package org.apache.maven.plugins.assembly.filter;
   
   /*
    * 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 org.apache.maven.plugins.assembly.utils.AssemblyFileUtils;
  import org.codehaus.plexus.archiver.Archiver;
  import org.codehaus.plexus.archiver.ArchiverException;
  import org.codehaus.plexus.archiver.UnArchiver;
  import org.codehaus.plexus.components.io.fileselectors.FileInfo;
  import org.codehaus.plexus.util.IOUtil;
  
  import javax.inject.Named;
  
  import java.io.File;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.OutputStreamWriter;
  import java.io.Reader;
  import java.io.StringWriter;
  import java.io.Writer;
  import java.nio.charset.StandardCharsets;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Date;
  import java.util.List;
  
  /**
   *
   */
  @Named( "file-aggregator" )
  public class SimpleAggregatingDescriptorHandler implements ContainerDescriptorHandler
  {
      // component configuration.
  
      @SuppressWarnings( "FieldCanBeLocal" )
      private final String commentChars = "#";
  
      private final StringWriter aggregateWriter = new StringWriter();
  
      private final List<String> filenames = new ArrayList<>();
  
      // calculated, temporary values.
  
      private String filePattern;
  
      private String outputPath;
  
      private boolean overrideFilterAction;
  
      @Override
      public void finalizeArchiveCreation( final Archiver archiver )
      {
          checkConfig();
  
          if ( outputPath.endsWith( "/" ) )
          {
              throw new ArchiverException( "Cannot write aggregated properties to a directory. "
                                               + "You must specify a file name in the outputPath configuration for this"
                                               + " handler. (handler: " + getClass().getName() );
          }
  
          if ( outputPath.startsWith( "/" ) )
          {
              outputPath = outputPath.substring( 1 );
          }
  
          final File temp = writePropertiesFile();
  
          overrideFilterAction = true;
  
          archiver.addFile( temp, outputPath );
  
          overrideFilterAction = false;
      }
  
      private File writePropertiesFile()
      {
          File f;
          try
          {
             f = File.createTempFile( "maven-assembly-plugin", "tmp" );
             f.deleteOnExit();
 
             try ( Writer writer = getWriter( f ) )
             {
                 writer.write( commentChars + " Aggregated on " + new Date() + " from: " );
 
                 for ( final String filename : filenames )
                 {
                     writer.write( "\n" + commentChars + " " + filename );
                 }
 
                 writer.write( "\n\n" );
                 writer.write( aggregateWriter.toString() );
             }
         }
         catch ( final IOException e )
         {
             throw new ArchiverException(
                 "Error adding aggregated properties to finalize archive creation. Reason: " + e.getMessage(), e );
         }
 
         return f;
     }
 
     private Writer getWriter( File f )
         throws FileNotFoundException
     {
         Writer writer;
         writer = AssemblyFileUtils.isPropertyFile( f )
                      ? new OutputStreamWriter( new FileOutputStream( f ), StandardCharsets.ISO_8859_1 )
                      : new OutputStreamWriter( new FileOutputStream( f ) ); // Still platform encoding
         return writer;
     }
 
     @Override
     public void finalizeArchiveExtraction( final UnArchiver unarchiver )
     {
     }
 
     @Override
     public List<String> getVirtualFiles()
     {
         checkConfig();
 
         return Collections.singletonList( outputPath );
     }
 
     @Override
     public boolean isSelected( final FileInfo fileInfo )
         throws IOException
     {
         checkConfig();
 
         if ( overrideFilterAction )
         {
             return true;
         }
 
         String name = AssemblyFileUtils.normalizeFileInfo( fileInfo );
 
         if ( fileInfo.isFile() && name.matches( filePattern ) )
         {
             readProperties( fileInfo );
             filenames.add( name );
 
             return false;
         }
 
         return true;
     }
 
     private void checkConfig()
     {
         if ( filePattern == null || outputPath == null )
         {
             throw new IllegalStateException(
                 "You must configure filePattern and outputPath in your containerDescriptorHandler declaration." );
         }
     }
 
     private void readProperties( final FileInfo fileInfo )
         throws IOException
     {
         try ( StringWriter writer = new StringWriter();
             Reader reader = AssemblyFileUtils.isPropertyFile( fileInfo.getName() )
                 ? new InputStreamReader( fileInfo.getContents(), StandardCharsets.ISO_8859_1 )
                 : new InputStreamReader( fileInfo.getContents() ) ) // platform encoding
         {
             IOUtil.copy( reader, writer );
             final String content = writer.toString();
             aggregateWriter.write( "\n" );
             aggregateWriter.write( content );
         }
     }
 
     @SuppressWarnings( "UnusedDeclaration" )
     public String getFilePattern()
     {
         return filePattern;
     }
 
     @SuppressWarnings( "UnusedDeclaration" )
     public void setFilePattern( final String filePattern )
     {
         this.filePattern = filePattern;
     }
 
     @SuppressWarnings( "UnusedDeclaration" )
     public String getOutputPath()
     {
         return outputPath;
     }
 
     @SuppressWarnings( "UnusedDeclaration" )
     public void setOutputPath( final String outputPath )
     {
         this.outputPath = outputPath;
     }
 
 }