/*
 *  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.routing.weighting;

import com.graphhopper.routing.util.FlagEncoder;
import com.graphhopper.util.EdgeIteratorState;
import com.graphhopper.util.PMap;
import com.graphhopper.util.Parameters.Routing;

/**
 * Calculates the fastest route with the specified vehicle (VehicleEncoder). Calculates the weight
 * in seconds.
 * <p>
 *
 * @author Peter Karich
 */
public class FastestWeighting extends AbstractWeighting {
    /**
     * Converting to seconds is not necessary but makes adding other penalties easier (e.g. turn
     * costs or traffic light costs etc)
     */
    protected final static double SPEED_CONV = 3.6;
    private final double headingPenalty;
    private final long headingPenaltyMillis;
    private final double maxSpeed;

    public FastestWeighting(FlagEncoder encoder, PMap pMap) {
        super(encoder);
        headingPenalty = pMap.getDouble(Routing.HEADING_PENALTY, Routing.DEFAULT_HEADING_PENALTY);
        headingPenaltyMillis = Math.round(headingPenalty * 1000);
        maxSpeed = encoder.getMaxSpeed() / SPEED_CONV;
    }

    public FastestWeighting(FlagEncoder encoder) {
        this(encoder, new PMap(0));
    }

    @Override
    public double getMinWeight(double distance) {
        return distance / maxSpeed;
    }

    @Override
    public double calcWeight(EdgeIteratorState edge, boolean reverse, int prevOrNextEdgeId) {
        double speed = reverse ? flagEncoder.getReverseSpeed(edge.getFlags()) : flagEncoder.getSpeed(edge.getFlags());
        if (speed == 0)
            return Double.POSITIVE_INFINITY;

        double time = edge.getDistance() / speed * SPEED_CONV;

        // add direction penalties at start/stop/via points
        boolean unfavoredEdge = edge.getBool(EdgeIteratorState.K_UNFAVORED_EDGE, false);
        if (unfavoredEdge)
            time += headingPenalty;

        return time;
    }

    @Override
    public long calcMillis(EdgeIteratorState edgeState, boolean reverse, int prevOrNextEdgeId) {
        // TODO move this to AbstractWeighting?
        long time = 0;
        boolean unfavoredEdge = edgeState.getBool(EdgeIteratorState.K_UNFAVORED_EDGE, false);
        if (unfavoredEdge)
            time += headingPenaltyMillis;

        return time + super.calcMillis(edgeState, reverse, prevOrNextEdgeId);
    }

    @Override
    public String getName() {
        return "fastest";
    }
}