/*
    *   Licensed to the Apache Software Foundation (ASF) under one
    *   or more contributor license agreements.  See the NOTICE file
    *   distributed with this work for additional information
    *   regarding copyright ownership.  The ASF licenses this file
    *   to you under the Apache License, Version 2.0 (the
    *   "License"); you may not use this file except in compliance
    *   with the License.  You may obtain a copy of the License at
    *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   *   Unless required by applicable law or agreed to in writing,
   *   software distributed under the License is distributed on an
   *   "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   *   KIND, either express or implied.  See the License for the
   *   specific language governing permissions and limitations
   *   under the License.
   *
   */
  package org.apache.directory.server.core.api.schema.registries.synchronizers;
  
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.directory.api.ldap.model.constants.MetaSchemaConstants;
  import org.apache.directory.api.ldap.model.constants.SchemaConstants;
  import org.apache.directory.api.ldap.model.entry.Entry;
  import org.apache.directory.api.ldap.model.exception.LdapException;
  import org.apache.directory.api.ldap.model.exception.LdapInvalidDnException;
  import org.apache.directory.api.ldap.model.exception.LdapSchemaViolationException;
  import org.apache.directory.api.ldap.model.exception.LdapUnwillingToPerformException;
  import org.apache.directory.api.ldap.model.message.ResultCodeEnum;
  import org.apache.directory.api.ldap.model.name.Dn;
  import org.apache.directory.api.ldap.model.name.Rdn;
  import org.apache.directory.api.ldap.model.schema.LdapComparator;
  import org.apache.directory.api.ldap.model.schema.SchemaManager;
  import org.apache.directory.api.ldap.model.schema.registries.Schema;
  import org.apache.directory.api.util.Strings;
  import org.apache.directory.server.core.api.interceptor.context.ModifyOperationContext;
  import org.apache.directory.server.i18n.I18n;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * A handler for operations performed to add, delete, modify, rename and 
   * move schema comparators.
   *
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class ComparatorSynchronizer extends AbstractRegistrySynchronizer
  {
      /** A logger for this class */
      private static final Logger LOG = LoggerFactory.getLogger( ComparatorSynchronizer.class );
  
  
      /**
       * Creates a new instance of ComparatorSynchronizer.
       *
       * @param schemaManager The global schemaManager
       * @throws Exception If the initialization failed
       */
      public ComparatorSynchronizer( SchemaManager schemaManager ) throws Exception
      {
          super( schemaManager );
      }
  
  
      /**
       * {@inheritDoc}
       */
      @Override
      public boolean modify( ModifyOperationContext modifyContext, Entry targetEntry, boolean cascade )
          throws LdapException
      {
          Dn name = modifyContext.getDn();
          Entry entry = modifyContext.getEntry();
          String schemaName = getSchemaName( name );
          String oid = getOid( entry );
          LdapComparator<?> comparator = factory.getLdapComparator( schemaManager, targetEntry, schemaManager
              .getRegistries(), schemaName );
  
          if ( isSchemaEnabled( schemaName ) )
          {
              comparator.setSchemaName( schemaName );
  
              schemaManager.unregisterComparator( oid );
              schemaManager.add( comparator );
  
              return SCHEMA_MODIFIED;
          }
  
          return SCHEMA_UNCHANGED;
      }
  
  
      /**
       * {@inheritDoc}
      */
     @Override
     public void add( Entry entry ) throws LdapException
     {
         Dn dn = entry.getDn();
         Dn parentDn = dn.getParent();
 
         // The parent Dn must be ou=comparators,cn=<schemaName>,ou=schema
         checkParent( parentDn, schemaManager, SchemaConstants.COMPARATOR );
 
         // The new schemaObject's OID must not already exist
         checkOidIsUniqueForComparator( entry );
 
         // Build the new Comparator from the given entry
         String schemaName = getSchemaName( dn );
 
         LdapComparator<?> comparator = factory.getLdapComparator( schemaManager, entry, schemaManager.getRegistries(),
             schemaName );
 
