// Author: Simon-Pierre Boucher
// Contact: contact@spboucher.ai
// Project: chat.spboucher.ai

// Service worker: cache the app shell + static assets for instant cold starts.
// Conversation data stays network-first — the server DB is the single source of truth.

const CACHE = "spb-shell-v1";
const SHELL = ["/manifest.webmanifest", "/icons/icon.svg"];

self.addEventListener("install", (event) => {
  event.waitUntil(caches.open(CACHE).then((c) => c.addAll(SHELL)));
  self.skipWaiting();
});

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

self.addEventListener("fetch", (event) => {
  const url = new URL(event.request.url);
  if (event.request.method !== "GET") return;

  // Never cache API traffic or streams.
  if (url.pathname.startsWith("/api/")) return;

  // Static assets: cache-first (immutable Next chunks + icons).
  if (url.pathname.startsWith("/_next/static/") || url.pathname.startsWith("/icons/")) {
    event.respondWith(
      caches.match(event.request).then(
        (hit) =>
          hit ||
          fetch(event.request).then((res) => {
            const copy = res.clone();
            caches.open(CACHE).then((c) => c.put(event.request, copy));
            return res;
          })
      )
    );
    return;
  }

  // Pages: network-first with cache fallback so the shell opens offline.
  event.respondWith(
    fetch(event.request)
      .then((res) => {
        if (res.ok && (url.pathname === "/" || url.pathname === "/login")) {
          const copy = res.clone();
          caches.open(CACHE).then((c) => c.put(event.request, copy));
        }
        return res;
      })
      .catch(() => caches.match(event.request).then((hit) => hit || caches.match("/")))
  );
});