// Windows/TimeUtils.cpp

#include "StdAfx.h"

#ifndef _WIN32
#include <sys/time.h>
#endif

#include "Defs.h"
#include "TimeUtils.h"

namespace NWindows {
namespace NTime {

static const UInt32 kNumTimeQuantumsInSecond = 10000000;
static const UInt32 kFileTimeStartYear = 1601;
#if !defined(_WIN32) || defined(UNDER_CE)
static const UInt32 kDosTimeStartYear = 1980;
#endif
static const UInt32 kUnixTimeStartYear = 1970;
static const UInt64 kUnixTimeOffset =
    (UInt64)60 * 60 * 24 * (89 + 365 * (kUnixTimeStartYear - kFileTimeStartYear));
static const UInt64 kNumSecondsInFileTime = (UInt64)(Int64)-1 / kNumTimeQuantumsInSecond;

bool DosTime_To_FileTime(UInt32 dosTime, FILETIME &ft) throw()
{
  #if defined(_WIN32) && !defined(UNDER_CE)
  return BOOLToBool(::DosDateTimeToFileTime((UInt16)(dosTime >> 16), (UInt16)(dosTime & 0xFFFF), &ft));
  #else
  ft.dwLowDateTime = 0;
  ft.dwHighDateTime = 0;
  UInt64 res;
  if (!GetSecondsSince1601(kDosTimeStartYear + (dosTime >> 25), (dosTime >> 21) & 0xF, (dosTime >> 16) & 0x1F,
      (dosTime >> 11) & 0x1F, (dosTime >> 5) & 0x3F, (dosTime & 0x1F) * 2, res))
    return false;
  res *= kNumTimeQuantumsInSecond;
  ft.dwLowDateTime = (UInt32)res;
  ft.dwHighDateTime = (UInt32)(res >> 32);
  return true;
  #endif
}

static const UInt32 kHighDosTime = 0xFF9FBF7D;
static const UInt32 kLowDosTime = 0x210000;

bool FileTime_To_DosTime(const FILETIME &ft, UInt32 &dosTime) throw()
{
  #if defined(_WIN32) && !defined(UNDER_CE)

  WORD datePart, timePart;
  if (!::FileTimeToDosDateTime(&ft, &datePart, &timePart))
  {
    dosTime = (ft.dwHighDateTime >= 0x01C00000) ? kHighDosTime : kLowDosTime;
    return false;
  }
  dosTime = (((UInt32)datePart) << 16) + timePart;

  #else

#define PERIOD_4 (4 * 365 + 1)
#define PERIOD_100 (PERIOD_4 * 25 - 1)
#define PERIOD_400 (PERIOD_100 * 4 + 1)

  unsigned year, mon, day, hour, min, sec;
  UInt64 v64 = ft.dwLowDateTime | ((UInt64)ft.dwHighDateTime << 32);
  Byte ms[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
  unsigned temp;
  UInt32 v;
  v64 += (kNumTimeQuantumsInSecond * 2 - 1);
  v64 /= kNumTimeQuantumsInSecond;
  sec = (unsigned)(v64 % 60);
  v64 /= 60;
  min = (unsigned)(v64 % 60);
  v64 /= 60;
  hour = (unsigned)(v64 % 24);
  v64 /= 24;

  v = (UInt32)v64;

  year = (unsigned)(kFileTimeStartYear + v / PERIOD_400 * 400);
  v %= PERIOD_400;

  temp = (unsigned)(v / PERIOD_100);
  if (temp == 4)
    temp = 3;
  year += temp * 100;
  v -= temp * PERIOD_100;

  temp = v / PERIOD_4;
  if (temp == 25)
    temp = 24;
  year += temp * 4;
  v -= temp * PERIOD_4;

  temp = v / 365;
  if (temp == 4)
    temp = 3;
  year += temp;
  v -= temp * 365;

  if (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0))
    ms[1] = 29;
  for (mon = 1; mon <= 12; mon++)
  {
    unsigned s = ms[mon - 1];
    if (v < s)
      break;
    v -= s;
  }
  day = (unsigned)v + 1;

  dosTime = kLowDosTime;
  if (year < kDosTimeStartYear)
    return false;
  year -= kDosTimeStartYear;
  dosTime = kHighDosTime;
  if (year >= 128)
    return false;
  dosTime = (year << 25) | (mon << 21) | (day << 16) | (hour << 11) | (min << 5) | (sec >> 1);
  #endif
  return true;
}


bool UtcFileTime_To_LocalDosTime(const FILETIME &utc, UInt32 &dosTime) throw()
{
  FILETIME loc = { 0, 0 };
  const UInt64 u1 = FILETIME_To_UInt64(utc);
  const UInt64 kDelta = ((UInt64)1 << 41); // it's larger than quantums in 1 sec.
  if (u1 >= kDelta)
  {
    if (!FileTimeToLocalFileTime(&utc, &loc))
      loc = utc;
    else
    {
      const UInt64 u2 = FILETIME_To_UInt64(loc);
      const UInt64 delta = u1 < u2 ? (u2 - u1) : (u1 - u2);
      if (delta > kDelta) // if FileTimeToLocalFileTime() overflow, we use UTC time
        loc = utc;
    }
  }
  return FileTime_To_DosTime(loc, dosTime);
}

