import { useEffect, useRef } from 'react'

export default function useInterval(callback: () => void, delay: null | number) {
  const savedCallback = useRef<() => void>()

  // Remember the latest callback.
  useEffect(() => {
    savedCallback.current = callback
  }, [callback])

  // Set up the interval.
  useEffect(() => {
    function tick() {
      const current = savedCallback.current
      current && current()
    }

    if (delay !== null) {
      const id = setInterval(tick, delay)
      return () => clearInterval(id)
    }
    return
  }, [delay])
}
