/**

  * Distribution License:

  * JSword is free software; you can redistribute it and/or modify it under

  * the terms of the GNU Lesser General Public License, version 2.1 or later

  * as published by the Free Software Foundation. This program is distributed

  * in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even

  * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

  * See the GNU Lesser General Public License for more details.

  *

  * The License is available on the internet at:

  *      http://www.gnu.org/copyleft/lgpl.html

  * or by writing to:

  *      Free Software Foundation, Inc.

  *      59 Temple Place - Suite 330

  *      Boston, MA 02111-1307, USA

  *

  * © CrossWire Bible Society, 2007 - 2016

  *

  */

 package org.crosswire.jsword.index.lucene.analysis;

 import java.io.IOException;

 import java.io.Reader;

 import org.apache.lucene.analysis.LowerCaseTokenizer;

 import org.apache.lucene.analysis.PorterStemFilter;

 import org.apache.lucene.analysis.StopAnalyzer;

 import org.apache.lucene.analysis.StopFilter;

 import org.apache.lucene.analysis.TokenStream;

 import org.apache.lucene.util.Version;

 /**

  * English Analyzer works like lucene SimpleAnalyzer + Stemming.

  * (LowerCaseTokenizer > PorterStemFilter). Like the AbstractAnalyzer,

  * {@link StopFilter} is off by default.

  * 

  * 

  * @see gnu.lgpl.License The GNU Lesser General Public License for details.

  * @author sijo cherian

  */

 public class EnglishLuceneAnalyzer extends AbstractBookAnalyzer {

     public EnglishLuceneAnalyzer() {

         stopSet = StopAnalyzer.ENGLISH_STOP_WORDS_SET;

     }

     /**

      * Constructs a {@link LowerCaseTokenizer} filtered by a language filter

      * {@link StopFilter} and {@link PorterStemFilter} for English.

      */

     @Override

     public final TokenStream tokenStream(String fieldName, Reader reader) {

         TokenStream result = new LowerCaseTokenizer(reader);

         if (doStopWords && stopSet != null) {

             result = new StopFilter(StopFilter.getEnablePositionIncrementsVersionDefault(matchVersion), result, stopSet);

         }

         // Using Porter Stemmer

         if (doStemming) {

             result = new PorterStemFilter(result);

         }

         return result;

     }

     /* (non-Javadoc)

      * @see org.apache.lucene.analysis.Analyzer#reusableTokenStream(java.lang.String, java.io.Reader)

      */

     @Override

     public TokenStream reusableTokenStream(String fieldName, Reader reader) throws IOException {

         SavedStreams streams = (SavedStreams) getPreviousTokenStream();

         if (streams == null) {

             streams = new SavedStreams(new LowerCaseTokenizer(reader));

             if (doStopWords && stopSet != null) {

                 streams.setResult(new StopFilter(StopFilter.getEnablePositionIncrementsVersionDefault(matchVersion), streams.getResult(), stopSet));

             }

             if (doStemming) {

                 streams.setResult(new PorterStemFilter(streams.getResult()));

             }

             setPreviousTokenStream(streams);

         } else {

             streams.getSource().reset(reader);

         }

         return streams.getResult();

     }

     private final Version matchVersion = Version.LUCENE_29;

 }