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#include "HsTime.h"
#include <stdio.h>
long int get_current_timezone_seconds (time_t t,int* pdst,char const* * pname)
{
#if defined(_MSC_VER) || defined(__MINGW32__) || defined(_WIN32)
// When compiling with MinGW (which does not provide a full POSIX
// layer as opposed to Cygwin) it's better to use the CRT's
// underscore-prefixed `_tzset()` variant to avoid linker issues
// as Microsoft considers the POSIX named `tzset()` function
// deprecated (see http://msdn.microsoft.com/en-us/library/ms235384.aspx)
_tzset();
#else
tzset();
#endif
#if HAVE_LOCALTIME_R
struct tm tmd;
struct tm* ptm = localtime_r(&t,&tmd);
#else
struct tm* ptm = localtime(&t);
#endif
if (ptm)
{
int dst = ptm -> tm_isdst;
*pdst = dst;
#if HAVE_TM_ZONE
*pname = ptm -> tm_zone;
return ptm -> tm_gmtoff;
#elif defined(_MSC_VER) || defined(__MINGW32__) || defined(_WIN32)
// We don't have a better API to use on Windows, the logic to
// decide whether a given date/time falls within DST is
// implemented as part of localtime() in the CRT. This is_dst
// flag is all we need here.
*pname = dst ? _tzname[1] : _tzname[0];
return - (dst ? _timezone - 3600 : _timezone);
#else
# if HAVE_TZNAME
*pname = *tzname;
# else
# error "Don't know how to get timezone name on your OS"
# endif
# if HAVE_DECL_ALTZONE
return dst ? altzone : timezone;
# else
return dst ? timezone - 3600 : timezone;
# endif
#endif // HAVE_TM_ZONE
}
else return 0x80000000;
}
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