/*
    *  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.api.ldap.model.schema.registries.helper;
  
  import java.util.List;
  
  import org.apache.directory.api.i18n.I18n;
  import org.apache.directory.api.ldap.model.exception.LdapException;
  import org.apache.directory.api.ldap.model.exception.LdapSchemaException;
  import org.apache.directory.api.ldap.model.exception.LdapSchemaExceptionCodes;
  import org.apache.directory.api.ldap.model.schema.AttributeType;
  import org.apache.directory.api.ldap.model.schema.ObjectClass;
  import org.apache.directory.api.ldap.model.schema.ObjectClassTypeEnum;
  import org.apache.directory.api.ldap.model.schema.registries.AttributeTypeRegistry;
  import org.apache.directory.api.ldap.model.schema.registries.ObjectClassRegistry;
  import org.apache.directory.api.ldap.model.schema.registries.Registries;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * An helper class used to store all the methods associated with an ObjectClass
   * in relation with the Registries and SchemaManager.
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public final class ObjectClassHelper
  {
      private ObjectClassHelper()
      {
      }
  
      /** A logger for this class */
      private static final Logger LOG = LoggerFactory.getLogger( ObjectClassHelper.class );
  
      /**
       * Inject the ObjectClass into the registries, updating the references to
       * other SchemaObject
       *
       * @param objectClass The ObjectClass to add to the Registries
       * @param errors The errors we got while adding the ObjectClass to the Registries
       * @param registries The Registries
       * @throws LdapException on failure
       */
      public static void addToRegistries( ObjectClass objectClass, List<Throwable> errors, Registries registries ) throws LdapException
      {
          if ( registries != null )
          {
              try
              {
                  objectClass.unlock();
                  
                  // The superiors
                  buildSuperiors( objectClass, errors, registries );
      
                  // The MAY AttributeTypes
                  buildMay( objectClass, errors, registries );
      
                  // The MUST AttributeTypes
                  buildMust( objectClass, errors, registries );
      
                  /**
                   * Add the OC references (using and usedBy) :
                   * OC -> AT (MAY and MUST)
                   * OC -> OC (SUPERIORS)
                   */
                  for ( AttributeType mayAttributeType : objectClass.getMayAttributeTypes() )
                  {
                      registries.addReference( objectClass, mayAttributeType );
                  }
      
                  for ( AttributeType mustAttributeType : objectClass.getMustAttributeTypes() )
                  {
                      registries.addReference( objectClass, mustAttributeType );
                  }
      
                  for ( ObjectClass superiorObjectClass : objectClass.getSuperiors() )
                  {
                      registries.addReference( objectClass, superiorObjectClass );
                  }
              }
              finally
              {
                 objectClass.lock();
             }
         }
     }
 
 
     /**
      * Build the references to this ObjectClass SUPERIORS, checking that the type
      * hierarchy is correct.
      */
     private static void buildSuperiors( ObjectClass objectClass, List<Throwable> errors, Registries registries )
     {
         ObjectClassRegistry ocRegistry = registries.getObjectClassRegistry();
         List<String> superiorOids = objectClass.getSuperiorOids();
 
         if ( superiorOids != null )
         {
             objectClass.getSuperiors().clear();
 
             for ( String superiorName : superiorOids )
             {
                 try
                 {
                     ObjectClass superior = ocRegistry.lookup( ocRegistry.getOidByName( superiorName ) );
 
                     // Before adding the superior, check that the ObjectClass type is consistent
                     switch ( objectClass.getType() )
                     {
                         case ABSTRACT:
                             if ( superior.getType() != ObjectClassTypeEnum.ABSTRACT )
                             {
                                 // An ABSTRACT OC can only inherit from ABSTRACT OCs
                                 String msg = I18n.err( I18n.ERR_04318, objectClass.getOid(), superior.getObjectType(), superior );
 
                                 LdapSchemaException ldapSchemaException = new LdapSchemaException(
                                     LdapSchemaExceptionCodes.OC_ABSTRACT_MUST_INHERIT_FROM_ABSTRACT_OC, msg );
                                 ldapSchemaException.setSourceObject( objectClass );
                                 errors.add( ldapSchemaException );
                                 LOG.info( msg );
 
                                 continue;
                             }
 
                             break;
 
                         case AUXILIARY:
                             if ( superior.getType() == ObjectClassTypeEnum.STRUCTURAL )
                             {
                                 // An AUXILIARY OC cannot inherit from STRUCTURAL OCs
                                 String msg = I18n.err( I18n.ERR_04319, objectClass.getOid(), superior );
 
                                 LdapSchemaException ldapSchemaException = new LdapSchemaException(
                                     LdapSchemaExceptionCodes.OC_AUXILIARY_CANNOT_INHERIT_FROM_STRUCTURAL_OC, msg );
                                 ldapSchemaException.setSourceObject( objectClass );
                                 errors.add( ldapSchemaException );
                                 LOG.info( msg );
 
