package org.codehaus.mojo.wagon.shared;
   
   /*
    * 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.File;
  import java.io.FileInputStream;
  import java.io.FileReader;
  import java.io.FileWriter;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.Reader;
  import java.io.Writer;
  import java.security.MessageDigest;
  import java.security.NoSuchAlgorithmException;
  
  import org.apache.maven.artifact.repository.metadata.Metadata;
  import org.apache.maven.artifact.repository.metadata.io.xpp3.MetadataXpp3Reader;
  import org.apache.maven.artifact.repository.metadata.io.xpp3.MetadataXpp3Writer;
  import org.apache.maven.plugin.logging.Log;
  import org.apache.maven.shared.model.fileset.FileSet;
  import org.apache.maven.wagon.ResourceDoesNotExistException;
  import org.apache.maven.wagon.Wagon;
  import org.apache.maven.wagon.WagonException;
  import org.codehaus.plexus.component.annotations.Component;
  import org.codehaus.plexus.component.annotations.Requirement;
  import org.codehaus.plexus.util.DirectoryScanner;
  import org.codehaus.plexus.util.FileUtils;
  import org.codehaus.plexus.util.IOUtil;
  import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
  
  /**
   * A copy of stage's plugin RepositoryCopier but use WagonUpload and WagonDownload instead.
   */
  @Component(role = MavenRepoMerger.class, hint = "default")
  public class DefaultMavenRepoMerger
      implements MavenRepoMerger
  {
      @Requirement
      private WagonDownload downloader;
  
      @Requirement
      private WagonUpload uploader;
  
      @Override
      public void merge( Wagon src, Wagon target, boolean optimize, Log logger )
          throws WagonException, IOException
      {
  
          // copy src to a local dir
          File downloadSrcDir = createTempDirectory( "wagon-maven-plugin" );
  
          WagonFileSet srcFileSet = new WagonFileSet();
          srcFileSet.setDownloadDirectory( downloadSrcDir );
          // ignore archiva/nexus .index at root dir
          String[] excludes = { ".*/**", "archetype-catalog.xml*" };
          srcFileSet.setExcludes( excludes );
  
          try
          {
              downloader.download( src, srcFileSet, logger );
  
              // merge metadata
              DirectoryScanner scanner = new DirectoryScanner();
              scanner.setBasedir( downloadSrcDir );
              String[] includes = { "**/" + MAVEN_METADATA };
              scanner.setIncludes( includes );
              scanner.scan();
              String[] files = scanner.getIncludedFiles();
  
              for ( String file : files )
              {
                  File srcMetadaFile = new File( downloadSrcDir, file + IN_PROCESS_MARKER );
  
                  try
                  {
                      target.get( file.replace( '\\', '/' ), srcMetadaFile );
                  } catch ( ResourceDoesNotExistException e )
                  {
                      // We don't have an equivalent on the targetRepositoryUrl side because we have something
                      // new on the sourceRepositoryUrl side so just skip the metadata merging.
                      continue;
                  }
 
                 try
                 {
                     mergeMetadata( srcMetadaFile, logger );
                 } catch ( XmlPullParserException e )
                 {
                     throw new IOException( "Metadata file is corrupt " + file + " Reason: " + e.getMessage() );
                 }
 
             }
 
             // upload to target
             FileSet tobeUploadedFileSet = new FileSet();
             tobeUploadedFileSet.setDirectory( downloadSrcDir.getAbsolutePath() );
 
             this.uploader.upload( target, tobeUploadedFileSet, optimize, logger );
 
         }
         finally
         {
             FileUtils.deleteDirectory( downloadSrcDir );
         }
 
     }
 
     private void mergeMetadata( File existingMetadata, Log logger )
         throws IOException, XmlPullParserException
     {
 
         Writer stagedMetadataWriter = null;
         Reader existingMetadataReader = null;
         Reader stagedMetadataReader = null;
         File stagedMetadataFile;
 
         try
         {
             MetadataXpp3Reader xppReader = new MetadataXpp3Reader();
             MetadataXpp3Writer xppWriter = new MetadataXpp3Writer();
 
             // Existing Metadata in target stage
             existingMetadataReader = new FileReader( existingMetadata );
             Metadata existing = xppReader.read( existingMetadataReader );
 
             // Staged Metadata
             stagedMetadataFile = new File( existingMetadata.getParentFile(), MAVEN_METADATA );
             stagedMetadataReader = new FileReader( stagedMetadataFile );
             Metadata staged = xppReader.read( stagedMetadataReader );
 
             // Merge and write back to staged metadata to replace the remote one
             existing.merge( staged );
 
             stagedMetadataWriter = new FileWriter( stagedMetadataFile );
             xppWriter.write( stagedMetadataWriter, existing );
 
             logger.info( "Merging metadata file: " + stagedMetadataFile );
 
         }
         finally
         {
             IOUtil.close( stagedMetadataWriter );
             IOUtil.close( stagedMetadataReader );
             IOUtil.close( existingMetadataReader );
 
             existingMetadata.delete();
         }
 
         // Mark all metadata as in-process and regenerate the checksums as they will be different
         // after the merger
 
         try
         {
             File newMd5 = new File( stagedMetadataFile.getParentFile(), MAVEN_METADATA + ".md5" );
             FileUtils.fileWrite( newMd5.getAbsolutePath(), checksum( stagedMetadataFile, MD5 ) );
 
             File newSha1 = new File( stagedMetadataFile.getParentFile(), MAVEN_METADATA + ".sha1" );
             FileUtils.fileWrite( newSha1.getAbsolutePath(), checksum( stagedMetadataFile, SHA1 ) );
         }
         catch ( NoSuchAlgorithmException e )
         {
             throw new RuntimeException( e );
         }
 
         // We have the new merged copy so we're good
 
     }
 
     private String checksum( File file, String type )
         throws IOException, NoSuchAlgorithmException
     {
         MessageDigest md5 = MessageDigest.getInstance( type );
 
         InputStream is = new FileInputStream( file );
 
         byte[] buf = new byte[8192];
 
         int i;
 
         while ( ( i = is.read( buf ) ) > 0 )
         {
             md5.update( buf, 0, i );
         }
 
         IOUtil.close( is );
 
         return encode( md5.digest() );
     }
 
     private String encode( byte[] binaryData )
     {
         if ( binaryData.length != 16 && binaryData.length != 20 )
         {
             int bitLength = binaryData.length * 8;
             throw new IllegalArgumentException( "Unrecognised length for binary data: " + bitLength + " bits" );
         }
 
         String retValue = "";
 
         for ( byte aBinaryData : binaryData )
         {
             String t = Integer.toHexString( aBinaryData & 0xff );
 
             if ( t.length() == 1 )
             {
                 retValue += ( "0" + t );
             }
             else
             {
                 retValue += t;
             }
         }
 
         return retValue.trim();
     }
 
     public static File createTempDirectory( String prefix )
         throws IOException
     {
         final File temp;
 
         temp = File.createTempFile( prefix, Long.toString( System.nanoTime() ) );
 
         if ( !( temp.delete() ) )
         {
             throw new IOException( "Could not delete temp file: " + temp.getAbsolutePath() );
         }
 
         if ( !( temp.mkdir() ) )
         {
             throw new IOException( "Could not create temp directory: " + temp.getAbsolutePath() );
         }
 
         return ( temp );
     }
 
 }