/*
 / _____)             _              | |
( (____  _____ ____ _| |_ _____  ____| |__
 \____ \| ___ |    (_   _) ___ |/ ___)  _ \
 _____) ) ____| | | || |_| ____( (___| | | |
(______/|_____)_|_|_| \__)_____)\____)_| |_|
  (C)2013 Semtech-Cycleo

Description:
	Minimum test program for the loragw_gps 'library'

License: Revised BSD License, see LICENSE.TXT file include in the project
Maintainer: Sylvain Miermont
*/


/* -------------------------------------------------------------------------- */
/* --- DEPENDANCIES --------------------------------------------------------- */

/* fix an issue between POSIX and C99 */
#if __STDC_VERSION__ >= 199901L
	#define _XOPEN_SOURCE 600
#else
	#define _XOPEN_SOURCE 500
#endif

#include <stdint.h>		/* C99 types */
#include <stdbool.h>	/* bool type */
#include <stdio.h>		/* printf */
#include <string.h>		/* memset */
#include <signal.h>		/* sigaction */
#include <stdlib.h>		/* exit */
#include <unistd.h>		/* read */

#include "loragw_hal.h"
#include "loragw_gps.h"
#include "loragw_aux.h"

/* -------------------------------------------------------------------------- */
/* --- PRIVATE VARIABLES ---------------------------------------------------- */

static int exit_sig = 0; /* 1 -> application terminates cleanly (shut down hardware, close open files, etc) */
static int quit_sig = 0; /* 1 -> application terminates without shutting down the hardware */

/* -------------------------------------------------------------------------- */
/* --- PRIVATE FUNCTIONS DECLARATION ---------------------------------------- */

static void sig_handler(int sigio);

/* -------------------------------------------------------------------------- */
/* --- PRIVATE FUNCTIONS DEFINITION ----------------------------------------- */

static void sig_handler(int sigio) {
	if (sigio == SIGQUIT) {
		quit_sig = 1;;
	} else if ((sigio == SIGINT) || (sigio == SIGTERM)) {
		exit_sig = 1;
	}
}

/* -------------------------------------------------------------------------- */
/* --- MAIN FUNCTION -------------------------------------------------------- */

int main()
{
	struct sigaction sigact; /* SIGQUIT&SIGINT&SIGTERM signal handling */
	
	int i;
	char tmp_str[80];
	
	/* serial variables */
	char serial_buff[128]; /* buffer to receive GPS data */
	ssize_t nb_char;
	int gps_tty_dev; /* file descriptor to the serial port of the GNSS module */
	
	/* NMEA variables */
	enum gps_msg latest_msg; /* keep track of latest NMEA message parsed */
	
	/* variables for PPM pulse GPS synchronization */
	uint32_t ppm_tstamp;
	struct timespec ppm_utc;
	struct tref ppm_ref;
	
	/* variables for timestamp <-> UTC conversions */
	uint32_t x, z;
	struct timespec y;
	
	/* configure signal handling */
	sigemptyset(&sigact.sa_mask);
	sigact.sa_flags = 0;
	sigact.sa_handler = sig_handler;
	sigaction(SIGQUIT, &sigact, NULL);
	sigaction(SIGINT, &sigact, NULL);
	sigaction(SIGTERM, &sigact, NULL);
	
	/* Intro message and library information */
	printf("Beginning of test for loragw_gps.c\n");
	printf("*** Library version information ***\n%s\n***\n", lgw_version_info());
	
	/* Open and configure GPS */
	i = lgw_gps_enable("/dev/ttyACM0", NULL, 0, &gps_tty_dev);
	if (i != LGW_GPS_SUCCESS) {
		printf("ERROR: IMPOSSIBLE TO ENABLE GPS\n");
		exit(EXIT_FAILURE);
	}
	
	/* start concentrator */
	lgw_start();
	
	/* initialize some variables before loop */
	memset(serial_buff, 0, sizeof serial_buff);
	memset(&ppm_ref, 0, sizeof ppm_ref);
	
	/* loop until user action */
	while ((quit_sig != 1) && (exit_sig != 1)) {
		/* blocking canonical read on serial port */
		nb_char = read(gps_tty_dev, serial_buff, sizeof(serial_buff)-1);
		if (nb_char <= 0) {
			printf("Warning: read() returned value <= 0\n");
			continue;
		} else {
			serial_buff[nb_char] = 0;
		}
		
		/* parse the received NMEA */
		latest_msg = lgw_parse_nmea(serial_buff, sizeof(serial_buff));
		
		if (latest_msg == NMEA_RMC) {
			
			printf("\n~~ RMC NMEA sentence, triggering synchronization attempt ~~\n");
			
			/* get UTC time for synchronization */
			i = lgw_gps_get(&ppm_utc, NULL, NULL);
			if (i != LGW_GPS_SUCCESS) {
				printf("    No valid reference UTC time available, synchronization impossible.\n");
				continue;
			}
			/* get timestamp for synchronization */
			i = lgw_get_trigcnt(&ppm_tstamp);
			if (i != LGW_HAL_SUCCESS) {
				printf("    Failed to read timestamp, synchronization impossible.\n");
				continue;
			}
			/* try to update synchronize time reference with the new UTC & timestamp */
			i = lgw_gps_sync(&ppm_ref, ppm_tstamp, ppm_utc);
			if (i != LGW_GPS_SUCCESS) {
				printf("    Synchronization error.\n");
				continue;
			}
			/* display result */
			printf("    * Synchronization successful *\n");
			strftime(tmp_str, sizeof(tmp_str), "%F %T", gmtime(&(ppm_ref.utc.tv_sec)));
			printf("    UTC reference time: %s.%09ldZ\n", tmp_str, ppm_ref.utc.tv_nsec);
			printf("    Internal counter reference value: %u\n", ppm_ref.count_us);
			printf("    Clock error: %.9f\n", ppm_ref.xtal_err);
			
			x = ppm_tstamp + 500000;
			printf("    * Test of timestamp counter <-> UTC value conversion *\n");
			printf("    Test value: %u\n", x);
			lgw_cnt2utc(ppm_ref, x, &y);
			strftime(tmp_str, sizeof(tmp_str), "%F %T", gmtime(&(y.tv_sec)));
			printf("    Conversion to UTC: %s.%09ldZ\n", tmp_str, y.tv_nsec);
			lgw_utc2cnt(ppm_ref, y, &z);
			printf("    Converted back: %u\n", z);
		}
	}
	
	/* clean up before leaving */
	if (exit_sig == 1) {
		lgw_stop();
	}
	
	printf("\nEnd of test for loragw_gps.c\n");
	exit(EXIT_SUCCESS);
}

/* --- EOF ------------------------------------------------------------------ */