package com.ruoyi.web.controller.tool;

public class CoordinateTransform {
    
    private static final double PI = 3.1415926535897932384626;
    private static final double A = 6378245.0;
    private static final double EE = 0.00669342162296594323;
    private static final double X_PI = 3.14159265358979324 * 3000.0 / 180.0;
    
    /**
     * WGS84转GCJ-02坐标
     * @param wgLat WGS84坐标纬度
     * @param wgLon WGS84坐标经度
     * @return 转换后的GCJ-02坐标[纬度, 经度]
     */
    public static double[] wgs84ToGcj02(double wgLat, double wgLon) {
        if (outOfChina(wgLat, wgLon)) {
            return new double[]{wgLat, wgLon};
        }
        double dLat = transformLat(wgLon - 105.0, wgLat - 35.0);
        double dLon = transformLon(wgLon - 105.0, wgLat - 35.0);
        double radLat = wgLat / 180.0 * PI;
        double magic = Math.sin(radLat);
        magic = 1 - EE * magic * magic;
        double sqrtMagic = Math.sqrt(magic);
        dLat = (dLat * 180.0) / ((A * (1 - EE)) / (magic * sqrtMagic) * PI);
        dLon = (dLon * 180.0) / (A / sqrtMagic * Math.cos(radLat) * PI);
        double mgLat = wgLat + dLat;
        double mgLon = wgLon + dLon;
        return new double[]{mgLat, mgLon};
    }
    
    /**
     * GCJ-02转BD09坐标（百度坐标系，腾讯地图部分接口可能使用）
     * @param ggLat GCJ-02坐标纬度
     * @param ggLon GCJ-02坐标经度
     * @return 转换后的BD09坐标[纬度, 经度]
     */
    public static double[] gcj02ToBd09(double ggLat, double ggLon) {
        double x = ggLon, y = ggLat;
        double z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * X_PI);
        double theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * X_PI);
        double bdLon = z * Math.cos(theta) + 0.0065;
        double bdLat = z * Math.sin(theta) + 0.006;
        return new double[]{bdLat, bdLon};
    }
    
    /**
     * WGS84直接转BD09坐标
     * @param wgLat WGS84坐标纬度
     * @param wgLon WGS84坐标经度
     * @return 转换后的BD09坐标[纬度, 经度]
     */
    public static double[] wgs84ToBd09(double wgLat, double wgLon) {
        double[] gcj02 = wgs84ToGcj02(wgLat, wgLon);
        return gcj02ToBd09(gcj02[0], gcj02[1]);
    }
    
    private static boolean outOfChina(double lat, double lon) {
        if (lon < 72.004 || lon > 137.8347)
            return true;
        if (lat < 0.8293 || lat > 55.8271)
            return true;
        return false;
    }
    
    private static double transformLat(double x, double y) {
        double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));
        ret += (20.0 * Math.sin(6.0 * x * PI) + 20.0 * Math.sin(2.0 * x * PI)) * 2.0 / 3.0;
        ret += (20.0 * Math.sin(y * PI) + 40.0 * Math.sin(y / 3.0 * PI)) * 2.0 / 3.0;
        ret += (160.0 * Math.sin(y / 12.0 * PI) + 320 * Math.sin(y * PI / 30.0)) * 2.0 / 3.0;
        return ret;
    }
    
    private static double transformLon(double x, double y) {
        double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
        ret += (20.0 * Math.sin(6.0 * x * PI) + 20.0 * Math.sin(2.0 * x * PI)) * 2.0 / 3.0;
        ret += (20.0 * Math.sin(x * PI) + 40.0 * Math.sin(x / 3.0 * PI)) * 2.0 / 3.0;
        ret += (150.0 * Math.sin(x / 12.0 * PI) + 300.0 * Math.sin(x / 30.0 * PI)) * 2.0 / 3.0;
        return ret;
    }
    
    // 测试方法

}