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.commons.lang.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.stereotype.Service;
  
  import java.io.File;
  import java.util.ArrayList;
  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
      implements PostDownloadPolicy
  {
      private Logger log = LoggerFactory.getLogger( ChecksumPolicy.class );
  
      /**
       * 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 String IGNORE = "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 String FAIL = "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 String FIX = "fix";
  
      private ChecksumAlgorithm[] algorithms = new ChecksumAlgorithm[]{ ChecksumAlgorithm.SHA1, ChecksumAlgorithm.MD5 };
  
      private List<String> options = new ArrayList<>( 3 );
  
      public ChecksumPolicy()
      {
          options.add( FAIL );
          options.add( FIX );
          options.add( IGNORE );
      }
  
      @Override
      public void applyPolicy( String policySetting, Properties request, File 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.getAbsolutePath() + " does not exist to check." );
         }
 
         if ( FAIL.equals( policySetting ) )
         {
             ChecksummedFile checksum = new ChecksummedFile( localFile );
             if ( checksum.isValidChecksums( algorithms ) )
             {
                 return;
             }
 
             for ( ChecksumAlgorithm algorithm : algorithms )
             {
                 File file = new File( localFile.getAbsolutePath() + "." + algorithm.getExt() );
                 if ( file.exists() )
                 {
                     file.delete();
                 }
             }
 
             localFile.delete();
             throw new PolicyViolationException(
                 "Checksums do not match, policy set to FAIL, " + "deleting checksum files and local file "
                     + localFile.getAbsolutePath() + "." );
         }
 
         if ( FIX.equals( policySetting ) )
         {
             ChecksummedFile checksum = new ChecksummedFile( localFile );
             if ( checksum.fixChecksums( algorithms ) )
             {
                 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.getAbsolutePath() + "." );
             }
         }
 
         throw new PolicyConfigurationException(
             "Unable to process checksum policy of [" + policySetting + "], please file a bug report." );
     }
 
     @Override
     public String getDefaultOption()
     {
         return FIX;
     }
 
     @Override
     public String getId()
     {
         return "checksum";
     }
 
     @Override
     public String getName()
     {
         return "Checksum";
     }
 
     @Override
     public List<String> getOptions()
     {
         return options;
     }
 }