/**
 * @typedef {{
 *   now(): number,
 *   sleep(milliseconds: number, signal?: AbortSignal): Promise<void>
 * }} ClockPort
 */

/** @type {ClockPort} */
export const systemClock = Object.freeze({
  now: () => Date.now(),
  sleep(milliseconds, signal) {
    return new Promise((resolve, reject) => {
      if (signal?.aborted) {
        reject(signal.reason);
        return;
      }

      const timer = setTimeout(resolve, milliseconds);
      signal?.addEventListener(
        "abort",
        () => {
          clearTimeout(timer);
          reject(signal.reason);
        },
        { once: true },
      );
    });
  },
});