package org.apache.maven.index.context;

 /*

  * 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.Reader;

 import org.apache.lucene.analysis.Analyzer;

 import org.apache.lucene.analysis.CharTokenizer;

 import org.apache.lucene.analysis.TokenStream;

 import org.apache.lucene.analysis.Tokenizer;

 import org.apache.maven.index.creator.JarFileContentsIndexCreator;

 /**

  * A Nexus specific analyzer. Only difference from Lucene's SimpleAnalyzer is that we use LetterOrDigitTokenizer instead

  * of LowerCaseTokenizer. LetterOrDigitTokenizer does pretty much the same as LowerCaseTokenizer, it normalizes to lower

  * case letter, but it takes letters and numbers too (as opposed to LowerCaseTokenizer) as token chars.

  * 

  * @author Eugene Kuleshov

  * @author cstamas

  */

 public final class NexusAnalyzer

     extends Analyzer

 {

     public TokenStream tokenStream( String fieldName, Reader reader )

     {

         return getTokenizer( fieldName, reader );

     }

     protected Tokenizer getTokenizer( String fieldName, Reader reader )

     {

         if ( JarFileContentsIndexCreator.FLD_CLASSNAMES_KW.getKey().equals( fieldName ) )

         {

             // To keep "backward" compatibility, we have to use old flawed tokenizer.

             return new DeprecatedClassnamesTokenizer( reader );

         }

         else

         {

             return new LetterOrDigitTokenizer( reader );

         }

     }

     // ==

     public static class NoopTokenizer

         extends CharTokenizer

     {

         public NoopTokenizer( Reader in )

         {

             super( in );

         }

         @Override

         protected boolean isTokenChar( char c )

         {

             return true;

         }

     }

     @Deprecated

     public static class DeprecatedClassnamesTokenizer

         extends CharTokenizer

     {

         public DeprecatedClassnamesTokenizer( Reader in )

         {

             super( in );

         }

         @Override

         protected boolean isTokenChar( char c )

         {

             return c != '\n';

         }

         @Override

         protected char normalize( char c )

         {

             return Character.toLowerCase( c );

         }

     }

     public static class LetterOrDigitTokenizer

         extends CharTokenizer

     {

         public LetterOrDigitTokenizer( Reader in )

         {

             super( in );

         }

         @Override

         protected boolean isTokenChar( char c )

         {

             return Character.isLetterOrDigit( c );

         }

         @Override

         protected char normalize( char c )

         {

             return Character.toLowerCase( c );

         }

     }

 }