/*
    * 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.commons.weaver.test;
  
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.junit.Rule;
  import org.junit.rules.TemporaryFolder;
  
  /**
   * Base class for Weaver tests.
   */
  public abstract class WeaverTestBase {
  
      @Rule
      public TemporaryFolder temporaryFolder = new TemporaryFolder();
  
      private File targetFolder;
  
      private List<String> classPathEntries;
  
      private static final String TARGET_FOLDER = "target";
  
      public void cleanup() {
          targetFolder = null;
      }
  
      /**
       * Add a class (and its inner classes) to the temporary folder.
       * 
       * @param clazz
       */
      protected void addClassForScanning(Class<?> clazz) throws IOException {
          String clazzDirName = clazz.getPackage().getName().replace(".", "/");
          File targetDirFile = new File(getTargetFolder(), clazzDirName);
          targetDirFile.mkdirs();
  
          String fileName = baseName(clazz) + ".class";
          String clazzFileName = clazzDirName + "/" + fileName;
          URL clazzUrl = getClass().getClassLoader().getResource(clazzFileName);
          File targetClazzFile = new File(targetDirFile, fileName);
  
          byte[] buffer = new byte[0xFFFF];
  
          FileOutputStream fos = new FileOutputStream(targetClazzFile);
  
          InputStream inputStream = clazzUrl.openStream();
          int len;
          while ((len = inputStream.read(buffer)) > 0) {
              fos.write(buffer, 0, len);
          }
          fos.flush();
          fos.close();
  
          for (Class<?> inner : clazz.getClasses()) {
              addClassForScanning(inner);
          }
      }
  
      private String baseName(Class<?> clazz) {
          if (clazz.getDeclaringClass() == null) {
              return clazz.getSimpleName();
          }
          final StringBuilder result = new StringBuilder();
          Class<?> current = clazz;
          while (current != null) {
              if (result.length() > 0) {
                  result.insert(0, '$');
              }
              result.insert(0, current.getSimpleName());
              current = current.getDeclaringClass();
          }
          return result.toString();
      }
  
      /**
       * Resolves the 'target' folder where the classes should get placed
      */
     protected File getTargetFolder() {
         if (targetFolder == null) {
             targetFolder = new File(temporaryFolder.getRoot(), TARGET_FOLDER);
         }
         return targetFolder;
     }
 
     protected List<String> getClassPathEntries() {
         if (classPathEntries == null) {
             classPathEntries = new ArrayList<String>(1);
             try {
                 classPathEntries.add(getTargetFolder().getCanonicalPath());
             } catch (IOException ioe) {
                 throw new RuntimeException(ioe);
             }
         }
 
         return classPathEntries;
     }
 
 }