import { useMemo } from "react";

/**
 * Returns true when a stream is within the last 10% of its retention window.
 * For example, with 24h retention, this fires when < 2.4h remain.
 */
export function useExpiringSoon(
  lastChildCreatedAt: Date | undefined,
  retentionHours: number,
): boolean {
  return useMemo(() => {
    if (!lastChildCreatedAt) return false;

    const retentionMs = retentionHours * 60 * 60 * 1000;
    const expiresAt = lastChildCreatedAt.getTime() + retentionMs;
    const remaining = expiresAt - Date.now();

    return remaining > 0 && remaining < retentionMs * 0.1;
  }, [lastChildCreatedAt, retentionHours]);
}