import { useEffect, useRef } from "react";

// An agency practice refuses every staff read until its owner accepts. Each read keeps its own error, so
// the acceptance is announced once and every read that failed before it asks again.
const PRACTICE_UNLOCKED = "akashic:practice-unlocked";

export const announcePracticeUnlocked = (): void => {
  window.dispatchEvent(new Event(PRACTICE_UNLOCKED));
};

/** Runs `reread` when the practice is unlocked; the caller decides whether it has anything to reread. */
export const usePracticeUnlocked = (reread: () => void): void => {
  const latest = useRef(reread);
  latest.current = reread;
  useEffect(() => {
    const onUnlocked = () => latest.current();
    window.addEventListener(PRACTICE_UNLOCKED, onUnlocked);
    return () => window.removeEventListener(PRACTICE_UNLOCKED, onUnlocked);
  }, []);
};