/*
 * 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 legal-notices/CDDLv1_0.txt
 * or http://forgerock.org/license/CDDLv1.0.html.
 * 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 legal-notices/CDDLv1_0.txt.
 * 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
 *
 *
 *      Copyright 2008-2010 Sun Microsystems, Inc.
 *      Portions Copyright 2011-2014 ForgeRock AS
 */
package org.opends.server.workflowelement.localbackend;

import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.locks.Lock;

import org.opends.messages.Message;
import org.opends.messages.MessageBuilder;
import org.opends.server.api.Backend;
import org.opends.server.api.ChangeNotificationListener;
import org.opends.server.api.ClientConnection;
import org.opends.server.api.SynchronizationProvider;
import org.opends.server.api.plugin.PluginResult;
import org.opends.server.controls.*;
import org.opends.server.core.*;
import org.opends.server.loggers.debug.DebugTracer;
import org.opends.server.types.*;
import org.opends.server.types.operation.PostOperationModifyDNOperation;
import org.opends.server.types.operation.PostResponseModifyDNOperation;
import org.opends.server.types.operation.PostSynchronizationModifyDNOperation;
import org.opends.server.types.operation.PreOperationModifyDNOperation;

import static org.opends.messages.CoreMessages.*;
import static org.opends.server.loggers.ErrorLogger.*;
import static org.opends.server.loggers.debug.DebugLogger.*;
import static org.opends.server.util.ServerConstants.*;
import static org.opends.server.util.StaticUtils.*;

/**
 * This class defines an operation used to move an entry in a local backend
 * of the Directory Server.
 */
public class LocalBackendModifyDNOperation
  extends ModifyDNOperationWrapper
  implements PreOperationModifyDNOperation,
             PostOperationModifyDNOperation,
             PostResponseModifyDNOperation,
             PostSynchronizationModifyDNOperation
{
  /**
   * The tracer object for the debug logger.
   */
  private static final DebugTracer TRACER = getTracer();



  /**
   * The backend in which the operation is to be processed.
   */
  private Backend backend;

  /**
   * Indicates whether the no-op control was included in the request.
   */
  private boolean noOp;

  /**
   * The client connection on which this operation was requested.
   */
  private ClientConnection clientConnection;

  /**
   * The original DN of the entry.
   */
  private DN entryDN;

  /**
   * The current entry, before it is renamed.
   */
  private Entry currentEntry;

  /**
   * The new entry, as it will appear after it has been renamed.
   */
  private Entry newEntry;

  /** The LDAP post-read request control, if present in the request. */
  private LDAPPostReadRequestControl postReadRequest;

  /** The LDAP pre-read request control, if present in the request. */
  private LDAPPreReadRequestControl preReadRequest;

  /**
   * The new RDN for the entry.
   */
  private RDN newRDN;



  /**
   * Creates a new operation that may be used to move an entry in a
   * local backend of the Directory Server.
   *
   * @param operation The operation to enhance.
   */
  public LocalBackendModifyDNOperation (ModifyDNOperation operation)
  {
    super(operation);
    LocalBackendWorkflowElement.attachLocalOperation (operation, this);
  }



  /**
   * Retrieves the current entry, before it is renamed.  This will not be
   * available to pre-parse plugins or during the conflict resolution portion of
   * the synchronization processing.
   *
   * @return  The current entry, or <CODE>null</CODE> if it is not yet
   *           available.
   */
  @Override
  public final Entry getOriginalEntry()
  {
    return currentEntry;
  }



  /**
   * Retrieves the new entry, as it will appear after it is renamed.  This will
   * not be  available to pre-parse plugins or during the conflict resolution
   * portion of the synchronization processing.
   *
   * @return  The updated entry, or <CODE>null</CODE> if it is not yet
   *           available.
   */
  @Override
  public final Entry getUpdatedEntry()
  {
    return newEntry;
  }



  /**
   * Process this modify DN operation in a local backend.
   *
   * @param wfe
   *          The local backend work-flow element.
   * @throws CanceledOperationException
   *           if this operation should be cancelled
   */
  public void processLocalModifyDN(final LocalBackendWorkflowElement wfe)
      throws CanceledOperationException
  {
    this.backend = wfe.getBackend();

    clientConnection = getClientConnection();

    // Check for a request to cancel this operation.
    checkIfCanceled(false);

    try
    {
      BooleanHolder executePostOpPlugins = new BooleanHolder(false);
      processModifyDN(executePostOpPlugins);

