
  }



  /**
   * {@inheritDoc}
   */
  @Override()
  public DN nextMemberDN()
         throws MembershipException
  {
    assert debugEnter(CLASS_NAME, "nextMemberDN");

    if (memberDNIterator.hasNext())
    {
      return memberDNIterator.next();
    }

    return null;
  }



  /**
   * {@inheritDoc}
   */
  @Override()
  public Entry nextMemberEntry()
         throws MembershipException
  {
    assert debugEnter(CLASS_NAME, "nextMemberEntry");

    if (memberDNIterator.hasNext())
    {
      DN memberDN = memberDNIterator.next();

      try
      {
        Entry memberEntry = DirectoryConfig.getEntry(memberDN);
        if (memberEntry == null)
        {
          int    msgID   = MSGID_STATICMEMBERS_NO_SUCH_ENTRY;
          String message = getMessage(msgID, String.valueOf(memberDN),
                                      String.valueOf(groupDN));
          throw new MembershipException(msgID, message, true);
        }

        return memberEntry;
      }
      catch (DirectoryException de)
      {
        assert debugException(CLASS_NAME, "nextMemberEntry", de);

        int    msgID   = MSGID_STATICMEMBERS_CANNOT_GET_ENTRY;
        String message = getMessage(msgID, String.valueOf(memberDN),
                                    String.valueOf(groupDN),
                                    String.valueOf(de.getErrorMessage()));
        throw new MembershipException(msgID, message, true, de);
      }
    }

    return null;
  }



  /**
   * {@inheritDoc}
   */
  @Override()
  public void close()
  {
    assert debugEnter(CLASS_NAME, "close");

    // No implementation is required.
  }
}