package SunshineCalculateForPhone;

public class SunshineCalculator {

final static double PHI = Math.PI;

final static double TWO_PHI = 2 * PHI;

final static double SUN_DIAMETER = 0.53;

final static double AIR_REF = (34.0 / 60.0);

private static int sunRise_hour;

private static int sunRise_minute;

private static int sunSet_hour;

private static int sunSet_minute;

private static double tmp_longitude;

private static int tmp_hour;

private static int tmp_minute;

// Get the days to J2000

// h is UT in decimal hours

// getJulianDay only works between 1901 to 2099

// 이 함수는 J2000 1월 1일 12시 DT를 기준으로 날수(Day Number)를 구합니다.

// 입력값은 년,월,일,시간(실수값)입니다.

private static double getJulianDay(int year, int month, int day) {

double temp = -7.0f * ((double) year + ((double) month + 9.0f) / 12.0f)

/ 4.0f + 275.0f * (double) month / 9.0f + (double) day;

// type casting necessary on PC DOS and TClite to avoid overflow

temp += (double) (year * 367);

return (temp - 730531.5f + 12.0f / 24.0f);

}

// the function below returns an angle in the range

// 0 to 2*pi

// 들어온 값을 항상 0~2pi 값안으로 normalize시킵니다.

private static double getRangeRadian(double x) {

double b = x / TWO_PHI;

double a = TWO_PHI * (b - (long) (b));

if (a < 0)

a = TWO_PHI + a;

return a;

}

// Calculating the hourangle

// 시간각을 계산합니다.

// lat:위도 declin:적위

private static double getHourAngle(double lat, double declin) {

double fo, dfo;

// Correction: different sign at S HS

dfo = PHI / 180.0 * (0.5 * SUN_DIAMETER + AIR_REF);

if (lat < 0.0)

dfo = -dfo;

fo = Math.tan(declin + dfo) * Math.tan(lat * PHI / 180.0);

if (fo > 0.99999)

fo = 1.0; // to avoid overflow //

fo = Math.asin(fo) + PHI / 2.0;

return fo;

}

// Find the ecliptic longitude of the Sun

// 태양의 황경을 구합니다.

private static double getSunLongitude(double days) {

double g;

// mean longitude of the Sun (태양의 평균 황경)

tmp_longitude = getRangeRadian(280.461 * PHI / 180.0 + .9856474 * PHI

/ 180.0 * days);

// mean anomaly of the Sun (태양의 평균근점이각)

g = getRangeRadian(357.528 * PHI / 180.0 + .9856003 * PHI / 180.0

* days);

// Ecliptic longitude of the Sun (태양의 황경계산)

return getRangeRadian(tmp_longitude + 1.915 * PHI / 180.0 * Math.sin(g)

+ .02 * PHI / 180.0 * Math.sin(2 * g));

}

private static void convertDtime2Rtime(double dHour) {

tmp_hour = (int) dHour;

tmp_minute = (int) ((dHour - (double) tmp_hour) * 60);

}

private static boolean detectCurrentInDayTime(int year, int month, int day,

int hour, int minute, double latitude, double longitude) {

double tzone;

double lambda, obliq;

double alpha, delta;

double LL, days;

double equation, ha, sunRiseTime, sunSetTime;

int dSunRiseT, dSunSetT, dNowT;

// 관측장소의 경도(단위 degree),위도(단위 degree),타임존(단위시간) 값을 입력받습니다.

/*

* year = 2011; month = 1; day = 1; latitude = 37.279198; //한국내 임의 위치의

* 위도 입력 longitude = 127.044032; //한국내 임의 위치의 경도 입력

*/

tzone = 9.0f; // 한국은 Time Zone이 +9 임

days = getJulianDay(year, month, day);

// 태양의 황경

lambda = getSunLongitude(days);

// Obliquity of the ecliptic (s황도기울기 계산)

obliq = 23.439 * PHI / 180.0 - .0000004 * PHI / 180.0 * days;

// Find the RA and DEC of the Sun (태양의 적경,적위 계산)

alpha = Math.atan2(Math.cos(obliq) * Math.sin(lambda),

Math.cos(lambda)); // 태양의 적경

delta = Math.asin(Math.sin(obliq) * Math.sin(lambda)); // 태양의 적위

// Find the Equation of Time in minutes

// Correction suggested by David Smith

// 균시차 계산

LL = tmp_longitude - alpha;

if (tmp_longitude < PHI)

LL += TWO_PHI;

equation = 1440.0 * (1.0 - LL / TWO_PHI);

ha = getHourAngle(latitude, delta);

sunRiseTime = 12.0 - 12.0 * ha / PHI + tzone - longitude / 15.0

+ equation / 60.0;

sunSetTime = 12.0 + 12.0 * ha / PHI + tzone - longitude / 15.0

+ equation / 60.0;

if (sunRiseTime > 24.0)

sunRiseTime -= 24.0;

if (sunSetTime > 24.0)

sunSetTime -= 24.0;

convertDtime2Rtime(sunRiseTime);

sunRise_hour = tmp_hour;

sunRise_minute = tmp_minute;

convertDtime2Rtime(sunSetTime);

sunSet_hour = tmp_hour;

sunSet_minute = tmp_minute;

// hour = 16; minute = 12; //임의의 Local Time을 설정하여 테스트

/*

* System.out.printf("Now Time: %d:%d\n",hour,minute);

* System.out.printf("Sunrise: %d:%d\n",sunRise_hour,sunRise_minute);

* System.out.printf("Sunrise: %d:%d\n",sunSet_hour,sunSet_minute);

*/

dNowT = hour * 60 + minute;

dSunRiseT = sunRise_hour * 60 + sunRise_minute;

dSunSetT = sunSet_hour * 60 + sunSet_minute;

if (dNowT <= dSunRiseT || dNowT >= dSunSetT) {

// System.out.printf("Night\n");

return false;

} else {

// System.out.printf("Day\n");

return true;

}

}

public static boolean detectSunshine(int year, int month, int day,

int hour, int minute, double latitude, double longitude,

double accuracy) {

if (accuracy > 50.0)

return false; // Indoor

// Outdoor, Check State of Sun in Input Time and Location

boolean isCIDT = false;

isCIDT = SunshineCalculator.detectCurrentInDayTime(year, month, day,

hour, minute, latitude, longitude);

return isCIDT;

}

public static void main(String[] args) {

int year = 2018;

int month = 7;

int day = 25;

int hour = 17;

int minute = 13;

double latitude = 37.279198;

double longitude = 127.044032;

double accuracy = 20.4718;

boolean isSun = false;

isSun = SunshineCalculator.detectSunshine(year, month, day, hour,

minute, latitude, longitude, accuracy);

System.out.println(isSun);

}

}