      // Invoke the post-operation or post-synchronization modify DN plugins.
      PluginConfigManager pluginConfigManager =
          DirectoryServer.getPluginConfigManager();
      if (isSynchronizationOperation())
      {
        if (getResultCode() == ResultCode.SUCCESS)
        {
          pluginConfigManager.invokePostSynchronizationModifyDNPlugins(this);
        }
      }
      else if (executePostOpPlugins.value)
      {
        PluginResult.PostOperation postOpResult =
            pluginConfigManager.invokePostOperationModifyDNPlugins(this);
        if (!postOpResult.continueProcessing())
        {
          setResultCode(postOpResult.getResultCode());
          appendErrorMessage(postOpResult.getErrorMessage());
          setMatchedDN(postOpResult.getMatchedDN());
          setReferralURLs(postOpResult.getReferralURLs());
          return;
        }
      }
    }
    finally
    {
      LocalBackendWorkflowElement.filterNonDisclosableMatchedDN(this);
    }

    // Register a post-response call-back which will notify persistent
    // searches and change listeners.
    if (getResultCode() == ResultCode.SUCCESS)
    {
      registerPostResponseCallback(new Runnable()
      {

        @Override
        public void run()
        {
          // Notify persistent searches.
          for (PersistentSearch psearch : wfe.getPersistentSearches())
          {
            psearch.processModifyDN(newEntry, getChangeNumber(), currentEntry
                .getName());
          }

          // Notify change listeners.
          for (ChangeNotificationListener changeListener : DirectoryServer
              .getChangeNotificationListeners())
          {
            try
            {
              changeListener.handleModifyDNOperation(
                  LocalBackendModifyDNOperation.this, currentEntry, newEntry);
            }
            catch (Exception e)
            {
              if (debugEnabled())
              {
                TRACER.debugCaught(DebugLogLevel.ERROR, e);
              }

              Message message =
                  ERR_MODDN_ERROR_NOTIFYING_CHANGE_LISTENER
                      .get(getExceptionMessage(e));
              logError(message);
            }
          }
        }
      });
    }
  }

  private void processModifyDN(BooleanHolder executePostOpPlugins)
      throws CanceledOperationException
  {
    // Process the entry DN, newRDN, and newSuperior elements from their raw
    // forms as provided by the client to the forms required for the rest of
    // the modify DN processing.
    entryDN = getEntryDN();

    newRDN = getNewRDN();
    if (newRDN == null)
    {
      return;
    }

    DN newSuperior = getNewSuperior();
    if (newSuperior == null && getRawNewSuperior() != null)
    {
      return;
    }

    // Construct the new DN to use for the entry.
    DN parentDN;
    if (newSuperior == null)
    {
      parentDN = entryDN.getParentDNInSuffix();
    }
    else
    {
      if (newSuperior.isDescendantOf(entryDN))
      {
        setResultCode(ResultCode.UNWILLING_TO_PERFORM);
        appendErrorMessage(ERR_MODDN_NEW_SUPERIOR_IN_SUBTREE.get(String
            .valueOf(entryDN), String.valueOf(newSuperior)));
        return;
      }
      parentDN = newSuperior;
    }

    if (parentDN == null || parentDN.isRootDN())
    {
      setResultCode(ResultCode.UNWILLING_TO_PERFORM);
      appendErrorMessage(ERR_MODDN_NO_PARENT.get(String.valueOf(entryDN)));
      return;
    }

    DN newDN = parentDN.child(newRDN);

    // Get the backend for the current entry, and the backend for the new
    // entry. If either is null, or if they are different, then fail.
    Backend currentBackend = backend;
    if (currentBackend == null)
    {
      setResultCode(ResultCode.NO_SUCH_OBJECT);
      appendErrorMessage(ERR_MODDN_NO_BACKEND_FOR_CURRENT_ENTRY.get(String
          .valueOf(entryDN)));
      return;
    }

    Backend newBackend = DirectoryServer.getBackend(newDN);
    if (newBackend == null)
    {
      setResultCode(ResultCode.NO_SUCH_OBJECT);
      appendErrorMessage(ERR_MODDN_NO_BACKEND_FOR_NEW_ENTRY.get(String
          .valueOf(entryDN), String.valueOf(newDN)));
      return;
    }
    else if (!currentBackend.equals(newBackend))
    {
      setResultCode(ResultCode.UNWILLING_TO_PERFORM);
      appendErrorMessage(ERR_MODDN_DIFFERENT_BACKENDS.get(String
          .valueOf(entryDN), String.valueOf(newDN)));
      return;
    }

