// @(#)root/base:$Id$
// Author: Rene Brun   05/01/95

/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

/** \class TDatime
This class stores the date and time with a precision of one second
in an unsigned 32 bit word (950130 124559).
The date is stored with the origin being the 1st January 1995.

This class has no support for time zones. The time is assumed
to be in the local time of the machine where the object was created.
As a result, TDatime objects are not portable between machines
operating in different time zones and unsuitable for storing the
date/time of data taking events and the like. If absolute time is
required, use TTimeStamp.
*/

#include "RConfig.h"

#include <time.h>

#ifdef WIN32
#include "Windows4Root.h"
#include <string.h>
#endif

#include "TBuffer.h"
#include "Strlen.h"
#include "TDatime.h"
#include "TError.h"
#include "Bytes.h"
#include "TString.h"


ClassImp(TDatime)

////////////////////////////////////////////////////////////////////////////////
/// Create a TDatime and set it to the current time.

TDatime::TDatime()
{
   Set();
}

////////////////////////////////////////////////////////////////////////////////
/// Create a TDatime and set it to the specified date and time.
/// See Set(Int_t, Int_t) about the date, time format.

TDatime::TDatime(Int_t date, Int_t time)
{
   Set(date, time);
}

////////////////////////////////////////////////////////////////////////////////
/// Create a TDatime and set it to the specified year, month,
/// day, time, hour, minute and second. See Set() about the format.

TDatime::TDatime(Int_t year, Int_t month, Int_t day,
                 Int_t hour, Int_t min, Int_t sec)
{
   Set(year, month, day, hour, min, sec);
}

////////////////////////////////////////////////////////////////////////////////
/// Expects as input a string in SQL date/time compatible format, like:
/// yyyy-mm-dd hh:mm:ss.

TDatime::TDatime(const char *sqlDateTime)
{
   Set(sqlDateTime);
}

////////////////////////////////////////////////////////////////////////////////
/// Returns day of week, with Monday being day 1 and Sunday day 7.

Int_t TDatime::GetDayOfWeek() const
{
   static TString weekDays[7] = { "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun" };
   TString wd = AsString();
   int  day;
   for (day = 0; day < 7; day++) {
      if (wd(0, 3) == weekDays[day])
         break;
   }
   return (day < 7) ? day+1: -1;
}

////////////////////////////////////////////////////////////////////////////////
/// Return the date & time as a string (ctime() format).
/// Copy result because it points to a statically allocated string.

const char *TDatime::AsString() const
{
   time_t t = Convert();
   char *retStr = ctime(&t);
   if (retStr) {
      *(retStr + 24) = 0;
      return retStr;
   } else {
      static const char *defaulttime = "15/06/96";
      Error("TDatime::AsString", "could not get time string");
      return defaulttime;
   }
}

////////////////////////////////////////////////////////////////////////////////
/// Return the date & time as a string (ctime() format).
/// Result is copied into out (and out is returned). Make sure
/// out can at least contain 26 characters. Thread safe.

const char *TDatime::AsString(char *out) const
{
   time_t t = Convert();
#ifdef _REENTRANT
#if defined(R__SOLARIS) && (_POSIX_C_SOURCE - 0 < 199506L)
   char *retStr = ctime_r(&t, out, 26);
#else
   char *retStr = ctime_r(&t, out);
#endif
#else
   char *retStr = ctime(&t);
#endif
   if (retStr) {
      *(retStr + 24) = 0;
#ifndef _REENTRANT
      strcpy(out, retStr);
#endif
      return retStr;
   } else {
      static const char *defaulttime = "15/06/96";
      strcpy(out, defaulttime);
      Error("TDatime::AsString", "could not get time string");
      return defaulttime;
   }
}

////////////////////////////////////////////////////////////////////////////////
/// Return the date & time in SQL compatible string format, like:
/// 1997-01-15 20:16:28. The returned string buffer is static and
/// will be reused.

const char *TDatime::AsSQLString() const
{
   static char sqldate[20];

   UInt_t year  = fDatime>>26;
   UInt_t month = (fDatime<<6)>>28;
   UInt_t day   = (fDatime<<10)>>27;
   UInt_t hour  = (fDatime<<15)>>27;
   UInt_t min   = (fDatime<<20)>>26;
   UInt_t sec   = (fDatime<<26)>>26;

   snprintf(sqldate,20, "%04d-%02d-%02d %02d:%02d:%02d", (year+1995), month, day,
           hour, min, sec);

   return sqldate;
}

////////////////////////////////////////////////////////////////////////////////
/// Convert fDatime from TDatime format to the standard time_t format.
/// If toGMT is true, the time offset of the current local time zone is
/// subtracted from the returned time_t. One use of such a non-standard time_t
/// value is to convert a TDatime object that contains local time to GMT,
/// as in this example:
/// ~~~ {.cpp}
/// TDatime now;
/// now.Set(now.Convert(kTRUE));
/// ~~~
/// Caution: the time_t returned from Convert(kTRUE) is incompatible with
/// regular Unix time - it contains an artificial, locale-dependent offset.

