import { mount } from 'svelte'
import './app.css'
import App from './App.svelte'
import DemoBoard from './lib/components/DemoBoard.svelte'
import { demoActor } from './lib/demo'

// `/demo/<handle>` is its own page, not a mode of the app: it renders another
// account's *public* records read-only, so it must not load IndexedDB, start an
// OAuth session, or let the app rewrite the address bar (see url.ts). Branching
// at the mount is what keeps all of that out of the picture.
const target = document.getElementById('app')!
const actor = demoActor()
const app = actor
  ? mount(DemoBoard, { target, props: { actor } })
  : mount(App, { target })

// Register the service worker (built by serviceWorkerPlugin in vite.config) so
// the app cold-loads offline. Prod-only — there's no sw.js during `vite dev`.
// `updateViaCache: "none"` keeps the SW script itself always revalidated so a
// new deploy is picked up promptly.
//
// A long-lived tab must not be allowed to keep running an old bundle: every
// instance at this origin shares one OAuth session store, so an outdated
// instance can sign the user out from under a healthy one. That first showed up
// as @atproto/oauth-client deleting the shared session after a stale call came
// back 401 invalid_token; the same hazard applies to the current PDS-issued
// session, where a stale tab holds a stale access token and can rotate the
// refresh token out from under this one. So: check for a new worker
// whenever the tab comes back to the foreground, and reload as soon as one takes
// control (the new SW calls skipWaiting, so control changes on its first
// activation).
if (import.meta.env.PROD && 'serviceWorker' in navigator) {
  // A controller change on a page that had none is just the first-ever SW
  // claiming this load — nothing to reload for.
  const hadController = navigator.serviceWorker.controller != null
  let reloading = false
  navigator.serviceWorker.addEventListener('controllerchange', () => {
    if (!hadController || reloading) return
    reloading = true
    window.location.reload()
  })

  window.addEventListener('load', () => {
    navigator.serviceWorker
      .register('/sw.js', { updateViaCache: 'none' })
      .then((reg) => {
        const check = () => {
          if (!document.hidden) void reg.update().catch(() => {})
        }
        document.addEventListener('visibilitychange', check)
        // Backstop for an instance that stays visible for days (a pinned tab or
        // a dock/home-screen window that is never re-focused).
        setInterval(check, 60 * 60 * 1000)
      })
      .catch(() => {})
  })
}

export default app