/*
  This file is part of the Astrometry.net suite.
  Copyright 2006, 2007 Dustin Lang, Keir Mierle and Sam Roweis.

  The Astrometry.net suite is free software; you can redistribute
  it and/or modify it under the terms of the GNU General Public License
  as published by the Free Software Foundation, version 2.

  The Astrometry.net suite is distributed in the hope that it will be
  useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with the Astrometry.net suite ; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
*/

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "healpix.h"
#include "healpix-utils.h"
#include "starutil.h"
#include "mathutil.h"
#include "bl.h"

#define OPTIONS "hdN:npH:drR:"

void print_help(char* progname) {
    printf("usage:\n"
		   "  %s [options] ra dec\n"
		   "     [-r]: values in radians; default is in decimal degrees or H:M:S\n"
		   "  OR,\n"
		   "  %s x y z\n\n"
 		   "    [-H <healpix>]: take healpix number as input and print center as output.\n"
		   "    [-N nside]  (default 1)\n"
		   "    [-n]: print neighbours\n"
		   "    [-R <range>]: print healpixes within radius <range> in degrees\n"
		   "    [-p]: project position within healpix\n"
		   "If your values are negative, add \"--\" in between \"-r\" (if you're using it) and \"ra\" or \"x\".\n\n",
		   progname, progname);
}

int main(int argc, char** args) {
    int healpix = -1;
    int i;
    anbool degrees = TRUE;
	double radius = HUGE_VAL;
    int nargs;
    int c;
	int Nside = 1;
	anbool neighbours = FALSE;
	anbool project = FALSE;
	double xyz[3];
	anbool fromhp = FALSE;

    if (argc == 1) {
		print_help(args[0]);
		exit(0);
    }

    while ((c = getopt(argc, args, OPTIONS)) != -1) {
        switch (c) {
		case '?':
        case 'h':
			print_help(args[0]);
			exit(0);
		case 'H':
			fromhp = TRUE;
			healpix = atoi(optarg);
			break;
		case 'd':
			// No-op
			break;
		case 'r':
			degrees = FALSE;
			break;
		case 'R':
			radius = atof(optarg);
			break;
		case 'N':
			Nside = atoi(optarg);
			break;
		case 'n':
			neighbours = TRUE;
			break;
		case 'p':
			project = TRUE;
		}
    }

    nargs = argc - optind;
	args += optind;

	if (!fromhp) {
		double ra, dec;
		if (!((nargs == 2) || (nargs == 3))) {
			print_help(args[0]);
			exit(-1);
		}
		if (nargs == 2) {
			ra  = atora (args[0]);
			dec = atodec(args[1]);
			if (!degrees) {
				ra  = rad2deg(ra);
				dec = rad2deg(dec);
			}
			healpix = radecdegtohealpix(ra, dec, Nside);
			if (!degrees)
				printf("(RA, DEC) = (%g, %g) radians\n", ra, dec);
			printf("(RA, DEC) = (%g, %g) degrees\n", ra, dec);
			radecdeg2xyzarr(ra, dec, xyz);

