#include "../../shared/MiscSupport.h"

#include "ImportData.h"

static time_t importFromDelphi(double delphiTime)
{
  const int days = (int)delphiTime;
  // Note:  Delphi time is precise to the millisecond.  4.999 seconds means
  // that we will hit 5 seconds in 1 millisecond, so we should still call it
  // 4 seconds.  4.999999997 means that there was roundoff error, and this
  // should be interpreted as 5.000 seconds.  So we round to the neareast
  // millisecond, then truncate to the correct second.  We have to follow this
  // algorithm to show the right time.  Clocks that display things precise to
  // the minute still hit midnight at the same time as clocks that are precise
  // to the millisecond.  If we rounded more, the clock that was precise to the
  // minute would chime 30 seconds too soon.
  const int second = (int)((delphiTime - days)*24*60*60+0.0005);
  struct tm brokenDown;
  brokenDown.tm_sec = second;
  brokenDown.tm_min = 0;
  brokenDown.tm_hour = 0;
  brokenDown.tm_mday = days - 29220; // 29221.0 in delphi -> 1/1/1980
  brokenDown.tm_mon = 0;  // 0 = January.
  brokenDown.tm_year = 80;  // 0 = 1900.
  brokenDown.tm_isdst = -1;  // Unknown.  Linux figures it out correctly.
  return mktime(&brokenDown);
}

static time_t importFromDelphi(std::string const &rawTime)
{
  return importFromDelphi(strtodDefault(rawTime, 0.0));
}

time_t importTime(std::string const &rawTime)
{
  if (rawTime.find('.') != rawTime.npos)
    return importFromDelphi(rawTime);
  int64_t asInt = strtollDefault(rawTime, 0);
  static const int64_t MIN_DELPHI_TIME = 3654;
  static const int64_t MAX_DELPHI_TIME = 76703;
  // MIN_DELPHI_TIME would be 1/1/1910 if we interpreted it as a Delphi time,
  // or 1/1/1970 1:00:54 AM Pacific if we interpreted it as UNIX time.
  // MAX_DELPHI_TIME would be 1/1/2110 if we interpreted it as a Delphi time,
  // or 1/1/1970 9:18:23 PM.  If a value is between these two values, we 
  // assume the input was a Delphi time.  Otherwise we assume it's a UNIX time.
  // This seems like a reasonable guess.
  if ((asInt < MAX_DELPHI_TIME) && (asInt > MIN_DELPHI_TIME))
    return importFromDelphi(asInt);
  return asInt;
}

#ifdef __UNIT_TEXT_IMPORT_TIME_

static TclList testTime(double delphi, std::string expected)
{
  TclList result;
  result<<"delphi"<<delphi
	<<"importFromDelphi(delphi)"<<importFromDelphi(delphi)
	<<"expected"<<expected
	<<"ctimeString()"<<ctimeString(importFromDelphi(delphi));
  return result;
}

static TclList testImportTime()
{
  TclList msg;
  msg<<__FILE__<<__LINE__<<__FUNCTION__;
  msg<<testTime(3654, "1/1/1910");
  msg<<testTime(40179, "1/1/2010");
  msg<<testTime(76703, "1/1/2110");
  msg<<testTime(29221, "1/1/1980");
  msg<<testTime(40243.840225544, "3/6/2010 8:09:55 PM");
  msg<<testTime(40425.840225544, "9/4/2010 8:09:55 PM");
  return msg;
}

#endif