content: /*
   * 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.cassandra.index.sai.analyzer.filter;
  
  import java.text.Normalizer;
  import java.util.Locale;
  
  import org.apache.lucene.analysis.miscellaneous.ASCIIFoldingFilter;
  
  import static org.apache.cassandra.utils.LocalizeString.toLowerCaseLocalized;
  
  public class BasicFilters
  {
      private static final Locale DEFAULT_LOCALE = Locale.getDefault();
  
      public static class LowerCase extends FilterPipeline.Task
      {
          private final Locale locale;
  
          public LowerCase()
          {
              this.locale = DEFAULT_LOCALE;
          }
  
          @Override
          public String process(String input)
          {
              return toLowerCaseLocalized(input, locale);
          }
      }
  
      public static class Normalize extends FilterPipeline.Task
      {
          public Normalize() { }
  
          @Override
          public String process(String input)
          {
              if (input == null) return null;
              return Normalizer.isNormalized(input, Normalizer.Form.NFC) ? input : Normalizer.normalize(input, Normalizer.Form.NFC);
          }
      }
  
      public static class Ascii extends FilterPipeline.Task
      {
          public Ascii() { }
  
          @Override
          public String process(String input)
          {
              if (input == null) return null;
              char[] inputChars = input.toCharArray();
              // The output can (potentially) be 4 times the size of the input
              char[] outputChars = new char[inputChars.length * 4];
              int outputSize = ASCIIFoldingFilter.foldToASCII(inputChars, 0, outputChars, 0, inputChars.length);
              return new String(outputChars, 0, outputSize);
          }
      }
  
      public static class NoOperation extends FilterPipeline.Task
      {
          @Override
          public String process(String input)
          {
              return input;
          }
      }
  }
  