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.graphql.model.types;
  
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import jakarta.inject.Inject;
  
  import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
  import org.springframework.context.annotation.Bean;
  import org.springframework.context.annotation.Configuration;
  import org.springframework.stereotype.Component;
  
  import org.apache.causeway.viewer.graphql.applib.marshallers.ScalarMarshaller;
  
  import graphql.schema.GraphQLScalarType;
  import lombok.RequiredArgsConstructor;
  
  /**
   * Internal (default) implementation of {@link ScalarMapper} that implements the chain-of-responsibility
   * pattern over an injected list of all known {@link ScalarMarshaller} components.
   */
  @Component
  @RequiredArgsConstructor(onConstructor_ = {@Inject})
  public class ScalarMapperUsingScalarMarshallers implements ScalarMapper {
  
      @Configuration
      public static class AutoConfiguration {
  
          @Bean
          @ConditionalOnMissingBean(ScalarMapperUsingScalarMarshallers.class)
          public ScalarMapper defaultScalarMapper(final List<ScalarMarshaller<?>> scalarMarshallers) {
              return new ScalarMapperUsingScalarMarshallers(scalarMarshallers);
          }
      }
  
      private final List<ScalarMarshaller<?>> scalarMarshallers;
  
      /**
       * Lazily populated cache
       */
      final Map<Class<?>, ScalarMarshaller<?>> scalarMarshallerByClass = new HashMap<>();
  
      @Override
      public GraphQLScalarType scalarTypeFor(final Class<?> clazz){
          return scalarMarshallerFor(clazz).getGqlScalarType();
      }
  
      @Override
      public Object unmarshal(
              final Object argumentValue,
              final Class<?> targetType) {
  
          ScalarMarshaller<?> scalarMarshaller = scalarMarshallerFor(targetType);
          return scalarMarshaller.unmarshal(argumentValue, targetType);
      }
  
      private ScalarMarshaller<?> scalarMarshallerFor(Class<?> c) {
          return scalarMarshallerByClass.computeIfAbsent(c, cls -> {
              for (ScalarMarshaller<?> scalarMarshaller : scalarMarshallers) {
                  if (scalarMarshaller.handles(cls)) {
                      return scalarMarshaller;
                  }
              }
              // should never happen because we have ScalarMarshallerObject to act as a fallback.
              throw new IllegalArgumentException("Could not locate a ScalarMarshaller to handle class " + c);
          });
      }
  
  }
  