UInt_t TDatime::Convert(Bool_t toGMT) const
{
   UInt_t year  = fDatime>>26;
   UInt_t month = (fDatime<<6)>>28;
   UInt_t day   = (fDatime<<10)>>27;
   UInt_t hour  = (fDatime<<15)>>27;
   UInt_t min   = (fDatime<<20)>>26;
   UInt_t sec   = (fDatime<<26)>>26;

   struct tm tp;
   tp.tm_year  = year+95;
   tp.tm_mon   = month-1;
   tp.tm_mday  = day;
   tp.tm_hour  = hour;
   tp.tm_min   = min;
   tp.tm_sec   = sec;
   tp.tm_isdst = -1;

   time_t t = mktime(&tp);
   if ((int)t == -1) {
      Error("TDatime::Convert", "error converting fDatime to time_t");
      return 0;
   }
   if (toGMT) {
#ifdef _REENTRANT
      struct tm tg;
      struct tm *tgp = gmtime_r(&t, &tg);
#else
      struct tm *tgp = gmtime(&t);
#endif
      tgp->tm_isdst = -1;
      t  = mktime(tgp);
   }
   return (UInt_t)t;
}

////////////////////////////////////////////////////////////////////////////////
/// Copy this to datime.

void TDatime::Copy(TDatime &datime) const
{
   datime.fDatime = fDatime;
}

////////////////////////////////////////////////////////////////////////////////
/// Encode Date/Time into buffer, used by I/O system.

void TDatime::FillBuffer(char *&buffer)
{
   tobuf(buffer, fDatime);
}

////////////////////////////////////////////////////////////////////////////////
/// Return raw date/time as encoded by TDatime. Note, this value cannot
/// be used to e.g. calculate time differences, as it is an encoded value.
/// To calculate time differences use the Convert() method to get a time
/// in seconds and then subtract the values.

UInt_t TDatime::Get() const
{
   return fDatime;
}

////////////////////////////////////////////////////////////////////////////////
/// Return date in form of 19971224 (i.e. 24/12/1997)

Int_t TDatime::GetDate() const
{
   UInt_t year  = fDatime>>26;
   UInt_t month = (fDatime<<6)>>28;
   UInt_t day   = (fDatime<<10)>>27;
   return 10000*(year+1995) + 100*month + day;
}

////////////////////////////////////////////////////////////////////////////////
/// Return time in form of 123623 (i.e. 12:36:23)

Int_t TDatime::GetTime() const
{
   UInt_t hour  = (fDatime<<15)>>27;
   UInt_t min   = (fDatime<<20)>>26;
   UInt_t sec   = (fDatime<<26)>>26;
   return 10000*hour + 100*min + sec;
}

////////////////////////////////////////////////////////////////////////////////
/// Print date and time.

void TDatime::Print(Option_t *) const
{
   printf("Date/Time = %s\n", AsString());
}

////////////////////////////////////////////////////////////////////////////////
/// Decode Date/Time from output buffer, used by I/O system.

void TDatime::ReadBuffer(char *&buffer)
{
   frombuf(buffer, &fDatime);
}

////////////////////////////////////////////////////////////////////////////////
/// Set Date/Time to current time as reported by the system.
/// Date and Time are encoded into one single unsigned 32 bit word.
/// Date is stored with the origin being the 1st January 1995.
/// Time has 1 second precision.

void TDatime::Set()
{
#ifndef WIN32
   time_t tloc   = time(0);
#ifdef _REENTRANT
   struct tm tpa;
   struct tm *tp = localtime_r(&tloc, &tpa);
#else
   struct tm *tp = localtime(&tloc);
#endif
   UInt_t year   = tp->tm_year;
   UInt_t month  = tp->tm_mon + 1;
   UInt_t day    = tp->tm_mday;
   UInt_t hour   = tp->tm_hour;
   UInt_t min    = tp->tm_min;
   UInt_t sec    = tp->tm_sec;
#else
   SYSTEMTIME tp;
   GetLocalTime(&tp);
   UInt_t year   = tp.wYear-1900;
   UInt_t month  = tp.wMonth;
   UInt_t day    = tp.wDay;
   UInt_t hour   = tp.wHour;
   UInt_t min    = tp.wMinute;
   UInt_t sec    = tp.wSecond;
#endif

   fDatime = (year-95)<<26 | month<<22 | day<<17 | hour<<12 | min<<6 | sec;
}

////////////////////////////////////////////////////////////////////////////////
/// The input arg is a time_t value returned by time() or a value
/// returned by Convert(). This value is the number of seconds since
/// the EPOCH (i.e. 00:00:00 on Jan 1m 1970). If dosDate is true then
/// the input is a dosDate value.