    // Check for a request to cancel this operation.
    checkIfCanceled(false);

    // Acquire write locks for the current and new DN.
    final Lock currentLock = LockManager.lockWrite(entryDN);
    Lock newLock = null;

    try
    {
      if (currentLock == null)
      {
        setResultCode(ResultCode.BUSY);
        appendErrorMessage(ERR_MODDN_CANNOT_LOCK_CURRENT_DN.get(
            String.valueOf(entryDN)));
        return;
      }

      try
      {
        newLock = LockManager.lockWrite(newDN);
        if (newLock == null)
        {
          setResultCode(ResultCode.BUSY);
          appendErrorMessage(ERR_MODDN_CANNOT_LOCK_NEW_DN.get(
              String.valueOf(entryDN), String.valueOf(newDN)));
          return;
        }
      }
      catch (Exception e)
      {
        if (debugEnabled())
        {
          TRACER.debugCaught(DebugLogLevel.ERROR, e);
        }

        setResultCodeAndMessageNoInfoDisclosure(null, newDN,
            DirectoryServer.getServerErrorResultCode(),
            ERR_MODDN_EXCEPTION_LOCKING_NEW_DN.get(String.valueOf(entryDN),
                String.valueOf(newDN), getExceptionMessage(e)));
        return;
      }

      // Check for a request to cancel this operation.
      checkIfCanceled(false);

      // Get the current entry from the appropriate backend. If it doesn't
      // exist, then fail.
      currentEntry = currentBackend.getEntry(entryDN);

      if (getOriginalEntry() == null)
      {
        // See if one of the entry's ancestors exists.
        setMatchedDN(findMatchedDN(entryDN));

        setResultCode(ResultCode.NO_SUCH_OBJECT);
        appendErrorMessage(ERR_MODDN_NO_CURRENT_ENTRY.get(String
            .valueOf(entryDN)));
        return;
      }

      // Check to see if there are any controls in the request. If so, then
      // see if there is any special processing required.
      handleRequestControls();

      // Check to see if the client has permission to perform the
      // modify DN.

      // FIXME: for now assume that this will check all permission
      // pertinent to the operation. This includes proxy authorization
      // and any other controls specified.

      // FIXME: earlier checks to see if the entry or new superior
      // already exists may have already exposed sensitive information
      // to the client.
      try
      {
        if (!AccessControlConfigManager.getInstance().getAccessControlHandler()
            .isAllowed(this))
        {
          setResultCodeAndMessageNoInfoDisclosure(currentEntry, entryDN,
              ResultCode.INSUFFICIENT_ACCESS_RIGHTS,
              ERR_MODDN_AUTHZ_INSUFFICIENT_ACCESS_RIGHTS.get(String
                  .valueOf(entryDN)));
          return;
        }
      }
      catch (DirectoryException e)
      {
        setResultCode(e.getResultCode());
        appendErrorMessage(e.getMessageObject());
        return;
      }

      // Duplicate the entry and set its new DN. Also, create an empty list
      // to hold the attribute-level modifications.
      newEntry = currentEntry.duplicate(false);
      newEntry.setDN(newDN);

      // init the modifications
      addModification(null);
      List<Modification> modifications = getModifications();

      if (!handleConflictResolution())
      {
        return;
      }

      // If the operation is not a synchronization operation,
      // - Apply the RDN changes.
      // - Invoke the pre-operation modify DN plugins.
      // - apply additional modifications provided by the plugins.
      // If the operation is a synchronization operation
      // - apply the operation as it was originally done on the master.
      if (!isSynchronizationOperation())
      {
        // Apply any changes to the entry based on the change in its RDN.
        // Also perform schema checking on the updated entry.
        applyRDNChanges(modifications);

        // Check for a request to cancel this operation.
        checkIfCanceled(false);

        // Get a count of the current number of modifications. The
        // pre-operation plugins may alter this list, and we need to be able
        // to identify which changes were made after they're done.
        int modCount = modifications.size();

        executePostOpPlugins.value = true;
        PluginResult.PreOperation preOpResult =
            DirectoryServer.getPluginConfigManager()
                .invokePreOperationModifyDNPlugins(this);
        if (!preOpResult.continueProcessing())
        {
          setResultCode(preOpResult.getResultCode());
          appendErrorMessage(preOpResult.getErrorMessage());
          setMatchedDN(preOpResult.getMatchedDN());
          setReferralURLs(preOpResult.getReferralURLs());
          return;
        }

