package org.apache.maven.surefire.junitcore;
   
   /*
    * 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 java.util.Iterator;
  import java.util.List;
  import java.util.concurrent.ExecutionException;
  import org.apache.maven.surefire.common.junit4.JUnit4RunListener;
  import org.apache.maven.surefire.testset.TestSetFailedException;
  import org.apache.maven.surefire.util.TestsToRun;
  
  import org.junit.runner.Computer;
  import org.junit.runner.JUnitCore;
  import org.junit.runner.Request;
  import org.junit.runner.Result;
  import org.junit.runner.Runner;
  import org.junit.runner.manipulation.Filter;
  import org.junit.runner.manipulation.NoTestsRemainException;
  import org.junit.runner.notification.RunListener;
  
  /**
   * Encapsulates access to JUnitCore
   *
   * @author Kristian Rosenvold
   */
  
  class JUnitCoreWrapper
  {
      private static class FilteringRequest
          extends Request
      {
          private Runner filteredRunner;
  
          public FilteringRequest( Request req, Filter filter )
          {
              try
              {
                  Runner runner = req.getRunner();
                  filter.apply( runner );
                  filteredRunner = runner;
              }
              catch ( NoTestsRemainException e )
              {
                  filteredRunner = null;
              }
          }
  
          @Override
          public Runner getRunner()
          {
              return filteredRunner;
          }
      }
  
      public static void execute( TestsToRun testsToRun, JUnitCoreParameters jUnitCoreParameters,
                                  List<RunListener> listeners, Filter filter )
          throws TestSetFailedException
      {
          Computer computer = getComputer( jUnitCoreParameters );
  
          JUnitCore junitCore = createJUnitCore( listeners );
  
          try
          {
              if ( testsToRun.allowEagerReading() )
              {
                  executeEager( testsToRun, filter, computer, junitCore );
              }
              else
              {
                  exeuteLazy( testsToRun, filter, computer, junitCore );
              }
          }
          finally
          {
              closeIfConfigurable( computer );
          }
      }
  
      private static JUnitCore createJUnitCore( List<RunListener> listeners )
      {
          JUnitCore junitCore = new JUnitCore();
         for ( RunListener runListener : listeners )
         {
             junitCore.addListener( runListener );
         }
         return junitCore;
     }
 
     private static void executeEager(TestsToRun testsToRun, Filter filter, Computer computer, JUnitCore junitCore)
             throws TestSetFailedException 
     {
         Class[] tests = testsToRun.getLocatedClasses();
         createReqestAndRun( filter, computer, junitCore, tests );
     }
 
     private static void exeuteLazy(TestsToRun testsToRun, Filter filter, Computer computer, JUnitCore junitCore)
             throws TestSetFailedException
     {
         // in order to support LazyTestsToRun, the iterator must be used
         Iterator<?> classIter = testsToRun.iterator();
         while ( classIter.hasNext() )
         {
             createReqestAndRun( filter, computer, junitCore, new Class[]{ (Class<?>) classIter.next() } );
         }
     }
 
     private static void createReqestAndRun( Filter filter, Computer computer, JUnitCore junitCore, Class<?>[] classesToRun )
             throws TestSetFailedException
     {
         Request req = Request.classes( computer, classesToRun );
         if ( filter != null )
         {
             req = new FilteringRequest( req, filter );
             if ( req.getRunner() == null )
             {
                 // nothing to run
                 return;
             }
         }
 
         final Result run = junitCore.run( req );
         JUnit4RunListener.rethrowAnyTestMechanismFailures( run );
     }
 
     private static void closeIfConfigurable( Computer computer )
         throws TestSetFailedException
     {
         if ( computer instanceof ConfigurableParallelComputer )
         {
             try
             {
                 ( (ConfigurableParallelComputer) computer ).close();
             }
             catch ( ExecutionException e )
             {
                 throw new TestSetFailedException( e );
             }
         }
     }
 
     private static Computer getComputer( JUnitCoreParameters jUnitCoreParameters )
         throws TestSetFailedException
     {
         if ( jUnitCoreParameters.isNoThreading() )
         {
             return new Computer();
         }
         return getConfigurableParallelComputer( jUnitCoreParameters );
     }
 
     private static Computer getConfigurableParallelComputer( JUnitCoreParameters jUnitCoreParameters )
         throws TestSetFailedException
     {
         if ( jUnitCoreParameters.isUseUnlimitedThreads() )
         {
             return new ConfigurableParallelComputer();
         }
         else
         {
             return new ConfigurableParallelComputer(
                 jUnitCoreParameters.isParallelClasses() | jUnitCoreParameters.isParallelBoth(),
                 jUnitCoreParameters.isParallelMethod() | jUnitCoreParameters.isParallelBoth(),
                 jUnitCoreParameters.getThreadCount(), jUnitCoreParameters.isPerCoreThreadCount() );
         }
     }
 
 }