/*
    *  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 org.apache.directory.api.ldap.model.constants.SchemaConstants;
  import org.apache.directory.api.ldap.model.name.Dn;
  import org.apache.directory.api.ldap.model.schema.SyntaxChecker;
  import org.apache.directory.api.util.Strings;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * A SyntaxChecker which verifies that a value is a valid Name and Optional UID.
   * 
   * This element is a composition of two parts : a Dn and an optional UID :
   * NameAndOptionalUID = distinguishedName [ SHARP BitString ]
   * 
   * Both part already have their syntax checkers, so we will just call them
   * after having splitted the element in two ( if necessary)
   * 
   * We just check that the Dn is valid, we don't need to verify each of the Rdn
   * syntax.
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  @SuppressWarnings("serial")
  public class NameAndOptionalUIDSyntaxChecker extends SyntaxChecker
  {
      /** A logger for this class */
      private static final Logger LOG = LoggerFactory.getLogger( NameAndOptionalUIDSyntaxChecker.class );
  
  
      /**
       * Creates a new instance of NameAndOptionalUIDSyntaxChecker.
       */
      public NameAndOptionalUIDSyntaxChecker()
      {
          super( SchemaConstants.NAME_AND_OPTIONAL_UID_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();
          }
  
          if ( strValue.length() == 0 )
          {
              LOG.debug( "Syntax invalid for '{}'", value );
              return false;
          }
  
          // Let's see if we have an UID part
          int sharpPos = strValue.lastIndexOf( '#' );
  
          if ( sharpPos != -1 )
          {
              // Now, check that we don't have another '#'
              if ( strValue.indexOf( '#' ) != sharpPos )
             {
                 // Yes, we have one : this is not allowed, it should have been
                 // escaped.
                 LOG.debug( "Syntax invalid for '{}'", value );
                 return false;
             }
 
             // This is an UID if the '#' is immediatly
             // followed by a BitString, except if the '#' is
             // on the last position
             // We shoould not find a
             if ( BitStringSyntaxChecker.isValid( strValue.substring( sharpPos + 1 ) )
                 && ( sharpPos < strValue.length() ) )
             {
                 // Ok, we have a BitString, now check the Dn,
                 // except if the '#' is in first position
                 if ( sharpPos > 0 )
                 {
                     boolean result = Dn.isValid( strValue.substring( 0, sharpPos ) );
 
                     if ( result )
                     {
                         LOG.debug( "Syntax valid for '{}'", value );
                     }
                     else
                     {
                         LOG.debug( "Syntax invalid for '{}'", value );
                     }
 
                     return result;
 
                 }
                 else
                 {
                     // The Dn must not be null ?
                     LOG.debug( "Syntax invalid for '{}'", value );
                     return false;
                 }
             }
             else
             {
                 // We have found a '#' but no UID part.
                 LOG.debug( "Syntax invalid for '{}'", value );
                 return false;
             }
         }
         else
         {
             // No UID, the strValue is a Dn
             // Check that the value is a valid Dn
             boolean result = Dn.isValid( strValue );
 
             if ( result )
             {
                 LOG.debug( "Syntax valid for '{}'", value );
             }
             else
             {
                 LOG.debug( "Syntax invalid for '{}'", value );
             }
 
             return result;
         }
     }
 }