         // At this point, the constructed LdapComparator has not been checked against the 
         // existing Registries. It will be checked there, if the schema and the 
         // LdapComparator are both enabled.
         Schema schema = schemaManager.getLoadedSchema( schemaName );
 
         if ( schema.isEnabled() && comparator.isEnabled() )
         {
             if ( schemaManager.add( comparator ) )
             {
                 LOG.debug( "Added {} into the enabled schema {}", dn.getName(), schemaName );
             }
             else
             {
                 // We have some error : reject the addition and get out
                 String msg = I18n.err( I18n.ERR_350, entry.getDn().getName(), Strings.listToString(
                     schemaManager.getErrors() ) );
                 LOG.info( msg );
                 throw new LdapUnwillingToPerformException( ResultCodeEnum.UNWILLING_TO_PERFORM, msg );
             }
         }
         else
         {
             LOG.debug( "The Comparator {} cannot be added in the disabled schema {}", dn.getName(), schemaName );
         }
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void delete( Entry entry, boolean cascade ) throws LdapException
     {
         Dn dn = entry.getDn();
         Dn parentDn = dn.getParent();
 
         // The parent Dn must be ou=comparators,cn=<schemaName>,ou=schema
         checkParent( parentDn, schemaManager, SchemaConstants.COMPARATOR );
 
         // Get the SchemaName
         String schemaName = getSchemaName( entry.getDn() );
 
         // Get the Schema
         Schema schema = schemaManager.getLoadedSchema( schemaName );
 
         if ( schema.isDisabled() )
         {
             // The schema is disabled, nothing to do.
             LOG.debug( "The Comparator {} cannot be deleted from the disabled schema {}", dn.getName(), schemaName );
 
             return;
         }
 
         // Test that the Oid exists
         LdapComparator<?> comparator = null;
 
         try
         {
             comparator = checkComparatorOidExists( entry );
         }
         catch ( LdapSchemaViolationException lsve )
         {
             // The comparator does not exist
             comparator = factory.getLdapComparator( schemaManager, entry, schemaManager.getRegistries(), schemaName );
 
             if ( schemaManager.getRegistries().contains( comparator ) )
             {
                 // Remove the Comparator from the schema/SchemaObject Map
                 schemaManager.getRegistries().dissociateFromSchema( comparator );
 
                 // Ok, we can exit. 
                 return;
             }
             else
             {
                 // Ok, definitively an error
                 String msg = I18n.err( I18n.ERR_351, entry.getDn().getName() );
                 LOG.info( msg );
                 throw new LdapSchemaViolationException( ResultCodeEnum.UNWILLING_TO_PERFORM, msg );
             }
         }
 
         List<Throwable> errors = new ArrayList<>();
 
         if ( schema.isEnabled() && comparator.isEnabled() )
         {
             if ( schemaManager.delete( comparator ) )
             {
                 LOG.debug( "Deleted {} from the enabled schema {}", dn.getName(), schemaName );
             }
             else
             {
                 String msg = I18n.err( I18n.ERR_352, entry.getDn().getName(), Strings.listToString(
                     errors ) );
                 LOG.info( msg );
                 throw new LdapUnwillingToPerformException( ResultCodeEnum.UNWILLING_TO_PERFORM, msg );
             }
         }
         else
         {
             LOG.debug( "The Comparator {} cannot be deleted from the disabled schema {}", dn.getName(), schemaName );
         }
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void rename( Entry entry, Rdn newRdn, boolean cascade ) throws LdapException
     {
         String oldOid = getOid( entry );
 
         if ( schemaManager.getMatchingRuleRegistry().contains( oldOid ) )
         {
             throw new LdapUnwillingToPerformException( ResultCodeEnum.UNWILLING_TO_PERFORM,
                 I18n.err( I18n.ERR_353, oldOid ) );
         }
 
         String oid = newRdn.getValue();
         checkOidIsUniqueForComparator( oid );
 
         String schemaName = getSchemaName( entry.getDn() );
 
         if ( isSchemaEnabled( schemaName ) )
         {
             // Inject the new OID in the entry
             Entry targetEntry = entry.clone();
             String newOid = newRdn.getValue();
             checkOidIsUnique( newOid );
             targetEntry.put( MetaSchemaConstants.M_OID_AT, newOid );
 
             // Inject the new Dn
             Dn newDn = targetEntry.getDn().getParent();
             newDn = newDn.add( newRdn );
             targetEntry.setDn( newDn );
 
