package com.hollywood.applet.utils;

import java.text.DecimalFormat;

public class DistanceCalculator {
    public static void main(String[] args) {
        String coord1 = "40.7128";
        String coord2 = "-74.0060";
        String coord3 = "34.0522";
        String coord4 = "-118.2437";

        double distance = calculateDistance(coord1, coord2, coord3, coord4);
        DecimalFormat df = new DecimalFormat("#.##"); // 创建格式化对象，保留两位小数
        String formattedDistance = df.format(distance); // 格式化距离
        System.out.println("两个坐标点的距离为: " + formattedDistance + " km");
    }

    public static double calculateDistance(String lat1, String lon1, String lat2, String lon2) {
        double lat1Double = Double.parseDouble(lat1);
        double lon1Double = Double.parseDouble(lon1);
        double lat2Double = Double.parseDouble(lat2);
        double lon2Double = Double.parseDouble(lon2);

        int R = 6371; // 地球半径，单位：km
        double latDistance = Math.toRadians(lat2Double - lat1Double);
        double lonDistance = Math.toRadians(lon2Double - lon1Double);
        double a = Math.sin(latDistance / 2) * Math.sin(latDistance / 2)
                + Math.cos(Math.toRadians(lat1Double)) * Math.cos(Math.toRadians(lat2Double))
                * Math.sin(lonDistance / 2) * Math.sin(lonDistance / 2);
        double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
        double distanceInKm = R * c;

// 返回结果保留两位小数
        String formattedDistance = String.format("%.2f", distanceInKm);
        double roundedDistance = Math.round(distanceInKm * 100) / 100.0; // 四舍五入到两位小数
        return roundedDistance;
    }
}