/*
    *  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.ldap.model.constants.SchemaConstants;
  import org.apache.directory.api.ldap.model.schema.SyntaxChecker;
  import org.apache.directory.api.ldap.model.schema.parsers.MatchingRuleDescriptionSchemaParser;
  import org.apache.directory.api.util.Strings;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * A SyntaxChecker which verifies that a value follows the
   * matching rule descripton syntax according to RFC 4512, par 4.2.3:
   * 
   *  <pre>
   * MatchingRuleDescription = LPAREN WSP
   *    numericoid                 ; object identifier
   *    [ SP "NAME" SP qdescrs ]   ; short names (descriptors)
   *    [ SP "DESC" SP qdstring ]  ; description
   *    [ SP "OBSOLETE" ]          ; not active
   *    SP "SYNTAX" SP numericoid  ; assertion syntax
   *    extensions WSP RPAREN      ; extensions
   * 
   * extensions = *( SP xstring SP qdstrings )
   * xstring = "X" HYPHEN 1*( ALPHA / HYPHEN / USCORE ) 
   * 
   * </pre>
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  @SuppressWarnings("serial")
  public class MatchingRuleDescriptionSyntaxChecker extends SyntaxChecker
  {
      /** A logger for this class */
      private static final Logger LOG = LoggerFactory.getLogger( MatchingRuleDescriptionSyntaxChecker.class );
  
      /** The schema parser used to parse the MatchingRuleDescription Syntax */
      private MatchingRuleDescriptionSchemaParser schemaParser = new MatchingRuleDescriptionSchemaParser();
  
  
      /**
       * 
       * Creates a new instance of MatchingRuleDescriptionSchemaParser.
       *
       */
      public MatchingRuleDescriptionSyntaxChecker()
      {
          super( SchemaConstants.MATCHING_RULE_DESCRIPTION_SYNTAX );
      }
  
  
      /**
       * {@inheritDoc}
       */
      public boolean isValidSyntax( Object value )
      {
          String strValue = null;
  
          if ( value == null )
          {
              LOG.debug( "Syntax invalid for '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.parseMatchingRuleDescription( strValue );
             LOG.debug( "Syntax valid for '{}'", value );
 
             return true;
         }
         catch ( ParseException pe )
         {
             LOG.debug( "Syntax invalid for '{}'", value );
             return false;
         }
     }
 
 }