		} else if (nargs == 3) {
			xyz[0] = atof(args[0]);
			xyz[1] = atof(args[1]);
			xyz[2] = atof(args[2]);
			healpix = xyzarrtohealpix(xyz, Nside);
			printf("(x, y, z) = (%g, %g, %g)\n", xyz[0], xyz[1], xyz[2]);
			xyzarr2radecdeg(xyz, &ra, &dec);
			printf("(RA, DEC) = (%g, %g) degrees\n", ra, dec);
		}
	}
	{
		int ri;
		int ringnum, longind;
		int bighp, x, y;
        double ra, dec;
        double ramin, ramax;
        double decmin, decmax;
		healpix_decompose_xy(healpix, &bighp, &x, &y, Nside);
		printf("Healpix=%i in the XY scheme (bighp=%i, x=%i, y=%i)\n",
			   healpix, bighp, x, y);
		ri = healpix_xy_to_ring(healpix, Nside);
		healpix_decompose_ring(ri, Nside, &ringnum, &longind);
		printf("  healpix=%i in the RING scheme (ringnum=%i, longind=%i)\n",
			   ri, ringnum, longind);
		if (is_power_of_two(Nside)) {
			int ni = healpix_xy_to_nested(healpix, Nside);
			printf("  healpix=%i in the NESTED scheme.\n", ni);
		}
		healpix_to_radecdeg(healpix, Nside, 0.5, 0.5, &ra, &dec);
		printf("Healpix center is (%.8g, %.8g) degrees\n", ra, dec);
		// the point with smallest RA is (0,1); largest is (1,0).
		// southmost (min Dec) is (0,0); northmost is (1,1).
        healpix_to_radecdeg(healpix, Nside, 0.0, 1.0, &ramin, &dec);
        healpix_to_radecdeg(healpix, Nside, 1.0, 0.0, &ramax, &dec);
        healpix_to_radecdeg(healpix, Nside, 0.0, 0.0, &ra, &decmin);
        healpix_to_radecdeg(healpix, Nside, 1.0, 1.0, &ra, &decmax);
        printf("Healpix is bounded by RA=[%g, %g], Dec=[%g, %g] degrees.\n",
               ramin, ramax, decmin, decmax);
	}

	if (neighbours) {
		int neigh[8];
		int nneigh;
		nneigh = healpix_get_neighbours(healpix, neigh, Nside);
		printf("Neighbours=[ ");
		for (i=0; i<nneigh; i++)
			printf("%i ", neigh[i]);
		printf("]\n");
	}

	if (radius != HUGE_VAL) {
		il* hps;
		printf("Healpixes within radius %g degrees: [", radius);
		hps = healpix_rangesearch_xyz(xyz, radius, Nside, NULL);
		for (i=0; i<il_size(hps); i++) {
			printf("%i ", il_get(hps, i));
		}
		printf("]\n");
	}

	printf("Healpix scale is %g arcsec.\n", 60*healpix_side_length_arcmin(Nside));

	if (!fromhp && project) {
		double origin[3];
		double vx[3];
		double vy[3];
		double normal[3];
		double proj1[3];
		double proj2[3];
		double max1, max2;
		int d;
		double dot1, dot2;
		double bdydist;
		double* bdydir;
		double d2;

		healpix_to_xyzarr(healpix, Nside, 0.0, 0.0, origin);
		healpix_to_xyzarr(healpix, Nside, 1.0, 0.0, vx);
		healpix_to_xyzarr(healpix, Nside, 0.0, 1.0, vy);
		for (d=0; d<3; d++) {
			vx[d] -= origin[d];
			vy[d] -= origin[d];
		}
		cross_product(vx, vy, normal);
		cross_product(normal, vx, proj1);
		cross_product(vy, normal, proj2);
		max1 = max2 = 0.0;
		for (d=0; d<3; d++) {
			max1 += vy[d] * proj1[d];
			max2 += vx[d] * proj2[d];
		}

		dot1 = dot2 = 0.0;
		for (d=0; d<3; d++) {
			dot1 += proj1[d] * (xyz[d] - origin[d]);
			dot2 += proj2[d] * (xyz[d] - origin[d]);
		}

		printf("Projects to [%g, %g]\n", dot1/max1, dot2/max2);

		// which boundary is it closest to?
		bdydir = vx;
		if (dot1/max1 < 0.5)
			bdydist = dot1/max1;
		else
			bdydist = 1.0 - dot1/max1;

		if (dot2/max2 < bdydist) {
			bdydist = dot2/max2;
			bdydir = vy;
		} else if ((1.0 - dot2/max2) < bdydist) {
			bdydist = 1.0 - dot2/max2;
			bdydir = vy;
		}

		d2 = bdydir[0]*bdydir[0] + bdydir[1]*bdydir[1] + bdydir[2]*bdydir[2];
		d2 *= bdydist*bdydist;

		printf("Closest boundary %g arcsec away.\n", distsq2arcsec(d2));

	}


    return 0;
}
