// Returns a rune-wrapped boolean that mirrors the source getter, but only
// flips to true after the source has been true for delayMs continuously.
// Flips back to false immediately when the source becomes false.
//
// Used to suppress flash-of-skeleton on cache-hit navigation: skeletons
// only render for loads that take longer than ~100ms.
export function useDelayed(
  source: () => boolean,
  delayMs = 100
): { readonly value: boolean } {
  let delayed = $state(false);
  let timeout: ReturnType<typeof setTimeout> | null = null;

  $effect(() => {
    const v = source();
    if (timeout) {
      clearTimeout(timeout);
      timeout = null;
    }
    if (v) {
      timeout = setTimeout(() => {
        delayed = true;
        timeout = null;
      }, delayMs);
    } else {
      delayed = false;
    }
    return () => {
      if (timeout) {
        clearTimeout(timeout);
        timeout = null;
      }
    };
  });

  return { get value() { return delayed; } };
}