/*
 * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.yangtools.yang.binding;

import static java.util.Objects.requireNonNull;

import java.util.Map;
import org.eclipse.jdt.annotation.NonNull;
import org.eclipse.jdt.annotation.Nullable;

/**
 * Augmentable (extensible) object which could carry additional data defined by a third-party extension, without
 * introducing conflict between various extension.
 *
 * <p>
 * This interface uses extended version of ExtensibleInterface pattern which also adds marker interface for
 * augmentations (extensions) - {@link Augmentable}.
 *
 * @param <T> Base class which should implements this interface and is target for augmentation.
 * @author Tony Tkacik
 */
public interface Augmentable<T> {
    /**
     * Returns instance of augmentation.
     *
     * @param augmentationType Type of augmentation to be returned.
     * @param <A> Type capture for augmentation type
     * @return instance of augmentation, or null if the augmentationType is not present.
     * @throws NullPointerException if augmentationType is null
     */
    @SuppressWarnings("unchecked")
    default <A extends Augmentation<T>> @Nullable A augmentation(final Class<A> augmentationType) {
        return (A) augmentations().get(requireNonNull(augmentationType));
    }

    /**
     * Returns map of all augmentations.
     *
     * @return map of all augmentations.
     */
    @NonNull Map<Class<? extends Augmentation<T>>, Augmentation<T>> augmentations();
}