// @flow
// based on: https://reacttraining.com/react-router/web/guides/scroll-restoration
import * as React from "react";
import { useLocation } from "react-router-dom";
import usePrevious from "hooks/usePrevious";

type Props = {|
  children: React.Node,
|};

export default function ScrollToTop({ children }: Props) {
  const location = useLocation();
  const previousLocationPathname = usePrevious(location.pathname);

  React.useEffect(() => {
    if (location.pathname === previousLocationPathname) return;

    // exception for when entering or exiting document edit, scroll position should not reset
    if (
      location.pathname.match(/\/edit\/?$/) ||
      previousLocationPathname?.match(/\/edit\/?$/)
    )
      return;

    window.scrollTo(0, 0);
  }, [location.pathname, previousLocationPathname]);

  return children;
}