/*
 * twa_t.c:
 *
 * Copyright (c) 2017 James McKenzie <foss@madingley.org>,
 * All rights reserved.
 *
 */

#include "project.h"

void
tw_dt_to_tm (TW_DateTime * tw_dt, struct tm *tm)
{
  memset (tm, 0, sizeof (*tm));

  tm->tm_sec = tw_dt->tw_sec;
  tm->tm_min = tw_dt->tw_min;
  tm->tm_hour = tw_dt->tw_hour;
  tm->tm_mday = tw_dt->tw_day;
  tm->tm_mon = tw_dt->tw_month - 1;
  tm->tm_year = le16_to_cpu(tw_dt->tw_year - 1900);
}



void
tm_to_tw_dt (struct tm *tm, TW_DateTime * tw_dt)
{
  memset (tw_dt, 0, sizeof (*tw_dt));

  tw_dt->tw_sec = tm->tm_sec;
  tw_dt->tw_min = tm->tm_min;
  tw_dt->tw_hour = tm->tm_hour;
  tw_dt->tw_day = tm->tm_mday;
  tw_dt->tw_month = tm->tm_mon + 1;
  tw_dt->tw_year = cpu_to_le16(tm->tm_year + 1900);
}


static int
show_ctrl_time (int fd)
{
  TW_DateTime dt;
  ssize_t ret;
  struct tm tm;


  ret =
    twa_get_parameter (fd, TW_TIMEKEEP_TABLE, TW_TIMEKEEP_DATETIME, &dt,
                       sizeof (dt));

  if (ret != sizeof (dt))
    {
      fprintf (stderr, "Failed to get controller time\n");
      return -1;
    }

  tw_dt_to_tm (&dt, &tm);

  printf ("Controller time is: %s", asctime (&tm));

  return 0;
}



static int
set_ctrl_time (int fd)
{
  TW_DateTime dt;
  int ret;
  struct tm tm;
  time_t t;


  time (&t);

  localtime_r (&t, &tm);

  tm_to_tw_dt (&tm, &dt);

  ret =
    twa_set_parameter (fd, TW_TIMEKEEP_TABLE, TW_TIMEKEEP_DATETIME, &dt,
                       sizeof (dt));

  if (ret)
    {
      fprintf (stderr, "Failed to set controller time\n");
      return -1;
    }
  return 0;
}


static int
check_ctrl_time (int fd)
{
  TW_DateTime dt;
  ssize_t ret;
  struct tm tm;
  time_t ctrl_time, local_time;
  double d;
  int rc = 0;

  ret =
    twa_get_parameter (fd, TW_TIMEKEEP_TABLE, TW_TIMEKEEP_DATETIME, &dt,
                       sizeof (dt));

  if (ret != sizeof (dt))
    {
      fprintf (stderr, "Failed to get controller time\n");
      rc |= -1;
      return rc;
    }

  tw_dt_to_tm (&dt, &tm);

  printf ("Controller time is: %s", asctime (&tm));

  ctrl_time = mktime (&tm);

  time (&local_time);
  localtime_r (&local_time, &tm);
  local_time = mktime (&tm);

  d = difftime (local_time, ctrl_time);

  printf ("Controller time difference is %.1lf seconds\n", d);

  if ((d > 15.0) || (d < -15.0))
    {
      printf ("Setting controller time\n");
      rc |= set_ctrl_time (fd);
      rc |= show_ctrl_time (fd);
    }

  return rc;
}


int
main (int argc, char *argv[])
{
  char *dev = "/dev/twa0";
  int fd;
  int ret = 0;

  if (argc == 2)
    dev = argv[1];

  fd = open (dev, O_RDWR);

  if (fd < 0)
    {
      fprintf (stderr, "Failed to open %s: %m\n", dev);
      ret |= -1;
      return ret;
    }


  return check_ctrl_time (fd);
}