(function (root) {
  'use strict';
  function progressiveSource(current, videoSource) {
    return current?.eqAudioUrl || current?.localUrl || current?.audioUrl || videoSource || '';
  }
  function needsAlignment(time, clock, threshold = 0.3) {
    return Number.isFinite(time) && Number.isFinite(clock) && Math.abs(time - clock) >= threshold;
  }
  function create() {
    const pending = new WeakMap();
    function play(element) {
      if (pending.has(element)) return pending.get(element);
      if (!element.paused) return Promise.resolve();
      let request;
      try { request = Promise.resolve(element.play()); } catch (error) { request = Promise.reject(error); }
      // Preserve the intent to play after an OS interruption; the watchdog retries.
      request = request.catch(() => {}).finally(() => { if (pending.get(element) === request) pending.delete(element); });
      pending.set(element, request); return request;
    }
    function resume(element, clock) {
      // An ended element is finished, not interrupted: play() would restart it from 0.
      if (!element || !element.paused || element.ended || pending.has(element)) return;
      if (clock && element !== clock && needsAlignment(element.currentTime, clock.currentTime)) element.currentTime = clock.currentTime;
      return play(element);
    }
    return { play, resume, reset: element => pending.delete(element) };
  }
  const api = { progressiveSource, needsAlignment, create };
  if (typeof module !== 'undefined' && module.exports) module.exports = api;
  else { root.AudioContinuity = api; root.audioContinuity = create(); }
})(globalThis);