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.solr.analysis;
  
  import java.lang.reflect.Method;
  import java.util.HashMap;
  import java.util.Locale;
  import java.util.Map;
  import java.util.concurrent.locks.Lock;
  import java.util.concurrent.locks.ReentrantLock;
  
  import org.apache.commons.codec.Encoder;
  import org.apache.commons.codec.language.Caverphone;
  import org.apache.commons.codec.language.ColognePhonetic;
  import org.apache.commons.codec.language.DoubleMetaphone;
  import org.apache.commons.codec.language.Metaphone;
  import org.apache.commons.codec.language.RefinedSoundex;
  import org.apache.commons.codec.language.Soundex;
  import org.apache.lucene.analysis.TokenStream;
  import org.apache.solr.common.SolrException;
  
  /**
   * Factory for {@link PhoneticFilter}.
   * 
   * Create tokens based on phonetic encoders
   * 
   * http://jakarta.apache.org/commons/codec/api-release/org/apache/commons/codec/language/package-summary.html
   * 
   * This takes two arguments:
   *  "encoder" required, one of "DoubleMetaphone", "Metaphone", "Soundex", "RefinedSoundex"
   * 
   * "inject" (default=true) add tokens to the stream with the offset=0
   *
   * <pre class="prettyprint" >
   * &lt;fieldType name="text_phonetic" class="solr.TextField" positionIncrementGap="100"&gt;
   *   &lt;analyzer&gt;
   *     &lt;tokenizer class="solr.WhitespaceTokenizerFactory"/&gt;
   *     &lt;filter class="solr.PhoneticFilterFactory" encoder="DoubleMetaphone" inject="true"/&gt;
   *   &lt;/analyzer&gt;
   * &lt;/fieldType&gt;</pre>
   * 
   * @version $Id: PhoneticFilterFactory.java 1195102 2011-10-30 03:15:25Z rmuir $
   * @see PhoneticFilter
   */
  public class PhoneticFilterFactory extends BaseTokenFilterFactory 
  {
    public static final String ENCODER = "encoder";
    public static final String INJECT = "inject"; // boolean
    private static final String PACKAGE_CONTAINING_ENCODERS = "org.apache.commons.codec.language.";
    
    private static final Map<String, Class<? extends Encoder>> registry = new HashMap<String, Class<? extends Encoder>>()
    {{
      put( "DoubleMetaphone".toUpperCase(Locale.ENGLISH), DoubleMetaphone.class );
      put( "Metaphone".toUpperCase(Locale.ENGLISH),       Metaphone.class );
      put( "Soundex".toUpperCase(Locale.ENGLISH),         Soundex.class );
      put( "RefinedSoundex".toUpperCase(Locale.ENGLISH),  RefinedSoundex.class );
      put( "Caverphone".toUpperCase(Locale.ENGLISH),      Caverphone.class );
      put( "ColognePhonetic".toUpperCase(Locale.ENGLISH), ColognePhonetic.class );
    }};
    private static final Lock lock = new ReentrantLock();
    
    protected boolean inject = true;
    protected String name = null;
    protected Encoder encoder = null;
  
    @Override
    public void init(Map<String,String> args) {
      super.init( args );
  
      inject = getBoolean(INJECT, true);
      
      String name = args.get( ENCODER );
      if( name == null ) {
        throw new SolrException( SolrException.ErrorCode.SERVER_ERROR, "Missing required parameter: "+ENCODER
            +" ["+registry.keySet()+"]" );
      }
      Class<? extends Encoder> clazz = registry.get(name.toUpperCase(Locale.ENGLISH));
      if( clazz == null ) {
        lock.lock();
        try {
          clazz = resolveEncoder(name);
        } finally {
          lock.unlock();
        }
      }
      
      try {
        encoder = clazz.newInstance();
        
        // Try to set the maxCodeLength
        String v = args.get( "maxCodeLength" );
        if( v != null ) {
          Method setter = encoder.getClass().getMethod( "setMaxCodeLen", int.class );
          setter.invoke( encoder, Integer.parseInt( v ) );
        }
      } 
      catch (Exception e) {
        throw new SolrException( SolrException.ErrorCode.SERVER_ERROR, "Error initializing: "+name + "/"+clazz, e , false);
      }
    }
    
    private Class<? extends Encoder> resolveEncoder(String name) {
      Class<? extends Encoder> clazz = null;
      try {
        clazz = lookupEncoder(PACKAGE_CONTAINING_ENCODERS+name);
      } catch (ClassNotFoundException e) {
        try {
          clazz = lookupEncoder(name);
        } catch (ClassNotFoundException cnfe) {
          throw new SolrException( SolrException.ErrorCode.SERVER_ERROR, "Unknown encoder: "+name +" ["+registry.keySet()+"]" );
        }
      }
      catch (ClassCastException e) {
        throw new SolrException( SolrException.ErrorCode.SERVER_ERROR, "Not an encoder: "+name +" ["+registry.keySet()+"]" );
      }
      return clazz;
    }
    
    private Class<? extends Encoder> lookupEncoder(String name)
        throws ClassNotFoundException {
      Class<? extends Encoder> clazz = Class.forName(name).asSubclass(Encoder.class);
      registry.put( name.toUpperCase(Locale.ENGLISH), clazz );
      return clazz;
    }
  
    public PhoneticFilter create(TokenStream input) {
      return new PhoneticFilter(input,encoder,name,inject);
    }
  }
  