/* times.cc

   Copyright 1996, 1997, 1998, 1999, 2000, 2001 Red Hat, Inc.

This file is part of Cygwin.

This software is a copyrighted work licensed under the terms of the
Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
details. */

#include "winsup.h"
#include <time.h>
#include <sys/times.h>
#include <sys/timeb.h>
#include <utime.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include "cygerrno.h"
#include "perprocess.h"
#include "security.h"
#include "fhandler.h"
#include "path.h"
#include "sync.h"
#include "sigproc.h"
#include "pinfo.h"

#define FACTOR (0x19db1ded53e8000LL)
#define NSPERSEC 10000000LL

static void __stdcall timeval_to_filetime (timeval *time, FILETIME *out);

/* Cygwin internal */
static unsigned long long __stdcall
__to_clock_t (FILETIME * src, int flag)
{
  unsigned long long total = ((unsigned long long) src->dwHighDateTime << 32) + ((unsigned)src->dwLowDateTime);
  syscall_printf ("dwHighDateTime %u, dwLowDateTime %u", src->dwHighDateTime, src->dwLowDateTime);

  /* Convert into clock ticks - the total is in 10ths of a usec.  */
  if (flag)
    total -= FACTOR;

  total /= (unsigned long long) (NSPERSEC / CLOCKS_PER_SEC);
  syscall_printf ("total %08x %08x\n", (unsigned)(total>>32), (unsigned)(total));
  return total;
}

/* times: POSIX 4.5.2.1 */
extern "C" clock_t
times (struct tms * buf)
{
  FILETIME creation_time, exit_time, kernel_time, user_time;

  DWORD ticks = GetTickCount ();
  /* Ticks is in milliseconds, convert to our ticks. Use long long to prevent
     overflow. */
  clock_t tc = (clock_t) ((long long) ticks * CLOCKS_PER_SEC / 1000);
  if (iswinnt)
    {
      GetProcessTimes (hMainProc, &creation_time, &exit_time,
		       &kernel_time, &user_time);

      syscall_printf ("ticks %d, CLOCKS_PER_SEC %d", ticks, CLOCKS_PER_SEC);
      syscall_printf ("user_time %d, kernel_time %d, creation_time %d, exit_time %d",
		      user_time, kernel_time, creation_time, exit_time);
      buf->tms_stime = __to_clock_t (&kernel_time, 0);
      buf->tms_utime = __to_clock_t (&user_time, 0);
      timeval_to_filetime (&myself->rusage_children.ru_stime, &kernel_time);
      buf->tms_cstime = __to_clock_t (&kernel_time, 1);
      timeval_to_filetime (&myself->rusage_children.ru_utime, &user_time);
      buf->tms_cutime = __to_clock_t (&user_time, 1);
    }
  else
    /* GetProcessTimes() does not work for non-NT versions of Windows.  The
       return values are undefined, so instead just copy the ticks value
       into utime so that clock() will work properly on these systems */
    {
      buf->tms_utime = tc;
      buf->tms_stime = 0;
      buf->tms_cstime = 0;
      buf->tms_cutime = 0;
    }

   return tc;
}

extern "C" clock_t
_times (struct tms * buf)
{
  return times (buf);
}

/* settimeofday: BSD */
extern "C" int
settimeofday (const struct timeval *tv, const struct timezone *tz)
{
  SYSTEMTIME st;
  struct tm *ptm;
  int res;

  tz = tz;			/* silence warning about unused variable */

  ptm = gmtime(&tv->tv_sec);
  st.wYear         = ptm->tm_year + 1900;
  st.wMonth        = ptm->tm_mon + 1;
  st.wDayOfWeek    = ptm->tm_wday;
  st.wDay          = ptm->tm_mday;
  st.wHour         = ptm->tm_hour;
  st.wMinute       = ptm->tm_min;
  st.wSecond       = ptm->tm_sec;
  st.wMilliseconds = tv->tv_usec / 1000;

  res = !SetSystemTime(&st);

  syscall_printf ("%d = settimeofday (%x, %x)", res, tv, tz);

  return res;
}

/* timezone: standards? */
extern "C" char *
timezone ()
{
#ifdef _MT_SAFE
  char *b=_reent_winsup()->timezone_buf;
#else
  static NO_COPY char b[20] = {0};
#endif

  tzset();
  __small_sprintf (b,"GMT%+d:%02d", (int) (-_timezone / 3600), (int) (abs(_timezone / 60) % 60));
  return b;
}

