/*
   Copyright (C) 2005-2012, by the President and Fellows of Harvard College.

   Licensed 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.

   Dataverse Network - A web application to share, preserve and analyze research data.
   Developed at the Institute for Quantitative Social Science, Harvard University.
   Version 3.0.
*/
package edu.harvard.iq.dvn.core.index;

import org.apache.lucene.analysis.*;

import java.io.IOException;
import java.io.Reader;
import org.apache.lucene.analysis.standard.StandardFilter;
import org.apache.lucene.analysis.standard.StandardTokenizer;
import org.apache.lucene.util.Version;

public class DVNSearchAnalyzer extends Analyzer {

  private boolean replaceInvalidAcronym = false;
  


  public TokenStream tokenStream(String fieldName, Reader reader) {
/* It seems that LUCENE_CURRENT is ultimately what we should use, but there is
 an ominous warning in the source code about using it -- using LUCENE_29 for now, will look into this further */
//    StandardTokenizer tokenStream = new StandardTokenizer(Version.LUCENE_CURRENT,reader);
    StandardTokenizer tokenStream = new StandardTokenizer(Version.LUCENE_29,reader);
    tokenStream.setMaxTokenLength(maxTokenLength);
    TokenStream result = new StandardFilter(tokenStream);
    result = new LowerCaseFilter(result);
    result = new PorterStemFilter(result);
    return result;
  }

  private static final class SavedStreams {
    StandardTokenizer tokenStream;
    TokenStream filteredTokenStream;
  }

  public static final int DEFAULT_MAX_TOKEN_LENGTH = 255;

  private int maxTokenLength = DEFAULT_MAX_TOKEN_LENGTH;


  public void setMaxTokenLength(int length) {
    maxTokenLength = length;
  }
    
  public int getMaxTokenLength() {
    return maxTokenLength;
  }
  
  public TokenStream reusableTokenStream(String fieldName, Reader reader) throws IOException {
    SavedStreams streams = (SavedStreams) getPreviousTokenStream();
    if (streams == null) {
      streams = new SavedStreams();
      setPreviousTokenStream(streams);
//      streams.tokenStream = new StandardTokenizer(Version.LUCENE_CURRENT, reader);
      streams.tokenStream = new StandardTokenizer(Version.LUCENE_29, reader);
      streams.filteredTokenStream = new StandardFilter(streams.tokenStream);
      streams.filteredTokenStream = new LowerCaseFilter(streams.filteredTokenStream);
      streams.filteredTokenStream = new PorterStemFilter(streams.filteredTokenStream);
    } else {
      streams.tokenStream.reset(reader);
    }
    streams.tokenStream.setMaxTokenLength(maxTokenLength);
    
    return streams.filteredTokenStream;
  }

  public boolean isReplaceInvalidAcronym() {
    return replaceInvalidAcronym;
  }

  public void setReplaceInvalidAcronym(boolean replaceInvalidAcronym) {
    this.replaceInvalidAcronym = replaceInvalidAcronym;
  }
}