        // Check to see if any of the pre-operation plugins made any changes
        // to the entry. If so, then apply them.
        if (modifications.size() > modCount)
        {
          applyPreOpModifications(modifications, modCount, true);
        }
      }
      else
      {
        // This is a synchronization operation
        // Apply the modifications as they were originally done.
        applyRDNChanges(modifications);
        applyPreOpModifications(modifications, 0, false);
      }

      LocalBackendWorkflowElement.checkIfBackendIsWritable(currentBackend,
          this, entryDN, ERR_MODDN_SERVER_READONLY, ERR_MODDN_BACKEND_READONLY);

      if (noOp)
      {
        appendErrorMessage(INFO_MODDN_NOOP.get());
        setResultCode(ResultCode.NO_OPERATION);
      }
      else
      {
        if (!processPreOperation())
        {
          return;
        }
        currentBackend.renameEntry(entryDN, newEntry, this);
      }

      // Attach the pre-read and/or post-read controls to the response if
      // appropriate.
      LocalBackendWorkflowElement.addPreReadResponse(this, preReadRequest,
          currentEntry);
      LocalBackendWorkflowElement.addPostReadResponse(this, postReadRequest,
          newEntry);

      if (!noOp)
      {
        setResultCode(ResultCode.SUCCESS);
      }
    }
    catch (DirectoryException de)
    {
      if (debugEnabled())
      {
        TRACER.debugCaught(DebugLogLevel.ERROR, de);
      }

      setResponseData(de);
      return;
    }
    finally
    {
      if (currentLock != null)
      {
        LockManager.unlock(entryDN, currentLock);
      }
      if (newLock != null)
      {
        LockManager.unlock(newDN, newLock);
      }
      processSynchPostOperationPlugins();
    }
  }

  private DirectoryException newDirectoryException(Entry entry,
      ResultCode resultCode, Message message) throws DirectoryException
  {
    return LocalBackendWorkflowElement.newDirectoryException(this, entry, null,
        resultCode, message, ResultCode.NO_SUCH_OBJECT,
        ERR_MODDN_NO_CURRENT_ENTRY.get(String.valueOf(entryDN)));
  }

  private void setResultCodeAndMessageNoInfoDisclosure(Entry entry, DN entryDN,
      ResultCode realResultCode, Message realMessage) throws DirectoryException
  {
    LocalBackendWorkflowElement.setResultCodeAndMessageNoInfoDisclosure(this,
        entry, entryDN, realResultCode, realMessage, ResultCode.NO_SUCH_OBJECT,
        ERR_MODDN_NO_CURRENT_ENTRY.get(String.valueOf(entryDN)));
  }

  private DN findMatchedDN(DN entryDN)
  {
    try
    {
      DN matchedDN = entryDN.getParentDNInSuffix();
      while (matchedDN != null)
      {
        if (DirectoryServer.entryExists(matchedDN))
        {
          return matchedDN;
        }

        matchedDN = matchedDN.getParentDNInSuffix();
      }
    }
    catch (Exception e)
    {
      if (debugEnabled())
      {
        TRACER.debugCaught(DebugLogLevel.ERROR, e);
      }
    }
    return null;
  }

  /**
   * Processes the set of controls included in the request.
   *
   * @throws  DirectoryException  If a problem occurs that should cause the
   *                              modify DN operation to fail.
   */
  private void handleRequestControls() throws DirectoryException
  {
    LocalBackendWorkflowElement.removeAllDisallowedControls(entryDN, this);

    List<Control> requestControls = getRequestControls();
    if ((requestControls != null) && (! requestControls.isEmpty()))
    {
      for (int i=0; i < requestControls.size(); i++)
      {
        Control c   = requestControls.get(i);
        String  oid = c.getOID();

        if (oid.equals(OID_LDAP_ASSERTION))
        {
          LDAPAssertionRequestControl assertControl =
                getRequestControl(LDAPAssertionRequestControl.DECODER);

