/*
 * The contents of this file are subject to the terms of the Common Development and
 * Distribution License (the License). You may not use this file except in compliance with the
 * License.
 *
 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
 * specific language governing permission and limitations under the License.
 *
 * When distributing Covered Software, include this CDDL Header Notice in each file and include
 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
 * Header, with the fields enclosed by brackets [] replaced by your own identifying
 * information: "Portions Copyright [year] [name of copyright owner]".
 *
 * Copyright 2007-2010 Sun Microsystems, Inc.
 * Portions Copyright 2012-2015 ForgeRock AS.
 */
package org.opends.admin.ads;

import static org.forgerock.util.Utils.*;
import static org.opends.messages.QuickSetupMessages.*;

import java.io.File;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.Map;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;

import javax.naming.CompositeName;
import javax.naming.InvalidNameException;
import javax.naming.NameAlreadyBoundException;
import javax.naming.NameNotFoundException;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.NoPermissionException;
import javax.naming.NotContextException;
import javax.naming.directory.Attribute;
import javax.naming.directory.Attributes;
import javax.naming.directory.BasicAttribute;
import javax.naming.directory.BasicAttributes;
import javax.naming.directory.DirContext;
import javax.naming.directory.SearchControls;
import javax.naming.directory.SearchResult;
import javax.naming.ldap.Control;
import javax.naming.ldap.InitialLdapContext;
import javax.naming.ldap.LdapContext;
import javax.naming.ldap.LdapName;
import javax.naming.ldap.Rdn;

import org.forgerock.i18n.LocalizableMessage;
import org.forgerock.i18n.slf4j.LocalizedLogger;
import org.opends.admin.ads.ADSContextException.ErrorType;
import org.opends.admin.ads.util.ConnectionUtils;
import org.opends.quicksetup.Constants;
import org.opends.server.schema.SchemaConstants;

/** Class used to update and read the contents of the Administration Data. */
public class ADSContext
{
  private static final LocalizedLogger logger = LocalizedLogger.getLoggerForThisClass();

  /**
   * Enumeration containing the different server properties syntaxes that could
   * be stored in the ADS.
   */
  public enum ADSPropertySyntax
  {
    /** String syntax. */
    STRING,
    /** Integer syntax. */
    INTEGER,
    /** Boolean syntax. */
    BOOLEAN,
    /** Certificate;binary syntax. */
    CERTIFICATE_BINARY
  }

  /** Enumeration containing the different server properties that are stored in the ADS. */
  public enum ServerProperty
  {
    /** The ID used to identify the server. */
    ID("id",ADSPropertySyntax.STRING),
    /** The host name of the server. */
    HOST_NAME("hostname",ADSPropertySyntax.STRING),
    /** The LDAP port of the server. */
    LDAP_PORT("ldapport",ADSPropertySyntax.INTEGER),
    /** The JMX port of the server. */
    JMX_PORT("jmxport",ADSPropertySyntax.INTEGER),
    /** The JMX secure port of the server. */
    JMXS_PORT("jmxsport",ADSPropertySyntax.INTEGER),
    /** The LDAPS port of the server. */
    LDAPS_PORT("ldapsport",ADSPropertySyntax.INTEGER),
    /** The administration connector port of the server. */
    ADMIN_PORT("adminport",ADSPropertySyntax.INTEGER),
    /** The certificate used by the server. */
    CERTIFICATE("certificate",ADSPropertySyntax.STRING),
    /** The path where the server is installed. */
    INSTANCE_PATH("instancepath",ADSPropertySyntax.STRING),
    /** The description of the server. */
    DESCRIPTION("description",ADSPropertySyntax.STRING),
    /** The OS of the machine where the server is installed. */
    HOST_OS("os",ADSPropertySyntax.STRING),
    /** Whether LDAP is enabled or not. */
    LDAP_ENABLED("ldapEnabled",ADSPropertySyntax.BOOLEAN),
    /** Whether LDAPS is enabled or not. */
    LDAPS_ENABLED("ldapsEnabled",ADSPropertySyntax.BOOLEAN),
    /** Whether ADMIN is enabled or not. */
    ADMIN_ENABLED("adminEnabled",ADSPropertySyntax.BOOLEAN),
    /** Whether StartTLS is enabled or not. */
    STARTTLS_ENABLED("startTLSEnabled",ADSPropertySyntax.BOOLEAN),
    /** Whether JMX is enabled or not. */
    JMX_ENABLED("jmxEnabled",ADSPropertySyntax.BOOLEAN),
    /** Whether JMX is enabled or not. */
    JMXS_ENABLED("jmxsEnabled",ADSPropertySyntax.BOOLEAN),
    /** The location of the server. */
    LOCATION("location",ADSPropertySyntax.STRING),
    /** The groups to which this server belongs. */
    GROUPS("memberofgroups",ADSPropertySyntax.STRING),
    /** The unique name of the instance key public-key certificate. */
    INSTANCE_KEY_ID("ds-cfg-key-id",ADSPropertySyntax.STRING),
    /**
     * The instance key-pair public-key certificate. Note: This attribute
     * belongs to an instance key entry, separate from the server entry and
     * named by the ds-cfg-key-id attribute from the server entry.
     */
    INSTANCE_PUBLIC_KEY_CERTIFICATE("ds-cfg-public-key-certificate", ADSPropertySyntax.CERTIFICATE_BINARY);

    private String attrName;
    private ADSPropertySyntax attSyntax;

    /**
     * Private constructor.
     *
     * @param n
     *          the name of the attribute.
     * @param s
     *          the name of the syntax.
     */
    private ServerProperty(String n, ADSPropertySyntax s)
    {
      attrName = n;
      attSyntax = s;
    }

    /**
     * Returns the attribute name.
     *
     * @return the attribute name.
     */
    public String getAttributeName()
    {
      return attrName;
    }

    /**
     * Returns the attribute syntax.
     *
     * @return the attribute syntax.
     */
    public ADSPropertySyntax getAttributeSyntax()
    {
      return attSyntax;
    }
  }

  /** Default global admin UID. */
  public static final String GLOBAL_ADMIN_UID = "admin";

  private static Map<String, ServerProperty> NAME_TO_SERVER_PROPERTY;

  /**
   * Get a ServerProperty associated to a name.
   *
   * @param name
   *          The name of the property to retrieve.
   * @return The corresponding ServerProperty or null if name doesn't match with
   *         an existing property.
   */
  public static ServerProperty getServerPropFromName(String name)
  {
    if (NAME_TO_SERVER_PROPERTY == null)
    {
      NAME_TO_SERVER_PROPERTY = new HashMap<>();
      for (ServerProperty s : ServerProperty.values())
      {
        NAME_TO_SERVER_PROPERTY.put(s.getAttributeName(), s);
      }
    }
    return NAME_TO_SERVER_PROPERTY.get(name);
  }

  /** The list of server properties that are multivalued. */
  private static final Set<ServerProperty> MULTIVALUED_SERVER_PROPERTIES = new HashSet<>();
  static
  {
    MULTIVALUED_SERVER_PROPERTIES.add(ServerProperty.GROUPS);
  }

  /** The default server group which will contain all registered servers. */
  public static final String ALL_SERVERGROUP_NAME = "all-servers";

  /** Enumeration containing the different server group properties that are stored in the ADS. */
  public enum ServerGroupProperty
  {
    /** The UID of the server group. */
    UID("cn"),
    /** The description of the server group. */
    DESCRIPTION("description"),
    /** The members of the server group. */
    MEMBERS("uniqueMember");

    private String attrName;

    /**
     * Private constructor.
     *
     * @param n
     *          the attribute name.
     */
    private ServerGroupProperty(String n)
    {
      attrName = n;
    }

    /**
     * Returns the attribute name.
     *
     * @return the attribute name.
     */
    public String getAttributeName()
    {
      return attrName;
    }
  }

  /** The list of server group properties that are multivalued. */
  private static final Set<ServerGroupProperty> MULTIVALUED_SERVER_GROUP_PROPERTIES = new HashSet<>();
  static
  {
    MULTIVALUED_SERVER_GROUP_PROPERTIES.add(ServerGroupProperty.MEMBERS);
  }

  /** The enumeration containing the different Administrator properties. */
  public enum AdministratorProperty
  {
    /** The UID of the administrator. */
    UID("id", ADSPropertySyntax.STRING),
    /** The password of the administrator. */
    PASSWORD("password", ADSPropertySyntax.STRING),
    /** The description of the administrator. */
    DESCRIPTION("description", ADSPropertySyntax.STRING),
    /** The DN of the administrator. */
    ADMINISTRATOR_DN("administrator dn", ADSPropertySyntax.STRING),
    /** The administrator privilege. */
    PRIVILEGE("privilege", ADSPropertySyntax.STRING);

    private String attrName;
    private ADSPropertySyntax attrSyntax;

    /**
     * Private constructor.
     *
     * @param n
     *          the name of the attribute.
     * @param s
     *          the name of the syntax.
     */
    private AdministratorProperty(String n, ADSPropertySyntax s)
    {
      attrName = n;
      attrSyntax = s;
    }

