import { RefObject } from 'react';

export function scrollToBottom(
  messageListRef: RefObject<HTMLDivElement>,
  behavior: ScrollBehavior = 'auto',
): void {
  messageListRef.current!.scrollTo({
    top: messageListRef.current!.scrollHeight,
    behavior: behavior,
  });
}

export function isTotallyScrolled(refHavingScroll: RefObject<HTMLDivElement>) {
  const fullScrollHeight = refHavingScroll.current?.scrollHeight;
  const heightVisibleAtOnce = refHavingScroll.current?.clientHeight;
  const heightScrolledFromTop = refHavingScroll.current?.scrollTop;
  if (fullScrollHeight && heightScrolledFromTop && heightVisibleAtOnce) {
    return fullScrollHeight - heightScrolledFromTop === heightVisibleAtOnce;
  }
  return false;
}