/**
 * Service Worker for PWA
 * Handles offline functionality and caching
 */

const CACHE_NAME = 'mipesca-v2';
const STATIC_CACHE = [
    './',
    'index.html',
    'css/styles.css',
    'js/app.js',
    'js/db.js',
    'js/geolocation.js',
    'js/api.js',
    'js/sync.js',
    'js/components/home.js',
    'js/components/species-selector.js',
    'js/components/capture-form.js',
    'js/components/confirmation.js',
    'js/components/history.js',
    'js/components/info.js',
    'manifest.json',
    'https://unpkg.com/dexie@3.2.4/dist/dexie.min.js'
];

// Install event - cache static assets
self.addEventListener('install', (event) => {
    console.log('Service Worker installing...');

    event.waitUntil(
        caches.open(CACHE_NAME)
            .then((cache) => {
                console.log('Caching static assets');
                return cache.addAll(STATIC_CACHE);
            })
            .then(() => self.skipWaiting())
    );
});

// Activate event - clean up old caches
self.addEventListener('activate', (event) => {
    console.log('Service Worker activating...');

    event.waitUntil(
        caches.keys().then((cacheNames) => {
            return Promise.all(
                cacheNames.map((cacheName) => {
                    if (cacheName !== CACHE_NAME) {
                        console.log('Deleting old cache:', cacheName);
                        return caches.delete(cacheName);
                    }
                })
            );
        }).then(() => self.clients.claim())
    );
});

// Fetch event - serve from cache, fallback to network
self.addEventListener('fetch', (event) => {
    const { request } = event;
    const url = new URL(request.url);

    // API requests - network first, then cache
    if (url.pathname.startsWith('/api/')) {
        event.respondWith(
            fetch(request)
                .then((response) => {
                    // Clone response to cache it
                    const responseClone = response.clone();
                    caches.open(CACHE_NAME).then((cache) => {
                        cache.put(request, responseClone);
                    });
                    return response;
                })
                .catch(() => {
                    // If network fails, try cache
                    return caches.match(request);
                })
        );
        return;
    }

    // Static assets - cache first, then network
    event.respondWith(
        caches.match(request)
            .then((cachedResponse) => {
                if (cachedResponse) {
                    return cachedResponse;
                }

                return fetch(request)
                    .then((response) => {
                        // Don't cache non-successful responses
                        if (!response || response.status !== 200 || response.type === 'error') {
                            return response;
                        }

                        // Clone response to cache it
                        const responseClone = response.clone();
                        caches.open(CACHE_NAME).then((cache) => {
                            cache.put(request, responseClone);
                        });

                        return response;
                    });
            })
            .catch(() => {
                // Return offline page if available
                if (request.mode === 'navigate') {
                    return caches.match('/index.html');
                }
            })
    );
});

// Background sync for captures
self.addEventListener('sync', (event) => {
    if (event.tag === 'sync-captures') {
        console.log('Background sync triggered');
        event.waitUntil(
            // Notify clients to sync
            self.clients.matchAll().then((clients) => {
                clients.forEach((client) => {
                    client.postMessage({
                        type: 'BACKGROUND_SYNC',
                        action: 'sync-captures'
                    });
                });
            })
        );
    }
});