    /**
     * Returns the attribute name.
     *
     * @return the attribute name.
     */
    public String getAttributeName()
    {
      return attrName;
    }

    /**
     * Returns the attribute syntax.
     *
     * @return the attribute syntax.
     */
    public ADSPropertySyntax getAttributeSyntax()
    {
      return attrSyntax;
    }
  }

  private static HashMap<String, AdministratorProperty> nameToAdminUserProperty;

  /**
   * Get a AdministratorProperty associated to a name.
   *
   * @param name
   *          The name of the property to retrieve.
   * @return The corresponding AdministratorProperty or null if name doesn't
   *         match with an existing property.
   */
  public static AdministratorProperty getAdminUserPropFromName(String name)
  {
    if (nameToAdminUserProperty == null)
    {
      nameToAdminUserProperty = new HashMap<>();
      for (AdministratorProperty u : AdministratorProperty.values())
      {
        nameToAdminUserProperty.put(u.getAttributeName(), u);
      }
    }
    return nameToAdminUserProperty.get(name);
  }

  /** The context used to retrieve information. */
  private final InitialLdapContext dirContext;

  /**
   * Constructor of the ADSContext.
   *
   * @param dirContext
   *          the DirContext that must be used to retrieve information.
   */
  public ADSContext(InitialLdapContext dirContext)
  {
    this.dirContext = dirContext;
  }

  /**
   * Returns the DirContext used to retrieve information by this ADSContext.
   *
   * @return the DirContext used to retrieve information by this ADSContext.
   */
  public InitialLdapContext getDirContext()
  {
    return dirContext;
  }

  /**
   * Method called to register a server in the ADS.
   *
   * @param serverProperties
   *          the properties of the server.
   * @throws ADSContextException
   *           if the server could not be registered.
   */
  public void registerServer(Map<ServerProperty, Object> serverProperties) throws ADSContextException
  {
    LdapName dn = makeDNFromServerProperties(serverProperties);
    BasicAttributes attrs = makeAttrsFromServerProperties(serverProperties, true);
    try
    {
      // This check is required because by default the server container entry
      // does not exist.
      if (!isExistingEntry(nameFromDN(getServerContainerDN())))
      {
        createContainerEntry(getServerContainerDN());
      }
      dirContext.createSubcontext(dn, attrs).close();
      if (serverProperties.containsKey(ServerProperty.INSTANCE_PUBLIC_KEY_CERTIFICATE))
      {
        registerInstanceKeyCertificate(serverProperties, dn);
      }

      // register this server into "all" groups
      Map<ServerGroupProperty, Object> serverGroupProperties = new HashMap<>();
      Set<String> memberList = getServerGroupMemberList(ALL_SERVERGROUP_NAME);
      if (memberList == null)
      {
        memberList = new HashSet<>();
      }
      String newMember = "cn=" + Rdn.escapeValue(serverProperties.get(ServerProperty.ID));

      memberList.add(newMember);
      serverGroupProperties.put(ServerGroupProperty.MEMBERS, memberList);

      updateServerGroup(ALL_SERVERGROUP_NAME, serverGroupProperties);

      // Update the server property "GROUPS"
      Set<?> rawGroupList = (Set<?>) serverProperties.get(ServerProperty.GROUPS);
      Set<String> groupList = new HashSet<>();
      if (rawGroupList != null)
      {
        for (Object elm : rawGroupList)
        {
          groupList.add(elm.toString());
        }
      }
      groupList.add(ALL_SERVERGROUP_NAME);
      serverProperties.put(ServerProperty.GROUPS, groupList);
      updateServer(serverProperties, null);
    }
    catch (ADSContextException ace)
    {
      throw ace;
    }
    catch (NameAlreadyBoundException x)
    {
      throw new ADSContextException(ErrorType.ALREADY_REGISTERED);
    }
    catch (Exception x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
  }

  /**
   * Method called to update the properties of a server in the ADS.
   *
   * @param serverProperties
   *          the new properties of the server.
   * @param newServerId
   *          The new server Identifier, or null.
   * @throws ADSContextException
   *           if the server could not be registered.
   */
  public void updateServer(Map<ServerProperty, Object> serverProperties, String newServerId) throws ADSContextException
  {
    LdapName dn = makeDNFromServerProperties(serverProperties);

    try
    {
      if (newServerId != null)
      {
        Map<ServerProperty, Object> newServerProps = new HashMap<>(serverProperties);
        newServerProps.put(ServerProperty.ID, newServerId);
        LdapName newDn = makeDNFromServerProperties(newServerProps);
        dirContext.rename(dn, newDn);
        dn = newDn;
        serverProperties.put(ServerProperty.ID, newServerId);
      }
      BasicAttributes attrs = makeAttrsFromServerProperties(serverProperties, false);
      dirContext.modifyAttributes(dn, DirContext.REPLACE_ATTRIBUTE, attrs);
      if (serverProperties.containsKey(ServerProperty.INSTANCE_PUBLIC_KEY_CERTIFICATE))
      {
        registerInstanceKeyCertificate(serverProperties, dn);
      }
    }
    catch (ADSContextException ace)
    {
      throw ace;
    }
    catch (NameNotFoundException x)
    {
      throw new ADSContextException(ErrorType.NOT_YET_REGISTERED);
    }
    catch (Exception x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
  }

  /**
   * Method called to unregister a server in the ADS. Note that the server's
   * instance key-pair public-key certificate entry (created in
   * <tt>registerServer()</tt>) is left untouched.
   *
   * @param serverProperties
   *          the properties of the server.
   * @throws ADSContextException
   *           if the server could not be unregistered.
   */
  public void unregisterServer(Map<ServerProperty, Object> serverProperties) throws ADSContextException
  {
    LdapName dn = makeDNFromServerProperties(serverProperties);
    try
    {
      // Unregister the server from the server groups.
      String member = "cn=" + Rdn.escapeValue(serverProperties.get(ServerProperty.ID));
      Set<Map<ServerGroupProperty, Object>> serverGroups = readServerGroupRegistry();
      for (Map<ServerGroupProperty, Object> serverGroup : serverGroups)
      {
        Set<?> memberList = (Set<?>) serverGroup.get(ServerGroupProperty.MEMBERS);
        if (memberList != null && memberList.remove(member))
        {
          Map<ServerGroupProperty, Object> serverGroupProperties = new HashMap<>();
          serverGroupProperties.put(ServerGroupProperty.MEMBERS, memberList);
          String groupName = (String) serverGroup.get(ServerGroupProperty.UID);
          updateServerGroup(groupName, serverGroupProperties);
        }
      }

      dirContext.destroySubcontext(dn);
    }
    catch (NameNotFoundException x)
    {
      throw new ADSContextException(ErrorType.NOT_YET_REGISTERED);
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }

    // Unregister the server in server groups
    NamingEnumeration<SearchResult> ne = null;
    try
    {
      SearchControls sc = new SearchControls();

      String serverID = getServerID(serverProperties);
      if (serverID != null)
      {
        String memberAttrName = ServerGroupProperty.MEMBERS.getAttributeName();
        String filter = "(" + memberAttrName + "=cn=" + serverID + ")";
        sc.setSearchScope(SearchControls.ONELEVEL_SCOPE);
        ne = dirContext.search(getServerGroupContainerDN(), filter, sc);
        while (ne.hasMore())
        {
          SearchResult sr = ne.next();
          String groupDn = sr.getNameInNamespace();
          BasicAttribute newAttr = new BasicAttribute(memberAttrName);
          NamingEnumeration<? extends Attribute> attrs = sr.getAttributes().getAll();
          try
          {
            while (attrs.hasMore())
            {
              Attribute attr = attrs.next();
              String attrID = attr.getID();

              if (attrID.equalsIgnoreCase(memberAttrName))
              {
                NamingEnumeration<?> ae = attr.getAll();
                try
                {
                  while (ae.hasMore())
                  {
                    String value = (String) ae.next();
                    if (!value.equalsIgnoreCase("cn=" + serverID))
                    {
                      newAttr.add(value);
                    }
                  }
                }
                finally
                {
                  handleCloseNamingEnumeration(ae);
                }
              }
            }
          }
          finally
          {
            handleCloseNamingEnumeration(attrs);
          }
          BasicAttributes newAttrs = new BasicAttributes();
          newAttrs.put(newAttr);
          if (newAttr.size() > 0)
          {
            dirContext.modifyAttributes(groupDn, DirContext.REPLACE_ATTRIBUTE, newAttrs);
          }
          else
          {
            dirContext.modifyAttributes(groupDn, DirContext.REMOVE_ATTRIBUTE, newAttrs);
          }
        }
      }
    }
    catch (NameNotFoundException x)
    {
      throw new ADSContextException(ErrorType.BROKEN_INSTALL);
    }
    catch (NoPermissionException x)
    {
      throw new ADSContextException(ErrorType.ACCESS_PERMISSION);
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
    finally
    {
      handleCloseNamingEnumeration(ne);
    }
  }

