module ActiveModel::Type::Helpers::TimeValue

def apply_seconds_precision(value)
  return value unless precision && value.respond_to?(:nsec)
  number_of_insignificant_digits = 9 - precision
  round_power = 10**number_of_insignificant_digits
  rounded_off_nsec = value.nsec % round_power
  if rounded_off_nsec > 0
    value.change(nsec: value.nsec - rounded_off_nsec)
  else
    value
  end
end

def fast_string_to_time(string)
  return unless ISO_DATETIME =~ string
  usec = $7.to_i
  usec_len = $7&.length
  if usec_len&.< 6
    usec *= 10**(6 - usec_len)
  end
  if $8
    offset = $8 == "Z" ? 0 : $8.to_i * 3600 + $9.to_i * 60
  end
  new_time($1.to_i, $2.to_i, $3.to_i, $4.to_i, $5.to_i, $6.to_i, usec, offset)
end

def new_time(year, mon, mday, hour, min, sec, microsec, offset = nil)
  # Treat 0000-00-00 00:00:00 as nil.
  return if year.nil? || (year == 0 && mon == 0 && mday == 0)
  if offset
    time = ::Time.utc(year, mon, mday, hour, min, sec, microsec) rescue nil
    return unless time
    time -= offset unless offset == 0
    is_utc? ? time : time.getlocal
  elsif is_utc?
    ::Time.utc(year, mon, mday, hour, min, sec, microsec) rescue nil
  else
    ::Time.local(year, mon, mday, hour, min, sec, microsec) rescue nil
  end
end

def serialize(value)
  value = apply_seconds_precision(value)
  if value.acts_like?(:time)
    if is_utc?
      value = value.getutc if !value.utc?
    else
      value = value.getlocal
    end
  end
  value
end

def type_cast_for_schema(value)
  value.to_fs(:db).inspect
end

def user_input_in_time_zone(value)
  value.in_time_zone
end