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.facets.param.parameter.precpol;
  
  import java.util.Optional;
  
  import org.apache.causeway.applib.annotation.Parameter;
  import org.apache.causeway.commons.internal.base._Optionals;
  import org.apache.causeway.core.config.CausewayConfiguration;
  import org.apache.causeway.core.config.metamodel.facets.ParameterConfigOptions;
  import org.apache.causeway.core.metamodel.facetapi.FacetHolder;
  import org.apache.causeway.core.metamodel.facets.SingleValueFacet;
  
  /**
   * Determines how dependent parameter values should be updated,
   * if one of the earlier parameter values is changed.
   * <p>
   * Corresponds to annotating the action method {@link Parameter#precedingParamsPolicy()}.
   *
   * @since 2.0
   */
  public interface PrecedingParametersPolicyFacet
  extends SingleValueFacet<ParameterConfigOptions.PrecedingParametersPolicy> {
  
      static Optional<PrecedingParametersPolicyFacet> create(
              final Optional<Parameter> parameterIfAny,
              final CausewayConfiguration configuration,
              final FacetHolder holder) {
  
          final ParameterConfigOptions.PrecedingParametersPolicy defaultPolicyFromConfig =
                  ParameterConfigOptions.precedingParametersPolicy(configuration);
  
          return _Optionals.orNullable(
  
          parameterIfAny
          .map(Parameter::precedingParamsPolicy)
          .<PrecedingParametersPolicyFacet>map(policy -> {
              switch (policy) {
              case PRESERVE_CHANGES:
                  return new PrecedingParametersPolicyFacetForParameterAnnotation(
                          ParameterConfigOptions.PrecedingParametersPolicy.PRESERVE_CHANGES, holder);
              case RESET:
                  return new PrecedingParametersPolicyFacetForParameterAnnotation(
                          ParameterConfigOptions.PrecedingParametersPolicy.RESET, holder);
              case NOT_SPECIFIED:
              case AS_CONFIGURED:
                  return new PrecedingParametersPolicyFacetForParameterAnnotation(defaultPolicyFromConfig, holder);
              default:
              }
              throw new IllegalStateException("precedingParametersPolicy '" + policy + "' not recognised");
          })
          ,
          () -> new PrecedingParametersPolicyFacetFromConfiguration(defaultPolicyFromConfig, holder));
      }
  }
  