  /**
   * Returns whether a given server is already registered or not.
   *
   * @param serverProperties
   *          the server properties.
   * @return <CODE>true</CODE> if the server was registered and
   *         <CODE>false</CODE> otherwise.
   * @throws ADSContextException
   *           if something went wrong.
   */
  public boolean isServerAlreadyRegistered(Map<ServerProperty, Object> serverProperties) throws ADSContextException
  {
    return isExistingEntry(makeDNFromServerProperties(serverProperties));
  }

  /**
   * Returns whether a given administrator is already registered or not.
   *
   * @param uid
   *          the administrator UID.
   * @return <CODE>true</CODE> if the administrator was registered and
   *         <CODE>false</CODE> otherwise.
   * @throws ADSContextException
   *           if something went wrong.
   */
  public boolean isAdministratorAlreadyRegistered(String uid) throws ADSContextException
  {
    return isExistingEntry(makeDNFromAdministratorProperties(uid));
  }

  /**
   * A convenience method that takes some server properties as parameter and if
   * there is no server registered associated with those properties, registers
   * it and if it is already registered, updates it.
   *
   * @param serverProperties
   *          the server properties.
   * @return 0 if the server was registered; 1 if updated (i.e., the server
   *         entry was already in ADS).
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public int registerOrUpdateServer(Map<ServerProperty, Object> serverProperties) throws ADSContextException
  {
    try
    {
      registerServer(serverProperties);
      return 0;
    }
    catch (ADSContextException x)
    {
      if (x.getError() == ErrorType.ALREADY_REGISTERED)
      {
        updateServer(serverProperties, null);
        return 1;
      }

      throw x;
    }
  }

  /**
   * Returns the member list of a group of server.
   *
   * @param serverGroupId
   *          The group name.
   * @return the member list of a group of server.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public Set<String> getServerGroupMemberList(String serverGroupId) throws ADSContextException
  {
    LdapName dn = nameFromDN("cn=" + Rdn.escapeValue(serverGroupId) + "," + getServerGroupContainerDN());

    Set<String> result = new HashSet<>();
    NamingEnumeration<SearchResult> srs = null;
    NamingEnumeration<? extends Attribute> ne = null;
    try
    {
      SearchControls sc = new SearchControls();
      sc.setSearchScope(SearchControls.OBJECT_SCOPE);
      srs = getDirContext().search(dn, "(objectclass=*)", sc);

      if (!srs.hasMore())
      {
        return result;
      }
      Attributes attrs = srs.next().getAttributes();
      ne = attrs.getAll();
      while (ne.hasMore())
      {
        Attribute attr = ne.next();
        String attrID = attr.getID();

        if (!attrID.toLowerCase().equals(ServerGroupProperty.MEMBERS.getAttributeName().toLowerCase()))
        {
          continue;
        }

        // We have the members list
        NamingEnumeration<?> ae = attr.getAll();
        try
        {
          while (ae.hasMore())
          {
            result.add((String) ae.next());
          }
        }
        finally
        {
          handleCloseNamingEnumeration(ae);
        }
        break;
      }
    }
    catch (NameNotFoundException x)
    {
      result = new HashSet<>();
    }
    catch (NoPermissionException x)
    {
      throw new ADSContextException(ErrorType.ACCESS_PERMISSION);
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
    finally
    {
      handleCloseNamingEnumeration(srs);
      handleCloseNamingEnumeration(ne);
    }
    return result;
  }

  /**
   * Returns a set containing the servers that are registered in the ADS.
   *
   * @return a set containing the servers that are registered in the ADS.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public Set<Map<ServerProperty, Object>> readServerRegistry() throws ADSContextException
  {
    Set<Map<ServerProperty, Object>> result = new HashSet<>();
    NamingEnumeration<SearchResult> ne = null;
    try
    {
      SearchControls sc = new SearchControls();

      sc.setSearchScope(SearchControls.ONELEVEL_SCOPE);
      ne = dirContext.search(getServerContainerDN(), "(objectclass=*)", sc);
      while (ne.hasMore())
      {
        SearchResult sr = ne.next();
        Map<ServerProperty, Object> properties = makePropertiesFromServerAttrs(sr.getAttributes());
        Object keyId = properties.get(ServerProperty.INSTANCE_KEY_ID);
        if (keyId != null)
        {
          NamingEnumeration<SearchResult> ne2 = null;
          try
          {
            SearchControls sc1 = new SearchControls();
            sc1.setSearchScope(SearchControls.ONELEVEL_SCOPE);
            final String attrIDs[] = { "ds-cfg-public-key-certificate;binary" };
            sc1.setReturningAttributes(attrIDs);

            ne2 = dirContext.search(getInstanceKeysContainerDN(), "(ds-cfg-key-id=" + keyId + ")", sc);
            boolean found = false;
            while (ne2.hasMore())
            {
              SearchResult certEntry = ne2.next();
              Attribute certAttr = certEntry.getAttributes().get(attrIDs[0]);
              properties.put(ServerProperty.INSTANCE_PUBLIC_KEY_CERTIFICATE, certAttr.get());
              found = true;
            }
            if (!found)
            {
              logger.warn(LocalizableMessage.raw("Could not find public key for " + properties));
            }
          }
          catch (NameNotFoundException x)
          {
            logger.warn(LocalizableMessage.raw("Could not find public key for " + properties));
          }
          finally
          {
            handleCloseNamingEnumeration(ne2);
          }
        }
        result.add(properties);
      }
    }
    catch (NameNotFoundException x)
    {
      throw new ADSContextException(ErrorType.BROKEN_INSTALL);
    }
    catch (NoPermissionException x)
    {
      throw new ADSContextException(ErrorType.ACCESS_PERMISSION);
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
    finally
    {
      handleCloseNamingEnumeration(ne);
    }

    return result;
  }

  /**
   * Creates a Server Group in the ADS.
   *
   * @param serverGroupProperties
   *          the properties of the server group to be created.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public void createServerGroup(Map<ServerGroupProperty, Object> serverGroupProperties) throws ADSContextException
  {
    LdapName dn = makeDNFromServerGroupProperties(serverGroupProperties);
    BasicAttributes attrs = makeAttrsFromServerGroupProperties(serverGroupProperties);
    // Add the objectclass attribute value
    Attribute oc = new BasicAttribute("objectclass");
    oc.add("top");
    oc.add("groupOfUniqueNames");
    attrs.put(oc);
    try
    {
      DirContext ctx = dirContext.createSubcontext(dn, attrs);
      ctx.close();
    }
    catch (NameAlreadyBoundException x)
    {
      throw new ADSContextException(ErrorType.ALREADY_REGISTERED);
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.BROKEN_INSTALL, x);
    }
  }

  /**
   * Updates the properties of a Server Group in the ADS.
   *
   * @param serverGroupProperties
   *          the new properties of the server group to be updated.
   * @param groupID
   *          The group name.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public void updateServerGroup(String groupID, Map<ServerGroupProperty, Object> serverGroupProperties)
      throws ADSContextException
  {
    LdapName dn = nameFromDN("cn=" + Rdn.escapeValue(groupID) + "," + getServerGroupContainerDN());
    try
    {
      // Entry renaming ?
      if (serverGroupProperties.containsKey(ServerGroupProperty.UID))
      {
        String newGroupId = serverGroupProperties.get(ServerGroupProperty.UID).toString();
        if (!newGroupId.equals(groupID))
        {
          // Rename to entry
          LdapName newDN = nameFromDN("cn=" + Rdn.escapeValue(newGroupId) + "," + getServerGroupContainerDN());
          dirContext.rename(dn, newDN);
          dn = newDN;
        }

        // In any case, we remove the "cn" attribute.
        serverGroupProperties.remove(ServerGroupProperty.UID);
      }
      if (serverGroupProperties.isEmpty())
      {
        return;
      }

      BasicAttributes attrs = makeAttrsFromServerGroupProperties(serverGroupProperties);
      // attribute modification
      dirContext.modifyAttributes(dn, DirContext.REPLACE_ATTRIBUTE, attrs);
    }
    catch (NameNotFoundException x)
    {
      throw new ADSContextException(ErrorType.NOT_YET_REGISTERED);
    }
    catch (NameAlreadyBoundException x)
    {
      throw new ADSContextException(ErrorType.ALREADY_REGISTERED);
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
  }

  /**
   * Updates the properties of a Server Group in the ADS.
   *
   * @param serverGroupProperties
   *          the new properties of the server group to be updated.
   * @param groupID
   *          The group name.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public void removeServerGroupProp(String groupID, Set<ServerGroupProperty> serverGroupProperties)
      throws ADSContextException
  {
    LdapName dn = nameFromDN("cn=" + Rdn.escapeValue(groupID) + "," + getServerGroupContainerDN());
    BasicAttributes attrs = makeAttrsFromServerGroupProperties(serverGroupProperties);
    try
    {
      dirContext.modifyAttributes(dn, DirContext.REMOVE_ATTRIBUTE, attrs);
    }
    catch (NameAlreadyBoundException x)
    {
      throw new ADSContextException(ErrorType.ALREADY_REGISTERED);
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
  }

