#include "geomag.h"

#include <time.h>

#include <math.h>

static char usage[] = " Usage:\n"

                      "   magdec lon lat [year [month [day]]]\n"

                      "     lon, lat: in decimal degrees\n"

                      "     year, month, day: integer date\n"

                      "          or just decimal year\n"

                      "   If no date is given, the present date is used\n"

                      "   1 is substituted for missing month and/or day\n\n"

                      "   Prints to stdout: 4 floating point"

                      "  numbers separated by spaces:\n"

                      "     declination, inclination in degrees\n"

                      "     horizontal field, total field in nanoTeslas\n\n"

                      " "

                      " Note: this version uses IGRF11, released in Dec. 2009."

                      "       Model parameters are hard-coded; no external"

                      "       file is needed."

                      "";

int main(int argc, char **argv)

{

    struct model_t **model_array;

    int nmodels;

    double dtest, itest, htest, ftest;

    int year, month, day;

    double dyear;

    double lon, lat;

    struct tm *now;

    time_t now_seconds;

    int nscan;

    if (argc < 3 || argc > 6)

    {

        puts(usage);

        return 1;

    }

    nscan = sscanf(argv[1], "%lf", &lon);

    nscan += sscanf(argv[2], "%lf", &lat);

    if (nscan != 2)

    {

        puts(usage);

        return 1;

    }

    if (argc == 3)

    {

        now_seconds = time(NULL);

        now = gmtime(&now_seconds);

        year = now->tm_year + 1900;

        month = now->tm_mon + 1;

        day = now->tm_mday;

    }

    else

    {

        if (argc == 4)

        {

            dyear = atof(argv[3]);

            /* the rest won't actually be used in this case */

            year = (int)dyear;

            month = 1 + (int)((dyear - year) * 12);

            day = 1;

        }

        if (argc > 4)

        {

            year = atoi(argv[3]);

            month = atoi(argv[4]);

            day = 1;

        }

        if (argc == 6)

        {

            day = atoi(argv[5]);

        }

    }

    if (argc != 4)

    {

        dyear = julday(month, day, year);

        /* julday function is mis-named--it simply returns decimal year */

    }

    while (lon > 180.0)

    {

        lon -= 360.0;

    }

    while (lon < -180.0)

    {

        lon += 360.0;

    }

    /* printf("lon %lf lat %lf dyear %lf year %d month %d day %d\n",

     *       lon, lat, dyear, year, month, day);

     */

    nmodels = models_from_lines(&model_array);

    dihf_from_models(model_array, nmodels,

                        dyear, lon, lat,

                        &dtest, &itest, &htest, &ftest);

    printf("%lf %lf %lf %lf\n",

              dtest, itest, htest, ftest);

    free_models(model_array, nmodels);

    return 0;

}