/*
    *  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.normalizers;
  
  
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import org.apache.directory.api.ldap.model.entry.StringValue;
  import org.apache.directory.api.ldap.model.entry.Value;
  import org.apache.directory.api.ldap.model.schema.Normalizer;
  
  
  /**
   * A Normalizer that uses Perl5 based regular expressions to normalize values.
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  @SuppressWarnings("serial")
  public class RegexNormalizer extends Normalizer
  {
      /** the perl 5 regex engine */
      private final Pattern[] regexes;
  
      /** the set of regular expressions used to transform values */
      private final Matcher[] matchers;
  
  
      /**
       * Creates a Perl5 regular expression based normalizer.
       * 
       * @param oid The MR OID to use for this Normalizer
       * @param regexes the set of regular expressions used to transform values
       */
      public RegexNormalizer( String oid, Pattern[] regexes )
      {
          super( oid );
          if ( regexes != null )
          {
              this.regexes = new Pattern[regexes.length];
              System.arraycopy( regexes, 0, this.regexes, 0, regexes.length );
  
              matchers = new Matcher[regexes.length];
  
              for ( int i = 0; i < regexes.length; i++ )
              {
                  matchers[i] = regexes[i].matcher( "" );
              }
          }
          else
          {
              this.regexes = null;
              matchers = new Matcher[0];
          }
      }
  
  
      /**
       * {@inheritDoc}
       */
      @Override
      public Value<?> normalize( final Value<?> value )
      {
          if ( value == null )
          {
              return null;
          }
  
          if ( value.isHumanReadable() )
          {
              String str = value.getString();
  
              for ( int i = 0; i < matchers.length; i++ )
              {
  
                  str = matchers[i].replaceAll( str );
              }
  
              return new StringValue( str );
          }
  
          return value;
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public String normalize( String value )
     {
         if ( value == null )
         {
             return null;
         }
 
         String str = value;
 
         for ( int i = 0; i < matchers.length; i++ )
         {
 
             str = matchers[i].replaceAll( str );
         }
 
         return str;
     }
 
 
     /**
      * @see java.lang.Object#toString()
      */
     @Override
     public String toString()
     {
         StringBuilder buf = new StringBuilder();
         buf.append( "RegexNormalizer( " );
 
         for ( int i = 0; i < regexes.length; i++ )
         {
             buf.append( regexes[i] );
 
             if ( i < regexes.length - 1 )
             {
                 buf.append( ", " );
             }
         }
 
         buf.append( " )" );
         return buf.toString();
     }
 }