/*
# This file is part of the Astrometry.net suite.
# Licensed under a 3-clause BSD style license - see LICENSE
*/
#include <string.h>
#include <math.h>
#include <assert.h>

#include "os-features.h"
#include "plotgrid.h"
#include "sip-utils.h"
#include "cairoutils.h"
#include "ioutils.h"
#include "log.h"
#include "errors.h"

DEFINE_PLOTTER(grid);

plotgrid_t* plot_grid_get(plot_args_t* pargs) {
	return plotstuff_get_config(pargs, "grid");
}

void* plot_grid_init(plot_args_t* plotargs) {
	plotgrid_t* args = calloc(1, sizeof(plotgrid_t));
	args->dolabel = TRUE;
	args->raformat = strdup("%.2f");
	args->decformat = strdup("%.2f");
	return args;
}

int plot_grid_set_formats(plotgrid_t* args, const char* raformat, const char* decformat) {
	free(args->raformat);
	free(args->decformat);
	args->raformat = strdup_safe(raformat);
	args->decformat = strdup_safe(decformat);
	return 0;
}

static void pretty_label(const char* fmt, double x, char* buf) {
	int i;
	sprintf(buf, fmt, x);
	logverb("label: \"%s\"\n", buf);
	// Look for decimal point.
	if (!strchr(buf, '.')) {
		logverb("no decimal point\n");
		return;
	}
	// Trim trailing zeroes (after the decimal point)
	i = strlen(buf)-1;
	while (buf[i] == '0') {
		buf[i] = '\0';
		logverb("trimming trailing zero at %i: \"%s\"\n", i, buf);
		i--;
		assert(i > 0);
	}
	// Trim trailing decimal point, if it exists.
	i = strlen(buf)-1;
	if (buf[i] == '.') {
		buf[i] = '\0';
		logverb("trimming trailing decimal point at %i: \"%s\"\n", i, buf);
	}
}

static int setdir(int dir, int* dirs, int* ndir) {
	switch (dir) {
	case DIRECTION_DEFAULT:
	case DIRECTION_POSNEG:
		dirs[0] = 1;
		dirs[1] = -1;
		*ndir = 2;
		break;
	case DIRECTION_POS:
		dirs[0] = 1;
		*ndir = 1;
		break;
	case DIRECTION_NEG:
		dirs[0] = -1;
		*ndir = 1;
		break;
	case DIRECTION_NEGPOS:
		dirs[0] = -1;
		dirs[1] = 1;
		*ndir = 2;
		break;
	default:
		return -1;
	}
	return 0;
}

int plot_grid_find_dec_label_location(plot_args_t* pargs, double dec, double cra, double ramin, double ramax, int dirn, double* pra) {
	double out;
	double in = cra;
	int i, N;
	anbool gotit;
	int dirs[2];
	int j, Ndir=0;
	logverb("Labelling Dec=%g\n", dec);
	gotit = FALSE;
	if (setdir(dirn, dirs, &Ndir))
		return -1;

	// dir is first 1, then -1.
	for (j=0; j<Ndir; j++) {
		int dir = dirs[j];
		for (i=1;; i++) {
			// take 10-deg steps
			out = cra + i*dir*10.0;
			if (out > 370.0 || out <= -10)
				break;
			out = MIN(360, MAX(0, out));
			logverb("ra in=%g, out=%g\n", in, out);
			if (!plotstuff_radec_is_inside_image(pargs, out, dec)) {
				gotit = TRUE;
				break;
			}
			if (!isfinite(in) || !isfinite(out))
				break;
		}
		if (gotit)
			break;
	}
	if (!gotit) {
		ERROR("Couldn't find an RA outside the image for Dec=%g\n", dec);
		return -1;
	}
	i=0;
	N = 10;
	while (!plotstuff_radec_is_inside_image(pargs, in, dec)) {
		if (i == N)
			break;
		in = ramin + (double)i/(double)(N-1) * (ramax-ramin);
		i++;
	}
	if (!plotstuff_radec_is_inside_image(pargs, in, dec))
		return -1;
	while (fabs(out - in) > 1e-6) {
		// hahaha
		double half;
		anbool isin;
		half = (out + in) / 2.0;
		isin = plotstuff_radec_is_inside_image(pargs, half, dec);
		if (isin)
			in = half;
		else
			out = half;
	}
	*pra = in;
	return 0;
}

