package com.yuncai.core.common.utils;

import java.util.HashMap;
import java.util.Map;

/**
 * 計算兩個座標的距離
 * @author audaque
 *
 */
public class DistanceUtils {
     private static final  double EARTH_RADIUS = 6378137;//赤道半徑(單位m)  
     
     
     private DistanceUtils(){
        
     }
      
       /** 
 
        * 轉化為弧度(rad) 
        * */  
       private static double rad(double d)  
       {  
          return d * Math.PI / 180.0;
       }  
       /** 
        * 基於googleMap中的演算法得到兩經緯度之間的距離,計算精度與谷歌地圖的距離精度差不多，相差範圍在0.2米以下 
        * @param lng1 第一點的精度 
        * @param lat1 第一點的緯度 
        * @param lng2 第二點的精度 
 
        * @param lat2 第二點的緯度
        * @return 返回的距離(湊整)，單位m
        * */  
       public static int getDistance(double lng1,double lat1,double lng2, double lat2)  
       {  
          double radLat1 = rad(lat1);  
          double radLat2 = rad(lat2);  
          double a = radLat1 - radLat2;  
          double 
 
b = rad(lng1) - rad(lng2);  
          double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a/2),2)+ Math.cos(radLat1)* Math.cos(radLat2)* Math.pow(Math.sin(b/2),2)));
          s = s * EARTH_RADIUS;  
          return  (int) Math.ceil(s);
       }
       
       
       /* 
        * *
        * @param raidus 單位米
        * return minLng,minLat, maxLng,maxLat
        */
       public static double[] getAround(double lat, double lon, int raidus) {

           Double latitude = lat;
           Double longitude = lon;

           Double degree = (24901 * 1609) / 360.0;
           double raidusMile = raidus;

           Double dpmLat = 1 / degree;
           Double radiusLat = dpmLat * raidusMile;
           Double minLat = latitude - radiusLat;
           Double maxLat = latitude + radiusLat;

           Double mpdLng = degree * Math.cos(latitude * (Math.PI / 180));
           Double dpmLng = 1 / mpdLng;
           Double radiusLng = dpmLng * raidusMile;
           Double minLng = longitude - radiusLng;
           Double maxLng = longitude + radiusLng;
           return new double[]{minLng,minLat, maxLng,maxLat};
       }

   /**
    * 計算經緯度點對應正方形4個點的座標
    */
       public static class DistanceProperty{
          public final static String LEFT_TOP_POINT = "leftTopPoint" ;
          public final static String LEFT_BOTTOM_POINT = "leftBottomPoint";
          public final static String RIGHT_TOP_POINT = "rightTopPoint";
          public final static String RIGHT_BOTTOM_POINT = "rightBottomPoint";
       }
       public static Map<String, double[]> returnLLSquarePoint(double longitude, double latitude, double distance) {
           Map<String, double[]> squareMap = new HashMap<String, double[]>();
           // 計算經度弧度,從弧度轉換為角度
           double dLongitude = 2 * (Math.asin(Math.sin(distance
                   / (2 * EARTH_RADIUS))
                   / Math.cos(Math.toRadians(latitude))));
           dLongitude = Math.toDegrees(dLongitude);
           // 計算緯度角度
           double dLatitude = distance / EARTH_RADIUS;
           dLatitude = Math.toDegrees(dLatitude);
           // 正方形
           double[] leftTopPoint = { longitude - dLongitude,latitude + dLatitude };
           double[] rightTopPoint = {longitude + dLongitude,latitude + dLatitude };
           double[] leftBottomPoint = {longitude - dLongitude,latitude - dLatitude };
           double[] rightBottomPoint = { longitude + dLongitude ,latitude - dLatitude};
           squareMap.put(DistanceProperty.LEFT_TOP_POINT, leftTopPoint);
           squareMap.put(DistanceProperty.RIGHT_TOP_POINT, rightTopPoint);
           squareMap.put(DistanceProperty.LEFT_BOTTOM_POINT, leftBottomPoint);
           squareMap.put(DistanceProperty.RIGHT_BOTTOM_POINT, rightBottomPoint);
           return squareMap;
       }
       
       /**
        * 計算一個經緯度在指定距離範圍內的最大經緯度和最小經緯度
        * @param lng
        * @param lat
        * @param distance
        * @return Double[0] 最大經度   Double[1] 最小經度   Double[2] 最大緯度   Double[3] 最小緯度
        */
       public static Double[] getScopeGps(double lng, double lat, int distance){
          //每100米，經緯度的差值
          double lngPI =0.0009788;//經度
          double latPI = 0.0009;//緯度
          
          double maxResultLng = lng+distance/100*lngPI;
          double minResultLng = lng-distance/100*lngPI;
          double maxResultLat = lat+distance/100*latPI;
          double minResultLat = lat-distance/100*latPI;
          
          Double[] result =new Double[4];
          
          result[0]=minResultLng; 
          result[1]=maxResultLng;
          result[2]=minResultLat;
          result[3]=maxResultLat;    
          
          
         return result;
       }
       
       public static void main(String[] args) {
          int test = getDistance( 113.947971,22.554800,113.948654,22.553683);
          
          Double[] aa =getScopeGps(113.947875,22.555001,500);
          System.out.println(aa[0]);
          System.out.println(aa[1]);
          System.out.println(aa[2]);
          System.out.println(aa[3]);
          
          System.out.println(test);
      }
       
}