// public/sw-field.js — Tuxedo field-worker service worker.
//
// Cycle 6 sub-PWA, scoped to /water. Tighter cache strategy than
// the main shell SW because:
//   - The field app is a thin surface (PIN, headgate list, log form,
//     time tab). Few async chunks; mostly static + the latest data
//     snapshot.
//   - "Offline" here means "still see the cached PIN screen + headgate
//     list" — water entry without connectivity is a degraded but
//     non-blocking experience (the form queue handles drafts).
//
// Cache names are deliberately prefixed with `field-` so they never
// collide with the main `rc-shell-v*` / `rc-data-v*` caches.

const SHELL_CACHE = "field-shell-v1";
const DATA_CACHE = "field-data-v1";
const OFFLINE_URL = "/offline.html";

const SHELL_ASSETS = [
  "/water",
  "/manifest-field.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) => {
  // Only manage field-* caches — never touch the main app's caches.
  event.waitUntil(
    Promise.all([
      caches.keys().then((cacheNames) => {
        const toDelete = [];
        for (const name of cacheNames) {
          if (
            name !== SHELL_CACHE &&
            name !== DATA_CACHE &&
            name.startsWith("field-")
          ) {
            toDelete.push(caches.delete(name));
          }
        }
        return Promise.all(toDelete);
      }),
      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;

  // Out-of-scope requests: skip (let the main app SW handle them
  // if it's installed for that scope; fall through to network).
  if (!url.pathname.startsWith("/water")) 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.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/water* GETs → stale-while-revalidate (so the headgate list
  // and worker availability can hydrate from cache while we re-fetch).
  if (url.pathname.startsWith("/api/water")) {
    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)));
});