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import { useState, useEffect, useRef } from 'react'

export default function useNearScreen({
  externalRef,
  once = true,
  rootMargin = '100px'
}) {
  const [isNearScreen, setShow] = useState(false)
  const fromRef = useRef(null)

  useEffect(() => {
    const element = externalRef ? externalRef.current : fromRef.current

    const onChange = (entries, observer) => {
      const el = entries[0]

      if (el.isIntersecting) {
        setShow(true)

        once && observer.disconnect()
      } else {
        !once && setShow(false)
      }
    }

    const observer = new IntersectionObserver(onChange, {
      rootMargin
    })

    if (element) observer.observe(element)

    return () => observer && observer.disconnect()
  }, [externalRef, fromRef])

  return [isNearScreen, fromRef]
}