package org.apache.maven.index.creator;
   
   /*
    * 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 javax.inject.Named;
  import javax.inject.Singleton;
  import java.io.File;
  import java.io.IOException;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Enumeration;
  import java.util.zip.ZipEntry;
  import java.util.zip.ZipFile;
  
  import org.apache.lucene.document.Document;
  import org.apache.maven.index.ArtifactContext;
  import org.apache.maven.index.ArtifactInfo;
  import org.apache.maven.index.IndexerField;
  import org.apache.maven.index.IndexerFieldVersion;
  import org.apache.maven.index.MAVEN;
  import org.codehaus.plexus.util.StringUtils;
  
  /**
   * An index creator used to index Java class names from a Maven artifact (JAR, ZIP or WAR for now).
   * Will open up the file and collect all the class names from it.
   */
  @Singleton
  @Named( JarFileContentsIndexCreator.ID )
  public class JarFileContentsIndexCreator
      extends AbstractIndexCreator
      implements LegacyDocumentUpdater
  {
      public static final String ID = "jarContent";
  
      public static final IndexerField FLD_CLASSNAMES = new IndexerField( MAVEN.CLASSNAMES, IndexerFieldVersion.V3,
          "classnames", "Artifact Classes (tokenized)", IndexerField.ANALYZED_NOT_STORED );
  
      /**
       * NexusAnalyzer makes exception with this field only, to keep backward compatibility with old consumers of
       * nexus-indexer. This field is here for "backward" compat only! The order is important too! FLD_CLASSNAMES must be
       * registered BEFORE FLD_CLASSNAMES_KW!
       */
      public static final IndexerField FLD_CLASSNAMES_KW = new IndexerField( MAVEN.CLASSNAMES, IndexerFieldVersion.V1,
          "c", "Artifact Classes (tokenized on newlines only)", IndexerField.ANALYZED_STORED );
  
      public JarFileContentsIndexCreator()
      {
          super( ID );
      }
  
      public void populateArtifactInfo( final ArtifactContext artifactContext )
          throws IOException
      {
          ArtifactInfo ai = artifactContext.getArtifactInfo();
  
          File artifactFile = artifactContext.getArtifact();
  
          if ( artifactFile != null && artifactFile.isFile()
              && ( artifactFile.getName().endsWith( ".jar" )
                   || artifactFile.getName().endsWith( ".war" )
                   || artifactFile.getName().endsWith( ".zip" ) ) )
          {
              updateArtifactInfo( ai, artifactFile );
          }
      }
  
      public void updateDocument( final ArtifactInfo ai, final Document doc )
      {
          if ( ai.getClassNames() != null )
          {
              doc.add( FLD_CLASSNAMES_KW.toField( ai.getClassNames() ) );
              doc.add( FLD_CLASSNAMES.toField( ai.getClassNames() ) );
          }
      }
  
      public void updateLegacyDocument( final ArtifactInfo ai, final Document doc )
      {
          if ( ai.getClassNames() != null )
          {
              String classNames = ai.getClassNames();
  
              // downgrade the classNames if needed
             if ( classNames.length() > 0 && classNames.charAt( 0 ) == '/' )
             {
                 // conversion from the new format
                 String[] lines = classNames.split( "\\n" );
                 StringBuilder sb = new StringBuilder();
                 for ( String line : lines )
                 {
                     sb.append( line.substring( 1 ) ).append( '\n' );
                 }
 
                 classNames = sb.toString();
             }
 
             doc.add( FLD_CLASSNAMES_KW.toField( classNames ) );
         }
     }
 
     public boolean updateArtifactInfo( final Document doc, final ArtifactInfo artifactInfo )
     {
         String names = doc.get( FLD_CLASSNAMES_KW.getKey() );
 
         if ( names != null )
         {
             if ( names.length() == 0 || names.charAt( 0 ) == '/' )
             {
                 artifactInfo.setClassNames( names );
             }
             else
             {
                 // conversion from the old format
                 String[] lines = names.split( "\\n" );
                 StringBuilder sb = new StringBuilder();
                 for ( String line : lines )
                 {
                     sb.append( '/' ).append( line ).append( '\n' );
                 }
                 artifactInfo.setClassNames( sb.toString() );
             }
 
             return true;
         }
 
         return false;
     }
 
     private void updateArtifactInfo( final ArtifactInfo ai, final File f )
         throws IOException
     {
         if ( f.getName().endsWith( ".jar" ) || f.getName().endsWith( ".zip" ) )
         {
             updateArtifactInfo( ai, f, null );
         }
         else if ( f.getName().endsWith( ".war" ) )
         {
             updateArtifactInfo( ai, f, "WEB-INF/classes/" );
         }
     }
 
     private void updateArtifactInfo( final ArtifactInfo ai, final File f, final String strippedPrefix )
         throws IOException
     {
 
         try ( ZipFile zipFile = new ZipFile( f ) )
         {
             final Enumeration<? extends ZipEntry> entries = zipFile.entries();
 
             final StringBuilder sb = new StringBuilder();
 
             while ( entries.hasMoreElements() )
             {
                 String name = entries.nextElement().getName();
                 if ( name.endsWith( ".class" ) )
                 {
                     // TODO verify if class is public or protected
                     // TODO skip all inner classes for now
 
                     int i = name.indexOf( "$" );
 
                     if ( i == -1 )
                     {
                         if ( name.charAt( 0 ) != '/' )
                         {
                             sb.append( '/' );
                         }
 
                         if ( StringUtils.isBlank( strippedPrefix ) )
                         {
                             // class name without ".class"
                             sb.append( name, 0, name.length() - 6 ).append( '\n' );
                         }
                         else if ( name.startsWith( strippedPrefix )
                             && ( name.length() > ( strippedPrefix.length() + 6 ) ) )
                         {
                             // class name without ".class" and stripped prefix
                             sb.append( name, strippedPrefix.length(), name.length() - 6 ).append( '\n' );
                         }
                     }
                 }
             }
 
             final String fieldValue = sb.toString().trim();
 
             if ( fieldValue.length() != 0 )
             {
                 ai.setClassNames( fieldValue );
             }
             else
             {
                 ai.setClassNames( null );
             }
         }
     }
 
     @Override
     public String toString()
     {
         return ID;
     }
 
     @Override
     public Collection<IndexerField> getIndexerFields()
     {
         return Arrays.asList( FLD_CLASSNAMES, FLD_CLASSNAMES_KW );
     }
 }