/*
 *  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.defaults;

import org.apache.causeway.commons.collections.Can;
import org.apache.causeway.core.metamodel.facetapi.Facet;
import org.apache.causeway.core.metamodel.interactions.managed.ParameterNegotiationModel;
import org.apache.causeway.core.metamodel.object.ManagedObject;
import org.apache.causeway.core.metamodel.spec.feature.ObjectActionParameter;

import lombok.NonNull;

/**
 * Obtain defaults for each of the parameters of the action.
 *
 * <p>
 * In the standard Apache Causeway Programming Model, corresponds to invoking the
 * <tt>defaultsNXxx(...)</tt> support method for an action (where N is the
 * 0-based parameter number).
 */
public interface ActionParameterDefaultsFacet extends Facet {

    /**
     * default parameter value (scalar or non-scalar), depending on other pending parameters
     * @implNote this is low level, meant to be called only by
     * instances of {@link ObjectActionParameter}, other callers should
     * rather use {@link ObjectActionParameter#getDefault(ParameterNegotiationModel)}
     */
    Can<ManagedObject> getDefault(@NonNull ParameterNegotiationModel pendingArgs);
}
