package org.eclipse.aether.internal.impl;
   
   /*
    * 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.net.URI;
  import java.net.URISyntaxException;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Set;
  import java.util.stream.Collectors;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.internal.impl.checksum.DefaultChecksumAlgorithmFactorySelector;
  import org.eclipse.aether.metadata.Metadata;
  import org.eclipse.aether.repository.RemoteRepository;
  import org.eclipse.aether.spi.connector.checksum.ChecksumAlgorithmFactory;
  import org.eclipse.aether.spi.connector.checksum.ChecksumAlgorithmFactorySelector;
  import org.eclipse.aether.spi.connector.layout.RepositoryLayout;
  import org.eclipse.aether.spi.connector.layout.RepositoryLayoutFactory;
  import org.eclipse.aether.transfer.NoRepositoryLayoutException;
  import org.eclipse.aether.util.ConfigUtils;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Provides a Maven-2 repository layout for repositories with content type {@code "default"}.
   */
  @Singleton
  @Named( "maven2" )
  public final class Maven2RepositoryLayoutFactory
          implements RepositoryLayoutFactory
  {
  
      public static final String CONFIG_PROP_CHECKSUMS_ALGORITHMS = "aether.checksums.algorithms";
  
      private static final String DEFAULT_CHECKSUMS_ALGORITHMS = "SHA-1,MD5";
  
      public static final String CONFIG_PROP_OMIT_CHECKSUMS_FOR_EXTENSIONS =
              "aether.checksums.omitChecksumsForExtensions";
  
      private static final String DEFAULT_OMIT_CHECKSUMS_FOR_EXTENSIONS = ".asc";
  
      private float priority;
  
      private final ChecksumAlgorithmFactorySelector checksumAlgorithmFactorySelector;
  
      public float getPriority()
      {
          return priority;
      }
  
      /**
       * Service locator ctor.
       */
      @Deprecated
      public Maven2RepositoryLayoutFactory()
      {
          this( new DefaultChecksumAlgorithmFactorySelector() );
      }
  
      @Inject
      public Maven2RepositoryLayoutFactory( ChecksumAlgorithmFactorySelector checksumAlgorithmFactorySelector )
      {
          this.checksumAlgorithmFactorySelector = requireNonNull( checksumAlgorithmFactorySelector );
      }
  
      /**
       * Sets the priority of this component.
       *
       * @param priority The priority.
       * @return This component for chaining, never {@code null}.
       */
      public Maven2RepositoryLayoutFactory setPriority( float priority )
      {
         this.priority = priority;
         return this;
     }
 
     public RepositoryLayout newInstance( RepositorySystemSession session, RemoteRepository repository )
             throws NoRepositoryLayoutException
     {
         requireNonNull( session, "session cannot be null" );
         requireNonNull( repository, "repository cannot be null" );
         if ( !"default".equals( repository.getContentType() ) )
         {
             throw new NoRepositoryLayoutException( repository );
         }
         // ensure order and uniqueness of (potentially user set) algorithm list
         LinkedHashSet<String> checksumsAlgorithmNames = Arrays.stream( ConfigUtils.getString(
                         session, DEFAULT_CHECKSUMS_ALGORITHMS, CONFIG_PROP_CHECKSUMS_ALGORITHMS )
                 .split( "," )
         ).filter( s -> s != null && !s.trim().isEmpty() ).collect( Collectors.toCollection( LinkedHashSet::new ) );
 
         // validation: this loop implicitly validates the list above: selector will throw on unknown algorithm
         List<ChecksumAlgorithmFactory> checksumsAlgorithms = new ArrayList<>( checksumsAlgorithmNames.size() );
         for ( String checksumsAlgorithmName : checksumsAlgorithmNames )
         {
             checksumsAlgorithms.add( checksumAlgorithmFactorySelector.select( checksumsAlgorithmName ) );
         }
 
         // ensure uniqueness of (potentially user set) extension list
         Set<String> omitChecksumsForExtensions = Arrays.stream( ConfigUtils.getString(
                         session, DEFAULT_OMIT_CHECKSUMS_FOR_EXTENSIONS, CONFIG_PROP_OMIT_CHECKSUMS_FOR_EXTENSIONS )
                 .split( "," )
         ).filter( s -> s != null && !s.trim().isEmpty() ).collect( Collectors.toSet() );
 
