//
//  FATWGS84ConvertToGCJ02ForAMapView.m
//  FinApplet
//
//  Created by 杨涛 on 2018/8/9.
//  Copyright © 2018年 finogeeks. All rights reserved.
//

#import "FATWGS84ConvertToGCJ02.h"
#define RANGE_LON_MAX 137.8347
#define RANGE_LON_MIN 72.004
#define RANGE_LAT_MAX 55.8271
#define RANGE_LAT_MIN 0.8293
#define LAT_OFFSET_0(x,y) -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * sqrt(fabs(x))
#define LAT_OFFSET_1 (20.0 * sin(6.0 * x * M_PI) + 20.0 * sin(2.0 * x * M_PI)) * 2.0 / 3.0
#define LAT_OFFSET_2 (20.0 * sin(y * M_PI) + 40.0 * sin(y / 3.0 * M_PI)) * 2.0 / 3.0
#define LAT_OFFSET_3 (160.0 * sin(y / 12.0 * M_PI) + 320 * sin(y * M_PI / 30.0)) * 2.0 / 3.0

#define LON_OFFSET_0(x,y) 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * sqrt(fabs(x))
#define LON_OFFSET_1 (20.0 * sin(6.0 * x * M_PI) + 20.0 * sin(2.0 * x * M_PI)) * 2.0 / 3.0
#define LON_OFFSET_2 (20.0 * sin(x * M_PI) + 40.0 * sin(x / 3.0 * M_PI)) * 2.0 / 3.0
#define LON_OFFSET_3 (150.0 * sin(x / 12.0 * M_PI) + 300.0 * sin(x / 30.0 * M_PI)) * 2.0 / 3.0
#define jzA 6378245.0
#define jzEE 0.00669342162296594323

static const double fat_a = 6378245.0;
static const double fat_ee = 0.00669342162296594323;

@implementation FATWGS84ConvertToGCJ02ForAMapView
+ (CLLocationCoordinate2D)transformFromWGSToGCJ:(CLLocationCoordinate2D)wgsLoc {
    CLLocationCoordinate2D adjustLoc;
    if ([self isLocationOutOfChina:wgsLoc]) {
        adjustLoc = wgsLoc;
    } else {
        double adjustLat = [self transformLatWithX:wgsLoc.longitude - 105.0 withY:wgsLoc.latitude - 35.0];
        double adjustLon = [self transformLonWithX:wgsLoc.longitude - 105.0 withY:wgsLoc.latitude - 35.0];
        double radLat = wgsLoc.latitude / 180.0 * M_PI;
        double magic = sin(radLat);
        magic = 1 - fat_ee * magic * magic;
        double sqrtMagic = sqrt(magic);
        adjustLat = (adjustLat * 180.0) / ((fat_a * (1 - fat_ee)) / (magic * sqrtMagic) * M_PI);
        adjustLon = (adjustLon * 180.0) / (fat_a / sqrtMagic * cos(radLat) * M_PI);
        adjustLoc.latitude = wgsLoc.latitude + adjustLat - 0.00039900; // 减去这个数字 完全是凑数，准确性有待验证
        adjustLoc.longitude = wgsLoc.longitude + adjustLon;
    }
    return adjustLoc;
}

+ (CLLocationCoordinate2D)transformFromGCJToWGS:(CLLocationCoordinate2D)wgsLoc {
    return [self gcj02Decrypt:wgsLoc.latitude gjLon:wgsLoc.longitude];
}

+ (CLLocationCoordinate2D)gcj02Decrypt:(double)gjLat gjLon:(double)gjLon {
    CLLocationCoordinate2D  gPt = [self gcj02Encrypt:gjLat bdLon:gjLon];
    double dLon = gPt.longitude - gjLon;
    double dLat = gPt.latitude - gjLat;
    CLLocationCoordinate2D pt;
    pt.latitude = gjLat - dLat;
    pt.longitude = gjLon - dLon;
    return pt;
}

+ (CLLocationCoordinate2D)gcj02Encrypt:(double)ggLat bdLon:(double)ggLon {
    CLLocationCoordinate2D resPoint;
    double mgLat;
    double mgLon;
    if ([self outOfChina:ggLat bdLon:ggLon]) {
        resPoint.latitude = ggLat;
        resPoint.longitude = ggLon;
        return resPoint;
    }
    double dLat = [self transformLat:(ggLon - 105.0)bdLon:(ggLat - 35.0)];
    double dLon = [self transformLon:(ggLon - 105.0) bdLon:(ggLat - 35.0)];
    double radLat = ggLat / 180.0 * M_PI;
    double magic = sin(radLat);
    magic = 1 - jzEE * magic * magic;
    double sqrtMagic = sqrt(magic);
    dLat = (dLat * 180.0) / ((jzA * (1 - jzEE)) / (magic * sqrtMagic) * M_PI);
    dLon = (dLon * 180.0) / (jzA / sqrtMagic * cos(radLat) * M_PI);
    mgLat = ggLat + dLat;
    mgLon = ggLon + dLon;
    
    resPoint.latitude = mgLat;
    resPoint.longitude = mgLon;
    return resPoint;
}

+ (BOOL)outOfChina:(double)lat bdLon:(double)lon {
    if (lon < RANGE_LON_MIN || lon > RANGE_LON_MAX)
        return true;
    if (lat < RANGE_LAT_MIN || lat > RANGE_LAT_MAX)
        return true;
    return false;
}

+ (double)transformLat:(double)x bdLon:(double)y {
    double ret = LAT_OFFSET_0(x, y);
    ret += LAT_OFFSET_1;
    ret += LAT_OFFSET_2;
    ret += LAT_OFFSET_3;
    return ret;
}

+ (double)transformLon:(double)x bdLon:(double)y {
    double ret = LON_OFFSET_0(x, y);
    ret += LON_OFFSET_1;
    ret += LON_OFFSET_2;
    ret += LON_OFFSET_3;
    return ret;
}

//判断是不是在中国
+ (BOOL)isLocationOutOfChina:(CLLocationCoordinate2D)location {
    if (location.longitude < 72.004 || location.longitude > 137.8347 || location.latitude < 0.8293 || location.latitude > 55.8271)
        return YES;
    return NO;
}

+ (double)transformLatWithX:(double)x withY:(double)y {
    double lat = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * sqrt(fabs(x));
    lat += (20.0 * sin(6.0 * x * M_PI) + 20.0 * sin(2.0 * x * M_PI)) * 2.0 / 3.0;
    lat += (20.0 * sin(y * M_PI) + 40.0 * sin(y / 3.0 * M_PI)) * 2.0 / 3.0;
    lat += (160.0 * sin(y / 12.0 * M_PI) + 320 * sin(y * M_PI / 30.0)) * 2.0 / 3.0;
    return lat;
}

+ (double)transformLonWithX:(double)x withY:(double)y {
    double lon = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * sqrt(fabs(x));
    lon += (20.0 * sin(6.0 * x * M_PI) + 20.0 * sin(2.0 * x * M_PI)) * 2.0 / 3.0;
    lon += (20.0 * sin(x * M_PI) + 40.0 * sin(x / 3.0 * M_PI)) * 2.0 / 3.0;
    lon += (150.0 * sin(x / 12.0 * M_PI) + 300.0 * sin(x / 30.0 * M_PI)) * 2.0 / 3.0;
    return lon;
}

@end