// Posimai SW — stale-while-revalidate + update notification
const CACHE = 'posimai-roadmap-v1';
const STATIC = ['/', '/index.html', '/manifest.json', '/logo.png', '/roadmap.json'];

self.addEventListener('install', e => {
    e.waitUntil(caches.open(CACHE).then(c => c.addAll(STATIC)));
});

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())
    );
});

self.addEventListener('fetch', e => {
    if (e.request.method !== 'GET') return;
    if (!e.request.url.startsWith(self.location.origin)) return;

    e.respondWith(
        caches.open(CACHE).then(cache =>
            cache.match(e.request).then(cached => {
                const network = fetch(e.request).then(res => {
                    if (res.ok && res.type === 'basic') cache.put(e.request, res.clone());
                    return res;
                }).catch(() => cached);
                return cached || network;
            })
        )
    );
});