package org.apache.maven.plugins.shade.resource;

 /*

  * 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.maven.plugins.shade.relocation.Relocator;

 import org.codehaus.plexus.util.IOUtil;

 import java.io.ByteArrayInputStream;

 import java.io.ByteArrayOutputStream;

 import java.io.IOException;

 import java.io.InputStream;

 import java.util.HashMap;

 import java.util.List;

 import java.util.Map;

 import java.util.jar.JarEntry;

 import java.util.jar.JarOutputStream;

 /**

  * Resources transformer that appends entries in META-INF/services resources into

  * a single resource. For example, if there are several META-INF/services/org.apache.maven.project.ProjectBuilder

  * resources spread across many JARs the individual entries will all be concatenated into a single

  * META-INF/services/org.apache.maven.project.ProjectBuilder resource packaged into the resultant JAR produced

  * by the shading process.

  *

  * @author jvanzyl

  */

 public class ServicesResourceTransformer

     implements ResourceTransformer

 {

     private static final String SERVICES_PATH = "META-INF/services";

     private Map<String, ServiceStream> serviceEntries = new HashMap<String, ServiceStream>();

     public boolean canTransformResource( String resource )

     {

         if ( resource.startsWith( SERVICES_PATH ) )

         {

             return true;

         }

         return false;

     }

     public void processResource( String resource, InputStream is, List<Relocator> relocators )

         throws IOException

     {

         ServiceStream out = serviceEntries.get( resource );

         if ( out == null )

         {

             out = new ServiceStream();

             serviceEntries.put( resource, out );

         }

         out.append( is );

         is.close();

     }

     public boolean hasTransformedResource()

     {

         return serviceEntries.size() > 0;

     }

     public void modifyOutputStream( JarOutputStream jos )

         throws IOException

     {

         for ( Map.Entry<String, ServiceStream> entry : serviceEntries.entrySet() )

         {

             String key = entry.getKey();

             ServiceStream data = entry.getValue();

             jos.putNextEntry( new JarEntry( key ) );

             IOUtil.copy( data.toInputStream(), jos );

             data.reset();

         }

     }

     static class ServiceStream

         extends ByteArrayOutputStream

     {

         public ServiceStream()

         {

             super( 1024 );

         }

         public void append( InputStream is )

             throws IOException

         {

             if ( count > 0 && buf[count - 1] != '\n' && buf[count - 1] != '\r' )

             {

                 write( '\n' );

             }

             IOUtil.copy( is, this );

         }

         public InputStream toInputStream()

         {

             return new ByteArrayInputStream( buf, 0, count );

         }

     }

 }