/**
 *  Copyright 2019-2022 The ModiTect 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.moditect.deptective.internal.graph;

import java.util.Objects;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.StreamSupport;

/**
 * A node in a graph.
 *
 * @author Gerd W&uuml;therich (gw@code-kontor.io)
 * @author Gunnar Morling
 * @param <T> A specific sub-type, following the self-referential generic type pattern
 */
public interface Node<T extends Node<T>> {

    default Set<Dependency<T>> getOutgoingDependenciesTo(Iterable<? extends T> nodes) {
        return StreamSupport.stream(nodes.spliterator(), false)
                .map(c -> getOutgoingDependencyTo(c))
                .filter(Objects::nonNull)
                .collect(Collectors.toSet());
    }

    Dependency<T> getOutgoingDependencyTo(T node);

    boolean hasOutgoingDependencies();

    /**
     * Returns a concise string representation of this node, e.g. used when rendering this node in a diagram.
     */
    default String asShortString() {
        return toString();
    }
}
