package com.dji.sample.geo.utils;

import com.dji.sample.geo.entity.Feature;
import com.dji.sample.geo.entity.GeoJson;
import com.dji.sample.wayline.model.param.FlyAreaParam;
import com.dji.sample.wayline.model.param.PointPOJO;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;

/**
 * 空间计算工具类
 */
public class GeoUtils {
    /**
     * 默认地球半径
     */
    private static double EARTH_RADIUS = 6371000;//赤道半径(单位m)

    /**
     * 转化为弧度(rad)
     */
    private static double rad(double d) {
        return d * Math.PI / 180.0;
    }


    /**
     * 计算中心经纬度与目标经纬度的距离（米）
     *
     * @param centerLon 中心精度
     * @param centerLat 中心纬度
     * @param targetLon 需要计算的精度
     * @param targetLat 需要计算的纬度
     * @return 米
     */
    public static double distance(double centerLon, double centerLat, double targetLon, double targetLat) {

        double jl_jd = 102834.74258026089786013677476285;// 每经度单位米;
        double jl_wd = 111712.69150641055729984301412873;// 每纬度单位米;
        double b = Math.abs((centerLat - targetLat) * jl_jd);
        double a = Math.abs((centerLon - targetLon) * jl_wd);
        return Math.sqrt((a * a + b * b));
    }

    /**
     * 根据多个点计算中心点
     * @param list
     * @return
     */
    public static PointPOJO getCenterPoint(List<PointPOJO> list) {

        int total = list.size();
        double X = 0, Y = 0, Z = 0;

        for (int i = 0; i < list.size(); i++) {
            PointPOJO point = list.get(i);
            double lat, lon, x, y, z;
            lon = point.getLon() * Math.PI / 180;
            lat = point.getLat() * Math.PI / 180;
            x = Math.cos(lat) * Math.cos(lon);
            y = Math.cos(lat) * Math.sin(lon);
            z = Math.sin(lat);
            X += x;
            Y += y;
            Z += z;
        }


        X = X / total;
        Y = Y / total;
        Z = Z / total;
        double Lon = Math.atan2(Y, X);
        double Hyp = Math.sqrt(X * X + Y * Y);
        double Lat = Math.atan2(Z, Hyp);

        PointPOJO centerPoint = new PointPOJO();
        centerPoint.setLon( Lon * 180 / Math.PI);
        centerPoint.setLat(Lat * 180 / Math.PI);
        return centerPoint;
    }

    /**
     * 获取点区域并按从近到远排序
     * @param flyAreaParam
     * @return
     */
    public static List<PointPOJO> caculatePointList(FlyAreaParam flyAreaParam){
        List<List<PointPOJO>> areaList = flyAreaParam.getAreaList();
        PointPOJO dockPoint = flyAreaParam.getDockPoint();
        Double radius = flyAreaParam.getRadius();

        List<PointPOJO> centerPointList = new ArrayList<>();

        //根据区域获取中心点
        areaList.forEach(area -> {
            PointPOJO centerPoint = GeoUtils.getCenterPoint(area);
            centerPointList.add(centerPoint);
        });

        //巡逻目标集合
        List<PointPOJO> targetList = new ArrayList<>();
        //获取所有中心点之后,
        centerPointList.forEach(centerPoint -> {
            //判断各个中心点和机场点的距离
            double distance = GeoUtils.distance(dockPoint.getLon(), dockPoint.getLat(), centerPoint.getLon(), centerPoint.getLat());

            //当距离小于半径时,添加到目标集合中
            if (distance <= radius) {
                centerPoint.setDistance(distance);
                targetList.add(centerPoint);
            }
        });

        //按距离从近到远排序
        targetList.sort(Comparator.comparing(PointPOJO::getDistance));
        return targetList;
    }

    /**
     * 根据geojson获取点区域并按从近到远排序
     * @param geoJson
     * @return
     */
    public static List<PointPOJO> caculatePointList(GeoJson geoJson,PointPOJO dockPoint,Double radius){
        List<Feature> features = geoJson.getFeatures();

        List<List<PointPOJO>> areaList = new ArrayList<>();

        features.forEach(feature -> {
            List<PointPOJO> list = new ArrayList<>();
            List<List<Double>> coordinates = feature.getGeometry().getCoordinates().get(0);

            coordinates.forEach(coordinate ->{
                PointPOJO pointPOJO = new PointPOJO();

                pointPOJO.setLon(coordinate.get(0));
                pointPOJO.setLat(coordinate.get(1));

                list.add(pointPOJO);
            });
            areaList.add(list);
        });

        FlyAreaParam flyAreaParam = new FlyAreaParam();

        flyAreaParam.setDockPoint(dockPoint);
        flyAreaParam.setRadius(radius);
        flyAreaParam.setAreaList(areaList);

        List<PointPOJO> pointPOJOS = caculatePointList(flyAreaParam);

        return pointPOJOS;
    }

    /**
     * 读取json文件
     * @param path
     * @return
     */
    public static GeoJson readJsonFile(String path){

        try {
            File file = new File(path);
            ObjectMapper objectMapper = new ObjectMapper();

            objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

            return objectMapper.readValue(file, GeoJson.class);
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }

    }

}