/*
 * Copyright 2015 Amila Silva
 * Copyright 2016 Anton Tananaev (anton@traccar.org)
 *
 * 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.traccar;

import org.traccar.helper.DistanceCalculator;
import org.traccar.model.Position;

import java.math.BigDecimal;
import java.math.RoundingMode;

public class DistanceHandler extends BaseDataHandler {

    private Position getLastPosition(long deviceId) {
        if (Context.getIdentityManager() != null) {
            return Context.getIdentityManager().getLastPosition(deviceId);
        }
        return null;
    }

    public Position calculateDistance(Position position) {

        double distance = 0.0;
        double totalDistance = 0.0;

        Position last = getLastPosition(position.getDeviceId());
        if (last != null) {
            totalDistance = last.getDouble(Position.KEY_TOTAL_DISTANCE);

            if (!position.getAttributes().containsKey(Position.KEY_DISTANCE)) {
                distance = DistanceCalculator.distance(
                        position.getLatitude(), position.getLongitude(),
                        last.getLatitude(), last.getLongitude());

                distance = BigDecimal.valueOf(distance).setScale(2, RoundingMode.HALF_EVEN).doubleValue();
            } else {
                distance = position.getDouble(Position.KEY_DISTANCE);
            }
        }
        if (!position.getAttributes().containsKey(Position.KEY_DISTANCE)) {
            position.set(Position.KEY_DISTANCE, distance);
        }
        totalDistance = BigDecimal.valueOf(totalDistance + distance).setScale(2, RoundingMode.HALF_EVEN).doubleValue();
        position.set(Position.KEY_TOTAL_DISTANCE, totalDistance);

        return position;
    }

    @Override
    protected Position handlePosition(Position position) {
        return calculateDistance(position);
    }

}