/* $Id$ */
/* gpsclient.c -- support functions for GPSD clients */
#include <sys/time.h>
#include <stdio.h>
#ifndef S_SPLINT_S
#include <unistd.h>
#endif /* S_SPLINT_S */
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdarg.h>
#include <math.h>
#include <assert.h>

#include "gpsd_config.h"
#include "gps.h"
#include "gpsdclient.h"

#ifdef HAVE_SETLOCALE
#include <locale.h>
#endif

/* convert double degrees to a static string and return a pointer to it
 *
 * deg_str_type:
 *   	deg_dd     : return DD.dddddd
 *      deg_ddmm   : return DD MM.mmmm'
 *      deg_ddmmss : return DD MM' SS.sss"
 *
 */
/*@observer@*/char *deg_to_str( enum deg_str_type type,  double f) 
{
    static char str[40];
    int dsec, sec, deg, min;
    long frac_deg;
    double fdsec, fsec, fdeg, fmin;

    if ( f < 0 || f > 360 ) {
	(void)strlcpy( str, "nan", 40);
	return str;
    }

    fmin = modf( f, &fdeg);
    deg = (int)fdeg;
    frac_deg = (long)(fmin * 1000000);

    if ( deg_dd == type ) {
	/* DD.dddddd */
	(void)snprintf(str, sizeof(str), "%3d.%06ld", deg,frac_deg);
	return str;
    }
    fsec = modf( fmin * 60, &fmin);
    min = (int)fmin;
    sec = (int)(fsec * 10000.0);

    if ( deg_ddmm == type ) {
	/* DD MM.mmmm */
	(void)snprintf(str,sizeof(str), "%3d %02d.%04d'", deg,min,sec);
	return str;
    }
    /* else DD MM SS.sss */
    fdsec = modf( fsec * 60, &fsec);
    sec = (int)fsec;
    dsec = (int)(fdsec * 1000.0);
    (void)snprintf(str,sizeof(str), "%3d %02d' %02d.%03d\"", deg,min,sec,dsec);

    return str;
}

/* 
 * check the environment to determine proper GPS units
 *
 * clients should only call this if no user preference is specified on 
 * the command line or via X resources.
 *
 * return imperial    - Use miles/feet
 *        nautical    - Use knots/feet
 *        metric      - Use km/meters
 *        unspecified - use compiled default
 * 
 * In order check these environment vars:
 *    GPSD_UNITS one of: 
 *            	imperial   = miles/feet
 *              nautical   = knots/feet
 *              metric     = km/meters
 *    LC_MEASUREMENT
 *		en_US      = miles/feet
 *              C          = miles/feet
 *              POSIX      = miles/feet
 *              [other]    = km/meters
 *    LANG
 *		en_US      = miles/feet
 *              C          = miles/feet
 *              POSIX      = miles/feet
 *              [other]    = km/meters
 *
 * if none found then return compiled in default
 */
enum unit gpsd_units(void)
{
	char *envu = NULL;

#ifdef HAVE_SETLOCALE
	(void)setlocale(LC_NUMERIC, "C");
#endif
  	if ((envu = getenv("GPSD_UNITS")) != NULL && *envu != '\0') {
		if (0 == strcasecmp(envu, "imperial")) {
			return imperial;
		}
		if (0 == strcasecmp(envu, "nautical")) {
			return nautical;
		}
		if (0 == strcasecmp(envu, "metric")) {
			return metric;
		}
		/* unrecognized, ignore it */
	}
 	if (((envu = getenv("LC_MEASUREMENT")) != NULL && *envu != '\0') 
 	    || ((envu = getenv("LANG")) != NULL && *envu != '\0')) {
		if (strcasecmp(envu, "en_US")==0 
		    || strcasecmp(envu, "C")==0
		    || strcasecmp(envu, "POSIX")==0) {
			return imperial;
		}
		/* Other, must be metric */
		return metric;
	}
	/* TODO: allow a compile time default here */
	return unspecified;
}

/*@ -observertrans -statictrans -mustfreeonly -branchstate -kepttrans @*/
void gpsd_source_spec(const char *arg, struct fixsource_t *source)
/* standard parsing of a GPS data source spec */
{
    source->server = "127.0.0.1";
    source->port = DEFAULT_GPSD_PORT;
    source->device = NULL;

    if (arg != NULL) {
	char *colon1;
	source->spec = strdup(arg);
	assert(source->spec != NULL);
	colon1 = strchr(source->spec, ':');

	if (colon1 != NULL) {
	    char *colon2;
	    *colon1 = '\0';
	    if (colon1 != source->spec)
		source->server = source->spec;
	    source->port = colon1 + 1;
	    colon2 = strchr(source->port, ':');
	    if (colon2 != NULL) {
		*colon2 = '\0';
		source->device = colon2 + 1;
	    }
	} else if (strchr(source->spec, '/') != NULL) {
	    source->device = source->spec;
	} else {
	    source->server = source->spec;
	}
    }
}
/*@ +observertrans -statictrans +mustfreeonly +branchstate +kepttrans @*/

/* gpsclient.c ends here */