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.metamodel.facets;
  
  import java.util.function.BiConsumer;
  
  import org.apache.causeway.applib.events.domain.AbstractDomainEvent;
  import org.apache.causeway.commons.internal.assertions._Assert;
  import org.apache.causeway.core.metamodel.facetapi.Facet;
  import org.apache.causeway.core.metamodel.facetapi.FacetAbstract;
  import org.apache.causeway.core.metamodel.facetapi.FacetHolder;
  import org.apache.causeway.core.metamodel.object.MmEventUtils;
  import org.apache.causeway.core.metamodel.spec.ObjectSpecification;
  
  import org.jspecify.annotations.NonNull;
  
  /**
   * Base for any event-type holding facets,
   * while defining the facet-type is up to implementors.
   */
  public abstract class DomainEventFacetAbstract<T extends AbstractDomainEvent<?>>
  extends FacetAbstract
  implements DomainEventHolder<T> {
  
      public static enum EventTypeOrigin {
          /** {@link #getEventType} originates from configured defaults */
          DEFAULT,
          /** {@link #getEventType} originates from domain object annotation */
          ANNOTATED_OBJECT,
          /** {@link #getEventType} originates from member annotation */
          ANNOTATED_MEMBER;
          public boolean isDefault() { return this==DEFAULT; }
          public boolean isAnnotatedObject() { return this==ANNOTATED_OBJECT; }
          public boolean isAnnotatedMember() { return this==ANNOTATED_MEMBER; }
      }
  
      private DomainEventHolder<T> domainEventHolder;
      private final boolean isUpdateEventTypeAllowed;
  
      /**  using delegated event type holder, updateEventType not allowed */
      protected DomainEventFacetAbstract(
              final Class<? extends Facet> facetType,
              final DomainEventHolder<T> domainEventHolder,
              final FacetHolder holder) {
          super(facetType, holder);
          this.isUpdateEventTypeAllowed = false;
          this.domainEventHolder = domainEventHolder;
      }
  
      /** using eager event type, updateEventType allowed */
      protected DomainEventFacetAbstract(
              final Class<? extends Facet> facetType,
              final Class<? extends T> eventType,
              final EventTypeOrigin eventTypeOrigin,
              final FacetHolder holder) {
          super(facetType, holder);
          this.isUpdateEventTypeAllowed = true;
          updateEventType(eventType, eventTypeOrigin);
      }
  
      @Override
      public final Class<? extends T> getEventType() {
          return domainEventHolder.getEventType();
      }
  
      @Override
      public final EventTypeOrigin getEventTypeOrigin() {
          return domainEventHolder.getEventTypeOrigin();
      }
  
      @Override
      public final boolean isPostable() {
          return domainEventHolder.isPostable();
      }
  
      /** called during meta-model post-processing only */
      protected final void updateEventType(
              final Class<? extends T> eventType,
              final EventTypeOrigin eventTypeOrigin) {
          _Assert.assertTrue(isUpdateEventTypeAllowed, ()->
              "framework bug: this DomainEventHolder is bound to another DomainEventHolder,"
              + "the binding is immutable and cannot be changed");
          this.domainEventHolder = DomainEventHolder.eager(eventType, eventTypeOrigin, isPostable(eventType));
      }
  
      /**
       * Called by meta-model post-processors, to honor domain object annotations on mixees.
       * (required only, if this facet belongs to a mixed-in member)
       */
      public void initWithMixee(final ObjectSpecification mixeeSpec) {}
  
      /**
       * Whether given {@code eventType} is post-able.
       * <ul>
       * <li>If the Noop event-type is assignable from {@code eventType} then NO.</li>
       * <li>If {@code eventType} is the Default event-type and its configured to act as Noop then NO.</li>
       * <li>Otherwise YES.</li>
       * </ul>
       */
      protected final boolean isPostable(final Class<? extends T> eventType) {
          return MmEventUtils.isDomainEventPostable(getConfiguration(), eventType);
      }
  
      @Override
      public void visitAttributes(final BiConsumer<String, Object> visitor) {
          super.visitAttributes(visitor);
          if(DomainEventHolder.isEmpty(domainEventHolder)) {
              visitor.accept("eventType", "None "
                      + "(No execution related domain events for mixed-in prop/coll.)");
              visitor.accept("eventTypeOrigin", "NONE");
          } else {
              visitor.accept("eventType", getEventType());
              visitor.accept("eventTypeOrigin", getEventTypeOrigin().name());
          }
          visitor.accept("isPostable", isPostable());
      }
  
      @Override
      public boolean semanticEquals(final @NonNull Facet other) {
          return other instanceof DomainEventFacetAbstract
                  ? this.getEventType() == ((DomainEventFacetAbstract<?>)other).getEventType()
                  : false;
      }
  
  }
  