/**

 * 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 React, {useEffect, useState} from 'react';

export function Component() {

  const countState = useState(0);

  const count = countState[0];

  const setCount = countState[1];

  const darkMode = useIsDarkMode();

  const [isDarkMode] = darkMode;

  useEffect(() => {

    // ...

  }, []);

  const handleClick = () => setCount(count + 1);

  return (

    <>

      <div>Dark mode? {isDarkMode}</div>

      <div>Count: {count}</div>

      <button onClick={handleClick}>Update count</button>

    </>

  );

}

function useIsDarkMode() {

  const darkModeState = useState(false);

  const [isDarkMode] = darkModeState;

  useEffect(function useEffectCreate() {

    // Here is where we may listen to a "theme" event...

  }, []);

  return [isDarkMode, () => {}];

}