intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 93 insertions, 0 deletions

diff --git a/library/cpp/timezone_conversion/convert.cpp b/library/cpp/timezone_conversion/convert.cpp
new file mode 100644
index 00000000000..490bb4e2700
--- /dev/null
+++ b/library/cpp/timezone_conversion/convert.cpp
@@ -0,0 +1,93 @@
+#include "convert.h"
+
+#include <contrib/libs/cctz/include/cctz/civil_time.h>
+
+#include <util/generic/yexception.h>
+
+#include <chrono>
+
+namespace NDatetime {
+    static constexpr i64 TM_YEAR_OFFSET = 1900;
+    using TSystemClock = std::chrono::system_clock;
+    using TTimePoint = std::chrono::time_point<TSystemClock>;
+
+    static TSimpleTM CivilToTM(const cctz::civil_second& cs, const cctz::time_zone::absolute_lookup& al) {
+        cctz::civil_day cd(cs);
+        TSimpleTM tm;
+        tm.GMTOff = al.offset;
+        tm.Year = cs.year() - TM_YEAR_OFFSET;
+        tm.YDay = cctz::get_yearday(cd);
+        tm.Mon = cs.month() - 1;
+        tm.MDay = cs.day();
+        tm.Hour = cs.hour();
+        tm.Min = cs.minute();
+        tm.Sec = cs.second();
+        tm.IsDst = al.is_dst;
+        tm.IsLeap = LeapYearAD(cs.year());
+
+        switch (cctz::get_weekday(cd)) {
+            case cctz::weekday::monday:
+                tm.WDay = 1;
+                break;
+            case cctz::weekday::tuesday:
+                tm.WDay = 2;
+                break;
+            case cctz::weekday::wednesday:
+                tm.WDay = 3;
+                break;
+            case cctz::weekday::thursday:
+                tm.WDay = 4;
+                break;
+            case cctz::weekday::friday:
+                tm.WDay = 5;
+                break;
+            case cctz::weekday::saturday:
+                tm.WDay = 6;
+                break;
+            case cctz::weekday::sunday:
+                tm.WDay = 0;
+                break;
+        }
+
+        return tm;
+    }
+
+    /*
+    TTimeZone GetTimeZone(const TString& name) {
+        TTimeZone result;
+        if (!cctz::load_time_zone(name, &result)) {
+            ythrow yexception() << "Failed to load time zone " << name << ", " << result.name();
+        }
+        return result;
+    }
+    */
+
+    TTimeZone GetUtcTimeZone() {
+        return cctz::utc_time_zone();
+    }
+
+    TTimeZone GetLocalTimeZone() {
+        return cctz::local_time_zone();
+    }
+
+    TSimpleTM ToCivilTime(const TInstant& absoluteTime, const TTimeZone& tz) {
+        TTimePoint tp = TSystemClock::from_time_t(absoluteTime.TimeT());
+        return CivilToTM(cctz::convert(tp, tz), tz.lookup(tp));
+    }
+
+    TSimpleTM CreateCivilTime(const TTimeZone& tz, ui32 year, ui32 mon, ui32 day, ui32 h, ui32 m, ui32 s) {
+        cctz::civil_second cs(year, mon, day, h, m, s);
+        return CivilToTM(cs, tz.lookup(tz.lookup(cs).pre));
+    }
+
+    TInstant ToAbsoluteTime(const TSimpleTM& civilTime, const TTimeZone& tz) {
+        cctz::civil_second cs(
+            civilTime.Year + TM_YEAR_OFFSET,
+            civilTime.Mon + 1,
+            civilTime.MDay,
+            civilTime.Hour,
+            civilTime.Min,
+            civilTime.Sec);
+        return TInstant::Seconds(TSystemClock::to_time_t(tz.lookup(cs).pre));
+    }
+}