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.interactions.managed;
  
  import java.util.Optional;
  
  import org.jspecify.annotations.Nullable;
  
  import org.apache.causeway.applib.Identifier;
  import org.apache.causeway.applib.annotation.Where;
  import org.apache.causeway.commons.binding.Observable;
  import org.apache.causeway.commons.collections.Can;
  import org.apache.causeway.commons.internal.binding._Observables;
  import org.apache.causeway.commons.internal.binding._Observables.LazyObservable;
  import org.apache.causeway.core.metamodel.consent.InteractionInitiatedBy;
  import org.apache.causeway.core.metamodel.consent.Veto;
  import org.apache.causeway.core.metamodel.object.ManagedObject;
  import org.apache.causeway.core.metamodel.spec.feature.ObjectAction;
  import org.apache.causeway.core.metamodel.spec.feature.OneToOneAssociation;
  
  import lombok.Getter;
  import org.jspecify.annotations.NonNull;
  import lombok.extern.log4j.Log4j2;
  
  @Log4j2
  public final class ManagedProperty
  extends ManagedMember {
  
      // -- FACTORIES
  
      public static final ManagedProperty of(
              final @NonNull ManagedObject owner,
              final @NonNull OneToOneAssociation property,
              final @NonNull Where where) {
          return new ManagedProperty(owner, property, where);
      }
  
      public static final Optional<ManagedProperty> lookupProperty(
              final @NonNull ManagedObject owner,
              final @NonNull String memberId,
              final @NonNull Where where) {
  
          return ManagedMember.<OneToOneAssociation>lookup(owner.objSpec(), Identifier.Type.PROPERTY, memberId)
              .map(objectAction -> of(owner, objectAction, where));
      }
  
      // -- IMPLEMENTATION
  
      @Getter private final OneToOneAssociation property;
  
      //XXX suggestion: instead of holding the 'owner' object, let it hold a supplier of the 'owner' object,
      //such that the supplier always returns the actual owner evaluated lazily without memoization.
      //Such a change would better support eg.
      //org.apache.causeway.viewer.wicket.model.models.ScalarPropertyModel.getManagedProperty()
      //Or as an alternative use a memento instead of the ManagedObject.
      private ManagedProperty(
              final @NonNull ManagedObject owner,
              final @NonNull OneToOneAssociation property,
              final @NonNull Where where) {
          super(owner, where);
          this.property = property;
          observablePropValue = _Observables.lazy(this::reassessPropertyValue);
      }
  
      @Override
      public OneToOneAssociation getMetaModel() {
          return getProperty();
      }
  
      @Override
      public Identifier.Type getMemberType() {
          return Identifier.Type.PROPERTY;
      }
  
      public Can<ObjectAction> getAssociatedActions() {
          return Can.ofStream(ObjectAction.Util.findForAssociation(getOwner(), getProperty()));
      }
  
      // -- INTERACTION
  
      public Optional<InteractionVeto> checkValidity(final ManagedObject proposedNewValue) {
          try {
              var validityConsent =
                      property.isAssociationValid(getOwner(), proposedNewValue, InteractionInitiatedBy.USER);
  
              return validityConsent.isVetoed()
                      ? Optional.of(InteractionVeto.invalid(validityConsent))
                      : Optional.empty();
  
          } catch (final Exception ex) {
  
              log.warn(ex.getLocalizedMessage(), ex);
              return Optional.of(InteractionVeto.invalid(new Veto("failure during validity evaluation")));
  
          }
      }
  
      /**
       * @param newValue
       * @return non-empty if the interaction is not valid for given {@code proposedNewValue}
       */
      public Optional<InteractionVeto> modifyProperty(final @Nullable ManagedObject newValue) {
          var interactionVeto = checkValidity(newValue);
          if(interactionVeto.isPresent()) return interactionVeto;
  
          var updatedOwner = property.set(getOwner(), newValue, InteractionInitiatedBy.USER);
          setOwner(updatedOwner);
          observablePropValue.invalidate();
          return Optional.empty();
      }
  
      /**
       * If visibility is vetoed, returns an empty but specified ManagedObject.
       * @return the property value as to be used by the UI for representation
       */
      private ManagedObject reassessPropertyValue() {
          var property = getProperty();
          var owner = getOwner();
  
          return property.isVisible(owner, InteractionInitiatedBy.FRAMEWORK, getWhere()).isAllowed()
                  && property.isVisible(owner, InteractionInitiatedBy.USER, getWhere()).isAllowed()
              ? property.get(owner, InteractionInitiatedBy.USER)
              : ManagedObject.empty(property.getElementType());
      }
  
      // -- NEGOTIATION
  
      public PropertyNegotiationModel startNegotiation() {
          return new PropertyNegotiationModel(this);
      }
  
      // -- BINDING
  
      @NonNull private final LazyObservable<ManagedObject> observablePropValue;
  
      public Observable<ManagedObject> getValue() {
          return observablePropValue;
      }
  
      public ManagedObject getPropertyValue() {
          return getValue().getValue();
      }
  
  }
  