/*
    *  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.DitStructureRuleDescriptionSchemaParser;
  import org.apache.directory.api.util.Strings;
  
  
  /**
   * A SyntaxChecker which verifies that a value follows the
   * DIT structure rule descripton syntax according to RFC 4512, par 4.2.7.1:
   * 
   * <pre>
   * DITStructureRuleDescription = LPAREN WSP
   *   ruleid                     ; rule identifier
   *   [ SP "NAME" SP qdescrs ]   ; short names (descriptors)
   *   [ SP "DESC" SP qdstring ]  ; description
   *   [ SP "OBSOLETE" ]          ; not active
   *   SP "FORM" SP oid           ; NameForm
   *   [ SP "SUP" ruleids ]       ; superior rules
   *   extensions WSP RPAREN      ; extensions
   *
   * ruleids = ruleid / ( LPAREN WSP ruleidlist WSP RPAREN )
   * ruleidlist = ruleid *( SP ruleid )
   * ruleid = numbers
   * </pre>
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  @SuppressWarnings("serial")
  public final class DitStructureRuleDescriptionSyntaxChecker extends SyntaxChecker
  {
      /** The schema parser used to parse the DITContentRuleDescription Syntax */
      private transient DitStructureRuleDescriptionSchemaParser schemaParser = new DitStructureRuleDescriptionSchemaParser();
      
      /**
       * A static instance of DitStructureRuleDescriptionSyntaxChecker
       */
      public static final DitStructureRuleDescriptionSyntaxChecker INSTANCE = 
          new DitStructureRuleDescriptionSyntaxChecker( SchemaConstants.DIT_STRUCTURE_RULE_SYNTAX );
      
      /**
       * A static Builder for this class
       */
      public static final class Builder extends SCBuilder<DitStructureRuleDescriptionSyntaxChecker>
      {
          /**
           * The Builder constructor
           */
          private Builder()
          {
              super( SchemaConstants.DIT_STRUCTURE_RULE_SYNTAX );
          }
          
          
          /**
           * Create a new instance of DitStructureRuleDescriptionSyntaxChecker
           * @return A new instance of DitStructureRuleDescriptionSyntaxChecker
           */
          @Override
          public DitStructureRuleDescriptionSyntaxChecker build()
          {
              return new DitStructureRuleDescriptionSyntaxChecker( oid );
          }
      }
  
      
      /**
       * Creates a new instance of DITContentRuleDescriptionSyntaxChecker.
       * 
       * @param oid The OID to use for this SyntaxChecker
       */
      private DitStructureRuleDescriptionSyntaxChecker( 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.parseDITStructureRuleDescription( 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;
         }
     }
 }