int plot_grid_find_ra_label_location(plot_args_t* pargs, double ra, double cdec, double decmin, double decmax, int dirn, double* pdec) {
	double out;
	double in = cdec;
	int i, N;
	anbool gotit;
	int dirs[2];
	int j, Ndir=0;
	logverb("Labelling RA=%g\n", ra);
	// where does this line leave the image?
	// cdec is inside; take steps away until we go outside.
	gotit = FALSE;

	if (setdir(dirn, dirs, &Ndir))
		return -1;

	for (j=0; j<Ndir; j++) {
		int dir = dirs[j];
		logverb("direction: %i\n", dir);
		for (i=1;; i++) {
			// take 10-deg steps
			out = cdec + i*dir*10.0;
			logverb("trying Dec = %g\n", out);
			if (out >= 100.0 || out <= -100)
				break;
			out = MIN(90, MAX(-90, out));
			logverb("dec in=%g, out=%g\n", in, out);
			if (!plotstuff_radec_is_inside_image(pargs, ra, out)) {
				logverb("-> good!\n");
				gotit = TRUE;
				break;
			}
		}
		if (gotit)
			break;
	}
	if (!gotit) {
		ERROR("Couldn't find a Dec outside the image for RA=%g\n", ra);
		return -1;
	}
	// Now we've got a Dec inside the image (cdec)
	// and a Dec outside the image (out)
	// Now find the boundary.

	i=0;
	N = 10;
	while (!plotstuff_radec_is_inside_image(pargs, ra, in)) {
		if (i == N)
			break;
		in = decmin + (double)i/(double)(N-1) * (decmax-decmin);
		i++;
	}
	if (!plotstuff_radec_is_inside_image(pargs, ra, in))
		return -1;
	while (fabs(out - in) > 1e-6) {
		// hahaha
		double half;
		anbool isin;
		half = (out + in) / 2.0;
		isin = plotstuff_radec_is_inside_image(pargs, ra, half);
		if (isin)
			in = half;
		else
			out = half;
	}
	*pdec = in;
	return 0;
}

static int do_radec_labels(plot_args_t* pargs, plotgrid_t* args,
						   double ramin, double ramax,
						   double decmin, double decmax) {
	double cra, cdec;
	double ra, dec;

	args->dolabel = (args->ralabelstep > 0) || (args->declabelstep > 0);
	if (!args->dolabel)
		return 0;

	/*
	 if (args->ralabelstep == 0 || args->declabelstep == 0) {
	 // FIXME -- choose defaults
	 ERROR("Need grid_ralabelstep, grid_declabelstep");
	 return 0;
	 }
	 */
	logmsg("Adding grid labels...\n");
	plotstuff_get_radec_center_and_radius(pargs, &cra, &cdec, NULL);
	assert(cra >= ramin && cra <= ramax);
	assert(cdec >= decmin && cdec <= decmax);
	if (args->ralabelstep > 0) {
		double rlo, rhi;
		if (args->ralo != 0 || args->rahi != 0) {
			rlo = args->ralo;
			rhi = args->rahi;
		} else {
			rlo = args->ralabelstep * floor(ramin / args->ralabelstep);
			rhi = args->ralabelstep * ceil(ramax / args->ralabelstep);
		}
		for (ra = rlo; ra <= rhi; ra += args->ralabelstep) {
			double lra;
			if (plot_grid_find_ra_label_location(pargs, ra, cdec, decmin,
												 decmax, args->ralabeldir, &dec))
				continue;
			lra = ra;
			if (lra < 0)
				lra += 360;
			if (lra >= 360)
				lra -= 360;
			//logmsg("Label \"%s\" at (%g,%g)\n", label, ra, dec);
			plot_grid_add_label(pargs, ra, dec, lra, args->raformat);
		}
	}
	if (args->declabelstep > 0) {
		double dlo, dhi;
		if (args->declo != 0 || args->dechi != 0) {
			dlo = args->declo;
			dhi = args->dechi;
		} else {
			dlo = args->declabelstep * floor(decmin / args->declabelstep);
			dhi = args->declabelstep * ceil(decmax / args->declabelstep);
		}
		for (dec = dlo; dec <= dhi; dec += args->declabelstep) {
			if (plot_grid_find_dec_label_location(pargs, dec, cra, ramin,
												  ramax, args->declabeldir, &ra))
				continue;
			//logmsg("Label Dec=\"%s\" at (%g,%g)\n", label, ra, dec);
			plot_grid_add_label(pargs, ra, dec, dec, args->decformat);
		}
	}
	return 1;
}

