/*
 * Read network log files (satlinkstats) and create a list of failures and duration.
 *
 * $Id: net-failures.c,v 1.14 2019/10/17 05:28:07 grog Exp grog $
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "timefuncs.h"

#define SMALLBUF 20
#define DAY 86400

time_t start_timestamp;                         /* time to start evaluation */
# define END_OF_TIME 0x7ff00000
time_t end_timestamp = END_OF_TIME;              /* time to end evaluation */

time_t midnight;                                /* timestamp of midnight today */
time_t start_outage;                            /* timestamp current outage started */
time_t last_outage_end;                         /* timestamp previous outage ended */
time_t uptime;                                  /* time up between last outage and this one */

time_t first_sample;                            /* first entry in input */

int outages;                                    /* total number of outages */
int outage_time;                                /* and total time */
int longest_outage = 0;				/* time of longest outage */

/* these copies over entire time */
int total_outages;                              /* total number of outages */
int total_outage_time;                          /* and total time */

char todays_date [SMALLBUF];                    /* YYYYMMDD date */
char last_date [SMALLBUF];                      /* YYYYMMDD date */

/* Info from input */
time_t now;                                     /* current entry timestamp */
float linkstat;                                 /* link status */
int systems;                                    /* number of systems available */
char comments [1024];

char now_date [SMALLBUF];                       /* YYYYMMDD from last input */

int link_state = 1;                             /* current state of link */

char start_time [80];                           /* start time for printing */
char end_time [80];                             /* end time for printing */
char longest_outage_start [80];			/* and times to save */
char longest_outage_end [80];

int all_disconnects;                            /* set to count only link dropouts */
int summarystats;                               /* set if we want stats per day instead of per incident */
int summary;					/* for non-summary only: one line summary over total period */
/*
 * Verbosity.  1 is -v (more stuff, but not now), and -1 is "ignore days with
 * perfect record"
 */
int verbose = 0;
void usage (char *me)
{
  fprintf (stderr,
           "Usage:\n"
           "\t%s [-c] [-e end-date] [-s start-date] [-S] [-q] [-v]\n"
           "\t-c:\toutput count and duration of outages per day\n"
           "\t-e\tend at date\n"
           "\t-s\tstart at date\n"
           "\t-S\tproduce one-line summary\n"
           "\t-q\tbrief output (ignore days with perfect uptime)\n"
           "\t-v:\tverbose output\n"
           "\tOtherwise output details of each outage\n",
           me );
  exit (1);
}

/*
 * Read in a line and parse to global locations.
 * Return 1 for success, 0 for failure (presumably EOF).
 */
int getinfo ()
{
  char line [1024];
  if (fgets (line, 1024, stdin) == NULL)
    return 0;
  if (sscanf (line, "%d %f %d %s\n", (int *) &now, &linkstat, &systems, comments) != 4)
  {
    puts (line);
    return 0;
  }
  if ((all_disconnects == 0) && (systems > 0))
    linkstat = 1.0;                             /* no fake link down messages */
  strftime (now_date, 8, "%Y%m%d", localtime (&now));
  return 1;
}

char *HMS (int seconds, char *result)
{
  int minutes = seconds / 60;
  int hours = seconds / 3600;

  minutes -= hours* 60;
  seconds = seconds % 60;
  if (hours > 23)
  {
    int days = hours / 24;
    hours %= 24;
    sprintf (result, "%d days, %02d:%02d:%02d", days, hours, minutes, seconds);
  }
  else
    sprintf (result, "%02d:%02d:%02d", hours, minutes, seconds);
  return result;
}

/*
 * Print statistics for a day when using -c option.
 */
void print_stats ()
{
  int duration = DAY;                           /* default to a day at a time */
  time_t now = time (NULL);
  if ((now - midnight) < duration)
    duration = now - midnight;

