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 org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.transfer.AbstractTransferListener;
  import org.eclipse.aether.transfer.TransferCancelledException;
  import org.eclipse.aether.transfer.TransferEvent;
  import org.eclipse.aether.transfer.TransferListener;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import static java.util.Objects.requireNonNull;
  
  class SafeTransferListener
      extends AbstractTransferListener
  {
  
      private static final Logger LOGGER = LoggerFactory.getLogger( SafeTransferListener.class );
  
      private final TransferListener listener;
  
      public static TransferListener wrap( RepositorySystemSession session )
      {
          TransferListener listener = session.getTransferListener();
          if ( listener == null )
          {
              return null;
          }
          return new SafeTransferListener( listener );
      }
  
      protected SafeTransferListener( RepositorySystemSession session )
      {
          this( session.getTransferListener() );
      }
  
      private SafeTransferListener( TransferListener listener )
      {
          this.listener = listener;
      }
  
      private void logError( TransferEvent event, Throwable e )
      {
          LOGGER.debug( "Failed to dispatch transfer event '{}' to {}", event,  listener.getClass().getCanonicalName(),
                  e );
      }
  
      @Override
      public void transferInitiated( TransferEvent event )
          throws TransferCancelledException
      {
          requireNonNull( event, "event cannot be null" );
          if ( listener != null )
          {
              try
              {
                  listener.transferInitiated( event );
              }
              catch ( RuntimeException | LinkageError e )
              {
                  logError( event, e );
              }
          }
      }
  
      @Override
      public void transferStarted( TransferEvent event )
          throws TransferCancelledException
      {
          requireNonNull( event, "event cannot be null" );
          if ( listener != null )
          {
              try
              {
                  listener.transferStarted( event );
              }
              catch ( RuntimeException | LinkageError e )
              {
                  logError( event, e );
              }
          }
     }
 
     @Override
     public void transferProgressed( TransferEvent event )
         throws TransferCancelledException
     {
         requireNonNull( event, "event cannot be null" );
         if ( listener != null )
         {
             try
             {
                 listener.transferProgressed( event );
             }
             catch ( RuntimeException | LinkageError e )
             {
                 logError( event, e );
             }
         }
     }
 
     @Override
     public void transferCorrupted( TransferEvent event )
         throws TransferCancelledException
     {
         requireNonNull( event, "event cannot be null" );
         if ( listener != null )
         {
             try
             {
                 listener.transferCorrupted( event );
             }
             catch ( RuntimeException | LinkageError e )
             {
                 logError( event, e );
             }
         }
     }
 
     @Override
     public void transferSucceeded( TransferEvent event )
     {
         requireNonNull( event, "event cannot be null" );
         if ( listener != null )
         {
             try
             {
                 listener.transferSucceeded( event );
             }
             catch ( RuntimeException | LinkageError e )
             {
                 logError( event, e );
             }
         }
     }
 
     @Override
     public void transferFailed( TransferEvent event )
     {
         requireNonNull( event, "event cannot be null" );
         if ( listener != null )
         {
             try
             {
                 listener.transferFailed( event );
             }
             catch ( RuntimeException | LinkageError e )
             {
                 logError( event, e );
             }
         }
     }
 
 }