  /**
   * Deletes a Server Group in the ADS.
   *
   * @param serverGroupProperties
   *          the properties of the server group to be deleted.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public void deleteServerGroup(Map<ServerGroupProperty, Object> serverGroupProperties) throws ADSContextException
  {
    LdapName dn = makeDNFromServerGroupProperties(serverGroupProperties);
    try
    {
      dirContext.destroySubcontext(dn);
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
  }

  /**
   * Returns a set containing the server groups that are defined in the ADS.
   *
   * @return a set containing the server groups that are defined in the ADS.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public Set<Map<ServerGroupProperty, Object>> readServerGroupRegistry() throws ADSContextException
  {
    Set<Map<ServerGroupProperty, Object>> result = new HashSet<>();
    NamingEnumeration<SearchResult> ne = null;
    try
    {
      SearchControls sc = new SearchControls();

      sc.setSearchScope(SearchControls.ONELEVEL_SCOPE);
      ne = dirContext.search(getServerGroupContainerDN(), "(objectclass=*)", sc);
      while (ne.hasMore())
      {
        SearchResult sr = ne.next();
        Map<ServerGroupProperty, Object> properties = makePropertiesFromServerGroupAttrs(sr.getAttributes());
        result.add(properties);
      }
    }
    catch (NameNotFoundException x)
    {
      throw new ADSContextException(ErrorType.BROKEN_INSTALL);
    }
    catch (NoPermissionException x)
    {
      throw new ADSContextException(ErrorType.ACCESS_PERMISSION);
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
    finally
    {
      handleCloseNamingEnumeration(ne);
    }
    return result;
  }

  /**
   * Returns a set containing the administrators that are defined in the ADS.
   *
   * @return a set containing the administrators that are defined in the ADS.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public Set<Map<AdministratorProperty, Object>> readAdministratorRegistry() throws ADSContextException
  {
    Set<Map<AdministratorProperty, Object>> result = new HashSet<>();
    NamingEnumeration<SearchResult> ne = null;
    try
    {
      SearchControls sc = new SearchControls();

      sc.setSearchScope(SearchControls.ONELEVEL_SCOPE);
      String[] attList = { "cn", "userpassword", "ds-privilege-name", "description" };
      sc.setReturningAttributes(attList);
      ne = dirContext.search(getAdministratorContainerDN(), "(objectclass=*)", sc);
      while (ne.hasMore())
      {
        SearchResult sr = ne.next();
        Map<AdministratorProperty, Object> properties =
            makePropertiesFromAdministratorAttrs(getRdn(sr.getName()), sr.getAttributes());
        result.add(properties);
      }
    }
    catch (NameNotFoundException x)
    {
      throw new ADSContextException(ErrorType.BROKEN_INSTALL);
    }
    catch (NoPermissionException x)
    {
      throw new ADSContextException(ErrorType.ACCESS_PERMISSION);
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
    finally
    {
      handleCloseNamingEnumeration(ne);
    }

    return result;
  }

  /**
   * Creates the Administration Data in the server. The call to this method
   * assumes that OpenDJ.jar has already been loaded.
   *
   * @param backendName
   *          the backend name which will handle admin information.
   *          <CODE>null</CODE> to use the default backend name for the admin
   *          information.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public void createAdminData(String backendName) throws ADSContextException
  {
    // Add the administration suffix
    createAdministrationSuffix(backendName);
    createAdminDataContainers();
  }

  /** Create container entries. */
  private void createAdminDataContainers() throws ADSContextException
  {
    // Create the DIT below the administration suffix
    if (!isExistingEntry(nameFromDN(getAdministrationSuffixDN())))
    {
      createTopContainerEntry();
    }
    if (!isExistingEntry(nameFromDN(getAdministratorContainerDN())))
    {
      createAdministratorContainerEntry();
    }
    if (!isExistingEntry(nameFromDN(getServerContainerDN())))
    {
      createContainerEntry(getServerContainerDN());
    }
    if (!isExistingEntry(nameFromDN(getServerGroupContainerDN())))
    {
      createContainerEntry(getServerGroupContainerDN());
    }

    // Add the default "all-servers" group
    if (!isExistingEntry(nameFromDN(getAllServerGroupDN())))
    {
      Map<ServerGroupProperty, Object> allServersGroupsMap = new HashMap<>();
      allServersGroupsMap.put(ServerGroupProperty.UID, ALL_SERVERGROUP_NAME);
      createServerGroup(allServersGroupsMap);
    }

    // Create the CryptoManager instance key DIT below the administration suffix
    if (!isExistingEntry(nameFromDN(getInstanceKeysContainerDN())))
    {
      createContainerEntry(getInstanceKeysContainerDN());
    }

    // Create the CryptoManager secret key DIT below the administration suffix
    if (!isExistingEntry(nameFromDN(getSecretKeysContainerDN())))
    {
      createContainerEntry(getSecretKeysContainerDN());
    }
  }

  /**
   * Removes the administration data.
   *
   * @param removeAdministrators
   *          {@code true} if administrators should be removed. It may not be
   *          possible to remove administrators if the operation is being
   *          performed by one of the administrators because it will cause the
   *          administrator to be disconnected.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public void removeAdminData(boolean removeAdministrators) throws ADSContextException
  {
    String[] dns = { getServerContainerDN(), getServerGroupContainerDN(),
      removeAdministrators ? getAdministratorContainerDN() : null };
    try
    {
      Control[] controls = new Control[] { new SubtreeDeleteControl() };
      LdapContext tmpContext = dirContext.newInstance(controls);
      try
      {
        for (String dn : dns)
        {
          if (dn != null)
          {
            LdapName ldapName = nameFromDN(dn);
            if (isExistingEntry(ldapName))
            {
              tmpContext.destroySubcontext(dn);
            }
          }
        }
      }
      finally
      {
        try
        {
          tmpContext.close();
        }
        catch (Exception ex)
        {
          logger.warn(LocalizableMessage.raw("Error while closing LDAP connection after removing admin data", ex));
        }
      }
      // Recreate the container entries:
      createAdminDataContainers();
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
  }

  /**
   * Returns <CODE>true</CODE> if the server contains Administration Data and
   * <CODE>false</CODE> otherwise.
   *
   * @return <CODE>true</CODE> if the server contains Administration Data and
   *         <CODE>false</CODE> otherwise.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public boolean hasAdminData() throws ADSContextException
  {
    String[] dns = { getAdministratorContainerDN(), getAllServerGroupDN(), getServerContainerDN(),
      getInstanceKeysContainerDN(), getSecretKeysContainerDN() };
    boolean hasAdminData = true;
    for (int i = 0; i < dns.length && hasAdminData; i++)
    {
      hasAdminData = isExistingEntry(nameFromDN(dns[i]));
    }
    return hasAdminData;
  }

  /**
   * Returns the DN of the administrator for a given UID.
   *
   * @param uid
   *          the UID to be used to generate the DN.
   * @return the DN of the administrator for the given UID:
   */
  public static String getAdministratorDN(String uid)
  {
    return "cn=" + Rdn.escapeValue(uid) + "," + getAdministratorContainerDN();
  }

  /**
   * Creates an Administrator in the ADS.
   *
   * @param adminProperties
   *          the properties of the administrator to be created.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public void createAdministrator(Map<AdministratorProperty, Object> adminProperties) throws ADSContextException
  {
    LdapName dnCentralAdmin = makeDNFromAdministratorProperties(adminProperties);
    BasicAttributes attrs = makeAttrsFromAdministratorProperties(adminProperties, true, null);

    try
    {
      DirContext ctx = dirContext.createSubcontext(dnCentralAdmin, attrs);
      ctx.close();
    }
    catch (NameAlreadyBoundException x)
    {
      throw new ADSContextException(ErrorType.ALREADY_REGISTERED);
    }
    catch (NoPermissionException x)
    {
      throw new ADSContextException(ErrorType.ACCESS_PERMISSION);
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
  }

  /**
   * Deletes the administrator in the ADS.
   *
   * @param adminProperties
   *          the properties of the administrator to be deleted.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public void deleteAdministrator(Map<AdministratorProperty, Object> adminProperties) throws ADSContextException
  {
    LdapName dnCentralAdmin = makeDNFromAdministratorProperties(adminProperties);

    try
    {
      dirContext.destroySubcontext(dnCentralAdmin);
    }
    catch (NameNotFoundException | NotContextException x)
    {
      throw new ADSContextException(ErrorType.NOT_YET_REGISTERED);
    }
    catch (NoPermissionException x)
    {
      throw new ADSContextException(ErrorType.ACCESS_PERMISSION);
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
  }

  /**
   * Updates and administrator registered in the ADS.
   *
   * @param adminProperties
   *          the new properties of the administrator.
   * @param newAdminUserId
   *          The new admin user Identifier, or null.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public void updateAdministrator(Map<AdministratorProperty, Object> adminProperties, String newAdminUserId)
      throws ADSContextException
  {
    LdapName dnCentralAdmin = makeDNFromAdministratorProperties(adminProperties);

    boolean updatePassword = adminProperties.containsKey(AdministratorProperty.PASSWORD);