             // Register the new comparator, and unregister the old one
             LdapComparator<?> comparator = factory.getLdapComparator( schemaManager, targetEntry, schemaManager
                 .getRegistries(), schemaName );
             schemaManager.unregisterComparator( oldOid );
             schemaManager.add( comparator );
         }
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void moveAndRename( Dn oriChildName, Dn newParentName, Rdn newRdn, boolean deleteOldRn,
         Entry entry, boolean cascade ) throws LdapException
     {
         checkNewParent( newParentName );
         String oldOid = getOid( entry );
 
         if ( schemaManager.getMatchingRuleRegistry().contains( oldOid ) )
         {
             throw new LdapUnwillingToPerformException( ResultCodeEnum.UNWILLING_TO_PERFORM,
                 I18n.err( I18n.ERR_353, oldOid ) );
         }
 
         String oid = newRdn.getValue();
         checkOidIsUniqueForComparator( oid );
 
         String newSchemaName = getSchemaName( newParentName );
 
         LdapComparator<?> comparator = factory.getLdapComparator( schemaManager, entry, schemaManager.getRegistries(),
             newSchemaName );
 
         String oldSchemaName = getSchemaName( oriChildName );
 
         if ( isSchemaEnabled( oldSchemaName ) )
         {
             schemaManager.unregisterComparator( oldOid );
         }
 
         if ( isSchemaEnabled( newSchemaName ) )
         {
             schemaManager.add( comparator );
         }
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void move( Dn oriChildName, Dn newParentName, Entry entry, boolean cascade ) throws LdapException
     {
         checkNewParent( newParentName );
         String oid = getOid( entry );
 
         if ( schemaManager.getMatchingRuleRegistry().contains( oid ) )
         {
             throw new LdapUnwillingToPerformException( ResultCodeEnum.UNWILLING_TO_PERFORM,
                 I18n.err( I18n.ERR_354, oid ) );
         }
 
         String newSchemaName = getSchemaName( newParentName );
 
         LdapComparator<?> comparator = factory.getLdapComparator( schemaManager, entry, schemaManager.getRegistries(),
             newSchemaName );
 
         String oldSchemaName = getSchemaName( oriChildName );
 
         if ( isSchemaEnabled( oldSchemaName ) )
         {
             schemaManager.unregisterComparator( oid );
         }
 
         if ( isSchemaEnabled( newSchemaName ) )
         {
             schemaManager.add( comparator );
         }
     }
 
 
     private void checkOidIsUniqueForComparator( String oid ) throws LdapSchemaViolationException
     {
         if ( schemaManager.getComparatorRegistry().contains( oid ) )
         {
             throw new LdapSchemaViolationException( ResultCodeEnum.OTHER,
                 I18n.err( I18n.ERR_355, oid ) );
         }
     }
 
 
     private void checkOidIsUniqueForComparator( Entry entry ) throws LdapException
     {
         String oid = getOid( entry );
 
         if ( schemaManager.getComparatorRegistry().contains( oid ) )
         {
             throw new LdapSchemaViolationException( ResultCodeEnum.OTHER,
                 I18n.err( I18n.ERR_355, oid ) );
         }
     }
 
 
     /**
      * Check that a Comparator exists in the ComparatorRegistry, and if so,
      * return it.
      * 
      * @param entry the Entry we want to know it exists
      * @return The found comparator
      * @throws LdapException If teh comparator is not found
      */
     protected LdapComparator<?> checkComparatorOidExists( Entry entry ) throws LdapException
     {
         String oid = getOid( entry );
 
         if ( schemaManager.getComparatorRegistry().contains( oid ) )
         {
             return schemaManager.getComparatorRegistry().get( oid );
         }
         else
         {
             throw new LdapSchemaViolationException( ResultCodeEnum.OTHER,
                 I18n.err( I18n.ERR_336, oid ) );
         }
     }
 
 
     private void checkNewParent( Dn newParent ) throws LdapException
     {
         if ( newParent.size() != 3 )
         {
             throw new LdapInvalidDnException( ResultCodeEnum.NAMING_VIOLATION,
                 I18n.err( I18n.ERR_357 ) );
         }
 
         Rdn rdn = newParent.getRdn();
 
         if ( !schemaManager.getAttributeTypeRegistry().getOidByName( rdn.getNormType() ).equals(
             SchemaConstants.OU_AT_OID ) )
         {
             throw new LdapInvalidDnException( ResultCodeEnum.NAMING_VIOLATION, I18n.err( I18n.ERR_358 ) );
         }
 
         if ( !rdn.getValue().equalsIgnoreCase( SchemaConstants.COMPARATORS_AT ) )
         {
             throw new LdapInvalidDnException( ResultCodeEnum.NAMING_VIOLATION, I18n.err( I18n.ERR_359 ) );
         }
     }
 }