  if (link_state == 0)                          /* still down, */
  {
    outage_time += midnight + duration - start_outage;
    /*
     * We're making the implicit assumption here that our data are
     * complete.  If we miss a day, it means that we've been down all
     * that time.  But I don't check this when I print things out, at
     * least not at the moment, so we could end up with outages
     * lasting more than a day (correct) and availability < 0
     * (incorrect)..
     */
    start_outage = midnight + duration;         /* for next time */
  }
  /*
   * Convert to readable format.
   *
   * output format:
   * timestamp for start of day
   * number of outages
   * duration of outages
   * % uptime
   * # date
   */
  if (outages || (verbose >= 0))		/* no outages, print anyway */
    {
    strftime (start_time, 80, "%e %B %Y", localtime (&midnight));
    printf ("%d\t%3d\t%6d\t%6.2f%%\t# %s\n",
	    (int) midnight,
	    outages,
	    outage_time,
	    (float) (duration - outage_time) * 100 / duration,
	    start_time );
    total_outage_time += outage_time;
    if (outage_time > longest_outage)		/* we have a new front runner*/
      longest_outage = outage_time;
    outage_time = 0;
    total_outages += outages;
    outages = 0;
    }
}

int main (int argc, char *argv [])
{
  char total_hms [20];
  char average_hms [20];
  char duration_hms [20];
  char longest_hms [20];
  char mydate [80];

  time (&now);
  if (argc > 1)
    {
    int i;
    for (i = 1; i < argc; i++)
      {
      if (! strcmp (argv [i], "-a"))
        all_disconnects = 1;
      else if (! strcmp (argv [i], "-c"))
        summarystats = 1;
      else if (! strcmp (argv [i], "-e"))
	{
        i++;
        end_timestamp = get_date (argv, &i, now);
	}
      else if (! strcmp (argv [i], "-q"))
	verbose = -1;
      else if (! strcmp (argv [i], "-s"))
	{
        i++;
        start_timestamp = get_date (argv, &i, now);
	}
      else if (! strcmp (argv [i], "-S"))
	{
	summary = 1;
	verbose = -1;
	}
      else if (! strcmp (argv [i], "-v"))
        verbose = 1;
      else
        usage (argv [0]);
      }
    }

  /* Find the beginning of the period we're interested in. */
  do
    getinfo ();
  while (now < start_timestamp);
  first_sample = now;                           /* we now have the first sample  */
  if (summarystats)                             /* per day version */
    {
    int sample_duration;

    printf ("Date        Outages   Duration  Availability\n");
    do
      {
      strftime (todays_date, 80, "%e %B %Y", localtime (&now));
      if (strcmp (todays_date, last_date))    /* new day */
        {
	struct tm midnight_tm;

	if (*last_date)                       /* we already had something */
	  print_stats ();
	memset (&midnight_tm, 0, sizeof (midnight_tm));
	midnight_tm.tm_isdst = -1;            /* mktime should make up its own mind about DST */
	strptime (todays_date, " %e %B %Y", &midnight_tm);
	midnight = mktime (&midnight_tm);
	strcpy (last_date, todays_date);
        }

      if (link_state)                         /* we were up */
        {
	if (linkstat == 0.0)                  /* we've gone down now */
          {
	  outages++;                          /* another one */
	  start_outage = now;
	  link_state = 0;
          }
        }
      else
        {
	if (linkstat != 0.0)                  /* we've come up */
          {
	  outage_time += now - start_outage;
	  link_state = 1;
          }
        }
      /* XXX does this make any sense? */
      if (verbose > 0)
	printf ("%d %f %d %d %s\n", (int) now, linkstat, link_state, systems, comments);
      }
    while (getinfo () && (now < (end_timestamp + DAY)));
    print_stats ();
    /* Summary over period */
    /*
     * To calculate our uptime, don't go before start or beyond now */
    if (first_sample > start_timestamp)
      start_timestamp = first_sample;
    if (time (NULL) < end_timestamp)
      end_timestamp = time (NULL);
    sample_duration = end_timestamp - start_timestamp;
    printf ("Total:\t\t%3d outages, %6d seconds, longest %3d, availability%6.2f%%\n",
	    total_outages,
	    total_outage_time,
	    longest_outage,
	    (float) (sample_duration - total_outage_time) * 100 / sample_duration);
    exit (0);
    }

