Function durationInSeconds

packages/graph/src/TemporalTypes.ts:1814–1870

(start: TemporalValue, end: TemporalValue)

 * Compute the duration between two temporal values in seconds only.
 */
export function durationInSeconds(start: TemporalValue, end: TemporalValue): DurationValue | null {
  // Handle time types
  if (
    (start instanceof LocalTimeValue || start instanceof TimeValue) &&
    (end instanceof LocalTimeValue || end instanceof TimeValue)
  ) {
    let startSeconds: number;
    let endSeconds: number;

    if (start instanceof TimeValue) {
      startSeconds = start.hour * 3600 + start.minute * 60 + start.second - start.offset;
    } else {
      startSeconds = start.hour * 3600 + start.minute * 60 + start.second;
    }

    if (end instanceof TimeValue) {
      endSeconds = end.hour * 3600 + end.minute * 60 + end.second - end.offset;
    } else {
      endSeconds = end.hour * 3600 + end.minute * 60 + end.second;
    }

    const seconds = endSeconds - startSeconds;
    const nanoseconds =
      (end instanceof LocalTimeValue ? end.nanosecond : end.nanosecond) -
      (start instanceof LocalTimeValue ? start.nanosecond : start.nanosecond);

    return new DurationValue(0, 0, seconds, nanoseconds);
  }

  // Handle datetime types
  if (
    (start instanceof LocalDateTimeValue || start instanceof DateTimeValue) &&
    (end instanceof LocalDateTimeValue || end instanceof DateTimeValue)
  ) {
    const startDate = new Date(
      Date.UTC(start.year, start.month - 1, start.day, start.hour, start.minute, start.second),
    );
    if (start instanceof DateTimeValue) {
      startDate.setTime(startDate.getTime() - start.offset * 1000);
    }

    const endDate = new Date(
      Date.UTC(end.year, end.month - 1, end.day, end.hour, end.minute, end.second),
    );
    if (end instanceof DateTimeValue) {
      endDate.setTime(endDate.getTime() - end.offset * 1000);
    }

    const diffMs = endDate.getTime() - startDate.getTime();
    const seconds = Math.floor(diffMs / 1000);
    const nanoseconds = (diffMs % 1000) * 1_000_000 + (end.nanosecond - start.nanosecond);

    return new DurationValue(0, 0, seconds, nanoseconds);
  }

  return null;
}