import { useEffect, useRef } from "react";

const scrollToEnd = () => {
  window.scrollTo({
    top: document.body.scrollHeight,
    left: 0,
  });
};

export function useFollowScroll(shouldFollow: boolean) {
  const shouldFollowRef = useRef(shouldFollow);
  const scrollRef = useRef(false);
  const triggeredBySelfRef = useRef(false);

  useEffect(() => {
    const handleScroll = () => {
      if (triggeredBySelfRef.current) {
        triggeredBySelfRef.current = false;
        return;
      }
      scrollRef.current = true;
    };
    window.addEventListener("scroll", handleScroll);
    return () => window.removeEventListener("scroll", handleScroll);
  }, []);

  useEffect(() => {
    if (!scrollRef.current && shouldFollowRef.current) {
      setTimeout(() => {
        triggeredBySelfRef.current = true;
        scrollToEnd();
      });
    }
  });

  useEffect(() => {
    shouldFollowRef.current = shouldFollow;
    if (!shouldFollow) {
      // Reset scrollRef
      scrollRef.current = false;
    }
  }, [shouldFollow]);
}