content: // 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.cloudstack.network.contrail.management;
  
  import java.lang.reflect.Method;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.aopalliance.intercept.MethodInterceptor;
  import org.aopalliance.intercept.MethodInvocation;
  import org.apache.cloudstack.context.CallContext;
  import org.apache.cloudstack.framework.events.EventDistributor;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.springframework.beans.factory.NoSuchBeanDefinitionException;
  import org.springframework.stereotype.Component;
  
  import com.cloud.event.ActionEvent;
  import com.cloud.event.ActionEvents;
  import com.cloud.event.Event;
  import com.cloud.event.EventCategory;
  import com.cloud.event.EventTypes;
  import com.cloud.server.ManagementService;
  import com.cloud.utils.component.ComponentContext;
  import com.cloud.utils.component.ComponentMethodInterceptor;
  
  
  @Component
  public class EventUtils {
      protected static Logger LOGGER = LogManager.getLogger(EventUtils.class);
  
      private static EventDistributor eventDistributor;
  
      private static final String MODULE_TOP_LEVEL_PACKAGE =
              EventUtils.class.getPackage().getName().substring(0,
                      EventUtils.class.getPackage().getName().lastIndexOf('.'));
  
      public EventUtils() {
      }
  
      public static void setEventDistributor(EventDistributor eventDistributorImpl) {
          eventDistributor = eventDistributorImpl;
      }
  
      private static void publishOnMessageBus(String eventCategory, String eventType, String details, Event.State state) {
  
          if (state != com.cloud.event.Event.State.Completed) {
              return;
          }
  
          try {
              setEventDistributor(ComponentContext.getComponent(EventDistributor.class));
          } catch (NoSuchBeanDefinitionException nbe) {
               return; // no provider is configured to provide events bus, so just return
          }
  
          org.apache.cloudstack.framework.events.Event event =
              new org.apache.cloudstack.framework.events.Event(ManagementService.Name, eventCategory, eventType, EventTypes.getEntityForEvent(eventType), null);
  
          Map<String, String> eventDescription = new HashMap<>();
          eventDescription.put("event", eventType);
          eventDescription.put("status", state.toString());
          eventDescription.put("details", details);
          event.setDescription(eventDescription);
          eventDistributor.publish(event);
      }
  
      public static class EventInterceptor implements ComponentMethodInterceptor, MethodInterceptor {
  
      protected Logger LOGGER = LogManager.getLogger(getClass());
  
          public EventInterceptor() {
  
          }
  
          @Override
          public Object invoke(MethodInvocation invocation) throws Throwable {
              Method m = invocation.getMethod();
              Object target = invocation.getThis();
  
              if ( getActionEvents(m).size() == 0 ) {
                  /* Look for annotation on impl class */
                  m = target.getClass().getMethod(m.getName(), m.getParameterTypes());
              }
  
              Object interceptorData = null;
  
              boolean success = true;
              try {
                  interceptorData = interceptStart(m, target);
  
                  Object result = invocation.proceed();
                  success = true;
  
                  return result;
              } finally {
                  if ( success ) {
                      interceptComplete(m, target, interceptorData);
                  } else {
                      interceptException(m, target, interceptorData);
                  }
              }
          }
  
          protected List<ActionEvent> getActionEvents(Method m) {
              List<ActionEvent> result = new ArrayList<>();
  
              ActionEvents events = m.getAnnotation(ActionEvents.class);
  
              if ( events != null ) {
                  for ( ActionEvent e : events.value() ) {
                      result.add(e);
                  }
              }
  
              ActionEvent e = m.getAnnotation(ActionEvent.class);
  
              if ( e != null ) {
                  result.add(e);
              }
  
              return result;
          }
  
          @Override
          public Object interceptStart(Method method, Object target) {
              return null;
          }
  
          @Override
          public void interceptComplete(Method method, Object target, Object event) {
              ActionEvent actionEvent = method.getAnnotation(ActionEvent.class);
              boolean sameModule = false;
              if (target != null && target.getClass().getPackage() != null) {
                  sameModule = target.getClass().getPackage().getName().startsWith(MODULE_TOP_LEVEL_PACKAGE);
              }
              if (!sameModule) {
                  return;
              }
              if (actionEvent != null) {
                  CallContext ctx = CallContext.current();
                  if (!actionEvent.create()) {
                      publishOnMessageBus(EventCategory.ACTION_EVENT.getName(), actionEvent.eventType(), ctx.getEventDetails(), com.cloud.event.Event.State.Completed);
                  }
              }
          }
  
          @Override
          public void interceptException(Method method, Object target, Object event) {
              LOGGER.debug("interceptException");
          }
  
          @Override
          public boolean needToIntercept(Method method) {
              ActionEvent actionEvent = method.getAnnotation(ActionEvent.class);
              if (actionEvent != null) {
                  return true;
              }
  
              return false;
          }
      }
  }
  