/**
 * Service Worker for Shaarli Pro theme.
 *
 * Caches static theme assets (CSS, JS, icons, fonts) so the UI stays available
 * when the network is unreliable. Dynamic Shaarli pages are fetched from the
 * network first and only cached as a fallback.
 */
'use strict';

const CACHE_NAME = 'shaarli-pro-v1.1.0';

const STATIC_ASSETS = [
    'dist/style.min.css',
    'dist/themes.min.css',
    'dist/custom_views.min.css',
    'dist/awesomplete.min.css',
    'dist/i18n.min.js',
    'dist/a11y.min.js',
    'dist/shaarit-rules.min.js',
    'dist/theme.min.js',
    'dist/navigation.min.js',
    'dist/search.min.js',
    'dist/bulk-actions.min.js',
    'dist/script.min.js',
    'dist/custom_views.min.js',
    'dist/awesomplete.min.js',
    'dist/metadata.min.js',
    'img/favicon.png',
    'img/icons/icon-192x192.png',
    'img/icons/icon-512x512.png'
];

const isStaticAsset = function (url) {
    const pathname = url.pathname;
    return STATIC_ASSETS.some(function (asset) {
        return pathname.endsWith('/' + asset) || pathname === '/' + asset;
    });
};

self.addEventListener('install', function (event) {
    event.waitUntil(
        caches.open(CACHE_NAME).then(function (cache) {
            return cache.addAll(STATIC_ASSETS);
        }).catch(function () {
            // Silent failure: the SW still installs and will fetch on demand.
        })
    );
    self.skipWaiting();
});

self.addEventListener('activate', function (event) {
    event.waitUntil(
        caches.keys().then(function (cacheNames) {
            return Promise.all(
                cacheNames.map(function (cacheName) {
                    if (cacheName !== CACHE_NAME) {
                        return caches.delete(cacheName);
                    }
                })
            );
        })
    );
    self.clients.claim();
});

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

    // Only handle GET requests.
    if (request.method !== 'GET') {
        return;
    }

    if (isStaticAsset(url)) {
        // Cache-first for theme assets.
        event.respondWith(
            caches.match(request).then(function (cached) {
                return cached || fetch(request).then(function (response) {
                    if (!response || response.status !== 200 || response.type !== 'basic') {
                        return response;
                    }
                    const clone = response.clone();
                    caches.open(CACHE_NAME).then(function (cache) {
                        cache.put(request, clone);
                    });
                    return response;
                });
            })
        );
    } else {
        // Network-first for everything else (Shaarli pages, feeds, etc.).
        event.respondWith(
            fetch(request).catch(function () {
                return caches.match(request);
            })
        );
    }
});