    NamingEnumeration<?> currentPrivileges = null;
    try
    {
      // Entry renaming
      if (newAdminUserId != null)
      {
        Map<AdministratorProperty, Object> newAdminUserProps = new HashMap<>(adminProperties);
        newAdminUserProps.put(AdministratorProperty.UID, newAdminUserId);
        LdapName newDn = makeDNFromAdministratorProperties(newAdminUserProps);
        dirContext.rename(dnCentralAdmin, newDn);
        dnCentralAdmin = newDn;
        adminProperties.put(AdministratorProperty.UID, newAdminUserId);
      }

      // if modification includes 'privilege', we have to get first the
      // current privileges list.
      if (adminProperties.containsKey(AdministratorProperty.PRIVILEGE))
      {
        SearchControls sc = new SearchControls();
        sc.setSearchScope(SearchControls.OBJECT_SCOPE);
        String[] attList = { "ds-privilege-name" };
        sc.setReturningAttributes(attList);
        NamingEnumeration<SearchResult> ne = dirContext.search(dnCentralAdmin, "(objectclass=*)", sc);
        try
        {
          while (ne.hasMore())
          {
            currentPrivileges = ne.next().getAttributes().get("ds-privilege-name").getAll();
          }
        }
        finally
        {
          handleCloseNamingEnumeration(ne);
        }
      }

      // Replace properties, if needed.
      if (adminProperties.size() > 1)
      {
        BasicAttributes attrs =
            makeAttrsFromAdministratorProperties(adminProperties, updatePassword, currentPrivileges);
        dirContext.modifyAttributes(dnCentralAdmin, DirContext.REPLACE_ATTRIBUTE, attrs);
      }
    }
    catch (NameNotFoundException x)
    {
      throw new ADSContextException(ErrorType.NOT_YET_REGISTERED);
    }
    catch (NoPermissionException x)
    {
      throw new ADSContextException(ErrorType.ACCESS_PERMISSION);
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
    finally
    {
      handleCloseNamingEnumeration(currentPrivileges);
    }
  }

  /**
   * Returns the DN of the suffix that contains the administration data.
   *
   * @return the DN of the suffix that contains the administration data.
   */
  public static String getAdministrationSuffixDN()
  {
    return "cn=admin data";
  }

  /**
   * This method returns the DN of the entry that corresponds to the given host
   * name and installation path.
   *
   * @param hostname
   *          the host name.
   * @param ipath
   *          the installation path.
   * @return the DN of the entry that corresponds to the given host name and
   *         installation path.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  private static LdapName makeDNFromHostnameAndPath(String hostname, String ipath) throws ADSContextException
  {
    return nameFromDN("cn=" + Rdn.escapeValue(hostname + "@" + ipath) + "," + getServerContainerDN());
  }

  /**
   * This method returns the DN of the entry that corresponds to the given host
   * name port representation.
   *
   * @param serverUniqueId
   *          the host name and port.
   * @return the DN of the entry that corresponds to the given host name and
   *         port.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  private static LdapName makeDNFromServerUniqueId(String serverUniqueId) throws ADSContextException
  {
    return nameFromDN("cn=" + Rdn.escapeValue(serverUniqueId) + "," + getServerContainerDN());
  }

  /**
   * This method returns the DN of the entry that corresponds to the given
   * server group properties.
   *
   * @param serverGroupProperties
   *          the server group properties
   * @return the DN of the entry that corresponds to the given server group
   *         properties.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  private static LdapName makeDNFromServerGroupProperties(Map<ServerGroupProperty, Object> serverGroupProperties)
      throws ADSContextException
  {
    String serverGroupId = (String) serverGroupProperties.get(ServerGroupProperty.UID);
    if (serverGroupId == null)
    {
      throw new ADSContextException(ErrorType.MISSING_NAME);
    }
    return nameFromDN("cn=" + Rdn.escapeValue(serverGroupId) + "," + getServerGroupContainerDN());
  }

  /**
   * This method returns the DN of the entry that corresponds to the given
   * server properties.
   *
   * @param serverProperties
   *          the server properties.
   * @return the DN of the entry that corresponds to the given server
   *         properties.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  private static LdapName makeDNFromServerProperties(Map<ServerProperty, Object> serverProperties)
      throws ADSContextException
  {
    String serverID = getServerID(serverProperties);
    if (serverID != null)
    {
      return makeDNFromServerUniqueId(serverID);
    }

    String hostname = getHostname(serverProperties);
    try
    {
      String ipath = getInstallPath(serverProperties);
      return makeDNFromHostnameAndPath(hostname, ipath);
    }
    catch (ADSContextException ace)
    {
      ServerDescriptor s = ServerDescriptor.createStandalone(serverProperties);
      return makeDNFromServerUniqueId(s.getHostPort(true));
    }
  }

  /**
   * This method returns the DN of the entry that corresponds to the given
   * server properties.
   *
   * @param serverProperties
   *          the server properties.
   * @return the DN of the entry that corresponds to the given server
   *         properties.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public static String getServerIdFromServerProperties(Map<ServerProperty, Object> serverProperties)
      throws ADSContextException
  {
    LdapName ldapName = makeDNFromServerProperties(serverProperties);
    String rdn = ldapName.get(ldapName.size() - 1);
    int pos = rdn.indexOf("=");
    return rdn.substring(pos + 1);
  }

  /**
   * This method returns the DN of the entry that corresponds to the given
   * administrator properties.
   *
   * @param adminProperties
   *          the administrator properties.
   * @return the DN of the entry that corresponds to the given administrator
   *         properties.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  private static LdapName makeDNFromAdministratorProperties(Map<AdministratorProperty, Object> adminProperties)
      throws ADSContextException
  {
    return makeDNFromAdministratorProperties(getAdministratorUID(adminProperties));
  }

  /**
   * This method returns the DN of the entry that corresponds to the given
   * administrator properties.
   *
   * @param adminUid
   *          the administrator uid.
   * @return the DN of the entry that corresponds to the given administrator
   *         properties.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  private static LdapName makeDNFromAdministratorProperties(String adminUid) throws ADSContextException
  {
    return nameFromDN(getAdministratorDN(adminUid));
  }

  /**
   * Returns the attributes for some administrator properties.
   *
   * @param adminProperties
   *          the administrator properties.
   * @param passwordRequired
   *          Indicates if the properties should include the password.
   * @param currentPrivileges
   *          The current privilege list or null.
   * @return the attributes for the given administrator properties.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  private static BasicAttributes makeAttrsFromAdministratorProperties(
      Map<AdministratorProperty, Object> adminProperties, boolean passwordRequired,
      NamingEnumeration<?> currentPrivileges) throws ADSContextException
  {
    BasicAttributes attrs = new BasicAttributes();
    Attribute oc = new BasicAttribute("objectclass");
    if (passwordRequired)
    {
      attrs.put("userPassword", getAdministratorPassword(adminProperties));
    }
    oc.add("top");
    oc.add("person");
    attrs.put(oc);
    attrs.put("sn", GLOBAL_ADMIN_UID);
    if (adminProperties.containsKey(AdministratorProperty.DESCRIPTION))
    {
      attrs.put("description", adminProperties.get(AdministratorProperty.DESCRIPTION));
    }
    Attribute privilegeAtt;
    if (adminProperties.containsKey(AdministratorProperty.PRIVILEGE))
    {
      // We assume that privilege strings provided in
      // AdministratorProperty.PRIVILEGE
      // are valid privileges represented as a LinkedList of string.
      privilegeAtt = new BasicAttribute("ds-privilege-name");
      if (currentPrivileges != null)
      {
        while (currentPrivileges.hasMoreElements())
        {
          privilegeAtt.add(currentPrivileges.nextElement().toString());
        }
      }

      LinkedList<?> privileges = (LinkedList<?>) adminProperties.get(AdministratorProperty.PRIVILEGE);
      for (Object o : privileges)
      {
        String p = o.toString();
        if (p.startsWith("-"))
        {
          privilegeAtt.remove(p.substring(1));
        }
        else
        {
          privilegeAtt.add(p);
        }
      }
    }
    else
    {
      privilegeAtt = addRootPrivileges();
    }
    attrs.put(privilegeAtt);

    // Add the RootDNs Password policy so the password do not expire.
    attrs.put("ds-pwp-password-policy-dn", "cn=Root Password Policy,cn=Password Policies,cn=config");

    return attrs;
  }

  /**
   * Builds an attribute which contains 'root' privileges.
   *
   * @return The attribute which contains 'root' privileges.
   */
  private static Attribute addRootPrivileges()
  {
    Attribute privilege = new BasicAttribute("ds-privilege-name");
    privilege.add("bypass-acl");
    privilege.add("modify-acl");
    privilege.add("config-read");
    privilege.add("config-write");
    privilege.add("ldif-import");
    privilege.add("ldif-export");
    privilege.add("backend-backup");
    privilege.add("backend-restore");
    privilege.add("server-shutdown");
    privilege.add("server-restart");
    privilege.add("disconnect-client");
    privilege.add("cancel-request");
    privilege.add("password-reset");
    privilege.add("update-schema");
    privilege.add("privilege-change");
    privilege.add("unindexed-search");
    privilege.add("subentry-write");
    privilege.add("changelog-read");
    return privilege;
  }

