#include <stdio.h>
#include <string.h>
#include <stdlib.h>


/*
*    Evaluates Generic/DCF, PPS/SHM and average offset
*
*    Copyright (C) 2018 - 2024 R.J. van der Putten, Leiden, Holland, 
*    rob at sput dot nl.
* 
*    This program is free software; you can redistribute it and/or modify
*    it under the terms of the GNU General Public License version 3 as
*    published by the Free Software Foundation.
* 
*    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.
*/


int main(int argc, char **argv)
{
    FILE *p1;
    char line[128], remt[32];
    int df, i, reach, sumcnt;
    double avgoff, dcfoff, offset, ppsoff;

    p1 = NULL;
    memset(line, 0, 128);
    memset(remt, 0, 32);
    df = 0;
    i = 0;
    reach = 0;
    sumcnt = 0;		/*  Sum count  */
    avgoff = 0.0;	/*  Average offset  */
    dcfoff = 0.0;	/*  DCF offset  */
    offset = 0.0;	/*  Offset currently being read  */
    ppsoff = 0.0;	/*  PPS offset  */

    if (argc > 1) {
	for (i = 1; i < argc; i++) {
	    if(strcmp(argv[i], "-d") == 0)
		df = 1;
	}
    }

    if ((p1 = popen("/usr/bin/ntpq -p", "r")) == NULL) {
	fprintf(stderr, "Cant open: /usr/bin/ntpq -p\n");
	exit(1);
    }

    avgoff = 0.0;
    i = 0;
    sumcnt = 0;
    while (fgets(line, 128, p1)) {
	if (i > 1) {
	    /*  Ignore first two lines  */
	    if (sscanf(line, "%31s %*s %*s %*s %*s %*s %d %*s %lf %*s", \
	      remt, &reach, &offset) == 3) {
		/*   [ *+]Remote  */
		if (strncmp(line + 1, "RAWDCF_CONRAD", 13) == 0 || \
		  strncmp(line + 1, "127.127.8.", 10) == 0) {
		    dcfoff = offset;
		} else if (strncmp(line + 1, "SHM", 3) == 0 || \
		  strncmp(line + 1, "127.127.28.", 11) == 0) {
		    ppsoff = offset;
		} else if (strncmp(line + 1, "NMEA", 4) != 0 || \
		  strncmp(line + 1, "127.127.20.", 11) == 0) {
		    //if (reach != 0 && offset > -0.4 && offset < 0.4 ) {
		    if (reach != 0 && offset > -1.0 && offset < 1.0 ) {
			avgoff = avgoff + offset;
			if(df != 0)
			    printf("%d %s\t%f\n", sumcnt, remt, offset);
			sumcnt++;
		    }
		}
	    }
	}
	i++;
    }
    pclose(p1);

    if (sumcnt != 0)
	avgoff = avgoff / (double) sumcnt;
    if (df != 0) {
	printf("Cnt: %d\nDCF: %f\nPPS: %f\nAvg: %f\n", \
	  sumcnt, dcfoff, ppsoff, avgoff);
    }

    if(sumcnt < 2 || \
      //ppsoff < -0.2 || ppsoff > 0.2 || 
      ppsoff < -0.5 || ppsoff > 0.5 || \
      //avgoff < -0.2 || avgoff > 0.2)
      avgoff < -0.7 || avgoff > 0.7)
	/*  Dodgy sync  */
	printf("0\n");
    else
	printf("1\n");

    return(0);
}