/* Cygwin internal */
void __stdcall
totimeval (struct timeval *dst, FILETIME *src, int sub, int flag)
{
  long long x = __to_clock_t (src, flag);

  x *= (int) (1e6) / CLOCKS_PER_SEC; /* Turn x into usecs */
  x -= (long long) sub * (int) (1e6);

  dst->tv_usec = x % (long long) (1e6); /* And split */
  dst->tv_sec = x / (long long) (1e6);
}

/* gettimeofday: BSD */
extern "C" int
gettimeofday (struct timeval *p, struct timezone *z)
{
  int res = 0;

  if (p != NULL)
    {
      FILETIME f;

      GetSystemTimeAsFileTime (&f);
      totimeval (p, &f, 0, 1);
    }

  if (z != NULL)
    {
      tzset();
      z->tz_minuteswest = _timezone / 60;
      z->tz_dsttime = _daylight;
    }

  syscall_printf ("%d = gettimeofday (%x, %x)", res, p, z);

  return res;
}

extern "C"
int
_gettimeofday (struct timeval *p, struct timezone *z)
{
  return gettimeofday (p, z);
}

#if 0
/* Work out magic constant below */
genf ()
{
  SYSTEMTIME s;
  FILETIME f;
  s.wYear = 1970;
  s.wMonth = 1;
  s.wDayOfWeek = 4;
  s.wDay = 1;
  s.wHour = 0;
  s.wMinute = 0;
  s.wSecond = 0;
  s.wMilliseconds = 0;
  SystemTimeToFileTime (&s, &f);

  small_printf ("FILE TIME is %08x%08x\n",
	       f.dwHighDateTime,
	       f.dwLowDateTime);
}
#endif

/* Cygwin internal */
void
time_t_to_filetime (time_t time_in, FILETIME *out)
{
  long long x = time_in * NSPERSEC + FACTOR;
  out->dwHighDateTime = x >> 32;
  out->dwLowDateTime = x;
}

/* Cygwin internal */
static void __stdcall
timeval_to_filetime (timeval *time_in, FILETIME *out)
{
  long long x = time_in->tv_sec * NSPERSEC +
			time_in->tv_usec * (NSPERSEC/1000000) + FACTOR;
  out->dwHighDateTime = x >> 32;
  out->dwLowDateTime = x;
}

/* Cygwin internal */
static timeval __stdcall
time_t_to_timeval (time_t in)
{
  timeval res;
  res.tv_sec = in;
  res.tv_usec = 0;
  return res;
}

/* Cygwin internal */
/* Convert a Win32 time to "UNIX" format. */
long __stdcall
to_time_t (FILETIME *ptr)
{
  /* A file time is the number of 100ns since jan 1 1601
     stuffed into two long words.
     A time_t is the number of seconds since jan 1 1970.  */

  long rem;
  long long x = ((long long) ptr->dwHighDateTime << 32) + ((unsigned)ptr->dwLowDateTime);

  /* pass "no time" as epoch */
  if (x == 0)
    return 0;

  x -= FACTOR;			/* number of 100ns between 1601 and 1970 */
  rem = x % ((long long)NSPERSEC);
  rem += (NSPERSEC / 2);
  x /= (long long) NSPERSEC;		/* number of 100ns in a second */
  x += (long long) (rem / NSPERSEC);
  return x;
}

/* time: POSIX 4.5.1.1, C 4.12.2.4 */
/* Return number of seconds since 00:00 UTC on jan 1, 1970 */
extern "C"
time_t
time (time_t * ptr)
{
  time_t res;
  SYSTEMTIME systemtime;
  FILETIME filetime;

  GetSystemTime (&systemtime);
  SystemTimeToFileTime (&systemtime, &filetime);
  res = to_time_t (&filetime);
  if (ptr)
    *ptr = res;

  syscall_printf ("%d = time (%x)", res, ptr);

  return res;
}

/*
 * localtime_r.c
 * Original Author:	Adapted from tzcode maintained by Arthur David Olson.
 *
 * Converts the calendar time pointed to by tim_p into a broken-down time
 * expressed as local time. Returns a pointer to a structure containing the
 * broken-down time.
 */

