/*
 *  Licensed to GraphHopper GmbH under one or more contributor
 *  license agreements. See the NOTICE file distributed with this work for 
 *  additional information regarding copyright ownership.
 * 
 *  GraphHopper GmbH 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 com.graphhopper.storage;

import com.graphhopper.routing.util.AllCHEdgesIterator;
import com.graphhopper.routing.util.EdgeFilter;
import com.graphhopper.util.CHEdgeExplorer;
import com.graphhopper.util.CHEdgeIteratorState;

/**
 * Extended graph interface which supports Contraction Hierarchies. Ie. storing and retrieving the
 * levels for a node and creating shortcuts, which are additional 'artificial' edges to speedup
 * traversal in certain cases.
 * <p>
 *
 * @author Peter Karich
 */
public interface CHGraph extends Graph {
    /**
     * This methods sets the level of the specified node.
     */
    void setLevel(int nodeId, int level);

    /**
     * @return the level of the specified node.
     */
    int getLevel(int nodeId);

    boolean isShortcut(int edgeId);

    /**
     * This method creates a shortcut between a to b which is nearly identical to creating an edge
     * except that it can be excluded or included for certain traversals or algorithms.
     */
    CHEdgeIteratorState shortcut(int a, int b);

    @Override
    CHEdgeIteratorState getEdgeIteratorState(int edgeId, int endNode);

    @Override
    CHEdgeExplorer createEdgeExplorer();

    @Override
    CHEdgeExplorer createEdgeExplorer(EdgeFilter filter);

    @Override
    AllCHEdgesIterator getAllEdges();
}