/*
    Write points to Franson Technology GpsGate simulator
 
    Copyright (C) 2006  Robert Lipe, robertlipe@usa.net

    This program 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; either version 2 of the License, or
    (at your option) any later version.

    This program 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 this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111 USA

 */
 
#include "defs.h"

#define MYNAME "gpssim"

static FILE *fout;
static char *wayptspd;
static char *splitfiles_opt;
static int splitfiles;
static char *fnamestr;
static int trk_count;
static int doing_tracks;

static
arglist_t gpssim_args[] = {
	{ "wayptspd", &wayptspd, "Default speed for waypoints (knots/hr)", 
		NULL, ARGTYPE_FLOAT, ARG_NOMINMAX },
	{ "split", &splitfiles_opt, "Split input into separate files", 
		"0", ARGTYPE_BOOL, ARG_NOMINMAX },
	ARG_TERMINATOR
};

/*
 * The only thing kind of odd about this format is the "split"
 * option.  There's some trashing about with the 'splitfiles' toggle 
 * to ensure that waypoints land in one file and each track and each
 * route land in files of their own.
 */

static void
gpssim_wr_init(const char *fname)
{
	fnamestr =  xstrdup(fname);
	trk_count = 0;
	splitfiles = splitfiles_opt ? atoi(splitfiles_opt) : 0;

	/* If writing to stdout, never split files */
	if (0 == strcmp("-",splitfiles_opt)) {
		splitfiles = 0;
	}

	if (!splitfiles) {
		fout = xfopen(fname, "wb", MYNAME);
	}
}

static void
gpssim_wr_deinit(void)
{
	if (fout) {
		fclose(fout);
		fout = NULL;
	}

	xfree(fnamestr);
}


/*
 * All these files are written in binary mode, so put CR/NL pairs
 * in them explictly in case we're writing from a UNIX-like host.
 */

static void 
gpssim_write_sentence(const char *const s)
{
	fprintf(fout, "$%s*%02X\r\n", s, nmea_cksum(s));
}

static void
gpssim_write_spd(double knotsperhour)
{
	char obuf[1024];

	snprintf(obuf, sizeof(obuf), "FRSPD,%.2f", knotsperhour);
	gpssim_write_sentence(obuf);
}

#define mpsec2knots(n) ((n) * 1.9438445 / 0.51444444)

static void
gpssim_write_pt(const waypoint *wpt)
{
	char obuf[1024];
	double lat, lon;

	if (wpt->speed > 0) {
		gpssim_write_spd(mpsec2knots(wpt->speed));
	}

	lat = degrees2ddmm(wpt->latitude);
	lon = degrees2ddmm(wpt->longitude);

	snprintf(obuf, sizeof(obuf), "FRWPT,%10.5f,%c,%011.5f,%c,%.1f",
		fabs(lat), lat < 0 ? 'S' : 'N', 
		fabs(lon), lon < 0 ? 'W' : 'E', 
		wpt->altitude == unknown_alt ? 0 : wpt->altitude
	);

        if ( wpt->creation_time ) {
		char tbuf[20];
		int hms, ymd;
		struct tm *tm;  

		tm = gmtime(&wpt->creation_time);
                hms = tm->tm_hour * 10000 + tm->tm_min * 100 + tm->tm_sec;
                ymd = tm->tm_mday * 10000 + tm->tm_mon * 100 + tm->tm_year;
		snprintf(tbuf, sizeof(tbuf), ",%d,%d",ymd, hms);
		strcat(obuf, tbuf);
        }

	gpssim_write_sentence(obuf);
}

static void
gpssim_trk_hdr(const route_head *rh)
{
	if (splitfiles) {
		char c[1024];
		char *ofname = xstrdup(fnamestr);
		
		if (fout) {
			fatal(MYNAME ": output file already open.\n");
		}

		snprintf(c, sizeof(c), "%s%04d.gpssim", 
			doing_tracks ? "-track" : "-route",
			trk_count++);
		ofname = xstrappend(ofname, c);
		fout = xfopen(ofname, "wb", MYNAME);
		xfree(ofname);
	}
	track_recompute(rh, NULL);
}

static void
gpssim_trk_ftr(const route_head *rh)
{
	if (splitfiles) {
		fclose(fout);
		fout = NULL;
	}
}

static void
gpssim_write(void)
{
	if (waypt_count()) {
		if (splitfiles) {
			char *ofname = xstrdup(fnamestr);
			ofname = xstrappend(ofname, "-waypoints.gpssim");
			fout = xfopen(ofname, "wb", MYNAME);
			xfree(ofname);
		}
		if (wayptspd && wayptspd[0]) {
			gpssim_write_spd(atof(wayptspd));
		}
		waypt_disp_all(gpssim_write_pt);
		if (splitfiles) {
			fclose(fout);
			fout = NULL;
		}
	}

	doing_tracks = 1;
	track_disp_all(gpssim_trk_hdr, gpssim_trk_ftr, gpssim_write_pt);

	trk_count = 0;
	doing_tracks = 0;
	route_disp_all(gpssim_trk_hdr, gpssim_trk_ftr, gpssim_write_pt);
}


ff_vecs_t gpssim_vecs = {
	ff_type_file,
	{ ff_cap_write, ff_cap_write, ff_cap_write },
	NULL,	
	gpssim_wr_init,	
	NULL,	
	gpssim_wr_deinit,	
	NULL,
	gpssim_write,
	NULL,
	gpssim_args,
	CET_CHARSET_ASCII, 0
};