package org.apache.archiva.indexer.maven.merger;
   /*
    * 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.common.utils.FileUtils;
  import org.apache.archiva.indexer.UnsupportedBaseContextException;
  import org.apache.archiva.indexer.merger.IndexMerger;
  import org.apache.archiva.indexer.merger.IndexMergerException;
  import org.apache.archiva.indexer.merger.IndexMergerRequest;
  import org.apache.archiva.indexer.merger.TemporaryGroupIndex;
  import org.apache.archiva.repository.RepositoryRegistry;
  import org.apache.archiva.repository.RepositoryType;
  import org.apache.commons.lang.time.StopWatch;
  import org.apache.maven.index.Indexer;
  import org.apache.maven.index.context.ContextMemberProvider;
  import org.apache.maven.index.context.IndexCreator;
  import org.apache.maven.index.context.IndexingContext;
  import org.apache.maven.index.context.StaticContextMemberProvider;
  import org.apache.maven.index.packer.IndexPacker;
  import org.apache.maven.index.packer.IndexPackingRequest;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.scheduling.annotation.Async;
  import org.springframework.stereotype.Service;
  
  import javax.inject.Inject;
  import java.io.IOException;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.Collection;
  import java.util.List;
  import java.util.Objects;
  import java.util.Optional;
  import java.util.concurrent.CopyOnWriteArrayList;
  import java.util.stream.Collectors;
  
  /**
   * @author Olivier Lamy
   * @since 1.4-M2
   */
  @Service("indexMerger#default")
  public class DefaultIndexMerger
      implements IndexMerger
  {
  
      @Inject
      RepositoryRegistry repositoryRegistry;
  
      private Logger log = LoggerFactory.getLogger( getClass() );
  
  
      private final IndexPacker indexPacker;
  
      private Indexer indexer;
  
      private final List<IndexCreator> indexCreators;
  
      private List<TemporaryGroupIndex> temporaryGroupIndexes = new CopyOnWriteArrayList<>();
  
      private List<IndexingContext>  temporaryContextes = new CopyOnWriteArrayList<>(  );
  
      private List<String> runningGroups = new CopyOnWriteArrayList<>();
  
      @Inject
      public DefaultIndexMerger( Indexer indexer, IndexPacker indexPacker, List<IndexCreator> indexCreators )
      {
          this.indexer = indexer;
          this.indexPacker = indexPacker;
          this.indexCreators = indexCreators;
      }
  
      @Override
      public IndexingContext buildMergedIndex( IndexMergerRequest indexMergerRequest )
          throws IndexMergerException
      {
          String groupId = indexMergerRequest.getGroupId();
  
          if ( runningGroups.contains( groupId ) )
          {
              log.info( "skip build merge remote indexes for id: '{}' as already running", groupId );
              return null;
          }
  
         runningGroups.add( groupId );
 
         StopWatch stopWatch = new StopWatch();
         stopWatch.reset();
         stopWatch.start();
 
         Path mergedIndexDirectory = indexMergerRequest.getMergedIndexDirectory();
 
         String tempRepoId = mergedIndexDirectory.getFileName().toString();
 
         try
         {
             Path indexLocation = mergedIndexDirectory.resolve( indexMergerRequest.getMergedIndexPath() );
 
             List<IndexingContext> members = indexMergerRequest.getRepositoriesIds( ).stream( ).map( id ->
                 repositoryRegistry.getRepository( id ) ).filter( repo -> repo.getType().equals( RepositoryType.MAVEN ) )
                 .map( repo -> {
                     try
                     {
                         return repo.getIndexingContext().getBaseContext( IndexingContext.class );
                     }
                     catch ( UnsupportedBaseContextException e )
                     {
                         return null;
                         // Ignore
                     }
                 } ).filter( Objects::nonNull ).collect( Collectors.toList() );
             ContextMemberProvider memberProvider = new StaticContextMemberProvider(members);
             IndexingContext mergedCtx = indexer.createMergedIndexingContext( tempRepoId, tempRepoId, mergedIndexDirectory.toFile(),
                 indexLocation.toFile(), true, memberProvider);
             mergedCtx.optimize();
 
             if ( indexMergerRequest.isPackIndex() )
             {
                 IndexPackingRequest request = new IndexPackingRequest( mergedCtx, //
                                                                        mergedCtx.acquireIndexSearcher().getIndexReader(), //
                                                                        indexLocation.toFile() );
                 indexPacker.packIndex( request );
             }
 
             if ( indexMergerRequest.isTemporary() )
             {
                 temporaryGroupIndexes.add( new TemporaryGroupIndex( mergedIndexDirectory, tempRepoId, groupId,
                                                                     indexMergerRequest.getMergedIndexTtl() ) );
                 temporaryContextes.add(mergedCtx);
             }
             stopWatch.stop();
             log.info( "merged index for repos {} in {} s", indexMergerRequest.getRepositoriesIds(),
                       stopWatch.getTime() );
             return mergedCtx;
         }
         catch ( IOException e)
         {
             throw new IndexMergerException( e.getMessage(), e );
         }
         finally
         {
             runningGroups.remove( groupId );
         }
     }
 
     @Async
     @Override
     public void cleanTemporaryGroupIndex( TemporaryGroupIndex temporaryGroupIndex )
     {
         if ( temporaryGroupIndex == null )
         {
             return;
         }
 
         try
         {
 
             Optional<IndexingContext> ctxOpt = temporaryContextes.stream( ).filter( ctx -> ctx.getId( ).equals( temporaryGroupIndex.getIndexId( ) ) ).findFirst( );
             if (ctxOpt.isPresent()) {
                 IndexingContext ctx = ctxOpt.get();
                 indexer.closeIndexingContext( ctx, true );
                 temporaryGroupIndexes.remove( temporaryGroupIndex );
                 temporaryContextes.remove( ctx );
                 Path directory = temporaryGroupIndex.getDirectory();
                 if ( directory != null && Files.exists(directory) )
                 {
                     FileUtils.deleteDirectory( directory );
                 }
             }
         }
         catch ( IOException e )
         {
             log.warn( "fail to delete temporary group index {}", temporaryGroupIndex.getIndexId(), e );
         }
     }
 
     @Override
     public Collection<TemporaryGroupIndex> getTemporaryGroupIndexes()
     {
         return this.temporaryGroupIndexes;
     }
 }