#include <GeographicLib/UTMUPS.hpp>
#include <GeographicLib/MGRS.hpp>
#include <cstring>
#include <string>

int main(int argc, char **argv)
{
  if (argc < 3 || argc > 5)
  {
    fprintf(stderr, "Usage: %s <lon_degree> <lat_degree> [<precision>]\n", argv[0]);
    fprintf(stderr, "Usage: %s <lon_rad> <lat_rad> -r [<precision>]\n", argv[0]);
    return -1;
  }

  bool lonLatInRad = false;
  double lon = atof(argv[1]);
  double lat = atof(argv[2]);
  int prec = 5;
  if (argc >= 4)
  {
    int precArgId = -1;
    if (strcmp(argv[3], "-r") == 0)
    {
      lonLatInRad = true;
      if (argc == 5)
        precArgId = 4;
    }
    else
      precArgId = 3;
    if (precArgId > 0)
      prec = atoi(argv[precArgId]);
  }

  std::string mgrs;

  int zone;
  bool northp;
  double x, y;
  try
  {
    const double latDeg = lonLatInRad ? lat * 180 / M_PI : lat;
    const double lonDeg = lonLatInRad ? lon * 180 / M_PI : lon;
    GeographicLib::UTMUPS::Forward(latDeg, lonDeg, zone, northp, x, y);
    GeographicLib::MGRS::Forward(zone, northp, x, y, prec, mgrs);
  }
  catch (...)
  {
    fprintf(stderr, "Error converting %9.6f, %9.6f to MGRS coords\n", lat, lon);
    return -2;
  }
  std::string part1, part2, part3, part4;
  part1 = mgrs.substr(0, 3);
  part2 = mgrs.substr(3, 2);
  if (prec > 0)
  {
    part3 = mgrs.substr(5, prec);
    part4 = mgrs.substr(5 + prec, prec);
  }
  fprintf(stdout, "%13.10f, %13.10f = %s %s %s %s (UTM: %d %.2f, %.2f %c)\n",
          lon, lat,
          part1.c_str(), part2.c_str(), part3.c_str(), part4.c_str(),
          zone, x, y, northp ? 'N' : 'S');
  return 0;
}