// public/sw.js
// Route Commerce Service Worker
// Two-cache strategy: shell (cache-first) + data (stale-while-revalidate)

const SHELL_CACHE = "rc-shell-v3";
const DATA_CACHE = "rc-data-v3";
const OFFLINE_URL = "/offline.html";

const SHELL_ASSETS = [
  "/",
  "/manifest.json",
  "/favicon.svg",
  "/og-default.svg",
  "/offline.html",
  "/icons/icon-192x192.png",
  "/icons/icon-512x512.png",
];

self.addEventListener("install", (event) => {
  event.waitUntil(
    caches.open(SHELL_CACHE).then((cache) => cache.addAll(SHELL_ASSETS))
  );
  self.skipWaiting();
});

self.addEventListener("activate", (event) => {
  event.waitUntil(
    Promise.all([
      caches.keys().then((cacheNames) =>
        Promise.all(
          cacheNames
            .filter((name) => name !== SHELL_CACHE && name !== DATA_CACHE)
            .map((name) => caches.delete(name))
        )
      ),
      self.clients.claim(),
    ])
  );
});

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

  // Navigations → network-first, fall back to cache, fall back to offline page
  if (req.mode === "navigate") {
    event.respondWith(
      fetch(req)
        .then((res) => {
          const clone = res.clone();
          caches.open(SHELL_CACHE).then((cache) => cache.put(req, clone));
          return res;
        })
        .catch(() =>
          caches.match(req).then((cached) => cached || caches.match(OFFLINE_URL))
        )
    );
    return;
  }

  // Static assets → cache-first
  if (
    url.pathname.startsWith("/_next/static/") ||
    url.pathname.startsWith("/icons/") ||
    url.pathname.startsWith("/screenshots/") ||
    url.pathname.endsWith(".svg") ||
    url.pathname.endsWith(".woff2")
  ) {
    event.respondWith(
      caches.match(req).then((cached) => {
        if (cached) return cached;
        return fetch(req).then((res) => {
          const clone = res.clone();
          if (res.status === 200) {
            caches.open(SHELL_CACHE).then((cache) => cache.put(req, clone));
          }
          return res;
        });
      })
    );
    return;
  }

  // API GETs (read-only data) → stale-while-revalidate
  if (url.pathname.startsWith("/api/")) {
    event.respondWith(
      caches.open(DATA_CACHE).then((cache) =>
        cache.match(req).then((cached) => {
          const network = fetch(req)
            .then((res) => {
              if (res.status === 200) cache.put(req, res.clone());
              return res;
            })
            .catch(() => cached);
          return cached || network;
        })
      )
    );
    return;
  }

  // Default: try network, fall back to cache
  event.respondWith(
    fetch(req).catch(() => caches.match(req))
  );
});