          SearchFilter filter;
          try
          {
            filter = assertControl.getSearchFilter();
          }
          catch (DirectoryException de)
          {
            if (debugEnabled())
            {
              TRACER.debugCaught(DebugLogLevel.ERROR, de);
            }

            throw newDirectoryException(currentEntry, de.getResultCode(),
                ERR_MODDN_CANNOT_PROCESS_ASSERTION_FILTER.get(
                    String.valueOf(entryDN),
                    de.getMessageObject()));
          }

          // Check if the current user has permission to make
          // this determination.
          if (!AccessControlConfigManager.getInstance().
            getAccessControlHandler().isAllowed(this, currentEntry, filter))
          {
            throw new DirectoryException(
              ResultCode.INSUFFICIENT_ACCESS_RIGHTS,
              ERR_CONTROL_INSUFFICIENT_ACCESS_RIGHTS.get(oid));
          }

          try
          {
            if (!filter.matchesEntry(currentEntry))
            {
              throw newDirectoryException(currentEntry,
                  ResultCode.ASSERTION_FAILED,
                  ERR_MODDN_ASSERTION_FAILED.get(String
                      .valueOf(entryDN)));
            }
          }
          catch (DirectoryException de)
          {
            if (de.getResultCode() == ResultCode.ASSERTION_FAILED)
            {
              throw de;
            }

            if (debugEnabled())
            {
              TRACER.debugCaught(DebugLogLevel.ERROR, de);
            }

            throw newDirectoryException(currentEntry, de.getResultCode(),
                ERR_MODDN_CANNOT_PROCESS_ASSERTION_FILTER.get(
                    String.valueOf(entryDN),
                    de.getMessageObject()));
          }
        }
        else if (oid.equals(OID_LDAP_NOOP_OPENLDAP_ASSIGNED))
        {
          noOp = true;
        }
        else if (oid.equals(OID_LDAP_READENTRY_PREREAD))
        {
          preReadRequest =
                getRequestControl(LDAPPreReadRequestControl.DECODER);
          requestControls.set(i, preReadRequest);
        }
        else if (oid.equals(OID_LDAP_READENTRY_POSTREAD))
        {
          if (c instanceof LDAPPostReadRequestControl)
          {
            postReadRequest = (LDAPPostReadRequestControl) c;
          }
          else
          {
            postReadRequest =
                  getRequestControl(LDAPPostReadRequestControl.DECODER);
            requestControls.set(i, postReadRequest);
          }
        }
        else if (oid.equals(OID_PROXIED_AUTH_V1))
        {
          // Log usage of legacy proxy authz V1 control.
          addAdditionalLogItem(AdditionalLogItem.keyOnly(getClass(),
              "obsoleteProxiedAuthzV1Control"));

          // The requester must have the PROXIED_AUTH privilege in order to
          // be able to use this control.
          if (! clientConnection.hasPrivilege(Privilege.PROXIED_AUTH, this))
          {
            throw new DirectoryException(ResultCode.AUTHORIZATION_DENIED,
                           ERR_PROXYAUTH_INSUFFICIENT_PRIVILEGES.get());
          }

          ProxiedAuthV1Control proxyControl =
              getRequestControl(ProxiedAuthV1Control.DECODER);

          Entry authorizationEntry = proxyControl.getAuthorizationEntry();
          setAuthorizationEntry(authorizationEntry);
          if (authorizationEntry == null)
          {
            setProxiedAuthorizationDN(DN.rootDN());
          }
          else
          {
            setProxiedAuthorizationDN(authorizationEntry.getName());
          }
        }
        else if (oid.equals(OID_PROXIED_AUTH_V2))
        {
          // The requester must have the PROXIED_AUTH privilege in order to
          // be able to use this control.
          if (! clientConnection.hasPrivilege(Privilege.PROXIED_AUTH, this))
          {
            throw new DirectoryException(ResultCode.AUTHORIZATION_DENIED,
                           ERR_PROXYAUTH_INSUFFICIENT_PRIVILEGES.get());
          }

          ProxiedAuthV2Control proxyControl =
              getRequestControl(ProxiedAuthV2Control.DECODER);

          Entry authorizationEntry = proxyControl.getAuthorizationEntry();
          setAuthorizationEntry(authorizationEntry);
          if (authorizationEntry == null)
          {
            setProxiedAuthorizationDN(DN.rootDN());
          }
          else
          {
            setProxiedAuthorizationDN(authorizationEntry.getName());
          }
        }

        // NYI -- Add support for additional controls.

