package org.apache.lucene.analysis.phonetic;

/*
 * 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.util.Arrays;
import java.util.HashSet;
import java.util.Map;

import org.apache.commons.codec.language.bm.Languages.LanguageSet;
import org.apache.commons.codec.language.bm.NameType;
import org.apache.commons.codec.language.bm.PhoneticEngine;
import org.apache.commons.codec.language.bm.RuleType;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.phonetic.BeiderMorseFilter;
import org.apache.lucene.analysis.util.AbstractAnalysisFactory; // javadocs
import org.apache.lucene.analysis.util.TokenFilterFactory;

/** 
 * Factory for {@link BeiderMorseFilter}.
 * <pre class="prettyprint" >
 * <fieldType name="text_bm" class="solr.TextField" positionIncrementGap="100">
 *   <analyzer>
 *     <tokenizer class="solr.StandardTokenizerFactory"/>
 *     <filter class="solr.BeiderMorseFilterFactory"
 *        nameType="GENERIC" ruleType="APPROX" 
 *        concat="true" languageSet="auto"
 *     </filter>
 *   </analyzer>
 * </fieldType></pre>
 *
 */
public class BeiderMorseFilterFactory extends TokenFilterFactory {
  private PhoneticEngine engine;
  private LanguageSet languageSet;
  
  /** Sole constructor. See {@link AbstractAnalysisFactory} for initialization lifecycle. */
  public BeiderMorseFilterFactory() {}
  
  public void init(Map<String,String> args) {
    super.init(args);
    
    // PhoneticEngine = NameType + RuleType + concat
    // we use common-codec's defaults: GENERIC + APPROX + true
    String nameTypeArg = args.get("nameType");
    NameType nameType = (nameTypeArg == null) ? NameType.GENERIC : NameType.valueOf(nameTypeArg);

    String ruleTypeArg = args.get("ruleType");
    RuleType ruleType = (ruleTypeArg == null) ? RuleType.APPROX : RuleType.valueOf(ruleTypeArg);
    
    boolean concat = getBoolean("concat", true);
    engine = new PhoneticEngine(nameType, ruleType, concat);
    
    // LanguageSet: defaults to automagic, otherwise a comma-separated list.
    String languageSetArg = args.get("languageSet");
    if (languageSetArg == null || languageSetArg.equals("auto")) {
      languageSet = null;
    } else {
      languageSet = LanguageSet.from(new HashSet<String>(Arrays.asList(languageSetArg.split(","))));
    }
  }

  @Override
  public TokenStream create(TokenStream input) {
    return new BeiderMorseFilter(input, engine, languageSet);
  }
}