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.interceptor;
  
  import org.activiti.engine.impl.agenda.AbstractOperation;
  import org.activiti.engine.impl.context.Context;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
  
   */
  public class CommandInvoker extends AbstractCommandInterceptor {
  
      private static final Logger logger = LoggerFactory.getLogger(CommandInvoker.class);
  
      @Override
      @SuppressWarnings("unchecked")
      public <T> T execute(final CommandConfig config, final Command<T> command) {
          final CommandContext commandContext = Context.getCommandContext();
  
          // Execute the command.
          // This will produce operations that will be put on the agenda.
          commandContext
              .getAgenda()
              .planOperation(
                  new Runnable() {
                      @Override
                      public void run() {
                          commandContext.setResult(command.execute(commandContext));
                      }
                  }
              );
  
          // Run loop for agenda
          executeOperations(commandContext);
  
          // At the end, call the execution tree change listeners.
          // TODO: optimization: only do this when the tree has actually changed (ie check dbSqlSession).
          if (commandContext.hasInvolvedExecutions()) {
              Context.getAgenda().planExecuteInactiveBehaviorsOperation();
              executeOperations(commandContext);
          }
  
          return (T) commandContext.getResult();
      }
  
      protected void executeOperations(final CommandContext commandContext) {
          while (!commandContext.getAgenda().isEmpty()) {
              Runnable runnable = commandContext.getAgenda().getNextOperation();
              executeOperation(runnable);
          }
      }
  
      public void executeOperation(Runnable runnable) {
          if (runnable instanceof AbstractOperation) {
              AbstractOperation operation = (AbstractOperation) runnable;
  
              // Execute the operation if the operation has no execution (i.e. it's an operation not working on a process instance)
              // or the operation has an execution and it is not ended
              if (operation.getExecution() == null || !operation.getExecution().isEnded()) {
                  if (logger.isDebugEnabled()) {
                      logger.debug("Executing operation {} ", operation.getClass());
                  }
  
                  runnable.run();
              }
          } else {
              runnable.run();
          }
      }
  
      @Override
      public CommandInterceptor getNext() {
          return null;
      }
  
      @Override
      public void setNext(CommandInterceptor next) {
          throw new UnsupportedOperationException("CommandInvoker must be the last interceptor in the chain");
      }
  }
  