void plot_grid_add_label(plot_args_t* pargs, double ra, double dec,
						 double lval, const char* format) {
	char label[32];
	double x,y;
#if 0
	anbool ok;
#endif
	cairo_t* cairo = pargs->cairo;
	pretty_label(format, lval, label);
#if 0
	ok = plotstuff_radec2xy(pargs, ra, dec, &x, &y);
#else
	(void)plotstuff_radec2xy(pargs, ra, dec, &x, &y);
#endif
	plotstuff_stack_text(pargs, cairo, label, x, y);
	plotstuff_plot_stack(pargs, cairo);
}

int plot_grid_plot(const char* command,
					cairo_t* cairo, plot_args_t* pargs, void* baton) {
	plotgrid_t* args = (plotgrid_t*)baton;
	double ramin,ramax,decmin,decmax;
	double ra,dec;

	if (!pargs->wcs) {
		ERROR("No WCS was set -- can't plot grid lines");
		return -1;
	}
	// Find image bounds in RA,Dec...
	plotstuff_get_radec_bounds(pargs, 50, &ramin, &ramax, &decmin, &decmax);
	/*
	 if (args->rastep == 0 || args->decstep == 0) {
	 // FIXME -- choose defaults
	 ERROR("Need grid_rastep, grid_decstep");
	 return -1;
	 }
	 */

	plotstuff_builtin_apply(cairo, pargs);
	pargs->label_offset_x = 0;
	pargs->label_offset_y = 10;
	
	logverb("Image bounds: RA %g, %g, Dec %g, %g\n",
			ramin, ramax, decmin, decmax);
	if (args->rastep > 0) {
		for (ra = args->rastep * floor(ramin / args->rastep);
			 ra <= args->rastep * ceil(ramax / args->rastep);
			 ra += args->rastep) {
			plotstuff_line_constant_ra(pargs, ra, decmin, decmax, TRUE);
			cairo_stroke(pargs->cairo);
		}
	}
	if (args->decstep > 0) {
		for (dec = args->decstep * floor(decmin / args->decstep);
			 dec <= args->decstep * ceil(decmax / args->decstep);
			 dec += args->decstep) {
			plotstuff_line_constant_dec(pargs, dec, ramin, ramax);
			cairo_stroke(pargs->cairo);
		}
	}

	if (do_radec_labels(pargs, args, ramin, ramax, decmin, decmax)) {
		plotstuff_plot_stack(pargs, cairo);
	}
	return 0;
}




int plot_grid_command(const char* cmd, const char* cmdargs,
					   plot_args_t* pargs, void* baton) {
	plotgrid_t* args = (plotgrid_t*)baton;
	if (streq(cmd, "grid_rastep")) {
		args->rastep = atof(cmdargs);
	} else if (streq(cmd, "grid_decstep")) {
		args->decstep = atof(cmdargs);
	} else if (streq(cmd, "grid_ralabelstep")) {
		args->ralabelstep = atof(cmdargs);
	} else if (streq(cmd, "grid_declabelstep")) {
		args->declabelstep = atof(cmdargs);
	} else if (streq(cmd, "grid_step")) {
		args->declabelstep = args->ralabelstep =
			args->rastep = args->decstep = atof(cmdargs);
	} else {
		ERROR("Did not understand command \"%s\"", cmd);
		return -1;
	}
	return 0;
}

void plot_grid_free(plot_args_t* plotargs, void* baton) {
	plotgrid_t* args = (plotgrid_t*)baton;
	free(args->raformat);
	free(args->decformat);
	free(args);
}