#define SECSPERMIN	60
#define MINSPERHOUR	60
#define HOURSPERDAY	24
#define SECSPERHOUR	(SECSPERMIN * MINSPERHOUR)
#define SECSPERDAY	(SECSPERHOUR * HOURSPERDAY)
#define DAYSPERWEEK	7
#define MONSPERYEAR	12

#define YEAR_BASE	1900
#define EPOCH_YEAR      1970
#define EPOCH_WDAY      4

#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)

#if 0 /* POSIX_LOCALTIME */

static _CONST int mon_lengths[2][MONSPERYEAR] = {
  {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
  {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
};

static _CONST int year_lengths[2] = {
  365,
  366
};

/*
 * Convert a time_t into a struct tm *.
 * Does NO timezone conversion.
 */

/* Cygwin internal */
static struct tm * __stdcall
corelocaltime (const time_t * tim_p)
{
  long days, rem;
  int y;
  int yleap;
  _CONST int *ip;
#ifdef _MT_SAFE
  struct tm &localtime_buf=_reent_winsup()->_localtime_buf;
#else
  static NO_COPY struct tm localtime_buf = {0};
#endif

  time_t tim = *tim_p;
  struct tm *res = &localtime_buf;

  days = ((long) tim) / SECSPERDAY;
  rem = ((long) tim) % SECSPERDAY;

  while (rem < 0)
    {
      rem += SECSPERDAY;
      --days;
    }
  while (rem >= SECSPERDAY)
    {
      rem -= SECSPERDAY;
      ++days;
    }

  /* compute hour, min, and sec */
  res->tm_hour = (int) (rem / SECSPERHOUR);
  rem %= SECSPERHOUR;
  res->tm_min = (int) (rem / SECSPERMIN);
  res->tm_sec = (int) (rem % SECSPERMIN);

  /* compute day of week */
  if ((res->tm_wday = ((EPOCH_WDAY + days) % DAYSPERWEEK)) < 0)
    res->tm_wday += DAYSPERWEEK;

  /* compute year & day of year */
  y = EPOCH_YEAR;
  if (days >= 0)
    {
      for (;;)
	{
	  yleap = isleap (y);
	  if (days < year_lengths[yleap])
	    break;
	  y++;
	  days -= year_lengths[yleap];
	}
    }
  else
    {
      do
	{
	  --y;
	  yleap = isleap (y);
	  days += year_lengths[yleap];
	} while (days < 0);
    }

  res->tm_year = y - YEAR_BASE;
  res->tm_yday = days;
  ip = mon_lengths[yleap];
  for (res->tm_mon = 0; days >= ip[res->tm_mon]; ++res->tm_mon)
    days -= ip[res->tm_mon];
  res->tm_mday = days + 1;

  /* set daylight saving time flag */
  res->tm_isdst = -1;

  syscall_printf ("%d = corelocaltime (%x)", res, tim_p);

  return (res);
}

/* localtime: POSIX 8.1.1, C 4.12.3.4 */
/*
 * localtime takes a time_t (which is in UTC)
 * and formats it into a struct tm as a local time.
 */
extern "C"
struct tm *
localtime (const time_t *tim_p)
{
  time_t tim = *tim_p;
  struct tm *rtm;

  tzset();

  tim -= _timezone;

  rtm = corelocaltime (&tim);

  rtm->tm_isdst = _daylight;

  syscall_printf ("%x = localtime (%x)", rtm, tim_p);

  return rtm;
}

/* gmtime: C 4.12.3.3 */
/*
 * gmtime takes a time_t (which is already in UTC)
 * and just puts it into a struct tm.
 */
extern "C"
struct tm *
gmtime (const time_t *tim_p)
{
  time_t tim = *tim_p;

  struct tm *rtm = corelocaltime (&tim);
  /* UTC has no daylight savings time */
  rtm->tm_isdst = 0;

  syscall_printf ("%x = gmtime (%x)", rtm, tim_p);

  return rtm;
}

#endif /* POSIX_LOCALTIME */

/* utimes: standards? */
extern "C"
int
utimes (const char *path, struct timeval *tvp)
{
  int res = 0;
  struct timeval tmp[2];
  path_conv win32 (path);
  PSECURITY_DESCRIPTOR sd = NULL;
  DWORD sd_size;

  if (win32.error)
    {
      set_errno (win32.error);
      syscall_printf ("-1 = utimes (%s, %x)", path, tvp);
      return -1;
    }

