// Copyright (C) 2011 Philip Aston
   // All rights reserved.
   //
   // This file is part of The Grinder software distribution. Refer to
   // the file LICENSE which is part of The Grinder distribution for
   // licensing details. The Grinder distribution is available on the
   // Internet at http://grinder.sourceforge.net/
   //
   // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  // FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  // COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  // (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  // HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  // OF THE POSSIBILITY OF SUCH DAMAGE.
  
  package net.grinder.testutility;
  
  import static java.util.Arrays.asList;
  
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  import net.grinder.util.BlockingClassLoader;
  
  import org.junit.runner.Description;
  import org.junit.runner.Runner;
  import org.junit.runner.notification.RunNotifier;
  import org.junit.runners.BlockJUnit4ClassRunner;
  import org.junit.runners.Suite;
  import org.junit.runners.model.FrameworkMethod;
  import org.junit.runners.model.InitializationError;
  
  
  /**
   * A JUnit test class runner that sets up the context for different Jython
   * installations.
   *
   * @author Philip Aston
   */
  public abstract class JythonVersionRunner extends Suite {
  
    protected static List<String> getHomes(String... homesProperties) {
      final List<String> homes = new ArrayList<String>();
  
      for (String property : homesProperties) {
        final String pythonHome = System.getProperty(property);
  
        if (pythonHome == null) {
          System.err.println("***** " + property +
                             " not set, skipping tests for Jython version.");
        }
        else {
          homes.add(pythonHome);
        }
      }
  
      return homes;
    }
  
    private static final Set<String> ISOLATED_CLASSES =
      new HashSet<String>(asList("net.grinder.*",
                                 "org.python.*",
                                 "grinder.test.*",
                                 "org.mockito.*"));
  
    private static final Set<String> SHARED_CLASSES =
      new HashSet<String>(asList("net.grinder.util.weave.agent.*"));
  
    public JythonVersionRunner(Class<?> testClass,
                               List<String> pythonHomes)
      throws ClassNotFoundException, InitializationError, MalformedURLException{
  
      super(testClass, createRunners(testClass, pythonHomes));
    }
  
    private static List<Runner> createRunners(Class<?> testClass,
                                              List<String> pythonHomes)
     throws ClassNotFoundException, InitializationError, MalformedURLException {
  
      final List<Runner> runners = new ArrayList<Runner>();
  
      for (String pythonHome : pythonHomes) {
        final URL jythonJarURL =
          new URL("file://" + pythonHome + "/jython.jar");
  
        final ClassLoader loader =
          new BlockingClassLoader(Arrays.asList(jythonJarURL),
                                 Collections.<String>emptySet(),
                                 ISOLATED_CLASSES,
                                 SHARED_CLASSES,
                                 true);
 
       final Class<?> isolatedClass = loader.loadClass(testClass.getName());
 
       runners.add(new PythonHomeRunner(isolatedClass, pythonHome));
     }
 
     if (runners.size() == 0) {
       throw new InitializationError("No python home properties set");
     }
 
     return runners;
   }
 
   private static class PythonHomeRunner extends BlockJUnit4ClassRunner {
 
     private final String m_pythonHome;
 
     public PythonHomeRunner(Class<?> klass, String pythonHome)
       throws InitializationError {
       super(klass);
 
       m_pythonHome = pythonHome;
     }
 
     @Override public Description getDescription() {
       final Class<?> javaClass = getTestClass().getJavaClass();
 
       final Description result =
         Description.createSuiteDescription(
           javaClass.getSimpleName() + " [" + m_pythonHome + "]",
           javaClass.getAnnotations());
 
       for (Description child : super.getDescription().getChildren()) {
         result.addChild(child);
       }
 
       return result;
     }
 
     @Override protected String testName(FrameworkMethod method) {
       return super.testName(method) + " [" + m_pythonHome + "]";
     }
 
     @Override protected void runChild(FrameworkMethod method,
                                       RunNotifier notifier) {
       final String oldPythonHome = System.getProperty("python.home");
 
       System.setProperty("python.home", m_pythonHome);
 
       try {
         super.runChild(method, notifier);
       }
       finally {
         if (oldPythonHome != null) {
           System.setProperty("python.home", oldPythonHome);
         }
         else {
           System.clearProperty("python.home");
         }
       }
     }
   }
 }