  /**
   * Returns the attributes for some server properties.
   *
   * @param serverProperties
   *          the server properties.
   * @param addObjectClass
   *          Indicates if the object class has to be added.
   * @return the attributes for the given server properties.
   */
  private static BasicAttributes makeAttrsFromServerProperties(Map<ServerProperty, Object> serverProperties,
      boolean addObjectClass)
  {
    BasicAttributes result = new BasicAttributes();

    // Transform 'properties' into 'attributes'
    for (ServerProperty prop : serverProperties.keySet())
    {
      Attribute attr = makeAttrFromServerProperty(prop, serverProperties.get(prop));
      if (attr != null)
      {
        result.put(attr);
      }
    }
    if (addObjectClass)
    {
      // Add the objectclass attribute value
      // TODO: use another structural objectclass
      Attribute oc = new BasicAttribute("objectclass");
      oc.add("top");
      oc.add("ds-cfg-branch");
      oc.add("extensibleobject");
      result.put(oc);
    }
    return result;
  }

  /**
   * Returns the attribute for a given server property.
   *
   * @param property
   *          the server property.
   * @param value
   *          the value.
   * @return the attribute for a given server property.
   */
  private static Attribute makeAttrFromServerProperty(ServerProperty property, Object value)
  {
    Attribute result;

    switch (property)
    {
    case INSTANCE_PUBLIC_KEY_CERTIFICATE:
      result = null; // used in separate instance key entry
      break;
    case GROUPS:
      result = new BasicAttribute(ServerProperty.GROUPS.getAttributeName());
      for (Object o : ((Set<?>) value))
      {
        result.add(o);
      }
      break;
    default:
      result = new BasicAttribute(property.getAttributeName(), value);
    }
    return result;
  }

  /**
   * Returns the attributes for some server group properties.
   *
   * @param serverGroupProperties
   *          the server group properties.
   * @return the attributes for the given server group properties.
   */
  private static BasicAttributes makeAttrsFromServerGroupProperties(
      Map<ServerGroupProperty, Object> serverGroupProperties)
  {
    BasicAttributes result = new BasicAttributes();

    // Transform 'properties' into 'attributes'
    for (ServerGroupProperty prop : serverGroupProperties.keySet())
    {
      Attribute attr = makeAttrFromServerGroupProperty(prop, serverGroupProperties.get(prop));
      if (attr != null)
      {
        result.put(attr);
      }
    }
    return result;
  }

  /**
   * Returns the attributes for some server group properties.
   *
   * @param serverGroupProperties
   *          the server group properties.
   * @return the attributes for the given server group properties.
   */
  private static BasicAttributes makeAttrsFromServerGroupProperties(Set<ServerGroupProperty> serverGroupProperties)
  {
    BasicAttributes result = new BasicAttributes();

    // Transform 'properties' into 'attributes'
    for (ServerGroupProperty prop : serverGroupProperties)
    {
      Attribute attr = makeAttrFromServerGroupProperty(prop, null);
      if (attr != null)
      {
        result.put(attr);
      }
    }
    return result;
  }

  /**
   * Returns the attribute for a given server group property.
   *
   * @param property
   *          the server group property.
   * @param value
   *          the value.
   * @return the attribute for a given server group property.
   */
  private static Attribute makeAttrFromServerGroupProperty(ServerGroupProperty property, Object value)
  {
    switch (property)
    {
    case MEMBERS:
      Attribute result = new BasicAttribute(ServerGroupProperty.MEMBERS.getAttributeName());
      for (Object o : ((Set<?>) value))
      {
        result.add(o);
      }
      return result;
    default:
      return new BasicAttribute(property.getAttributeName(), value);
    }
  }

  /**
   * Returns the properties of a server group for some LDAP attributes.
   *
   * @param attrs
   *          the LDAP attributes.
   * @return the properties of a server group for some LDAP attributes.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  private Map<ServerGroupProperty, Object> makePropertiesFromServerGroupAttrs(Attributes attrs)
      throws ADSContextException
  {
    Map<ServerGroupProperty, Object> result = new HashMap<>();
    try
    {
      for (ServerGroupProperty prop : ServerGroupProperty.values())
      {
        Attribute attr = attrs.get(prop.getAttributeName());
        if (attr == null)
        {
          continue;
        }
        Object value;

        if (attr.size() >= 1 && MULTIVALUED_SERVER_GROUP_PROPERTIES.contains(prop))
        {
          Set<String> set = new HashSet<>();
          NamingEnumeration<?> ae = attr.getAll();
          try
          {
            while (ae.hasMore())
            {
              set.add((String) ae.next());
            }
          }
          finally
          {
            ae.close();
          }
          value = set;
        }
        else
        {
          value = attr.get(0);
        }

        result.put(prop, value);
      }
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
    return result;
  }

  /**
   * Returns the properties of a server for some LDAP attributes.
   *
   * @param attrs
   *          the LDAP attributes.
   * @return the properties of a server for some LDAP attributes.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  private Map<ServerProperty, Object> makePropertiesFromServerAttrs(Attributes attrs) throws ADSContextException
  {
    Map<ServerProperty, Object> result = new HashMap<>();
    try
    {
      NamingEnumeration<? extends Attribute> ne = attrs.getAll();
      while (ne.hasMore())
      {
        Attribute attr = ne.next();
        String attrID = attr.getID();
        Object value;

        if (attrID.endsWith(";binary"))
        {
          attrID = attrID.substring(0, attrID.lastIndexOf(";binary"));
        }

        ServerProperty prop = null;
        ServerProperty[] props = ServerProperty.values();
        for (int i = 0; i < props.length && prop == null; i++)
        {
          String v = props[i].getAttributeName();
          if (attrID.equalsIgnoreCase(v))
          {
            prop = props[i];
          }
        }
        if (prop == null)
        {
          // Do not handle it
        }
        else
        {
          if (attr.size() >= 1 && MULTIVALUED_SERVER_PROPERTIES.contains(prop))
          {
            Set<String> set = new HashSet<>();
            NamingEnumeration<?> ae = attr.getAll();
            try
            {
              while (ae.hasMore())
              {
                set.add((String) ae.next());
              }
            }
            finally
            {
              ae.close();
            }
            value = set;
          }
          else
          {
            value = attr.get(0);
          }

          result.put(prop, value);
        }
      }
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
    return result;
  }

  /**
   * Returns the properties of an administrator for some rdn and LDAP
   * attributes.
   *
   * @param rdn
   *          the RDN.
   * @param attrs
   *          the LDAP attributes.
   * @return the properties of an administrator for the given rdn and LDAP
   *         attributes.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  private Map<AdministratorProperty, Object> makePropertiesFromAdministratorAttrs(String rdn, Attributes attrs)
      throws ADSContextException
  {
    Map<AdministratorProperty, Object> result = new HashMap<>();
    LdapName nameObj;
    nameObj = nameFromDN(rdn);
    String dn = nameObj + "," + getAdministratorContainerDN();
    result.put(AdministratorProperty.ADMINISTRATOR_DN, dn);
    NamingEnumeration<? extends Attribute> ne = null;
    try
    {
      ne = attrs.getAll();
      while (ne.hasMore())
      {
        Attribute attr = ne.next();
        String attrID = attr.getID();
        Object value;

        if ("cn".equalsIgnoreCase(attrID))
        {
          value = attr.get(0);
          result.put(AdministratorProperty.UID, value);
        }
        else if ("userpassword".equalsIgnoreCase(attrID))
        {
          value = new String((byte[]) attr.get());
          result.put(AdministratorProperty.PASSWORD, value);
        }
        else if ("description".equalsIgnoreCase(attrID))
        {
          value = attr.get(0);
          result.put(AdministratorProperty.DESCRIPTION, value);
        }
        else if ("ds-privilege-name".equalsIgnoreCase(attrID))
        {
          LinkedHashSet<String> privileges = new LinkedHashSet<>();
          NamingEnumeration<?> attValueList = attr.getAll();
          while (attValueList.hasMoreElements())
          {
            privileges.add(attValueList.next().toString());
          }
          result.put(AdministratorProperty.PRIVILEGE, privileges);
        }
      }
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
    finally
    {
      handleCloseNamingEnumeration(ne);
    }

    return result;
  }

  /**
   * Returns the parent entry of the server entries.
   *
   * @return the parent entry of the server entries.
   */
  public static String getServerContainerDN()
  {
    return "cn=Servers," + getAdministrationSuffixDN();
  }

  /**
   * Returns the parent entry of the administrator entries.
   *
   * @return the parent entry of the administrator entries.
   */
  public static String getAdministratorContainerDN()
  {
    return "cn=Administrators," + getAdministrationSuffixDN();
  }

  /**
   * Returns the parent entry of the server group entries.
   *
   * @return the parent entry of the server group entries.
   */
  public static String getServerGroupContainerDN()
  {
    return "cn=Server Groups," + getAdministrationSuffixDN();
  }

