package org.apache.maven.repository.internal;
   
   /*
    * 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.util.Collection;
  import java.util.Collections;
  import java.util.Date;
  import java.util.LinkedHashMap;
  import java.util.Map;
  
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.impl.MetadataGenerator;
  import org.eclipse.aether.installation.InstallRequest;
  import org.eclipse.aether.metadata.Metadata;
  import org.eclipse.aether.util.ConfigUtils;
  
  /**
   * @author Benjamin Bentmann
   */
  class LocalSnapshotMetadataGenerator
      implements MetadataGenerator
  {
  
      private Map<Object, LocalSnapshotMetadata> snapshots;
  
      private final boolean legacyFormat;
  
      private final Date timestamp;
  
      LocalSnapshotMetadataGenerator( RepositorySystemSession session, InstallRequest request )
      {
          legacyFormat = ConfigUtils.getBoolean( session.getConfigProperties(), false, "maven.metadata.legacy" );
  
          timestamp = (Date) ConfigUtils.getObject( session, new Date(), "maven.startTime" );
  
          snapshots = new LinkedHashMap<>();
      }
  
      public Collection<? extends Metadata> prepare( Collection<? extends Artifact> artifacts )
      {
          for ( Artifact artifact : artifacts )
          {
              if ( artifact.isSnapshot() )
              {
                  Object key = LocalSnapshotMetadata.getKey( artifact );
                  LocalSnapshotMetadata snapshotMetadata = snapshots.get( key );
                  if ( snapshotMetadata == null )
                  {
                      snapshotMetadata = new LocalSnapshotMetadata( artifact, legacyFormat, timestamp );
                      snapshots.put( key, snapshotMetadata );
                  }
                  snapshotMetadata.bind( artifact );
              }
          }
  
          return Collections.emptyList();
      }
  
      public Artifact transformArtifact( Artifact artifact )
      {
          return artifact;
      }
  
      public Collection<? extends Metadata> finish( Collection<? extends Artifact> artifacts )
      {
          return snapshots.values();
      }
  
  }