/*
    *  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.syntaxCheckers;
  
  
  import java.text.ParseException;
  
  import org.apache.directory.api.i18n.I18n;
  import org.apache.directory.api.ldap.model.constants.SchemaConstants;
  import org.apache.directory.api.ldap.model.schema.SyntaxChecker;
  import org.apache.directory.api.ldap.model.schema.parsers.AttributeTypeDescriptionSchemaParser;
  import org.apache.directory.api.util.Strings;
  
  
  /**
   * A SyntaxChecker which verifies that a value follows the
   * attribute type descripton syntax according to RFC 4512, par 4.2.2:
   * 
  *  <pre>
   * AttributeTypeDescription = LPAREN WSP
   *     numericoid                    ; object identifier
   *     [ SP "NAME" SP qdescrs ]      ; short names (descriptors)
   *     [ SP "DESC" SP qdstring ]     ; description
   *     [ SP "OBSOLETE" ]             ; not active
   *     [ SP "SUP" SP oid ]           ; supertype
   *     [ SP "EQUALITY" SP oid ]      ; equality matching rule
   *     [ SP "ORDERING" SP oid ]      ; ordering matching rule
   *     [ SP "SUBSTR" SP oid ]        ; substrings matching rule
   *     [ SP "SYNTAX" SP noidlen ]    ; value syntax
   *     [ SP "SINGLE-VALUE" ]         ; single-value
   *     [ SP "COLLECTIVE" ]           ; collective
   *     [ SP "NO-USER-MODIFICATION" ] ; not user modifiable
   *     [ SP "USAGE" SP usage ]       ; usage
   *     extensions WSP RPAREN         ; extensions
   * 
   * usage = "userApplications"     /  ; user
   *         "directoryOperation"   /  ; directory operational
   *         "distributedOperation" /  ; DSA-shared operational
   *         "dSAOperation"            ; DSA-specific operational     
   * 
   * extensions = *( SP xstring SP qdstrings )
   * xstring = "X" HYPHEN 1*( ALPHA / HYPHEN / USCORE ) 
   * 
   * Each attribute type description must contain at least one of the SUP
   * or SYNTAX fields. 
   * 
   * COLLECTIVE requires usage userApplications.
   * 
   * NO-USER-MODIFICATION requires an operational usage.
   * </pre>
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  @SuppressWarnings("serial")
  public final class AttributeTypeDescriptionSyntaxChecker extends SyntaxChecker
  {
      /** The schema parser used to parse the AttributeTypeDescription Syntax */
      private transient AttributeTypeDescriptionSchemaParser schemaParser = new AttributeTypeDescriptionSchemaParser();
      
      /**
       * A static instance of AttributeTypeDescriptionSyntaxChecker
       */
      public static final AttributeTypeDescriptionSyntaxChecker INSTANCE = new AttributeTypeDescriptionSyntaxChecker( 
          SchemaConstants.ATTRIBUTE_TYPE_DESCRIPTION_SYNTAX );
  
      /**
       * A static Builder for this class
       */
      public static final class Builder extends SCBuilder<AttributeTypeDescriptionSyntaxChecker>
      {
          /**
           * The Builder constructor
           */
          private Builder()
          {
              super( SchemaConstants.ATTRIBUTE_TYPE_DESCRIPTION_SYNTAX );
          }
          
          
          /**
           * Create a new instance of AttributeTypeDescriptionSyntaxChecker
           * @return A new instance of AttributeTypeDescriptionSyntaxChecker
          */
         @Override
         public AttributeTypeDescriptionSyntaxChecker build()
         {
             return new AttributeTypeDescriptionSyntaxChecker( oid );
         }
     }
 
 
     /**
      * Creates a new instance of AttributeTypeDescriptionSchemaParser.
      * 
      * @param oid The OID to use for this SyntaxChecker
      *
      */
     private AttributeTypeDescriptionSyntaxChecker( String oid )
     {
         super( oid );
     }
 
 
     /**
      * @return An instance of the Builder for this class
      */
     public static Builder builder()
     {
         return new Builder();
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public boolean isValidSyntax( Object value )
     {
         String strValue;
 
         if ( value == null )
         {
             if ( LOG.isDebugEnabled() )
             {
                 LOG.debug( I18n.err( I18n.ERR_04488_SYNTAX_INVALID, "null" ) );
             }
             
             return false;
         }
 
         if ( value instanceof String )
         {
             strValue = ( String ) value;
         }
         else if ( value instanceof byte[] )
         {
             strValue = Strings.utf8ToString( ( byte[] ) value );
         }
         else
         {
             strValue = value.toString();
         }
 
         try
         {
             schemaParser.parseAttributeTypeDescription( strValue );
 
             if ( LOG.isDebugEnabled() )
             {
                 LOG.debug( I18n.msg( I18n.MSG_04489_SYNTAX_VALID, value ) );
             }
 
             return true;
         }
         catch ( ParseException pe )
         {
             if ( LOG.isDebugEnabled() )
             {
                 LOG.debug( I18n.err( I18n.ERR_04488_SYNTAX_INVALID, value ) );
             }
             
             return false;
         }
     }
 }