UInt64 UnixTime_To_FileTime64(UInt32 unixTime) throw()
{
  return (kUnixTimeOffset + (UInt64)unixTime) * kNumTimeQuantumsInSecond;
}

void UnixTime_To_FileTime(UInt32 unixTime, FILETIME &ft) throw()
{
  const UInt64 v = UnixTime_To_FileTime64(unixTime);
  ft.dwLowDateTime = (DWORD)v;
  ft.dwHighDateTime = (DWORD)(v >> 32);
}

UInt64 UnixTime64_To_FileTime64(Int64 unixTime) throw()
{
  return (UInt64)((Int64)kUnixTimeOffset + unixTime) * kNumTimeQuantumsInSecond;
}


bool UnixTime64_To_FileTime64(Int64 unixTime, UInt64 &fileTime) throw()
{
  if (unixTime > (Int64)(kNumSecondsInFileTime - kUnixTimeOffset))
  {
    fileTime = (UInt64)(Int64)-1;
    return false;
  }
  if (unixTime < -(Int64)kUnixTimeOffset)
  {
    fileTime = 0;
    return false;
  }
  fileTime = UnixTime64_To_FileTime64(unixTime);
  return true;
}


bool UnixTime64_To_FileTime(Int64 unixTime, FILETIME &ft) throw()
{
  UInt64 v;
  const bool res = UnixTime64_To_FileTime64(unixTime, v);
  ft.dwLowDateTime = (DWORD)v;
  ft.dwHighDateTime = (DWORD)(v >> 32);
  return res;
}


Int64 FileTime_To_UnixTime64(const FILETIME &ft) throw()
{
  const UInt64 winTime = (((UInt64)ft.dwHighDateTime) << 32) + ft.dwLowDateTime;
  return (Int64)(winTime / kNumTimeQuantumsInSecond) - (Int64)kUnixTimeOffset;
}

Int64 FileTime_To_UnixTime64_and_Quantums(const FILETIME &ft, UInt32 &quantums) throw()
{
  const UInt64 winTime = (((UInt64)ft.dwHighDateTime) << 32) + ft.dwLowDateTime;
  quantums = (UInt32)(winTime % kNumTimeQuantumsInSecond);
  return (Int64)(winTime / kNumTimeQuantumsInSecond) - (Int64)kUnixTimeOffset;
}

bool FileTime_To_UnixTime(const FILETIME &ft, UInt32 &unixTime) throw()
{
  UInt64 winTime = (((UInt64)ft.dwHighDateTime) << 32) + ft.dwLowDateTime;
  winTime /= kNumTimeQuantumsInSecond;
  if (winTime < kUnixTimeOffset)
  {
    unixTime = 0;
    return false;
  }
  winTime -= kUnixTimeOffset;
  if (winTime > (UInt32)0xFFFFFFFF)
  {
    unixTime = (UInt32)0xFFFFFFFF;
    return false;
  }
  unixTime = (UInt32)winTime;
  return true;
}

bool GetSecondsSince1601(unsigned year, unsigned month, unsigned day,
  unsigned hour, unsigned min, unsigned sec, UInt64 &resSeconds) throw()
{
  resSeconds = 0;
  if (year < kFileTimeStartYear || year >= 10000 || month < 1 || month > 12 ||
      day < 1 || day > 31 || hour > 23 || min > 59 || sec > 59)
    return false;
  UInt32 numYears = year - kFileTimeStartYear;
  UInt32 numDays = numYears * 365 + numYears / 4 - numYears / 100 + numYears / 400;
  Byte ms[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
  if (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0))
    ms[1] = 29;
  month--;
  for (unsigned i = 0; i < month; i++)
    numDays += ms[i];
  numDays += day - 1;
  resSeconds = ((UInt64)(numDays * 24 + hour) * 60 + min) * 60 + sec;
  return true;
}


void GetCurUtc_FiTime(CFiTime &ft) throw()
{
 #ifdef _WIN32

  // Both variants provide same low resolution on WinXP: about 15 ms.
  // But GetSystemTimeAsFileTime is much faster.
  #ifdef UNDER_CE
  SYSTEMTIME st;
  GetSystemTime(&st);
  SystemTimeToFileTime(&st, &ft);
  #else
  GetSystemTimeAsFileTime(&ft);
  #endif

 #else
  
  FiTime_Clear(ft);
  struct timeval now;
  if (gettimeofday(&now, 0 ) == 0)
  {
    ft.tv_sec = now.tv_sec;
    ft.tv_nsec = now.tv_usec * 1000;
  }

