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.viewer.wicket.model.models;
  
  import java.io.Serializable;
  import org.apache.wicket.model.IModel;
  import org.jspecify.annotations.NonNull;
  
  import org.apache.causeway.commons.internal.assertions._Assert;
  import org.apache.causeway.commons.internal.ref.TransientObjectRef;
  import org.apache.causeway.core.metamodel.context.HasMetaModelContext;
  import org.apache.causeway.core.metamodel.facets.object.value.CompositeValueUpdater;
  import org.apache.causeway.core.metamodel.object.ManagedObject;
  import org.apache.causeway.core.metamodel.objectmanager.memento.ObjectMemento;
  import org.apache.causeway.core.metamodel.spec.ObjectSpecification;
  import org.apache.causeway.core.metamodel.spec.feature.ObjectMember;
  
  /**
   * Represents a standalone value (used for standalone value page).
   */
  public record ValueModel(
          /**
           * The originating {@link ObjectMember} this {@link ValueModel} is provided by.
           */
          ObjectMember objectMember,
          ObjectMemento objectMemento,
          TransientObjectRef<ManagedObject> managedObjectRef)
  implements IModel<ManagedObject>, HasMetaModelContext {
  
      public ValueModel(@NonNull final ActionModel actionModel, final ManagedObject managedObject) {
          this(actionModel.getAction(), managedObject);
      }
  
      public ValueModel(
              final @NonNull ObjectMember objectMember,
              final @NonNull ManagedObject managedObject) {
          this(objectMember,
              managedObject.getMemento().orElseThrow(),
              new TransientObjectRef<>(managedObject));
      }
  
      // canonical constructor
      public ValueModel(
              final ObjectMember objectMember,
              final ObjectMemento objectMemento,
              final TransientObjectRef<ManagedObject> managedObjectRef) {
          this.objectMember = objectMember instanceof CompositeValueUpdater compositeValueUpdater
              ? compositeValueUpdater.mixedInAction()
              : objectMember;
          this.objectMemento = objectMemento;
          this.managedObjectRef = managedObjectRef;
  
          _Assert.assertTrue(this.objectMember instanceof Serializable);
      }
  
      @Override
      public ManagedObject getObject() {
          return managedObjectRef.computeIfAbsent(()->getObjectManager().demementify(objectMemento));
      }
  
      public ObjectSpecification elementType() {
          return getObject().objSpec();
      }
  
  }
  