/**

 * Copyright (c) Meta Platforms, Inc. and affiliates.

 *

 * This source code is licensed under the MIT license found in the

 * LICENSE file in the root directory of this source tree.

 *

 * @flow

 */

import * as React from 'react';

import * as ReactDOM from 'react-dom';

const {useLayoutEffect, useRef} = React;

const {unstable_createEventHandle} = ReactDOM;

type UseEventHandle = {

  setListener: (

    target: EventTarget,

    null | ((SyntheticEvent<EventTarget>) => void),

  ) => void,

  clear: () => void,

};

export default function useEvent(

  event: string,

  options?: {

    capture?: boolean,

  },

): UseEventHandle {

  const handleRef = useRef<UseEventHandle | null>(null);

  let useEventHandle = handleRef.current;

  if (useEventHandle === null) {

    const setEventHandle = unstable_createEventHandle(event, options);

    const clears = new Map<EventTarget, () => void>();

    useEventHandle = {

      setListener(

        target: EventTarget,

        callback: null | ((SyntheticEvent<EventTarget>) => void),

      ): void {

        let clear = clears.get(target);

        if (clear !== undefined) {

          clear();

        }

        if (callback === null) {

          clears.delete(target);

          return;

        }

        clear = setEventHandle(target, callback);

        clears.set(target, clear);

      },

      clear(): void {

        clears.forEach(c => {

          c();

        });

        clears.clear();

      },

    };

    handleRef.current = useEventHandle;

  }

  useLayoutEffect(() => {

    return () => {

      if (useEventHandle !== null) {

        useEventHandle.clear();

      }

      handleRef.current = null;

    };

  }, [useEventHandle]);

  return useEventHandle;

}