content: /*
   * Copyright 2010-2025 Hyland Software, Inc. and its affiliates.
   *
   * 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.bpmn.behavior;
  
  import org.activiti.bpmn.model.Activity;
  import org.activiti.bpmn.model.SubProcess;
  import org.activiti.engine.ActivitiException;
  import org.activiti.engine.ActivitiIllegalArgumentException;
  import org.activiti.engine.delegate.BpmnError;
  import org.activiti.engine.delegate.DelegateExecution;
  import org.activiti.engine.impl.context.Context;
  import org.activiti.engine.impl.delegate.ActivityBehavior;
  import org.activiti.engine.impl.persistence.entity.ExecutionEntity;
  import org.activiti.engine.impl.persistence.entity.ExecutionEntityManager;
  
  public class SequentialMultiInstanceBehavior extends MultiInstanceActivityBehavior {
  
      private static final long serialVersionUID = 1L;
  
      public SequentialMultiInstanceBehavior(Activity activity, AbstractBpmnActivityBehavior innerActivityBehavior) {
          super(activity, innerActivityBehavior);
      }
  
      /**
       * Handles the sequential case of spawning the instances. Will only create one instance, since at most one instance can be active.
       */
      protected int createInstances(DelegateExecution multiInstanceExecution) {
          int nrOfInstances = resolveNrOfInstances(multiInstanceExecution);
          if (nrOfInstances == 0) {
              return nrOfInstances;
          } else if (nrOfInstances < 0) {
              throw new ActivitiIllegalArgumentException(
                  "Invalid number of instances: must be a non-negative integer value" + ", but was " + nrOfInstances
              );
          }
  
          // Create child execution that will execute the inner behavior
          ExecutionEntity childExecution = Context.getCommandContext()
              .getExecutionEntityManager()
              .createChildExecution((ExecutionEntity) multiInstanceExecution);
          childExecution.setCurrentFlowElement(multiInstanceExecution.getCurrentFlowElement());
          multiInstanceExecution.setMultiInstanceRoot(true);
          multiInstanceExecution.setActive(false);
  
          // Set Multi-instance variables
          setLoopVariable(multiInstanceExecution, NUMBER_OF_INSTANCES, nrOfInstances);
          setLoopVariable(multiInstanceExecution, NUMBER_OF_COMPLETED_INSTANCES, 0);
          setLoopVariable(multiInstanceExecution, NUMBER_OF_ACTIVE_INSTANCES, 1);
          setLoopVariable(childExecution, getCollectionElementIndexVariable(), 0);
          logLoopDetails(multiInstanceExecution, "initialized", 0, 0, 1, nrOfInstances);
  
          executeOriginalBehavior(childExecution, 0);
          return nrOfInstances;
      }
  
      /**
       * Called when the wrapped {@link ActivityBehavior} calls the {@link AbstractBpmnActivityBehavior#leave(DelegateExecution)} method. Handles the completion of one instance, and executes the logic for
       * the sequential behavior.
       */
      public void leave(DelegateExecution childExecution) {
          DelegateExecution multiInstanceRootExecution = getMultiInstanceRootExecution(childExecution);
          int nrOfInstances = getLoopVariable(multiInstanceRootExecution, NUMBER_OF_INSTANCES);
          int loopCounter = getLoopVariable(childExecution, getCollectionElementIndexVariable()) + 1;
          int nrOfCompletedInstances = getLoopVariable(multiInstanceRootExecution, NUMBER_OF_COMPLETED_INSTANCES) + 1;
          int nrOfActiveInstances = getLoopVariable(multiInstanceRootExecution, NUMBER_OF_ACTIVE_INSTANCES);
  
          setLoopVariable(multiInstanceRootExecution, NUMBER_OF_COMPLETED_INSTANCES, nrOfCompletedInstances);
          setLoopVariable(childExecution, getCollectionElementIndexVariable(), loopCounter);
          logLoopDetails(
              childExecution,
              "instance completed",
              loopCounter,
              nrOfCompletedInstances,
              nrOfActiveInstances,
              nrOfInstances
          );
  
          updateResultCollection(childExecution, multiInstanceRootExecution);
  
          Context.getCommandContext().getHistoryManager().recordActivityEnd((ExecutionEntity) childExecution, null);
          callActivityEndListeners(childExecution);
  
          if (loopCounter >= nrOfInstances || completionConditionSatisfied(multiInstanceRootExecution)) {
              propagateLoopDataOutputRefToProcessInstance((ExecutionEntity) multiInstanceRootExecution);
              removeLocalLoopVariable(childExecution, getCollectionElementIndexVariable());
              multiInstanceRootExecution.setMultiInstanceRoot(false);
              multiInstanceRootExecution.setScope(false);
              multiInstanceRootExecution.setCurrentFlowElement(childExecution.getCurrentFlowElement());
              Context.getCommandContext()
                  .getExecutionEntityManager()
                  .deleteChildExecutions((ExecutionEntity) multiInstanceRootExecution, "MI_END");
              dispatchActivityCompletedEvent(childExecution);
              super.leave(multiInstanceRootExecution);
          } else {
              try {
                  if (childExecution.getCurrentFlowElement() instanceof SubProcess) {
                      ExecutionEntityManager executionEntityManager =
                          Context.getCommandContext().getExecutionEntityManager();
                      ExecutionEntity executionToContinue = executionEntityManager.createChildExecution(
                          (ExecutionEntity) multiInstanceRootExecution
                      );
                      executionToContinue.setCurrentFlowElement(childExecution.getCurrentFlowElement());
                      executionToContinue.setScope(true);
                      setLoopVariable(executionToContinue, getCollectionElementIndexVariable(), loopCounter);
                      executeOriginalBehavior(executionToContinue, loopCounter);
                  } else {
                      executeOriginalBehavior(childExecution, loopCounter);
                  }
                  dispatchActivityCompletedEvent(childExecution);
              } catch (BpmnError error) {
                  // re-throw business fault so that it can be caught by an Error
                  // Intermediate Event or Error Event Sub-Process in the process
                  throw error;
              } catch (Exception e) {
                  throw new ActivitiException("Could not execute inner activity behavior of multi instance behavior", e);
              }
          }
      }
  }
  