"use client";

import { useEffect, useRef, useState } from "react";
import { SESSION_EXPIRED_EVENT, SESSION_EXTENDED_EVENT } from "@/hooks/useGameTick";

/**
 * Tracks whether the session has expired (per the client-side watchdog).
 *
 * Returns both a reactive `expired` boolean (for rendering) and an
 * `expiredRef` (for use inside callbacks / the game loop without stale
 * closures). Consumers should gate start/retry/input and skip server saves
 * on `expiredRef.current`.
 */
export function useSessionExpired(): {
  expired: boolean;
  expiredRef: React.RefObject<boolean>;
} {
  const [expired, setExpired] = useState(false);
  const expiredRef = useRef(false);

  useEffect(() => {
    const lock = () => {
      expiredRef.current = true;
      setExpired(true);
    };
    const unlock = () => {
      expiredRef.current = false;
      setExpired(false);
    };
    window.addEventListener(SESSION_EXPIRED_EVENT, lock);
    window.addEventListener(SESSION_EXTENDED_EVENT, unlock);
    return () => {
      window.removeEventListener(SESSION_EXPIRED_EVENT, lock);
      window.removeEventListener(SESSION_EXTENDED_EVENT, unlock);
    };
  }, []);

  return { expired, expiredRef };
}