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.serializing;
  
  import java.io.Serializable;
  import java.util.Optional;
  
  import jakarta.annotation.Priority;
  import jakarta.inject.Inject;
  import jakarta.inject.Named;
  
  import org.springframework.beans.factory.annotation.Qualifier;
  import org.springframework.context.annotation.Lazy;
  import org.springframework.stereotype.Service;
  
  import org.apache.causeway.applib.annotation.PriorityPrecedence;
  import org.apache.causeway.applib.services.bookmark.Bookmark;
  import org.apache.causeway.applib.services.bookmark.BookmarkService;
  import org.apache.causeway.applib.services.bookmark.idstringifiers.PredefinedSerializables;
  import org.apache.causeway.applib.value.semantics.ValueDecomposition;
  import org.apache.causeway.applib.value.semantics.ValueSemanticsResolver;
  import org.apache.causeway.commons.internal.base._Casts;
  import org.apache.causeway.commons.internal.exceptions._Exceptions;
  import org.apache.causeway.commons.internal.memento._Mementos.SerializingAdapter;
  import org.apache.causeway.core.runtimeservices.CausewayModuleCoreRuntimeServices;
  
  import org.jspecify.annotations.NonNull;
  
  /**
   * Default implementation of {@link SerializingAdapter}, intended as an 'internal' service.
   *
   * <p>
   * @implNote uses {@link Bookmark} or {@link ValueDecomposition}
   * for identifiable objects or value types,
   * while some predefined serializable types that implement {@link Serializable}
   * are written/read directly
   * </p>
   *
   * @see PredefinedSerializables
   *
   * @since 2.0 {@index}
   */
  @Service
  @Named(CausewayModuleCoreRuntimeServices.NAMESPACE + ".SerializingAdapterDefault")
  @Priority(PriorityPrecedence.MIDPOINT)
  @Qualifier("Default")
  public class SerializingAdapterDefault implements SerializingAdapter {
  
      @Inject private BookmarkService bookmarkService;
  
      @Lazy
      @Inject private ValueSemanticsResolver valueSemanticsResolver;
  
      @Override
      public Serializable write(final @NonNull Object value) {
          if(PredefinedSerializables.isPredefinedSerializable(value.getClass())) {
              // the value can be stored/written directly without conversion to a bookmark
              return (Serializable) value;
          }
  
          // potentially is a value with value semantics
          return toValueDecomposition(value)
                  .map(Serializable.class::cast)
                  // if not fallback to bookmarkService
                  .or(()->bookmarkService.bookmarkFor(value))
                  .orElseThrow(()->
                      _Exceptions.unrecoverable("cannot create a memento for object of type %s", value.getClass()));
      }
  
      @Override
      public <T> T read(final @NonNull Class<T> valueClass, final @NonNull Serializable value) {
  
          // see if required/desired value-class is Bookmark, then just cast
          if(Bookmark.class.equals(valueClass)) {
              return _Casts.uncheckedCast(value);
          }
  
          // otherwise, perhaps the value itself is a Bookmark, in which case we treat it as a
          // reference to an Object (probably an entity) to be looked up
          if(Bookmark.class.isAssignableFrom(value.getClass())) {
              final Bookmark valueBookmark = (Bookmark) value;
              return _Casts.uncheckedCast(bookmarkService.lookup(valueBookmark)
                          .orElse(null));
          }
  
          // otherwise, perhaps the value itself is a ValueDecomposition, in which case we
          // re-compose the original value
          if(value instanceof ValueDecomposition) {
              var decomposition = (ValueDecomposition) value;
              return fromValueDecomposition(valueClass, (ValueDecomposition) value)
                      .orElseThrow(()->
                        _Exceptions.unrecoverable("cannot restore object of type %s from decomposition '%s'",
                                valueClass, decomposition.toJson()));
          }
  
          // otherwise, the value was directly stored/written, so just recover as is
          return _Casts.uncheckedCast(value);
      }
  
      // -- HELPER
  
      private <T> Optional<ValueDecomposition> toValueDecomposition(
              final @NonNull T value) {
  
          final Class<T> valueClass = _Casts.uncheckedCast(value.getClass());
  
          return valueSemanticsResolver.streamValueSemantics(valueClass)
                  .findFirst()
                  .map(vs->vs.decompose(value));
      }
  
      private <T> Optional<T> fromValueDecomposition(
              final @NonNull Class<T> valueClass,
              final @NonNull ValueDecomposition decomposition) {
  
          return valueSemanticsResolver.streamValueSemantics(valueClass)
                  .findFirst()
                  .map(vs->vs.compose(decomposition));
      }
  
  }
  