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.causeway.core.runtimeservices.wrapper;
  
  import java.util.Collection;
  import java.util.List;
  import java.util.Optional;
  import java.util.concurrent.Callable;
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Future;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.TimeoutException;
  
  import org.springframework.transaction.annotation.Propagation;
  
  import org.apache.causeway.applib.services.iactnlayer.InteractionContext;
  import org.apache.causeway.applib.services.iactnlayer.InteractionService;
  import org.apache.causeway.applib.services.xactn.TransactionService;
  import org.apache.causeway.commons.functional.ThrowingRunnable;
  import org.apache.causeway.commons.internal.exceptions._Exceptions;
  
  /**
   * Implements {@link ExecutorService} providing an interaction and optional transaction scope for each invocation.
   */
  record AsyncExecutor(
          InteractionService interactionService,
          TransactionService transactionService,
          InteractionContext interactionContext,
          /**
           * If empty then executes non-transactionally, similar to {@link Propagation#NEVER},
           * but does NOT throw any exceptions if a transaction exists.
           */
          Optional<Propagation> propagation,
          AsyncExecutionFinisher finisher,
          ExecutorService delegate) implements ExecutorService {
  
      @Override
      public <T> Future<T> submit(final Callable<T> task) {
          return delegate.submit(()->call(task));
      }
  
      @Override
      public <T> Future<T> submit(final Runnable task, final T result) {
          return delegate.submit(()->run(task::run), result);
      }
  
      @Override
      public Future<?> submit(final Runnable task) {
          return delegate.submit(()->run(task::run));
      }
  
      @Override
      public void execute(final Runnable command) {
          delegate.execute(()->run(command::run));
      }
  
      @Override
      public <T> List<Future<T>> invokeAll(final Collection<? extends Callable<T>> tasks) throws InterruptedException {
          throw _Exceptions.unsupportedOperation(); //return delegate.invokeAll(tasks);
      }
  
      @Override
      public <T> List<Future<T>> invokeAll(final Collection<? extends Callable<T>> tasks, final long timeout, final TimeUnit unit) throws InterruptedException {
          throw _Exceptions.unsupportedOperation(); //return delegate.invokeAll(tasks, timeout, unit);
      }
  
      @Override
      public <T> T invokeAny(final Collection<? extends Callable<T>> tasks) throws InterruptedException, ExecutionException {
          throw _Exceptions.unsupportedOperation(); //return delegate.invokeAny(tasks);
      }
  
      @Override
      public <T> T invokeAny(final Collection<? extends Callable<T>> tasks, final long timeout, final TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
          throw _Exceptions.unsupportedOperation(); //return delegate.invokeAny(tasks, timeout, unit);
      }
  
      @Override
      public void shutdown() {
          delegate.shutdown();
      }
  
      @Override
      public List<Runnable> shutdownNow() {
          return delegate.shutdownNow();
      }
  
      @Override
      public boolean awaitTermination(final long timeout, final TimeUnit unit) throws InterruptedException {
          return delegate.awaitTermination(timeout, unit);
      }
  
      @Override
      public boolean isShutdown() {
          return delegate.isShutdown();
      }
  
      @Override
      public boolean isTerminated() {
          return delegate.isTerminated();
      }
  
      // -- HELPER
  
      private void run(ThrowingRunnable runnable) {
          if(propagation.isEmpty())
              interactionService.run(interactionContext, ()->finish(runnable));
          else
              interactionService.run(interactionContext, ()->transactionService
                  .runTransactional(propagation().get(), ()->finish(runnable))
                  .ifFailureFail());
      }
  
      private <T> T call(Callable<T> callable) {
          return propagation.isEmpty()
              ? interactionService.call(interactionContext, ()->finish(callable))
              : interactionService.call(interactionContext, ()->transactionService
                  .callTransactional(propagation().get(), ()->finish(callable))
                  .valueAsNullableElseFail());
      }
  
      private <T> T finish(Callable<T> callable) throws Exception {
          return finisher.finish(callable.call());
      }
  
      private void finish(ThrowingRunnable runnable) throws Exception {
          runnable.run();
          finisher.finish(null);
      }
  
  }