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.publish;
  
  import java.util.List;
  
  import jakarta.annotation.Priority;
  import jakarta.inject.Inject;
  import jakarta.inject.Named;
  import jakarta.inject.Provider;
  
  import org.springframework.beans.factory.annotation.Qualifier;
  import org.jspecify.annotations.Nullable;
  import org.springframework.stereotype.Service;
  
  import org.apache.causeway.applib.annotation.PriorityPrecedence;
  import org.apache.causeway.applib.services.command.Command;
  import org.apache.causeway.applib.services.iactnlayer.InteractionLayerTracker;
  import org.apache.causeway.applib.services.publishing.spi.CommandSubscriber;
  import org.apache.causeway.commons.collections.Can;
  import org.apache.causeway.commons.having.HasEnabling;
  import org.apache.causeway.core.metamodel.services.publishing.CommandPublisher;
  import org.apache.causeway.core.runtimeservices.CausewayModuleCoreRuntimeServices;
  
  import org.jspecify.annotations.NonNull;
  import lombok.extern.log4j.Log4j2;
  
  /**
   * Default implementation of {@link CommandPublisher}.
   *
   * @since 2.0 {@index}
   */
  @Service
  @Named(CausewayModuleCoreRuntimeServices.NAMESPACE + ".CommandPublisherDefault")
  @Priority(PriorityPrecedence.MIDPOINT)
  @Qualifier("Default")
  @Log4j2
  public class CommandPublisherDefault implements CommandPublisher {
  
      final List<CommandSubscriber> subscribers;
      final Provider<InteractionLayerTracker> interactionServiceProvider;
  
      final Can<CommandSubscriber> enabledSubscribers;
  
      @Inject
      public CommandPublisherDefault(
              final List<CommandSubscriber> subscribers,
              final Provider<InteractionLayerTracker> interactionServiceProvider) {
          this.subscribers = subscribers;
          this.interactionServiceProvider = interactionServiceProvider;
  
          enabledSubscribers = Can.ofCollection(subscribers)
                  .filter(HasEnabling::isEnabled);
      }
  
      @Override
      public void ready(final @NonNull Command command) {
  
          var handle = _Xray.enterCommandReadyPublishing(
                  interactionServiceProvider.get(),
                  command,
                  enabledSubscribers,
                  ()->getCannotPublishReason(command));
  
          if(canPublish(command) && command.getPublishingPhase().isReady()) {
              log.debug("about to PUBLISH command {}: {} to {}", "ready", command, enabledSubscribers);
              enabledSubscribers.forEach(subscriber -> subscriber.onReady(command));
          }
  
          _Xray.exitPublishing(handle);
      }
  
      @Override
      public void start(final @NonNull Command command) {
  
          var handle = _Xray.enterCommandStartedPublishing(
                  interactionServiceProvider.get(),
                  command,
                  enabledSubscribers,
                  ()->getCannotPublishReason(command));
  
          if(canPublish(command) && command.getPublishingPhase().isStarted()) {
              log.debug("about to PUBLISH command {}: {} to {}", "started", command, enabledSubscribers);
              enabledSubscribers.forEach(subscriber -> subscriber.onStarted(command));
          }
  
          _Xray.exitPublishing(handle);
      }
  
      @Override
      public void complete(final @NonNull Command command) {
  
          var handle = _Xray.enterCommandCompletedPublishing(
                  interactionServiceProvider.get(),
                  command,
                  enabledSubscribers,
                  ()->getCannotPublishReason(command));
  
          if(canPublish(command) && command.getPublishingPhase().isCompleted()) {
              log.debug("about to PUBLISH command {}: {} to {}", "completed", command, enabledSubscribers);
              enabledSubscribers.forEach(subscriber -> subscriber.onCompleted(command));
          }
  
          _Xray.exitPublishing(handle);
      }
  
      // -- HELPER
  
      private boolean canPublish(final Command command) {
          return enabledSubscribers.isNotEmpty()
                  && command.getLogicalMemberIdentifier() != null; // eg null when seed fixtures
      }
  
      // x-ray support
      private @Nullable String getCannotPublishReason(final @NonNull Command command) {
          return enabledSubscribers.isEmpty()
                  ? "no subscribers"
                  : !command.getPublishingPhase().isReady()
                          ? String.format(
                                  "publishing not enabled for given command\n%s",
                                  _Xray.toText(command))
                          : command.getLogicalMemberIdentifier() == null
                                  ? String.format(
                                          "no logical-member-id for given command\n%s",
                                          _Xray.toText(command))
                                  : null;
      }
  
  }
  
  