        else if (c.isCritical())
        {
          if ((backend == null) || (! backend.supportsControl(oid)))
          {
            throw new DirectoryException(
                           ResultCode.UNAVAILABLE_CRITICAL_EXTENSION,
                           ERR_MODDN_UNSUPPORTED_CRITICAL_CONTROL.get(
                                String.valueOf(entryDN), oid));
          }
        }
      }
    }
  }



  /**
   * Updates the entry so that its attributes are changed to reflect the changes
   * to the RDN.  This also performs schema checking on the updated entry.
   *
   * @param  modifications  A list to hold the modifications made to the entry.
   *
   * @throws  DirectoryException  If a problem occurs that should cause the
   *                              modify DN operation to fail.
   */
  private void applyRDNChanges(List<Modification> modifications)
          throws DirectoryException
  {
    // If we should delete the old RDN values from the entry, then do so.
    if (deleteOldRDN())
    {
      RDN currentRDN = entryDN.rdn();
      int numValues  = currentRDN.getNumValues();
      for (int i=0; i < numValues; i++)
      {
        Attribute a = Attributes.create(
            currentRDN.getAttributeType(i),
            currentRDN.getAttributeName(i),
            currentRDN.getAttributeValue(i));

        // If the associated attribute type is marked NO-USER-MODIFICATION, then
        // refuse the update.
        if (a.getAttributeType().isNoUserModification())
        {
          if (! (isInternalOperation() || isSynchronizationOperation()))
          {
            throw new DirectoryException(ResultCode.CONSTRAINT_VIOLATION,
                           ERR_MODDN_OLD_RDN_ATTR_IS_NO_USER_MOD.get(
                                String.valueOf(entryDN), a.getName()));
          }
        }

        List<AttributeValue> missingValues = new LinkedList<AttributeValue>();
        newEntry.removeAttribute(a, missingValues);

        if (missingValues.isEmpty())
        {
          modifications.add(new Modification(ModificationType.DELETE, a));
        }
      }
    }


    // Add the new RDN values to the entry.
    int newRDNValues = newRDN.getNumValues();
    for (int i=0; i < newRDNValues; i++)
    {
      Attribute a = Attributes.create(
          newRDN.getAttributeType(i),
          newRDN.getAttributeName(i),
          newRDN.getAttributeValue(i));

      List<AttributeValue> duplicateValues = new LinkedList<AttributeValue>();
      newEntry.addAttribute(a, duplicateValues);

      if (duplicateValues.isEmpty())
      {
        // If the associated attribute type is marked NO-USER-MODIFICATION, then
        // refuse the update.
        if (a.getAttributeType().isNoUserModification())
        {
          if (! (isInternalOperation() || isSynchronizationOperation()))
          {
            throw new DirectoryException(ResultCode.CONSTRAINT_VIOLATION,
                           ERR_MODDN_NEW_RDN_ATTR_IS_NO_USER_MOD.get(
                                String.valueOf(entryDN), a.getName()));
          }
        }
        else
        {
          modifications.add(new Modification(ModificationType.ADD, a));
        }
      }
    }

    // If the server is configured to check the schema and the operation is not
    // a synchronization operation, make sure that the resulting entry is valid
    // as per the server schema.
    if ((DirectoryServer.checkSchema()) && (! isSynchronizationOperation()))
    {
      MessageBuilder invalidReason = new MessageBuilder();
      if (! newEntry.conformsToSchema(null, false, true, true,
                                      invalidReason))
      {
        throw new DirectoryException(ResultCode.OBJECTCLASS_VIOLATION,
                                     ERR_MODDN_VIOLATES_SCHEMA.get(
                                          String.valueOf(entryDN),
                                          String.valueOf(invalidReason)));
      }

      for (int i=0; i < newRDNValues; i++)
      {
        AttributeType at = newRDN.getAttributeType(i);
        if (at.isObsolete())
        {
          throw new DirectoryException(ResultCode.CONSTRAINT_VIOLATION,
                                       ERR_MODDN_NEWRDN_ATTR_IS_OBSOLETE.get(
                                            String.valueOf(entryDN),
                                            at.getNameOrOID()));
        }
      }
    }
  }