                                 continue;
                             }
 
                             break;
 
                         case STRUCTURAL:
                             if ( superior.getType() == ObjectClassTypeEnum.AUXILIARY )
                             {
                                 // A STRUCTURAL OC cannot inherit from AUXILIARY OCs
                                 String msg = I18n.err( I18n.ERR_04320, objectClass.getOid(), superior );
 
                                 LdapSchemaException ldapSchemaException = new LdapSchemaException(
                                     LdapSchemaExceptionCodes.OC_STRUCTURAL_CANNOT_INHERIT_FROM_AUXILIARY_OC, msg );
                                 ldapSchemaException.setSourceObject( objectClass );
                                 errors.add( ldapSchemaException );
                                 LOG.info( msg );
 
                                 continue;
                             }
 
                             break;
 
                         default:
                             throw new IllegalArgumentException( "Unexpected ObjectClassTypeEnum: "
                                 + objectClass.getType() );
                     }
 
                     objectClass.getSuperiors().add( superior );
                 }
                 catch ( LdapException ne )
                 {
                     // Cannot find the OC
                     String msg = I18n.err( I18n.ERR_04321, objectClass.getOid(), superiorName );
 
                     LdapSchemaException ldapSchemaException = new LdapSchemaException(
                         LdapSchemaExceptionCodes.OC_NONEXISTENT_SUPERIOR, msg, ne );
                     ldapSchemaException.setSourceObject( objectClass );
                     ldapSchemaException.setRelatedId( superiorName );
                     errors.add( ldapSchemaException );
                     LOG.info( msg );
 
                     return;
                 }
             }
         }
     }
 
 
     /**
      * Build and check the MUST AT for this ObjectClass.
      */
     private static void buildMust( ObjectClass objectClass, List<Throwable> errors, Registries registries )
     {
         AttributeTypeRegistry atRegistry = registries.getAttributeTypeRegistry();
         List<String> mustAttributeTypeOids = objectClass.getMustAttributeTypeOids();
 
         if ( mustAttributeTypeOids != null )
         {
             objectClass.getMustAttributeTypes().clear();
 
             for ( String mustAttributeTypeName : mustAttributeTypeOids )
             {
                 try
                 {
                     AttributeType attributeType = atRegistry.lookup( mustAttributeTypeName );
 
                     if ( attributeType.isCollective() )
                     {
                         // Collective Attributes are not allowed in MAY or MUST
                         String msg = I18n.err( I18n.ERR_04484_COLLECTIVE_NOT_ALLOWED_IN_MUST, mustAttributeTypeName,
                             objectClass.getOid() );
 
                         LdapSchemaException ldapSchemaException = new LdapSchemaException(
                             LdapSchemaExceptionCodes.OC_COLLECTIVE_NOT_ALLOWED_IN_MUST, msg );
                         ldapSchemaException.setSourceObject( objectClass );
                         ldapSchemaException.setRelatedId( mustAttributeTypeName );
                         errors.add( ldapSchemaException );
                         LOG.info( msg );
 
                         continue;
                     }
 
                     if ( objectClass.getMustAttributeTypes().contains( attributeType ) )
                     {
                         // Already registered : this is an error
                         String msg = I18n.err( I18n.ERR_04324, objectClass.getOid(), mustAttributeTypeName );
 
                         LdapSchemaException ldapSchemaException = new LdapSchemaException(
                             LdapSchemaExceptionCodes.OC_DUPLICATE_AT_IN_MUST, msg );
                         ldapSchemaException.setSourceObject( objectClass );
                         ldapSchemaException.setRelatedId( mustAttributeTypeName );
                         errors.add( ldapSchemaException );
                         LOG.info( msg );
 
                         continue;
                     }
 
                     // Check that the MUST AT is not also present in the MAY AT
                     if ( objectClass.getMayAttributeTypes().contains( attributeType ) )
                     {
                         // Already registered : this is an error
                         String msg = I18n.err( I18n.ERR_04325, objectClass.getOid(), mustAttributeTypeName );
 
                         LdapSchemaException ldapSchemaException = new LdapSchemaException(
                             LdapSchemaExceptionCodes.OC_DUPLICATE_AT_IN_MAY_AND_MUST,
                             msg );
                         ldapSchemaException.setSourceObject( objectClass );
                         ldapSchemaException.setRelatedId( mustAttributeTypeName );
                         errors.add( ldapSchemaException );
                         LOG.info( msg );
 
                         continue;
                     }
 
                     objectClass.getMustAttributeTypes().add( attributeType );
                 }
                 catch ( LdapException ne )
                 {
                     // Cannot find the AT
                     String msg = I18n.err( I18n.ERR_04326, objectClass.getOid(), mustAttributeTypeName );
 
