import { useEffect } from 'react'

/**
 * Registers the service worker, `src/sw.js`, which keeps the build's files and shows an offline
 * page when the app is opened without a connection. Only a production build has one, so in
 * development this removes any left by `pnpm preview` on the same port.
 */
export function useServiceWorker() {
  useEffect(() => {
    if (!('serviceWorker' in navigator)) return
    if (import.meta.env.PROD) {
      navigator.serviceWorker.register('/sw.js').catch(() => {
        // The app works the same without it, only not offline.
      })
      return
    }
    void navigator.serviceWorker.getRegistrations().then((registrations) => {
      for (const registration of registrations) void registration.unregister()
    })
  }, [])
}