/* 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.activiti.engine.impl.event;

import java.util.List;

import org.activiti.engine.ActivitiException;
import org.activiti.engine.delegate.event.impl.ActivitiEventBuilder;
import org.activiti.engine.impl.bpmn.helper.ScopeUtil;
import org.activiti.engine.impl.bpmn.parser.BpmnParse;
import org.activiti.engine.impl.interceptor.CommandContext;
import org.activiti.engine.impl.persistence.entity.CompensateEventSubscriptionEntity;
import org.activiti.engine.impl.persistence.entity.EventSubscriptionEntity;
import org.activiti.engine.impl.persistence.entity.ExecutionEntity;
import org.activiti.engine.impl.pvm.process.ActivityImpl;
import org.activiti.engine.impl.pvm.runtime.AtomicOperation;
import org.flowable.common.engine.api.delegate.event.FlowableEngineEventType;
import org.flowable.common.engine.impl.interceptor.EngineConfigurationConstants;

/**
 * @author Daniel Meyer
 */
public class CompensationEventHandler implements EventHandler {

    public static final String EVENT_HANDLER_TYPE = "compensate";

    @Override
    public String getEventHandlerType() {
        return EVENT_HANDLER_TYPE;
    }

    @Override
    public void handleEvent(EventSubscriptionEntity eventSubscription, Object payload, CommandContext commandContext) {

        String configuration = eventSubscription.getConfiguration();
        if (configuration == null) {
            throw new ActivitiException("Compensating execution not set for compensate event subscription with id " + eventSubscription.getId());
        }

        ExecutionEntity compensatingExecution = commandContext.getExecutionEntityManager()
                .findExecutionById(configuration);

        ActivityImpl compensationHandler = eventSubscription.getActivity();

        if ((compensationHandler.getProperty(BpmnParse.PROPERTYNAME_IS_FOR_COMPENSATION) == null
                || !(Boolean) compensationHandler.getProperty(BpmnParse.PROPERTYNAME_IS_FOR_COMPENSATION))
                && compensationHandler.isScope()) {

            // descend into scope:
            List<CompensateEventSubscriptionEntity> eventsForThisScope = compensatingExecution.getCompensateEventSubscriptions();
            ScopeUtil.throwCompensationEvent(eventsForThisScope, compensatingExecution, false);

        } else {
            try {

                if (commandContext.getProcessEngineConfiguration().getEventDispatcher().isEnabled()) {
                    commandContext.getProcessEngineConfiguration().getEventDispatcher().dispatchEvent(
                            ActivitiEventBuilder.createActivityEvent(FlowableEngineEventType.ACTIVITY_COMPENSATE,
                                    compensationHandler.getId(),
                                    (String) compensationHandler.getProperty("name"),
                                    compensatingExecution.getId(),
                                    compensatingExecution.getProcessInstanceId(),
                                    compensatingExecution.getProcessDefinitionId(),
                                    (String) compensatingExecution.getActivity().getProperties().get("type"),
                                    compensatingExecution.getActivity().getActivityBehavior().getClass().getCanonicalName()),
                            EngineConfigurationConstants.KEY_PROCESS_ENGINE_CONFIG);
                }
                compensatingExecution.setActivity(compensationHandler);

                // executing the atomic operation makes sure activity start events are fired
                compensatingExecution.performOperation(AtomicOperation.ACTIVITY_START);

            } catch (Exception e) {
                throw new ActivitiException("Error while handling compensation event " + eventSubscription, e);
            }

        }
    }

}
