/* Sunrise and sunset computation utilities - test program.

Paolo Bonzini, August 2008.

This source code is released for free distribution under the terms

of the GNU General Public License. */

#include <sys/types.h>

#include <stdio.h>

#include <stdlib.h>

#include <time.h>

#include <sys/time.h>

#include "sunrise.h"

int

main (void)

{

int year, month, day;

double lon, lat;

double len, rise, set, cur_time;

int rc;

char ch;

time_t t;

struct tm *tm;

t = time (NULL);

tm = gmtime (&t);

lon = 0;

sun_rise_set (tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,

lon, 0.0, &rise, &set);

cur_time = tm->tm_hour + tm->tm_min / 60.0;

lon += (rise - cur_time) * 15.0;

if (lon > 180.0)

lon -= 360.0;

if (lon < -180.0)

lon += 360.0;

printf ("==> Sun is rising at longitude %5.2fE, latitude 0.00N\n", lon);

printf ("Longitude (+ is east) and latitude (+ is north), or * for Lugano: ");

ch = getchar ();

if (ch == '*')

lon = 8.0 + 57.0/60.0, lat = 46.0;

else

{

ungetc (ch, stdin);

while (scanf ("%lf %lf", &lon, &lat) < 2)

;

}

tm = localtime (&t);

year = tm->tm_year + 1900;

month = tm->tm_mon + 1;

day = tm->tm_mday;

do

{

len = day_length (year, month, day, lon, lat);

printf ("==> Day length: %5.2f hours\n", len);

rc = sun_rise_set (year, month, day, lon, lat, &rise, &set);

if (rc == 1)

printf ("==> Sun never sets!\n");

else if (rc == -1)

printf ("==> Sun never rises!\n");

else

{

printf ("==> Midday: %5.2f GMT\n", (rise + set) / 2);

printf ("==> Sunrise: %5.2f, Sunset: %5.2f GMT\n", rise, set);

}

rc = civil_rise_set (year, month, day, lon, lat, &rise, &set);

if (rc == 1)

printf ("==> Sun never reaches civil dusk!\n");

else if (rc == -1)

printf ("==> Sun never reaches civil dawn!\n");

else

printf ("==> Civil sunrise: %5.2f, Sunset: %5.2f GMT\n", rise, set);

printf ("Date (yyyy mm dd) (ctrl-C exits): ");

while (scanf ("%d %d %d", &year, &month, &day) < 3 && !feof (stdin))

;

}

while (!feof (stdin));

return 0;

}