  /*
   * Default: print info for each outage.  Suppressed by -q flag (sets verbose = -1).
   */
  if (verbose >= 0)
    printf ("Start time End time\tDuration\tBadness\n");
  do
    {
    if (verbose > 0)
      printf ("%d %f %d %s\n", (int) now, linkstat, systems, comments);
    if (link_state)                             /* we were up */
      {
      if (linkstat == 0.0)                      /* we've gone down now */
	{
        outages++;                              /* another one */
        start_outage = now;
        link_state = 0;
	}
      }
    else
      {
      if (linkstat != 0.0)                      /* we've come up */
	{
	int this_outage = now - start_outage;

        outage_time += this_outage;
        if (last_outage_end)
          uptime = start_outage - last_outage_end;
        last_outage_end = now;
        /* convert to readable format */
        strftime (start_time, 80, "%e %B %Y %H:%M:%S", localtime (&start_outage));
        strftime (end_time, 80, "%e %B %Y %H:%M:%S", localtime (&now));
	if (verbose >= 0)
	  if (uptime)
	    printf ("%d %d %6d\t%7.3f\t# %s %s\n",
		    (int) start_outage,
		    (int) now,
		    this_outage,
		    3600 / (float) uptime,
		    start_time,
		    end_time );
	  else
	    printf ("%d %d %6d\t\t# %s %s\n",
		    (int) start_outage,
		    (int) now,
		    this_outage,
		    start_time,
		    end_time );
	if (longest_outage < this_outage)	/* we have a new front-runner */
	  {
	  longest_outage = this_outage;
	  strcpy (longest_outage_start, start_time);
	  strcpy (longest_outage_end, end_time);
	  }
        start_outage = 0;                       /* we don't really need this */
        link_state = 1;
	}
      }
    }
  while (getinfo () && (now < (end_timestamp + DAY)));

  HMS (outage_time, total_hms);
  if (outages)
    {
    int average_time = (int) (now - first_sample) / outages;
    int duration = outage_time / outages;
    float availability = (float) (now - first_sample - outage_time) * 100 / (float) (now - first_sample);

    if (summary)					/* really only one line */
      {
      if (start_timestamp)
	{
	strftime (mydate, 80, "%F", localtime (&start_timestamp));
	printf ("%s ", mydate);
	}
      else
	printf ("-");
      if (end_timestamp < END_OF_TIME)
	{
	strftime (mydate, 80, "%F", localtime (&end_timestamp));
	printf ("%s ", mydate);
	}
      else
	printf ("-");
      /* Format: start date  end date  count  total  longest time between  duration  availability */
      printf ("%3d\t%d\t%d\t%d\t%d\t%5.2f\n",
	      outages,
	      outage_time,
	      longest_outage,
	      average_time,
	      duration,
	      100.0 - availability );
      }
    else
      {
      HMS ((now - first_sample) / outages, average_hms);
      HMS (outage_time / outages, duration_hms);
      HMS (longest_outage, longest_hms);
      printf ("\nSummary");
      if (start_timestamp)
	{
	strftime (mydate, 80, "%e %B %G", localtime (&start_timestamp));
	printf (" from %s", mydate);
	}
      if (end_timestamp < END_OF_TIME)
	{
	strftime (mydate, 80, "%e %B %G", localtime (&end_timestamp));
	printf (" to %s", mydate);
	}
      printf ("\n"
	      "Total %d outages, total time %d seconds (%s)\n"
	      "Longest outage:\t\t\t%d seconds (%s)\n"
	      "   Start:\t\t\t%s\n"
	      "   End:\t\t\t\t%s\n"
	      "Average time between outages:\t%d seconds (%s)\n"
	      "Average duration:\t\t%d seconds (%s)\n"
	      "Availability:\t\t\t%5.2f%%\n",
	      outages,
	      outage_time,
	      total_hms,
	      longest_outage,
	      longest_hms,
	      longest_outage_start,
	      longest_outage_end,
	      average_time,
	      average_hms,
	      duration,
	      duration_hms,
	      availability );
      }
    }
  else
    if (summary)					/* really only one line */
      {
      if (start_timestamp)
	{
	strftime (mydate, 80, "%F", localtime (&start_timestamp));
	printf ("%s ", mydate);
	}
      else
	printf ("-");
      if (end_timestamp < END_OF_TIME)
	{
	strftime (mydate, 80, "%F", localtime (&end_timestamp));
	printf ("%s ", mydate);
	}
      else
	printf ("-");
      printf ("  0\t0\t0\t0\t0\t0\n");
      }
    else					/* normal output, no failures */
      {
      printf ("\nSummary");
      if (start_timestamp)
	{
	strftime (mydate, 80, "%e %B %G", localtime (&start_timestamp));
	printf (" from %s", mydate);
	}
      if (end_timestamp < END_OF_TIME)
	{
	strftime (mydate, 80, "%e %B %G", localtime (&end_timestamp));
	printf (" to %s", mydate);
	}
      printf ("\nNo outages\n" );
      }
  exit (0);
}