package org.eclipse.aether.internal.impl.synccontext.named;
   
   /*
    * 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.TreeSet;
  
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.metadata.Metadata;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Artifact GAV {@link NameMapper}, uses artifact and metadata coordinates to name their corresponding locks. Is not
   * considering local repository, only the artifact coordinates. May use custom prefixes and sufixes and separators,
   * hence this instance may or may not be filesystem friendly (depends on strings used).
   */
  public class GAVNameMapper implements NameMapper
  {
      private final boolean fileSystemFriendly;
  
      private final String artifactPrefix;
  
      private final String artifactSuffix;
  
      private final String metadataPrefix;
  
      private final String metadataSuffix;
  
      private final String fieldSeparator;
  
      public GAVNameMapper( boolean fileSystemFriendly,
                            String artifactPrefix, String artifactSuffix,
                            String metadataPrefix, String metadataSuffix,
                            String fieldSeparator )
      {
          this.fileSystemFriendly = fileSystemFriendly;
          this.artifactPrefix = requireNonNull( artifactPrefix );
          this.artifactSuffix = requireNonNull( artifactSuffix );
          this.metadataPrefix = requireNonNull( metadataPrefix );
          this.metadataSuffix = requireNonNull( metadataSuffix );
          this.fieldSeparator = requireNonNull( fieldSeparator );
      }
  
      @Override
      public boolean isFileSystemFriendly()
      {
          return fileSystemFriendly;
      }
  
      @Override
      public Collection<String> nameLocks( final RepositorySystemSession session,
                                           final Collection<? extends Artifact> artifacts,
                                           final Collection<? extends Metadata> metadatas )
      {
          // Deadlock prevention: https://stackoverflow.com/a/16780988/696632
          // We must acquire multiple locks always in the same order!
          TreeSet<String> keys = new TreeSet<>();
          if ( artifacts != null )
          {
              for ( Artifact artifact : artifacts )
              {
                  keys.add( getArtifactName( artifact ) );
              }
          }
  
          if ( metadatas != null )
          {
              for ( Metadata metadata : metadatas )
              {
                  keys.add( getMetadataName( metadata ) );
              }
          }
          return keys;
      }
  
      private String getArtifactName( Artifact artifact )
      {
          return artifactPrefix + artifact.getGroupId()
                  + fieldSeparator + artifact.getArtifactId()
                  + fieldSeparator + artifact.getBaseVersion()
                 + artifactSuffix;
     }
 
     private String getMetadataName( Metadata metadata )
     {
         String name = metadataPrefix;
         if ( !metadata.getGroupId().isEmpty() )
         {
             name += metadata.getGroupId();
             if ( !metadata.getArtifactId().isEmpty() )
             {
                 name += fieldSeparator + metadata.getArtifactId();
                 if ( !metadata.getVersion().isEmpty() )
                 {
                     name += fieldSeparator + metadata.getVersion();
                 }
             }
         }
         return name + metadataSuffix;
     }
 
     public static NameMapper gav()
     {
         return new GAVNameMapper( false, "artifact:", "", "metadata:", "", ":" );
     }
 
     public static NameMapper fileGav()
     {
         return new GAVNameMapper( true, "", ".lock", "", ".lock", "~" );
     }
 }