  /**
   * Returns the all server group entry DN.
   *
   * @return the all server group entry DN.
   */
  private static String getAllServerGroupDN()
  {
    return "cn=" + Rdn.escapeValue(ALL_SERVERGROUP_NAME) + "," + getServerGroupContainerDN();
  }

  /**
   * Returns the host name for the given properties.
   *
   * @param serverProperties
   *          the server properties.
   * @return the host name for the given properties.
   * @throws ADSContextException
   *           if the host name could not be found or its value is not valid.
   */
  private static String getHostname(Map<ServerProperty, Object> serverProperties) throws ADSContextException
  {
    String result = (String) serverProperties.get(ServerProperty.HOST_NAME);
    if (result == null)
    {
      throw new ADSContextException(ErrorType.MISSING_HOSTNAME);
    }
    else if (result.length() == 0)
    {
      throw new ADSContextException(ErrorType.NOVALID_HOSTNAME);
    }
    return result;
  }

  /**
   * Returns the Server ID for the given properties.
   *
   * @param serverProperties
   *          the server properties.
   * @return the server ID for the given properties or null.
   */
  private static String getServerID(Map<ServerProperty, Object> serverProperties)
  {
    String result = (String) serverProperties.get(ServerProperty.ID);
    if (result != null && result.length() == 0)
    {
      result = null;
    }
    return result;
  }

  /**
   * Returns the install path for the given properties.
   *
   * @param serverProperties
   *          the server properties.
   * @return the install path for the given properties.
   * @throws ADSContextException
   *           if the install path could not be found or its value is not valid.
   */
  private static String getInstallPath(Map<ServerProperty, Object> serverProperties) throws ADSContextException
  {
    String result = (String) serverProperties.get(ServerProperty.INSTANCE_PATH);
    if (result == null)
    {
      throw new ADSContextException(ErrorType.MISSING_IPATH);
    }
    else if (result.length() == 0)
    {
      throw new ADSContextException(ErrorType.NOVALID_IPATH);
    }
    return result;
  }

  /**
   * Returns the Administrator UID for the given properties.
   *
   * @param adminProperties
   *          the server properties.
   * @return the Administrator UID for the given properties.
   * @throws ADSContextException
   *           if the administrator UID could not be found.
   */
  private static String getAdministratorUID(Map<AdministratorProperty, Object> adminProperties)
      throws ADSContextException
  {
    String result = (String) adminProperties.get(AdministratorProperty.UID);
    if (result == null)
    {
      throw new ADSContextException(ErrorType.MISSING_ADMIN_UID);
    }
    return result;
  }

  /**
   * Returns the Administrator password for the given properties.
   *
   * @param adminProperties
   *          the server properties.
   * @return the Administrator password for the given properties.
   * @throws ADSContextException
   *           if the administrator password could not be found.
   */
  private static String getAdministratorPassword(Map<AdministratorProperty, Object> adminProperties)
      throws ADSContextException
  {
    String result = (String) adminProperties.get(AdministratorProperty.PASSWORD);
    if (result == null)
    {
      throw new ADSContextException(ErrorType.MISSING_ADMIN_PASSWORD);
    }
    return result;
  }

  // LDAP utilities
  /**
   * Returns the LdapName object for the given dn.
   *
   * @param dn
   *          the DN.
   * @return the LdapName object for the given dn.
   * @throws ADSContextException
   *           if a valid LdapName could not be retrieved for the given dn.
   */
  private static LdapName nameFromDN(String dn) throws ADSContextException
  {
    try
    {
      return new LdapName(dn);
    }
    catch (InvalidNameException x)
    {
      logger.error(LocalizableMessage.raw("Error parsing dn " + dn, x));
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
  }

  /**
   * Returns the String rdn for the given search result name.
   *
   * @param rdnName
   *          the search result name.
   * @return the String rdn for the given search result name.
   * @throws ADSContextException
   *           if a valid String rdn could not be retrieved for the given result
   *           name.
   */
  private static String getRdn(String rdnName) throws ADSContextException
  {
    // Transform the JNDI name into a RDN string
    try
    {
      return new CompositeName(rdnName).get(0);
    }
    catch (InvalidNameException x)
    {
      logger.error(LocalizableMessage.raw("Error parsing rdn " + rdnName, x));
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
  }

  /**
   * Tells whether an entry with the provided DN exists.
   *
   * @param dn
   *          the DN to check.
   * @return <CODE>true</CODE> if the entry exists and <CODE>false</CODE> if it
   *         does not.
   * @throws ADSContextException
   *           if an error occurred while checking if the entry exists or not.
   */
  private boolean isExistingEntry(LdapName dn) throws ADSContextException
  {
    try
    {
      SearchControls sc = new SearchControls();

      sc.setSearchScope(SearchControls.OBJECT_SCOPE);
      sc.setReturningAttributes(new String[] { SchemaConstants.NO_ATTRIBUTES });
      NamingEnumeration<SearchResult> sr = getDirContext().search(dn, "(objectclass=*)", sc);
      boolean result = false;
      try
      {
        while (sr.hasMore())
        {
          sr.next();
          result = true;
        }
      }
      finally
      {
        sr.close();
      }
      return result;
    }
    catch (NameNotFoundException x)
    {
      return false;
    }
    catch (NoPermissionException x)
    {
      throw new ADSContextException(ErrorType.ACCESS_PERMISSION);
    }
    catch (javax.naming.NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
  }

  /**
   * Creates a container entry with the given dn.
   *
   * @param dn
   *          the entry of the new entry to be created.
   * @throws ADSContextException
   *           if the entry could not be created.
   */
  private void createContainerEntry(String dn) throws ADSContextException
  {
    BasicAttributes attrs = new BasicAttributes();
    Attribute oc = new BasicAttribute("objectclass");
    oc.add("top");
    oc.add("ds-cfg-branch");
    attrs.put(oc);
    createEntry(dn, attrs);
  }

  /**
   * Creates the administrator container entry.
   *
   * @throws ADSContextException
   *           if the entry could not be created.
   */
  private void createAdministratorContainerEntry() throws ADSContextException
  {
    BasicAttributes attrs = new BasicAttributes();
    Attribute oc = new BasicAttribute("objectclass");
    oc.add("groupofurls");
    attrs.put(oc);
    attrs.put("memberURL", "ldap:///" + getAdministratorContainerDN() + "??one?(objectclass=*)");
    attrs.put("description", "Group of identities which have full access.");
    createEntry(getAdministratorContainerDN(), attrs);
  }

  /**
   * Creates the top container entry.
   *
   * @throws ADSContextException
   *           if the entry could not be created.
   */
  private void createTopContainerEntry() throws ADSContextException
  {
    BasicAttributes attrs = new BasicAttributes();
    Attribute oc = new BasicAttribute("objectclass");
    oc.add("top");
    oc.add("ds-cfg-branch");
    attrs.put(oc);
    createEntry(getAdministrationSuffixDN(), attrs);
  }

  /**
   * Creates an entry with the provided dn and attributes.
   *
   * @param dn
   *          the dn of the entry.
   * @param attrs
   *          the attributes of the entry.
   * @throws ADSContextException
   *           if the entry could not be created.
   */
  private void createEntry(String dn, Attributes attrs) throws ADSContextException
  {
    try
    {
      DirContext ctx = getDirContext().createSubcontext(nameFromDN(dn), attrs);
      ctx.close();
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
  }

  /**
   * Creates the Administration Suffix.
   *
   * @param backendName
   *          the backend name to be used for the Administration Suffix. If this
   *          value is null the default backendName for the Administration
   *          Suffix will be used.
   * @throws ADSContextException
   *           if something goes wrong.
   */
  public void createAdministrationSuffix(String backendName) throws ADSContextException
  {
    ADSContextHelper helper = new ADSContextHelper();
    String ben = backendName;
    if (backendName == null)
    {
      ben = getDefaultBackendName();
    }
    helper.createAdministrationSuffix(getDirContext(), ben);
  }

  /**
   * Returns the default backend name of the administration data.
   *
   * @return the default backend name of the administration data.
   */
  public static String getDefaultBackendName()
  {
    return "adminRoot";
  }

  /**
   * Returns the LDIF file of the administration data.
   *
   * @return the LDIF file of the administration data.
   */
  public static String getAdminLDIFFile()
  {
    return "config" + File.separator + "admin-backend.ldif";
  }

  /** CryptoManager related types, fields, and methods. */

  /**
   * Returns the parent entry of the server key entries in ADS.
   *
   * @return the parent entry of the server key entries in ADS.
   */
  public static String getInstanceKeysContainerDN()
  {
    return "cn=instance keys," + getAdministrationSuffixDN();
  }

  /**
   * Returns the parent entry of the secret key entries in ADS.
   *
   * @return the parent entry of the secret key entries in ADS.
   */
  public static String getSecretKeysContainerDN()
  {
    return "cn=secret keys," + getAdministrationSuffixDN();
  }