         // validation: enforce that all strings in this set are having leading dot
         if ( omitChecksumsForExtensions.stream().anyMatch( s -> !s.startsWith( "." ) ) )
         {
             throw new IllegalArgumentException(
                     String.format(
                             "The configuration %s contains illegal values: %s (all entries must start with '.' (dot))",
                             CONFIG_PROP_OMIT_CHECKSUMS_FOR_EXTENSIONS,
                             omitChecksumsForExtensions
                     )
             );
         }
 
         return new Maven2RepositoryLayout(
                 new ArrayList<>( checksumAlgorithmFactorySelector.getChecksumAlgorithmFactories() ),
                 checksumsAlgorithms,
                 omitChecksumsForExtensions
         );
     }
 
     private static class Maven2RepositoryLayout
             implements RepositoryLayout
     {
         private final List<ChecksumAlgorithmFactory> allChecksumAlgorithms;
 
         private final List<ChecksumAlgorithmFactory> configuredChecksumAlgorithms;
 
         private final Set<String> extensionsWithoutChecksums;
 
         private Maven2RepositoryLayout( List<ChecksumAlgorithmFactory> allChecksumAlgorithms,
                                         List<ChecksumAlgorithmFactory> configuredChecksumAlgorithms,
                                         Set<String> extensionsWithoutChecksums )
         {
             this.allChecksumAlgorithms = Collections.unmodifiableList( allChecksumAlgorithms );
             this.configuredChecksumAlgorithms = Collections.unmodifiableList( configuredChecksumAlgorithms );
             this.extensionsWithoutChecksums = requireNonNull( extensionsWithoutChecksums );
         }
 
         private URI toUri( String path )
         {
             try
             {
                 return new URI( null, null, path, null );
             }
             catch ( URISyntaxException e )
             {
                 throw new IllegalStateException( e );
             }
         }
 
         @Override
         public List<ChecksumAlgorithmFactory> getChecksumAlgorithmFactories()
         {
             return configuredChecksumAlgorithms;
         }
 
         @Override
         public boolean hasChecksums( Artifact artifact )
         {
             String artifactExtension = artifact.getExtension(); // ie. pom.asc
             for ( String extensionWithoutChecksums : extensionsWithoutChecksums )
             {
                 if ( artifactExtension.endsWith( extensionWithoutChecksums ) )
                 {
                     return false;
                 }
             }
             return true;
         }
 
         @Override
         public URI getLocation( Artifact artifact, boolean upload )
         {
             StringBuilder path = new StringBuilder( 128 );
 
             path.append( artifact.getGroupId().replace( '.', '/' ) ).append( '/' );
 
             path.append( artifact.getArtifactId() ).append( '/' );
 
             path.append( artifact.getBaseVersion() ).append( '/' );
 
             path.append( artifact.getArtifactId() ).append( '-' ).append( artifact.getVersion() );
 
             if ( artifact.getClassifier().length() > 0 )
             {
                 path.append( '-' ).append( artifact.getClassifier() );
             }
 
             if ( artifact.getExtension().length() > 0 )
             {
                 path.append( '.' ).append( artifact.getExtension() );
             }
 
             return toUri( path.toString() );
         }
 
         @Override
         public URI getLocation( Metadata metadata, boolean upload )
         {
             StringBuilder path = new StringBuilder( 128 );
 
             if ( metadata.getGroupId().length() > 0 )
             {
                 path.append( metadata.getGroupId().replace( '.', '/' ) ).append( '/' );
 
                 if ( metadata.getArtifactId().length() > 0 )
                 {
                     path.append( metadata.getArtifactId() ).append( '/' );
 
                     if ( metadata.getVersion().length() > 0 )
                     {
                         path.append( metadata.getVersion() ).append( '/' );
                     }
                 }
             }
 
             path.append( metadata.getType() );
 
             return toUri( path.toString() );
         }
 
         @Override
         public List<ChecksumLocation> getChecksumLocations( Artifact artifact, boolean upload, URI location )
         {
             if ( !hasChecksums( artifact ) || isChecksum( artifact.getExtension() ) )
             {
                 return Collections.emptyList();
             }
             return getChecksumLocations( location );
         }
 
         @Override
         public List<ChecksumLocation> getChecksumLocations( Metadata metadata, boolean upload, URI location )
         {
             return getChecksumLocations( location );
         }
 
         private List<ChecksumLocation> getChecksumLocations( URI location )
         {
             List<ChecksumLocation> checksumLocations = new ArrayList<>( configuredChecksumAlgorithms.size() );
             for ( ChecksumAlgorithmFactory checksumAlgorithmFactory : configuredChecksumAlgorithms )
             {
                 checksumLocations.add( ChecksumLocation.forLocation( location, checksumAlgorithmFactory ) );
             }
             return checksumLocations;
         }
 
         private boolean isChecksum( String extension )
         {
             return allChecksumAlgorithms.stream().anyMatch( a -> extension.endsWith( "." + a.getFileExtension() ) );
         }
     }
 }