// The service worker lets the site be installed as an app, and shows staff notifications. It caches
// nothing but the offline page: every request still goes to the network, so nobody sees stale bans
// or ranks.

const CACHE = "offline-v1";
const OFFLINE = "/static/offline.html";

self.addEventListener("install", (e) => {
  e.waitUntil(caches.open(CACHE).then((c) => c.add(OFFLINE)).then(() => self.skipWaiting()));
});

self.addEventListener("activate", (e) => {
  e.waitUntil(
    caches.keys()
      .then((keys) => Promise.all(keys.filter((k) => k !== CACHE).map((k) => caches.delete(k))))
      .then(() => self.clients.claim()),
  );
});

// Only page loads get the offline page; API calls fail as they always have, and the pages say so.
self.addEventListener("fetch", (e) => {
  if (e.request.mode !== "navigate") return;
  e.respondWith(fetch(e.request).catch(() => caches.match(OFFLINE)));
});

// Staff notifications (internal/web/notify.go). The panel sends title, body, icon, tag, url and
// actions; a notification with the same tag replaces the last one quietly.
self.addEventListener("push", (e) => {
  let d = {};
  try { d = e.data ? e.data.json() : {}; } catch { d = { body: e.data.text() }; }
  e.waitUntil(self.registration.showNotification(d.title || "zio.sh", {
    body: d.body || "",
    icon: d.icon || "/static/icon-192.png",
    badge: "/static/badge-96.png",
    tag: d.tag,
    timestamp: d.timestamp,
    actions: d.actions || [],
    data: { url: d.url || "/" },
  }));
});

// Tapping the notification or its "View player" button opens its page, in an open window if
// there is one.
self.addEventListener("notificationclick", (e) => {
  e.notification.close();
  const url = new URL(e.notification.data?.url || "/", self.location.origin).href;
  e.waitUntil((async () => {
    const wins = await self.clients.matchAll({ type: "window", includeUncontrolled: true });
    const win = wins.find((w) => new URL(w.url).origin === self.location.origin);
    if (win) {
      try {
        await win.focus();
        await win.navigate(url);
        return;
      } catch { /* not ours to navigate; open a new one */ }
    }
    await self.clients.openWindow(url);
  })());
});

// Browsers sometimes replace a subscription. Hand the new one to the panel so notifications keep
// coming; this only works while the staff member's session cookie is still valid.
self.addEventListener("pushsubscriptionchange", (e) => {
  e.waitUntil((async () => {
    const opts = e.oldSubscription?.options;
    const sub = e.newSubscription || (opts && await self.registration.pushManager.subscribe(opts));
    if (!sub) return;
    await fetch("/api/admin/notifications/subscribe", {
      method: "POST",
      credentials: "same-origin",
      headers: { "Content-Type": "application/json", "X-Requested-With": "simpleadmin-web" },
      body: JSON.stringify({ ...sub.toJSON(), userAgent: navigator.userAgent }),
    });
  })());
});