import * as React from "react"

const MOBILE_BREAKPOINT = 768

export function useIsMobile() {
  // Read on the first render, not after it: a node on the flow canvas draws
  // its handles for the direction this returns, and React Flow measures them
  // once. Starting at `false` drew them for a desktop first, so whether an
  // edge met its handle depended on which of the two React measured.
  const [isMobile, setIsMobile] = React.useState(
    () => window.innerWidth < MOBILE_BREAKPOINT,
  )

  React.useEffect(() => {
    const mql = window.matchMedia(`(max-width: ${MOBILE_BREAKPOINT - 1}px)`)
    const onChange = () => {
      setIsMobile(window.innerWidth < MOBILE_BREAKPOINT)
    }
    mql.addEventListener("change", onChange)
    setIsMobile(window.innerWidth < MOBILE_BREAKPOINT)
    return () => mql.removeEventListener("change", onChange)
  }, [])

  return isMobile
}