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.object;
  
  import java.util.ArrayList;
  import java.util.Optional;
  import java.util.stream.Collectors;
  
  import org.jspecify.annotations.NonNull;
  import org.jspecify.annotations.Nullable;
  
  import org.apache.causeway.commons.collections.Can;
  import org.apache.causeway.commons.internal.assertions._Assert;
  import org.apache.causeway.core.metamodel.objectmanager.memento.ObjectMemento;
  import org.apache.causeway.core.metamodel.spec.ObjectSpecification;
  
  /**
   * 'Collection' of {@link ManagedObject}s.
   * @see ManagedObject.Specialization#PACKED
   */
  public record PackedManagedObject(
      /** element spec */
      @NonNull ObjectSpecification objSpec,
      @NonNull Can<ManagedObject> nonScalar)
  implements
      ManagedObject, Bookmarkable.NoBookmark {
  
      public PackedManagedObject(
              final ObjectSpecification objSpec,
              final @Nullable Can<ManagedObject> nonScalar) {
          this.objSpec = objSpec;
          this.nonScalar = nonScalar!=null
                  ? nonScalar
                  : Can.empty();
          _Assert.assertTrue(objSpec().isSingular(), "a PackedManagedObject cannot containt non-scalars");
      }
  
      @Override
      public String getTitle() {
          return nonScalar.stream()
                      .map(ManagedObject::getTitle)
                      .collect(Collectors.joining(","));
      }
  
      @Override
      public Object getPojo() {
          // this algorithm preserves null pojos ...
          return nonScalar.stream()
                  .map(ManagedObject::getPojo)
                  .toList();
      }
  
      @Override
      public Optional<ObjectMemento> getMemento() {
          var listOfMementos = nonScalar.stream()
              .map(scalar->scalar.getMementoElseFail())
              .collect(Collectors.toCollection(ArrayList::new)); // ArrayList is serializable
          var memento = ObjectMemento.packed(
              logicalType(),
              listOfMementos);
          return Optional.of(memento);
      }
  
      public Can<ManagedObject> unpack(){
          return nonScalar;
      }
  
      @Override
      public Specialization specialization() {
          return Specialization.PACKED;
      }
  
  }
  