package org.apache.archiva.policies;
   
   /*
    * 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.archiva.checksum.ChecksumAlgorithm;
  import org.apache.archiva.checksum.ChecksummedFile;
  import org.apache.archiva.checksum.UpdateStatus;
  import org.apache.archiva.repository.storage.StorageAsset;
  import org.apache.commons.lang3.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.stereotype.Service;
  
  import java.io.IOException;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  import java.util.Properties;
  
  /**
   * ChecksumPolicy - a policy applied after the download to see if the file has been downloaded
   * successfully and completely (or not).
   *
   *
   */
  @Service( "postDownloadPolicy#checksum" )
  public class ChecksumPolicy
      extends AbstractPolicy implements PostDownloadPolicy
  {
      private Logger log = LoggerFactory.getLogger( ChecksumPolicy.class );
  
      private static final String ID = "checksum";
  
      /**
       * The IGNORE policy indicates that if the checksum policy is ignored, and
       * the state of, contents of, or validity of the checksum files are not
       * checked.
       */
      public static final ChecksumOption IGNORE = ChecksumOption.IGNORE;
  
      /**
       * The FAIL policy indicates that if the checksum does not match the
       * downloaded file, then remove the downloaded artifact, and checksum
       * files, and fail the transfer to the client side.
       */
      public static final ChecksumOption FAIL = ChecksumOption.FAIL;
  
      /**
       * The FIX policy indicates that if the checksum does not match the
       * downloaded file, then fix the checksum file locally, and return
       * to the client side the corrected checksum.
       */
      public static final ChecksumOption FIX = ChecksumOption.FIX;
  
      private List<ChecksumAlgorithm> algorithms = Arrays.asList( ChecksumAlgorithm.SHA256, ChecksumAlgorithm.SHA1, ChecksumAlgorithm.MD5 );
  
      private List<PolicyOption> options = new ArrayList<>( 3 );
  
      public ChecksumPolicy()
      {
          super();
          options.add( FAIL );
          options.add( FIX );
          options.add( IGNORE );
      }
  
      @Override
      public void applyPolicy( PolicyOption policySetting, Properties request, StorageAsset localFile )
          throws PolicyViolationException, PolicyConfigurationException
      {
          if ( "resource".equals( request.getProperty( "filetype" ) ) )
          {
              return;
          }
  
          if ( !options.contains( policySetting ) )
          {
              // Not a valid code. 
              throw new PolicyConfigurationException(
                  "Unknown checksum policy setting [" + policySetting + "], valid settings are [" + StringUtils.join(
                     options.iterator(), "," ) + "]" );
         }
 
         if ( IGNORE.equals( policySetting ) )
         {
             // Ignore.
             log.debug( "Checksum policy set to IGNORE." );
             return;
         }
 
         if ( !localFile.exists() )
         {
             // Local File does not exist.
             throw new PolicyViolationException(
                 "Checksum policy failure, local file " + localFile.getPath() + " does not exist to check." );
         }
 
         if ( FAIL.equals( policySetting ) && localFile.isFileBased() )
         {
             ChecksummedFile checksum = new ChecksummedFile( localFile.getFilePath() );
             if ( checksum.isValidChecksums( algorithms ) )
             {
                 return;
             }
 
             for ( ChecksumAlgorithm algorithm : algorithms )
             {
                 Path file = checksum.getChecksumFile( algorithm );
                 try
                 {
                     Files.deleteIfExists( file );
                 }
                 catch ( IOException e )
                 {
                     log.error("Could not delete file {}", file);
                 }
             }
 
             try
             {
                 localFile.getStorage().removeAsset( localFile );
             }
             catch ( IOException e )
             {
                 log.error("Could not delete file {}", localFile);
             }
             throw new PolicyViolationException(
                 "Checksums do not match, policy set to FAIL, " + "deleting checksum files and local file "
                     + localFile.getPath() + "." );
         }
 
         if ( FIX.equals( policySetting ) && localFile.isFileBased())
         {
             ChecksummedFile checksum = new ChecksummedFile( localFile.getFilePath() );
             if ( checksum.fixChecksums( algorithms ).getTotalStatus() != UpdateStatus.ERROR )
             {
                 log.debug( "Checksum policy set to FIX, checksum files have been updated." );
                 return;
             }
             else
             {
                 throw new PolicyViolationException(
                     "Checksum policy set to FIX, " + "yet unable to update checksums for local file "
                         + localFile.getPath() + "." );
             }
         }
 
         throw new PolicyConfigurationException(
             "Unable to process checksum policy of [" + policySetting + "], please file a bug report." );
     }
 
     @Override
     public PolicyOption getDefaultOption()
     {
         return FIX;
     }
 
     @Override
     public String getId()
     {
         return ID;
     }
 
     @Override
     public List<PolicyOption> getOptions()
     {
         return options;
     }
 }