  /* MSDN suggests using FILE_FLAG_BACKUP_SEMANTICS for accessing
     the times of directories.  FIXME: what about Win95??? */
  HANDLE h = CreateFileA (win32.get_win32 (),
			  GENERIC_WRITE,
			  FILE_SHARE_READ | FILE_SHARE_WRITE,
			  &sec_none_nih,
			  OPEN_EXISTING,
			  FILE_ATTRIBUTE_NORMAL | FILE_FLAG_BACKUP_SEMANTICS,
			  0);

  if (h == INVALID_HANDLE_VALUE)
    {
      if ((res = GetFileAttributes (win32.get_win32 ())) != -1 &&
		(res & FILE_ATTRIBUTE_DIRECTORY))
	{
	  /* What we can do with directories more? */
	  res = 0;
	}
      else if (allow_ntsec && win32.has_acls ())
        {
	  /* The following hack allows setting the correct filetime
	     on NTFS with ntsec ON even when the file is R/O for the
	     current user. This solves the `cp -p' problem and allows
	     a more UNIX like behaviour. Basically we save the file's
	     current security descriptor, change the file access so
	     that we have write access (if possible) and if that worked
	     fine, reset the old security descriptor at the end of the
	     function. */
	  sd_size = 4096;
	  sd = (PSECURITY_DESCRIPTOR) alloca (sd_size);
	  if (read_sd (win32.get_win32 (), sd, &sd_size) <= 0)
	    sd = NULL;
	  else if (set_file_attribute (TRUE, win32.get_win32 (), 0600))
	    sd = NULL;
	  else
	    h = CreateFileA (win32.get_win32 (),
			     GENERIC_WRITE,
			     FILE_SHARE_READ | FILE_SHARE_WRITE,
			     &sec_none_nih,
			     OPEN_EXISTING,
			     FILE_ATTRIBUTE_NORMAL | FILE_FLAG_BACKUP_SEMANTICS,
			     0);
	}
      else
	{
	  res = -1;
	  __seterrno ();
	}
    }
  if (h != INVALID_HANDLE_VALUE)
    {
      if (tvp == 0)
	{
	  gettimeofday (&tmp[0], 0);
	  tmp[1] = tmp[0];
	  tvp = tmp;
	}

      FILETIME lastaccess;
      FILETIME lastwrite;

      timeval_to_filetime (tvp + 0, &lastaccess);
      timeval_to_filetime (tvp + 1, &lastwrite);

      debug_printf ("incoming lastaccess %08x %08x",
		   tvp->tv_sec,
		   tvp->tv_usec);

//      dump_filetime (lastaccess);
//      dump_filetime (lastwrite);

      /* FIXME: SetFileTime needs a handle with a write lock
	 on the file whose time is being modified.  So calls to utime()
	 fail for read only files.  */

      if (!SetFileTime (h, 0, &lastaccess, &lastwrite))
	{
	  __seterrno ();
	  res = -1;
	}
      else
	res = 0;
      CloseHandle (h);
    }

  if (sd)
    write_sd (win32.get_win32 (), sd, sd_size);

  syscall_printf ("%d = utimes (%s, %x); (h%d)",
		  res, path, tvp, h);
  return res;
}

/* utime: POSIX 5.6.6.1 */
extern "C"
int
utime (const char *path, struct utimbuf *buf)
{
  struct timeval tmp[2];

  if (buf == 0)
    return utimes (path, 0);

  debug_printf ("incoming utime act %x", buf->actime);
  tmp[0] = time_t_to_timeval (buf->actime);
  tmp[1] = time_t_to_timeval (buf->modtime);

  return utimes (path, tmp);
}

/* ftime: standards? */
extern "C"
int
ftime (struct timeb *tp)
{
  struct timeval tv;
  struct timezone tz;

  if (gettimeofday (&tv, &tz) < 0)
    return -1;

  tp->time = tv.tv_sec;
  tp->millitm = tv.tv_usec / 1000;
  tp->timezone = tz.tz_minuteswest;
  tp->dstflag = tz.tz_dsttime;

  return 0;
}

/* obsolete, changed to cygwin_tzset when localtime.c was added - dj */
extern "C"
void
cygwin_tzset ()
{
}