  /**
   * Applies any modifications performed during pre-operation plugin processing.
   * This also performs schema checking for the updated entry.
   *
   * @param  modifications  A list containing the modifications made to the
   *                        entry.
   * @param  startPos       The position in the list at which the pre-operation
   *                        modifications start.
   * @param  checkSchema    A boolean allowing to control if schema must be
   *                        checked
   *
   * @throws  DirectoryException  If a problem occurs that should cause the
   *                              modify DN operation to fail.
   */
  private void applyPreOpModifications(List<Modification> modifications,
                                       int startPos, boolean checkSchema)
          throws DirectoryException
  {
    for (int i=startPos; i < modifications.size(); i++)
    {
      Modification m = modifications.get(i);
      Attribute    a = m.getAttribute();

      switch (m.getModificationType())
      {
        case ADD:
          List<AttributeValue> duplicateValues =
               new LinkedList<AttributeValue>();
          newEntry.addAttribute(a, duplicateValues);
          break;

        case DELETE:
          List<AttributeValue> missingValues = new LinkedList<AttributeValue>();
          newEntry.removeAttribute(a, missingValues);
          break;

        case REPLACE:
          newEntry.replaceAttribute(a);
          break;

        case INCREMENT:
          newEntry.incrementAttribute(a);
          break;
      }
    }


    // Make sure that the updated entry still conforms to the server
    // schema.
    if (DirectoryServer.checkSchema() && checkSchema)
    {
      MessageBuilder invalidReason = new MessageBuilder();
      if (! newEntry.conformsToSchema(null, false, true, true,
                                      invalidReason))
      {
        throw new DirectoryException(ResultCode.OBJECTCLASS_VIOLATION,
                                     ERR_MODDN_PREOP_VIOLATES_SCHEMA.get(
                                          String.valueOf(entryDN),
                                          String.valueOf(invalidReason)));
      }
    }
  }



  /**
   * Handle conflict resolution.
   * @return  {@code true} if processing should continue for the operation, or
   *          {@code false} if not.
   */
  private boolean handleConflictResolution()
  {
      for (SynchronizationProvider<?> provider :
          DirectoryServer.getSynchronizationProviders()) {
          try {
              SynchronizationProviderResult result =
                  provider.handleConflictResolution(this);
              if (!result.continueProcessing()) {
                  setResultCode(result.getResultCode());
                  appendErrorMessage(result.getErrorMessage());
                  setMatchedDN(result.getMatchedDN());
                  setReferralURLs(result.getReferralURLs());
                  return false;
              }
          } catch (DirectoryException de) {
              if (debugEnabled()) {
                  TRACER.debugCaught(DebugLogLevel.ERROR, de);
              }
              logError(ERR_MODDN_SYNCH_CONFLICT_RESOLUTION_FAILED.get(
                      getConnectionID(), getOperationID(),
                      getExceptionMessage(de)));

              setResponseData(de);
              return false;
          }
      }
      return true;
  }

  /**
   * Process pre operation.
   * @return  {@code true} if processing should continue for the operation, or
   *          {@code false} if not.
   */
  private boolean processPreOperation()
  {
      for (SynchronizationProvider<?> provider :
          DirectoryServer.getSynchronizationProviders()) {
          try {
              SynchronizationProviderResult result =
                  provider.doPreOperation(this);
              if (! result.continueProcessing()) {
                  setResultCode(result.getResultCode());
                  appendErrorMessage(result.getErrorMessage());
                  setMatchedDN(result.getMatchedDN());
                  setReferralURLs(result.getReferralURLs());
                  return false;
              }
          } catch (DirectoryException de) {
              if (debugEnabled()) {
                  TRACER.debugCaught(DebugLogLevel.ERROR, de);
              }
              logError(ERR_MODDN_SYNCH_PREOP_FAILED.get(getConnectionID(),
                      getOperationID(), getExceptionMessage(de)));
              setResponseData(de);
              return false;
          }
      }
      return true;
  }

  /**
   * Invoke post operation synchronization providers.
   */
  private void processSynchPostOperationPlugins()
  {
      for (SynchronizationProvider<?> provider : DirectoryServer
              .getSynchronizationProviders()) {
          try {
              provider.doPostOperation(this);
          } catch (DirectoryException de) {
              if (debugEnabled()) {
                  TRACER.debugCaught(DebugLogLevel.ERROR, de);
              }
              logError(ERR_MODDN_SYNCH_POSTOP_FAILED.get(getConnectionID(),
                      getOperationID(), getExceptionMessage(de)));
              setResponseData(de);
              return;
          }
      }
  }
}