  /**
   * Tells whether the provided server is registered in the registry.
   *
   * @param server
   *          the server.
   * @param registry
   *          the registry.
   * @return <CODE>true</CODE> if the server is registered in the registry and
   *         <CODE>false</CODE> otherwise.
   */
  public static boolean isRegistered(ServerDescriptor server, Set<Map<ADSContext.ServerProperty, Object>> registry)
  {
    for (Map<ADSContext.ServerProperty, Object> s : registry)
    {
      ServerDescriptor servInRegistry = ServerDescriptor.createStandalone(s);
      if (servInRegistry.getId().equals(server.getId()))
      {
        return true;
      }
    }
    return false;
  }

  /**
   * Register instance key-pair public-key certificate provided in
   * serverProperties: generate a key-id attribute if one is not provided (as
   * expected); add an instance key public-key certificate entry for the key
   * certificate; and associate the certificate entry with the server entry via
   * the key ID attribute.
   *
   * @param serverProperties
   *          Properties of the server being registered to which the instance
   *          key entry belongs.
   * @param serverEntryDn
   *          The server's ADS entry DN.
   * @throws NamingException
   *           In case some JNDI operation fails.
   * @throws CryptoManager.CryptoManagerException
   *           In case there is a problem getting the instance public key
   *           certificate ID.
   */
  private void registerInstanceKeyCertificate(Map<ServerProperty, Object> serverProperties, LdapName serverEntryDn)
      throws ADSContextException
  {
    ADSContextHelper helper = new ADSContextHelper();
    helper.registerInstanceKeyCertificate(dirContext, serverProperties, serverEntryDn);
  }

  /**
   * Return the set of valid (i.e., not tagged as compromised) instance key-pair
   * public-key certificate entries in ADS. NOTE: calling this method assumes
   * that all the jar files are present in the classpath.
   *
   * @return The set of valid (i.e., not tagged as compromised) instance
   *         key-pair public-key certificate entries in ADS represented as a Map
   *         from ds-cfg-key-id value to ds-cfg-public-key-certificate;binary
   *         value. Note that the collection might be empty.
   * @throws ADSContextException
   *           in case of problems with the entry search.
   * @see org.opends.server.crypto.CryptoManagerImpl#getTrustedCertificates
   */
  public Map<String, byte[]> getTrustedCertificates() throws ADSContextException
  {
    final Map<String, byte[]> certificateMap = new HashMap<>();
    final String baseDNStr = getInstanceKeysContainerDN();
    try
    {
      ADSContextHelper helper = new ADSContextHelper();
      final LdapName baseDN = new LdapName(baseDNStr);
      final String FILTER_OC_INSTANCE_KEY = "(objectclass=" + helper.getOcCryptoInstanceKey() + ")";
      final String FILTER_NOT_COMPROMISED = "(!(" + helper.getAttrCryptoKeyCompromisedTime() + "=*))";
      final String searchFilter = "(&" + FILTER_OC_INSTANCE_KEY + FILTER_NOT_COMPROMISED + ")";
      final SearchControls searchControls = new SearchControls();
      searchControls.setSearchScope(SearchControls.ONELEVEL_SCOPE);
      final String attrIDs[] =
          { ADSContext.ServerProperty.INSTANCE_KEY_ID.getAttributeName(),
            ADSContext.ServerProperty.INSTANCE_PUBLIC_KEY_CERTIFICATE.getAttributeName() + ";binary" };
      searchControls.setReturningAttributes(attrIDs);
      NamingEnumeration<SearchResult> keyEntries = dirContext.search(baseDN, searchFilter, searchControls);
      try
      {
        while (keyEntries.hasMore())
        {
          final SearchResult entry = keyEntries.next();
          final Attributes attrs = entry.getAttributes();
          final Attribute keyIDAttr = attrs.get(attrIDs[0]);
          final Attribute keyCertAttr = attrs.get(attrIDs[1]);
          if (null == keyIDAttr || null == keyCertAttr)
          {
            continue;// schema viol.
          }
          certificateMap.put((String) keyIDAttr.get(), (byte[]) keyCertAttr.get());
        }
      }
      finally
      {
        try
        {
          keyEntries.close();
        }
        catch (Exception ex)
        {
          logger.warn(LocalizableMessage.raw("Unexpected error closing enumeration on ADS key pairs", ex));
        }
      }
    }
    catch (NamingException x)
    {
      throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, x);
    }
    return certificateMap;
  }

  /**
   * Merge the contents of this ADSContext with the contents of the provided
   * ADSContext. Note that only the contents of this ADSContext will be updated.
   *
   * @param adsCtx
   *          the other ADSContext to merge the contents with.
   * @throws ADSContextException
   *           if there was an error during the merge.
   */
  public void mergeWithRegistry(ADSContext adsCtx) throws ADSContextException
  {
    try
    {
      mergeAdministrators(adsCtx);
      mergeServerGroups(adsCtx);
      mergeServers(adsCtx);
    }
    catch (ADSContextException adce)
    {
      LocalizableMessage msg = ERR_ADS_MERGE.get(ConnectionUtils.getHostPort(getDirContext()),
          ConnectionUtils.getHostPort(adsCtx.getDirContext()), adce.getMessageObject());
      throw new ADSContextException(ErrorType.ERROR_MERGING, msg, adce);
    }
  }

  /**
   * Merge the administrator contents of this ADSContext with the contents of
   * the provided ADSContext. Note that only the contents of this ADSContext
   * will be updated.
   *
   * @param adsCtx
   *          the other ADSContext to merge the contents with.
   * @throws ADSContextException
   *           if there was an error during the merge.
   */
  private void mergeAdministrators(ADSContext adsCtx) throws ADSContextException
  {
    Set<Map<AdministratorProperty, Object>> admins2 = adsCtx.readAdministratorRegistry();
    SortedSet<String> notDefinedAdmins = new TreeSet<>();
    for (Map<AdministratorProperty, Object> admin2 : admins2)
    {
      String uid = (String) admin2.get(AdministratorProperty.UID);
      if (!isAdministratorAlreadyRegistered(uid))
      {
        notDefinedAdmins.add(uid);
      }
    }
    if (!notDefinedAdmins.isEmpty())
    {
      LocalizableMessage msg = ERR_ADS_ADMINISTRATOR_MERGE.get(
          ConnectionUtils.getHostPort(adsCtx.getDirContext()), ConnectionUtils.getHostPort(getDirContext()),
          joinAsString(Constants.LINE_SEPARATOR, notDefinedAdmins), ConnectionUtils.getHostPort(getDirContext()));
      throw new ADSContextException(ErrorType.ERROR_MERGING, msg, null);
    }
  }

  /**
   * Merge the groups contents of this ADSContext with the contents of the
   * provided ADSContext. Note that only the contents of this ADSContext will be
   * updated.
   *
   * @param adsCtx
   *          the other ADSContext to merge the contents with.
   * @throws ADSContextException
   *           if there was an error during the merge.
   */
  private void mergeServerGroups(ADSContext adsCtx) throws ADSContextException
  {
    Set<Map<ServerGroupProperty, Object>> serverGroups1 = readServerGroupRegistry();
    Set<Map<ServerGroupProperty, Object>> serverGroups2 = adsCtx.readServerGroupRegistry();

    for (Map<ServerGroupProperty, Object> group2 : serverGroups2)
    {
      Map<ServerGroupProperty, Object> group1 = null;
      String uid2 = (String) group2.get(ServerGroupProperty.UID);
      for (Map<ServerGroupProperty, Object> gr : serverGroups1)
      {
        String uid1 = (String) gr.get(ServerGroupProperty.UID);
        if (uid1.equalsIgnoreCase(uid2))
        {
          group1 = gr;
          break;
        }
      }

      if (group1 != null)
      {
        // Merge the members, keep the description on this ADS.
        Set<String> member1List = getServerGroupMemberList(uid2);
        if (member1List == null)
        {
          member1List = new HashSet<>();
        }
        Set<String> member2List = adsCtx.getServerGroupMemberList(uid2);
        if (member2List != null && !member2List.isEmpty())
        {
          member1List.addAll(member2List);
          Map<ServerGroupProperty, Object> newProperties = new HashMap<>();
          newProperties.put(ServerGroupProperty.MEMBERS, member1List);
          updateServerGroup(uid2, newProperties);
        }
      }
      else
      {
        createServerGroup(group2);
      }
    }
  }

  /**
   * Merge the server contents of this ADSContext with the contents of the
   * provided ADSContext. Note that only the contents of this ADSContext will be
   * updated.
   *
   * @param adsCtx
   *          the other ADSContext to merge the contents with.
   * @throws ADSContextException
   *           if there was an error during the merge.
   */
  private void mergeServers(ADSContext adsCtx) throws ADSContextException
  {
    for (Map<ServerProperty, Object> server2 : adsCtx.readServerRegistry())
    {
      if (!isServerAlreadyRegistered(server2))
      {
        registerServer(server2);
      }
    }
  }

  private void handleCloseNamingEnumeration(NamingEnumeration<?> ne) throws ADSContextException
  {
    if (ne != null)
    {
      try
      {
        ne.close();
      }
      catch (NamingException ex)
      {
        throw new ADSContextException(ErrorType.ERROR_UNEXPECTED, ex);
      }
    }
  }
}