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.io.File;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import org.apache.lucene.analysis.CharStream;
  import org.apache.lucene.analysis.MappingCharFilter;
  import org.apache.lucene.analysis.NormalizeCharMap;
  import org.apache.solr.common.ResourceLoader;
  import org.apache.solr.common.util.StrUtils;
  import org.apache.solr.util.plugin.ResourceLoaderAware;
  
  /**
   * Factory for {@link MappingCharFilter}. 
   * <pre class="prettyprint" >
   * &lt;fieldType name="text_map" class="solr.TextField" positionIncrementGap="100"&gt;
   *   &lt;analyzer&gt;
   *     &lt;charFilter class="solr.MappingCharFilterFactory" mapping="mapping.txt"/&gt;
   *     &lt;tokenizer class="solr.WhitespaceTokenizerFactory"/&gt;
   *   &lt;/analyzer&gt;
   * &lt;/fieldType&gt;</pre>
   *
   * @version $Id: MappingCharFilterFactory.java 1073810 2011-02-23 16:27:55Z koji $
   * @since Solr 1.4
   *
   */
  public class MappingCharFilterFactory extends BaseCharFilterFactory implements
      ResourceLoaderAware {
  
    protected NormalizeCharMap normMap;
    private String mapping;
  
    public void inform(ResourceLoader loader) {
      mapping = args.get( "mapping" );
  
      if( mapping != null ){
        List<String> wlist = null;
        try{
          File mappingFile = new File( mapping );
          if( mappingFile.exists() ){
            wlist = loader.getLines( mapping );
          }
          else{
            List<String> files = StrUtils.splitFileNames( mapping );
            wlist = new ArrayList<String>();
            for( String file : files ){
              List<String> lines = loader.getLines( file.trim() );
              wlist.addAll( lines );
            }
          }
        }
        catch( IOException e ){
          throw new RuntimeException( e );
        }
        normMap = new NormalizeCharMap();
        parseRules( wlist, normMap );
      }
    }
  
    public CharStream create(CharStream input) {
      return new MappingCharFilter(normMap,input);
    }
  
    // "source" => "target"
    static Pattern p = Pattern.compile( "\"(.*)\"\\s*=>\\s*\"(.*)\"\\s*$" );
  
    protected void parseRules( List<String> rules, NormalizeCharMap normMap ){
      for( String rule : rules ){
        Matcher m = p.matcher( rule );
        if( !m.find() )
          throw new RuntimeException( "Invalid Mapping Rule : [" + rule + "], file = " + mapping );
        normMap.add( parseString( m.group( 1 ) ), parseString( m.group( 2 ) ) );
      }
    }
  
    char[] out = new char[256];
    
    protected String parseString( String s ){
      int readPos = 0;
      int len = s.length();
      int writePos = 0;
      while( readPos < len ){
        char c = s.charAt( readPos++ );
        if( c == '\\' ){
          if( readPos >= len )
            throw new RuntimeException( "Invalid escaped char in [" + s + "]" );
          c = s.charAt( readPos++ );
          switch( c ) {
            case '\\' : c = '\\'; break;
            case '"' : c = '"'; break;
            case 'n' : c = '\n'; break;
            case 't' : c = '\t'; break;
            case 'r' : c = '\r'; break;
            case 'b' : c = '\b'; break;
            case 'f' : c = '\f'; break;
            case 'u' :
              if( readPos + 3 >= len )
                throw new RuntimeException( "Invalid escaped char in [" + s + "]" );
              c = (char)Integer.parseInt( s.substring( readPos, readPos + 4 ), 16 );
              readPos += 4;
              break;
          }
        }
        out[writePos++] = c;
      }
      return new String( out, 0, writePos );
    }
  }
  