/// <summary>
/// Optimized conversion from an Instant to an OffsetDateTime in the specified calendar.
/// This is equivalent to <c>new OffsetDateTime(new LocalDateTime(instant.Plus(offset), calendar), offset)</c>
/// but with less overhead.
/// </summary>
internal OffsetDateTime(Instant instant, Offset offset, CalendarSystem calendar)
{
unchecked
{
int days = instant.DaysSinceEpoch;
long nanoOfDay = instant.NanosecondOfDay + offset.Nanoseconds;
if (nanoOfDay >= NanosecondsPerDay)
{
days++;
nanoOfDay -= NanosecondsPerDay;
}
else if (nanoOfDay < 0)
{
days--;
nanoOfDay += NanosecondsPerDay;
}
yearMonthDayCalendar = calendar.GetYearMonthDayFromDaysSinceEpoch(days).WithCalendar(calendar);
nanosecondsAndOffset = nanoOfDay | (((long)offset.Seconds) << NanosecondsBits);
}
}
/// <summary>
/// Constructs an instance from the number of days since the unix epoch, and a calendar
/// system. The calendar system is assumed to be non-null, but the days since the epoch are
/// validated.
/// </summary>
// TODO: See if we still need this.
internal LocalDate(int daysSinceEpoch, [Trusted][NotNull] CalendarSystem calendar)
{
Preconditions.DebugCheckNotNull(calendar, nameof(calendar));
this.yearMonthDayCalendar = calendar.GetYearMonthDayFromDaysSinceEpoch(daysSinceEpoch).WithCalendar(calendar);
}
