/*
    * Copyright 2018 SPF4J.
    *
    * Licensed 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.spf4j.test.log.junit4;
  
  import java.lang.reflect.Field;
  import java.util.List;
  import javax.annotation.Nullable;
  import javax.annotation.concurrent.ThreadSafe;
  import org.junit.runner.notification.RunListener;
  import org.junit.runner.notification.RunNotifier;
  import org.junit.runners.BlockJUnit4ClassRunner;
  import org.junit.runners.model.InitializationError;
  
  /**
   * @author Zoltan Farkas
   */
  @ThreadSafe
  public class Spf4jTestLogJUnitRunner extends BlockJUnit4ClassRunner {
  
    private static final Field LISTERES_FIELD = getListenersField();
  
    public Spf4jTestLogJUnitRunner(final Class<?> klass) throws InitializationError {
      super(klass);
    }
  
    /**
     * See JUnit doc if overwriting...
     * @param notifier
     */
    @Override
    public synchronized void run(final RunNotifier notifier) {
      if (LISTERES_FIELD != null) {
        try {
          List<RunListener> lstnrs =  (List<RunListener>) LISTERES_FIELD.get(notifier);
          for (RunListener lstnr : lstnrs) {
            if (lstnr instanceof Spf4jTestLogRunListener) {
              super.run(notifier);
              return;
            }
          }
        } catch (IllegalArgumentException | IllegalAccessException ex) {
          throw new RuntimeException(ex);
        }
      }
      Spf4jTestLogRunListenerSingleton listener = Spf4jTestLogRunListenerSingleton.getOrCreateListenerInstance();
      notifier.removeListener(listener);
      notifier.addListener(listener);
      super.run(notifier);
    }
  
    @Nullable
    private static Field getListenersField() {
      Field field;
      try {
        field = RunNotifier.class.getDeclaredField("listeners");
      } catch (NoSuchFieldException | SecurityException ex) {
        return null;
      }
      field.setAccessible(true);
      return field;
    }
  
  }