const API_CACHE_NAME = 'api-cache-v1'
const API_URL_PATTERN = /\/api\/(GetStopList)/;
const API_MAX_AGE = 72 * 60 * 60 * 1000; // 72 hours

self.addEventListener('install', (event) => {
    event.waitUntil(self.skipWaiting());
});

self.addEventListener('activate', (event) => {
    event.waitUntil(self.clients.claim());
});

self.addEventListener('fetch', async (event) => {
    const url = new URL(event.request.url);

    if (event.request.method !== "GET" || !API_URL_PATTERN.test(url.pathname)) {
        return;
    }

    event.respondWith(apiCacheFirst(event.request));
});

async function apiCacheFirst(request) {
    const cache = await caches.open(API_CACHE_NAME);
    const cachedResponse = await cache.match(request);

    if (cachedResponse) {
        const age = Date.now() - new Date(cachedResponse.headers.get('date')).getTime();
        if (age < API_MAX_AGE) {
            console.debug(`SW: Cache HIT for ${request.url}`);
            return cachedResponse;
        }

        // Cache is too old, fetch a fresh copy
        cache.delete(request);
    }

    try {
        const netResponse = await fetch(request);

        const responseToCache = netResponse.clone();

        cache.put(request, responseToCache);

        console.debug(`SW: Cache MISS for ${request.url}`);

        return netResponse;
    } catch (error) {
        throw error;
    }
}