//========================================================================
//
// glibc.h
//
// Emulate various non-portable glibc functions.
//
// This file is licensed under the GPLv2 or later
//
// Copyright (C) 2016 Adrian Johnson <ajohnson@redneon.com>
//
//========================================================================

#include "glibc.h"

#ifndef HAVE_GMTIME_R
struct tm *gmtime_r(const time_t *timep, struct tm *result)
{
    struct tm *gt;
    gt = gmtime(timep);
    if (gt)
        *result = *gt;
    return gt;
}
#endif

#ifndef HAVE_LOCALTIME_R
struct tm *localtime_r(const time_t *timep, struct tm *result)
{
    struct tm *lt;
    lt = localtime(timep);
    *result = *lt;
    return lt;
}
#endif

#ifndef HAVE_TIMEGM
// Get offset of local time from UTC in seconds. DST is ignored.
static time_t getLocalTimeZoneOffset()
{
    time_t utc, local;
    struct tm tm_utc;
    time(&utc);
    gmtime_r(&utc, &tm_utc);
    local = mktime(&tm_utc);
    return difftime(utc, local);
}

time_t timegm(struct tm *tm)
{
    tm->tm_isdst = 0;
    time_t t = mktime(tm);
    if (t == -1)
        return t;

    t += getLocalTimeZoneOffset();
    return t;
}
#endif