 #endif
}

#ifndef _WIN32
void GetCurUtcFileTime(FILETIME &ft) throw()
{
  UInt64 v = 0;
  struct timeval now;
  if (gettimeofday(&now, 0 ) == 0)
  {
    v = ((UInt64)now.tv_sec + kUnixTimeOffset) *
      kNumTimeQuantumsInSecond + (UInt64)now.tv_usec * 10;
  }
  ft.dwLowDateTime  = (DWORD)v;
  ft.dwHighDateTime = (DWORD)(v >> 32);
}
#endif


}}


#ifdef _WIN32

/*
void FiTime_Normalize_With_Prec(CFiTime &ft, unsigned prec)
{
  if (prec == k_PropVar_TimePrec_0
      || prec == k_PropVar_TimePrec_HighPrec
      || prec >= k_PropVar_TimePrec_100ns)
    return;
  UInt64 v = (((UInt64)ft.dwHighDateTime) << 32) + ft.dwLowDateTime;

  int numDigits = (int)prec - (int)k_PropVar_TimePrec_Base;
  UInt32 d;
  if (prec == k_PropVar_TimePrec_DOS)
  {
    // we round up as windows DosDateTimeToFileTime()
    v += NWindows::NTime::kNumTimeQuantumsInSecond * 2 - 1;
    d = NWindows::NTime::kNumTimeQuantumsInSecond * 2;
  }
  else
  {
    if (prec == k_PropVar_TimePrec_Unix)
      numDigits = 0;
    else if (numDigits < 0)
      return;
    d = 1;
    for (unsigned k = numDigits; k < 7; k++)
      d *= 10;
  }
  v /= d;
  v *= d;
  ft.dwLowDateTime = (DWORD)v;
  ft.dwHighDateTime = (DWORD)(v >> 32);
}
*/

#else

/*
void FiTime_Normalize_With_Prec(CFiTime &ft, unsigned prec)
{
  if (prec >= k_PropVar_TimePrec_1ns
      || prec == k_PropVar_TimePrec_HighPrec)
    return;

  int numDigits = (int)prec - (int)k_PropVar_TimePrec_Base;
  UInt32 d;
  if (prec == k_PropVar_TimePrec_Unix ||
      prec == (int)k_PropVar_TimePrec_Base)
  {
    ft.tv_nsec = 0;
    return;
  }
  if (prec == k_PropVar_TimePrec_DOS)
  {
    // we round up as windows DosDateTimeToFileTime()
    const unsigned sec1 = (ft.tv_sec & 1);
    if (ft.tv_nsec == 0 && sec1 == 0)
      return;
    ft.tv_nsec = 0;
    ft.tv_sec += 2 - sec1;
    return;
  }
  {
    if (prec == k_PropVar_TimePrec_0
        || numDigits < 0)
      numDigits = 7;
    d = 1;
    for (unsigned k = numDigits; k < 9; k++)
      d *= 10;
    ft.tv_nsec /= d;
    ft.tv_nsec *= d;
  }
}
*/

int Compare_FiTime(const CFiTime *a1, const CFiTime *a2)
{
  if (a1->tv_sec < a2->tv_sec) return -1;
  if (a1->tv_sec > a2->tv_sec) return 1;
  if (a1->tv_nsec < a2->tv_nsec) return -1;
  if (a1->tv_nsec > a2->tv_nsec) return 1;
  return 0;
}

bool FILETIME_To_timespec(const FILETIME &ft, timespec &ts)
{
  UInt32 quantums;
  const Int64 sec = NWindows::NTime::FileTime_To_UnixTime64_and_Quantums(ft, quantums);
  // time_t is long
  const time_t sec2 = (time_t)sec;
  if (sec2 == sec)
  {
    ts.tv_sec = sec2;
    ts.tv_nsec = (long)(quantums * 100);
    return true;
  }
  return false;
}

void FiTime_To_FILETIME_ns100(const CFiTime &ts, FILETIME &ft, unsigned &ns100)
{
  const UInt64 v = NWindows::NTime::UnixTime64_To_FileTime64(ts.tv_sec) + ((UInt64)ts.tv_nsec / 100);
  ns100 = (unsigned)((UInt64)ts.tv_nsec % 100);
  ft.dwLowDateTime = (DWORD)v;
  ft.dwHighDateTime = (DWORD)(v >> 32);
}

void FiTime_To_FILETIME(const CFiTime &ts, FILETIME &ft)
{
  const UInt64 v = NWindows::NTime::UnixTime64_To_FileTime64(ts.tv_sec) + ((UInt64)ts.tv_nsec / 100);
  ft.dwLowDateTime = (DWORD)v;
  ft.dwHighDateTime = (DWORD)(v >> 32);
}

#endif
