package org.apache.blur.analysis;

/**
 * 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.
 */
import java.io.IOException;
import java.io.Reader;

import org.apache.blur.lucene.LuceneVersionConstant;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.core.LowerCaseFilter;
import org.apache.lucene.analysis.core.StopAnalyzer;
import org.apache.lucene.analysis.core.StopFilter;
import org.apache.lucene.analysis.standard.StandardFilter;
import org.apache.lucene.analysis.standard.StandardTokenizer;
import org.apache.lucene.analysis.util.CharArraySet;
import org.apache.lucene.analysis.util.StopwordAnalyzerBase;

public class NoStopWordStandardAnalyzer extends StopwordAnalyzerBase {

  /** Default maximum allowed token length */
  public static final int DEFAULT_MAX_TOKEN_LENGTH = 255;

  private int maxTokenLength = DEFAULT_MAX_TOKEN_LENGTH;

  /**
   * An unmodifiable set containing some common English words that are usually
   * not useful for searching.
   */
  public static final CharArraySet STOP_WORDS_SET = StopAnalyzer.ENGLISH_STOP_WORDS_SET;

  public NoStopWordStandardAnalyzer() {
    super(LuceneVersionConstant.LUCENE_VERSION, CharArraySet.EMPTY_SET);
  }

  /**
   * Set maximum allowed token length. If a token is seen that exceeds this
   * length then it is discarded. This setting only takes effect the next time
   * tokenStream or tokenStream is called.
   */
  public void setMaxTokenLength(int length) {
    maxTokenLength = length;
  }

  /**
   * @see #setMaxTokenLength
   */
  public int getMaxTokenLength() {
    return maxTokenLength;
  }

  @Override
  protected TokenStreamComponents createComponents(final String fieldName, final Reader reader) {
    final StandardTokenizer src = new StandardTokenizer(matchVersion, reader);
    src.setMaxTokenLength(maxTokenLength);
    TokenStream tok = new StandardFilter(matchVersion, src);
    tok = new LowerCaseFilter(matchVersion, tok);
    tok = new StopFilter(matchVersion, tok, stopwords);
    return new TokenStreamComponents(src, tok) {
      @Override
      protected void setReader(final Reader reader) throws IOException {
        src.setMaxTokenLength(NoStopWordStandardAnalyzer.this.maxTokenLength);
        super.setReader(reader);
      }
    };
  }

}