/** Whether any bookable window, as a local-ISO start, begins on or after the start of today. */
export const opensFrom = (windows: { start: string }[], todayStart: Date): boolean =>
  windows.some((window) => new Date(window.start) >= todayStart);

/**
 * The schedules the patient picker lists: one per clinician, and only a clinician with an open window.
 * A clinician with none used to be listed and then answered "not currently available" once chosen.
 * A schedule naming no clinician is kept, as before.
 */
export function offerablePractitionerSchedules<S>(
  matching: S[],
  practitionerIdOf: (schedule: S) => string | undefined,
  hasOpenTimes: (practitionerId: string) => boolean,
): S[] {
  const seen = new Set<string>();
  return matching.filter((schedule) => {
    const practitionerId = practitionerIdOf(schedule);
    if (!practitionerId) return true;
    if (seen.has(practitionerId)) return false;
    seen.add(practitionerId);
    return hasOpenTimes(practitionerId);
  });
}