/*
    * 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.IOException;
  import java.io.InputStream;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Properties;
  import java.util.jar.JarEntry;
  import java.util.jar.JarOutputStream;
  
  import org.apache.maven.plugins.shade.relocation.Relocator;
  
  /**
   * Aggregate Apache Groovy extension modules descriptors
   */
  public class GroovyResourceTransformer extends AbstractCompatibilityTransformer {
  
      static final String EXT_MODULE_NAME_LEGACY = "META-INF/services/org.codehaus.groovy.runtime.ExtensionModule";
  
      // Since Groovy 2.5.x/Java 9 META-INF/services may only be used by Service Providers
      static final String EXT_MODULE_NAME = "META-INF/groovy/org.codehaus.groovy.runtime.ExtensionModule";
  
      private List<String> extensionClassesList = new ArrayList<>();
  
      private List<String> staticExtensionClassesList = new ArrayList<>();
  
      private String extModuleName = "no-module-name";
  
      private String extModuleVersion = "1.0";
  
      private long time = Long.MIN_VALUE;
  
      @Override
      public boolean canTransformResource(String resource) {
          return EXT_MODULE_NAME.equals(resource) || EXT_MODULE_NAME_LEGACY.equals(resource);
      }
  
      @Override
      public void processResource(String resource, InputStream is, List<Relocator> relocators, long time)
              throws IOException {
          Properties out = new Properties();
          try (InputStream props = is) {
              out.load(props);
          }
          String extensionClasses = out.getProperty("extensionClasses", "").trim();
          if (extensionClasses.length() > 0) {
              append(extensionClasses, extensionClassesList);
          }
          String staticExtensionClasses =
                  out.getProperty("staticExtensionClasses", "").trim();
          if (staticExtensionClasses.length() > 0) {
              append(staticExtensionClasses, staticExtensionClassesList);
          }
          if (time > this.time) {
              this.time = time;
          }
      }
  
      private void append(String entry, List<String> list) {
          if (entry != null) {
              Collections.addAll(list, entry.split("\\s*,\\s*"));
          }
      }
  
      @Override
      public boolean hasTransformedResource() {
          return extensionClassesList.size() > 0 && staticExtensionClassesList.size() > 0;
      }
  
      @Override
      public void modifyOutputStream(JarOutputStream os) throws IOException {
          if (hasTransformedResource()) {
              JarEntry jarEntry = new JarEntry(EXT_MODULE_NAME);
              jarEntry.setTime(time);
              os.putNextEntry(jarEntry);
  
              Properties desc = new Properties();
              desc.put("moduleName", extModuleName);
             desc.put("moduleVersion", extModuleVersion);
             if (extensionClassesList.size() > 0) {
                 desc.put("extensionClasses", join(extensionClassesList));
             }
             if (staticExtensionClassesList.size() > 0) {
                 desc.put("staticExtensionClasses", join(staticExtensionClassesList));
             }
             desc.store(os, null);
         }
     }
 
     private String join(Collection<String> strings) {
         Iterator<String> it = strings.iterator();
         switch (strings.size()) {
             case 0:
                 return "";
             case 1:
                 return it.next();
             default:
                 StringBuilder buff = new StringBuilder(it.next());
                 while (it.hasNext()) {
                     buff.append(",").append(it.next());
                 }
                 return buff.toString();
         }
     }
 
     public void setExtModuleName(String extModuleName) {
         this.extModuleName = extModuleName;
     }
 
     public void setExtModuleVersion(String extModuleVersion) {
         this.extModuleVersion = extModuleVersion;
     }
 }