/*
 * Copyright 2015 the original author or authors.
 *
 * Licensed 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.gradle.model.internal.core;

import com.google.common.base.Optional;
import org.gradle.model.internal.core.rule.describe.ModelRuleDescriptor;
import org.gradle.model.internal.type.ModelType;

/**
 * Projection used to resolve the type of a reference node when the target is {@code null}.
 */
public class EmptyReferenceProjection<T> extends TypeCompatibilityModelProjectionSupport<T> {
    public EmptyReferenceProjection(ModelType<T> type) {
        super(type);
    }

    @Override
    protected ModelView<T> toView(MutableModelNode modelNode, ModelRuleDescriptor ruleDescriptor, boolean writable) {
        return InstanceModelView.of(modelNode.getPath(), getType(), null);
    }

    @Override
    public Optional<String> getValueDescription(MutableModelNode mutableModelNode) {
        return Optional.absent();
    }
}