/*
 * Copyright 2015 Amila Silva
 * Copyright 2016 - 2019 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.handler;

import io.netty.channel.ChannelHandler;
import org.traccar.BaseDataHandler;
import org.traccar.config.Config;
import org.traccar.config.Keys;
import org.traccar.database.IdentityManager;
import org.traccar.helper.DistanceCalculator;
import org.traccar.model.Position;

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

@ChannelHandler.Sharable
public class DistanceHandler extends BaseDataHandler {

    private final IdentityManager identityManager;

    private final boolean filter;
    private final int coordinatesMinError;
    private final int coordinatesMaxError;

    public DistanceHandler(Config config, IdentityManager identityManager) {
        this.identityManager = identityManager;
        this.filter = config.getBoolean(Keys.COORDINATES_FILTER);
        this.coordinatesMinError = config.getInteger(Keys.COORDINATES_MIN_ERROR);
        this.coordinatesMaxError = config.getInteger(Keys.COORDINATES_MAX_ERROR);
    }

    @Override
    protected Position handlePosition(Position position) {

        double distance = 0.0;
        if (position.getAttributes().containsKey(Position.KEY_DISTANCE)) {
            distance = position.getDouble(Position.KEY_DISTANCE);
        }
        double totalDistance = 0.0;

        Position last = identityManager != null ? identityManager.getLastPosition(position.getDeviceId()) : null;
        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();
            }
            if (filter && last.getValid() && last.getLatitude() != 0 && last.getLongitude() != 0) {
                boolean satisfiesMin = coordinatesMinError == 0 || distance > coordinatesMinError;
                boolean satisfiesMax = coordinatesMaxError == 0
                        || distance < coordinatesMaxError || position.getValid();
                if (!satisfiesMin || !satisfiesMax) {
                    position.setLatitude(last.getLatitude());
                    position.setLongitude(last.getLongitude());
                    distance = 0;
                }
            }
        }
        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;
    }

}

@@ -52,10 +52,10 @@
 - 20
+2
 1
-9
  Ant
@@ -2557,27 +2557,8 @@
 r &&
- last.getValid() &&
  las
@@ -2775,32 +2775,8 @@
 == 0
-%0A                       
  %7C%7C 
@@ -2809,31 +2809,8 @@
 rror
- %7C%7C position.getValid()
 ;%0A  
@@ -2857,24 +2857,80 @@
 sfiesMax) %7B%0A
+                    position.setValid(last.getValid());%0A
             

Simplify coordinates filtering