/*
    * 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.
   */
  package org.apache.maven.plugins.shade.resource;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.List;
  import java.util.jar.JarEntry;
  import java.util.jar.JarOutputStream;
  
  import org.apache.maven.plugins.shade.relocation.Relocator;
  import org.codehaus.plexus.util.IOUtil;
  
  /**
   * A resource processor that appends content for a resource, separated by a newline.
   */
  public class AppendingTransformer extends AbstractCompatibilityTransformer {
      String resource;
  
      ByteArrayOutputStream data = new ByteArrayOutputStream();
  
      private long time = Long.MIN_VALUE;
  
      @Override
      public boolean canTransformResource(String r) {
          return resource != null && resource.equalsIgnoreCase(r);
      }
  
      @Override
      public void processResource(String resource, InputStream is, List<Relocator> relocators, long time)
              throws IOException {
          IOUtil.copy(is, data);
          data.write('\n');
          if (time > this.time) {
              this.time = time;
          }
      }
  
      @Override
      public boolean hasTransformedResource() {
          return data.size() > 0;
      }
  
      @Override
      public void modifyOutputStream(JarOutputStream jos) throws IOException {
          JarEntry jarEntry = new JarEntry(resource);
          jarEntry.setTime(time);
          jos.putNextEntry(jarEntry);
  
          jos.write(data.toByteArray());
          data.reset();
      }
  }