                     LdapSchemaException ldapSchemaException = new LdapSchemaException(
                         LdapSchemaExceptionCodes.OC_NONEXISTENT_MUST_AT, msg, ne );
                     ldapSchemaException.setSourceObject( objectClass );
                     ldapSchemaException.setRelatedId( mustAttributeTypeName );
                     errors.add( ldapSchemaException );
                     LOG.info( msg );
 
                     continue;
                 }
             }
         }
     }
     
     
     /**
      * Build and check the MAY AT for this ObjectClass
      */
     private static void buildMay( ObjectClass objectClass, List<Throwable> errors, Registries registries )
     {
         AttributeTypeRegistry atRegistry = registries.getAttributeTypeRegistry();
         List<String> mayAttributeTypeOids = objectClass.getMayAttributeTypeOids();
 
         if ( mayAttributeTypeOids != null )
         {
             objectClass.getMayAttributeTypes().clear();
 
             for ( String mayAttributeTypeName : mayAttributeTypeOids )
             {
                 try
                 {
                     AttributeType attributeType = atRegistry.lookup( mayAttributeTypeName );
 
                     if ( attributeType.isCollective() )
                     {
                         // Collective Attributes are not allowed in MAY or MUST
                         String msg = I18n.err( I18n.ERR_04485_COLLECTIVE_NOT_ALLOWED_IN_MAY, mayAttributeTypeName, objectClass.getOid() );
 
                         LdapSchemaException ldapSchemaException = new LdapSchemaException(
                             LdapSchemaExceptionCodes.OC_COLLECTIVE_NOT_ALLOWED_IN_MAY, msg );
                         ldapSchemaException.setSourceObject( objectClass );
                         ldapSchemaException.setRelatedId( mayAttributeTypeName );
                         errors.add( ldapSchemaException );
                         LOG.info( msg );
 
                         continue;
                     }
 
                     if ( objectClass.getMayAttributeTypes().contains( attributeType ) )
                     {
                         // Already registered : this is an error
                         String msg = I18n.err( I18n.ERR_04322, objectClass.getOid(), mayAttributeTypeName );
 
                         LdapSchemaException ldapSchemaException = new LdapSchemaException(
                             LdapSchemaExceptionCodes.OC_DUPLICATE_AT_IN_MAY, msg );
                         ldapSchemaException.setSourceObject( objectClass );
                         ldapSchemaException.setRelatedId( mayAttributeTypeName );
                         errors.add( ldapSchemaException );
                         LOG.info( msg );
 
                         continue;
                     }
 
                     objectClass.getMayAttributeTypes().add( attributeType );
                 }
                 catch ( LdapException ne )
                 {
                     // Cannot find the AT
                     String msg = I18n.err( I18n.ERR_04323, objectClass.getOid(), mayAttributeTypeName );
 
                     LdapSchemaException ldapSchemaException = new LdapSchemaException(
                         LdapSchemaExceptionCodes.OC_NONEXISTENT_MAY_AT, msg, ne );
                     ldapSchemaException.setSourceObject( objectClass );
                     ldapSchemaException.setRelatedId( mayAttributeTypeName );
                     errors.add( ldapSchemaException );
                     LOG.info( msg );
 
                     continue;
                 }
             }
         }
     }
     
     
     /**
      * Remove the ObjectClass from the registries, updating the references to
      * other SchemaObject.
      *
      * If one of the referenced SchemaObject does not exist (SUPERIORS, MAY, MUST),
      * an exception is thrown.
      *
      * @param objectClass The ObjectClass to remove fro the registries
      * @param errors The errors we got while removing the ObjectClass from the registries
      * @param registries The Registries
      * @throws LdapException If the ObjectClass is not valid
      */
     public static void removeFromRegistries( ObjectClass objectClass, List<Throwable> errors, Registries registries ) throws LdapException
     {
         if ( registries != null )
         {
             ObjectClassRegistry objectClassRegistry = registries.getObjectClassRegistry();
 
             // Unregister this ObjectClass into the Descendant map
             objectClassRegistry.unregisterDescendants( objectClass, objectClass.getSuperiors() );
 
             /**
              * Remove the OC references (using and usedBy) :
              * OC -> AT (for MAY and MUST)
              * OC -> OC
              */
             if ( objectClass.getMayAttributeTypes() != null )
             {
                 for ( AttributeType may : objectClass.getMayAttributeTypes() )
                 {
                     registries.delReference( objectClass, may );
                 }
             }
 
             if ( objectClass.getMustAttributeTypes() != null )
             {
                 for ( AttributeType must : objectClass.getMustAttributeTypes() )
                 {
                     registries.delReference( objectClass, must );
                 }
             }
 
             if ( objectClass.getSuperiors() != null )
             {
                 for ( ObjectClass superior : objectClass.getSuperiors() )
                 {
                     registries.delReference( objectClass, superior );
                 }
             }
         }
     }
 }