/**
 * Auto-mount the SSE notification stream once the app is up AND the user is
 * authenticated. Each event becomes an in-app toast via Nuxt UI's useToast().
 *
 * This is the primary in-app notification surface — independent of the OS
 * web-push pipeline (sw-notifications.js), which stays as a best-effort
 * outside-the-app supplement. As long as the browser tab is open the toast
 * is delivered regardless of macOS Focus mode / notification permissions.
 *
 * Auth gate: the stream needs a valid logship_it cookie. Opening it on the
 * login page (no cookie yet) just yields a 401 + a wasteful 30s retry loop and
 * noisy console errors. We therefore only connect when logged in, mirroring
 * the chat plugin (04.chat-socket.client.ts). Login is an SPA navigation
 * (router.push('/'), no full reload — see signin.vue), so a one-time boot check
 * would never start the stream post-login; we re-evaluate on every navigation
 * instead, and read document.cookie directly because a useCookie() ref does not
 * reliably react to the cookie being set server-side via Set-Cookie at login.
 */

// Tab-title badge: when notifications arrive while the tab is not focused,
// mutate document.title to "🔔 (N) <original>" so the browser tab visibly
// surfaces unread count. Clear on focus / visibility change to visible.
//
// stripBadge handles the case where the title changes mid-flight (page
// navigation, page-set titles) — always re-derive the base from the current
// title rather than caching once at boot.
const BADGE_RE = /^🔔 \(\d+\) /
const stripBadge = (t: string) => t.replace(BADGE_RE, '')

export default defineNuxtPlugin((nuxtApp) => {
  if (!process.client) return

  // Capture useToast() now, while we're still in Nuxt context. The toast
  // callback runs later and has no current Nuxt instance, which makes
  // useToast() return a no-op (silently — no toast renders even though
  // .add() resolves). Holding the handle from out here avoids that trap.
  const nuxtToast = useToast()
  const { start, stop } = useNotificationStream()

  // Tab-title badge state. Bump on each unseen notification, clear on focus.
  let unread = 0
  const applyBadge = () => {
    const base = stripBadge(document.title)
    document.title = unread > 0 ? `🔔 (${unread}) ${base}` : base
  }
  const clearBadge = () => {
    if (unread === 0) return
    unread = 0
    applyBadge()
  }
  // Both events: visibilitychange catches background-tab → focused-tab, focus
  // catches alt-tabbing back into the browser window itself.
  document.addEventListener('visibilitychange', () => {
    if (!document.hidden) clearBadge()
  })
  window.addEventListener('focus', clearBadge)

  const onNotification = (data: any) => {
    const url = data?.url || '/'
    const title = data?.title || 'Benachrichtigung'
    const description = (data?.body || '').toString()
    // The bus payload reuses the web-push payload's `icon` field, which
    // contains a URL (e.g. '/favicon.ico'). Nuxt UI's toast `icon` prop only
    // accepts Iconify identifiers (e.g. 'i-heroicons-bell-alert'), so a URL
    // value triggers a failed icon load. Map anything that looks URL-ish
    // back to the default iconify name.
    const rawIcon = data?.icon
    const icon = (typeof rawIcon === 'string' && rawIcon.startsWith('i-'))
      ? rawIcon
      : 'i-heroicons-bell-alert'

    console.log('[NotifStreamPlugin] toast →', title)

    // Only badge the title if the tab is currently NOT visible — if the
    // user is already looking at LogShip the toast itself is enough.
    if (document.hidden) {
      unread++
      applyBadge()
    }

    const open = () => {
      clearBadge()
      try { navigateTo(url) } catch { window.location.href = url }
    }

    // Run inside the captured Nuxt context so any composables nuxtToast
    // depends on (useState, useRouter for navigation, etc.) still resolve.
    nuxtApp.runWithContext(() => {
      nuxtToast.add({
        // Nuxt UI v2 used `timeout`, v3 uses `duration`. We're on ^3.1.3 but
        // the rest of the codebase still uses v2-style keys (see
        // pages/sales/orders/[id]/edit.vue:1421). Pass both — extra keys
        // are ignored and one of them will stick.
        duration: 12000,
        timeout: 12000,
        title,
        description,
        icon,
        // Nuxt UI v3 expects semantic colour names (primary/success/error/...)
        // rather than CSS colours. Use 'primary' so we work on both.
        color: 'primary',
        actions: [{
          label: 'Öffnen',
          click: open,
          onClick: open
        }]
      } as any)
    })
  }

  // Freshest possible client-side read of the login cookie (see header note on
  // why we don't use a useCookie() ref here). Empty value (logship_user_id=) → false.
  const isLoggedIn = () =>
    document.cookie.split('; ').some(c => c.startsWith('logship_user_id=') && c.slice(c.indexOf('=') + 1) !== '')

  // Start when authenticated, stop when not. Idempotent: start() guards against
  // a double connection, and we only stop() what we started.
  let started = false
  const sync = () => {
    if (isLoggedIn()) {
      if (!started) {
        started = true
        start(onNotification)
      }
    } else if (started) {
      started = false
      stop()
    }
  }

  // afterEach covers SPA navigations — crucially the post-login router.push('/')
  // and the logout redirect — but does NOT fire for the initial hydrated route,
  // so a delayed initial sync() handles a fresh load onto an already-authed page.
  useRouter().afterEach(() => sync())
  setTimeout(sync, 1500)
})