void TDatime::Set(UInt_t tloc, Bool_t dosDate)
{
   UInt_t year, month, day, hour, min, sec;

   if (dosDate) {
      year  = ((tloc >> 25) & 0x7f) + 80;
      month = ((tloc >> 21) & 0xf);
      day   = (tloc >> 16) & 0x1f;
      hour  = (tloc >> 11) & 0x1f;
      min   = (tloc >> 5) & 0x3f;
      sec   = (tloc & 0x1f) * 2;
   } else {
      time_t t = (time_t) tloc;
#ifdef _REENTRANT
      struct tm tpa;
      struct tm *tp = localtime_r(&t, &tpa);
#else
      struct tm *tp = localtime(&t);
#endif
      year   = tp->tm_year;
      month  = tp->tm_mon + 1;
      day    = tp->tm_mday;
      hour   = tp->tm_hour;
      min    = tp->tm_min;
      sec    = tp->tm_sec;
   }

   fDatime = (year-95)<<26 | month<<22 | day<<17 | hour<<12 | min<<6 | sec;
}

////////////////////////////////////////////////////////////////////////////////
/// Set date and time. Data must be in format 980418 or 19980418 and time in
/// 224512 (second precision). The date must
/// be >= 950101.
///
/// For years >= 2000, date can be given in the form 20001127 or 1001127
/// internally the date will be converted to 1001127

void TDatime::Set(Int_t date, Int_t time)
{
   if (date > 19000000) date -= 19000000;
   if (date < 950101) {
      Error("TDatime::Set", "year smaller than 1995");
      return;
   }

   Int_t year  = date/10000;
   Int_t month = (date-year*10000)/100;
   Int_t day   = date%100;

   Int_t hour, min, sec;

   hour = time/10000;
   min  = (time-hour*10000)/100;
   sec  = time%100;

   fDatime = (year-95)<<26 | month<<22 | day<<17 | hour<<12 | min<<6 | sec;
}

////////////////////////////////////////////////////////////////////////////////
/// Set date and time. Year may be xx where 95 <= xx <= 158 (158 being 2058).
/// The year must be >= 1995.

void TDatime::Set(Int_t year, Int_t month, Int_t day,
                  Int_t hour, Int_t min, Int_t sec)
{
   if (year < 159) year += 1900;
   if (year < 1995) {
      Error("TDatime::Set", "year must be >= 1995");
      return;
   }

   fDatime = (year-1995)<<26 | month<<22 | day<<17 | hour<<12 | min<<6 | sec;
}

////////////////////////////////////////////////////////////////////////////////
/// Expects as input a string in SQL date/time compatible format, like:
/// yyyy-mm-dd hh:mm:ss.

void TDatime::Set(const char* sqlDateTime)
{
   Int_t yy, mm, dd, hh, mi, ss;

   if (sscanf(sqlDateTime, "%d-%d-%d %d:%d:%d", &yy, &mm, &dd, &hh, &mi, &ss) == 6)
      Set(yy, mm, dd, hh, mi, ss);
   else {
      Error("TDatime(sqlDatTime)", "input string not in right format, set"
            " to current date/time");
      Set();
   }
}

////////////////////////////////////////////////////////////////////////////////
/// Stream a object of type TDatime.

void TDatime::Streamer(TBuffer &b)
{
   if (b.IsReading()) {
      b >> fDatime;
   } else {
      b << fDatime;
   }
}

////////////////////////////////////////////////////////////////////////////////
/// Static function that returns the date and time. The input is
/// in TDatime format (as obtained via TDatime::Get()).
/// Date is returned in the format 950223  February 23 1995.
/// Time is returned in the format 102459 10h 24m 59s.

void TDatime::GetDateTime(UInt_t datetime, Int_t &date, Int_t &time)
{
   UInt_t year  = datetime>>26;
   UInt_t month = (datetime<<6)>>28;
   UInt_t day   = (datetime<<10)>>27;
   UInt_t hour  = (datetime<<15)>>27;
   UInt_t min   = (datetime<<20)>>26;
   UInt_t sec   = (datetime<<26)>>26;
   date         =  10000*(year+1995) + 100*month + day;
   time         =  10000*hour + 100*min + sec;
}

////////////////////////////////////////////////////////////////////////////////
/// Print a TDatime at the prompt.

std::string cling::printValue(const TDatime &val) {
   char buf[30];
   return std::string(val.AsString(buf));
}