/**
 * Service Worker для обработки Web Push уведомлений
 * 
 * Этот файл должен находиться в /public/ для Next.js.
 * Service Worker перехватывает push-события от браузера и показывает
 * нативные уведомления даже когда страница закрыта.
 */

const SW_VERSION = '2.1.1';
const STATIC_CACHE = `eusrr-static-${SW_VERSION}`;
const PRECACHE_URLS = [
    '/manifest.webmanifest',
    '/favicon-source.svg',
    '/notification-badge.png',
    '/logo.png',
    '/logo.webp',
    '/icon-192.png',
    '/icon-512.png',
    '/icon-512-maskable.png',
    '/apple-touch-icon.png',
];

// Настройки по умолчанию для уведомлений
const DEFAULT_NOTIFICATION_OPTIONS = {
    icon: '/icon-192.png',
    badge: '/notification-badge.png',
    vibrate: [100, 50, 100],
    requireInteraction: false,
    renotify: true,
};

/**
 * Событие установки Service Worker
 */
self.addEventListener('install', (event) => {
    console.log('[SW] Service Worker installing, version:', SW_VERSION);
    event.waitUntil(
        caches
            .open(STATIC_CACHE)
            .then((cache) => cache.addAll(PRECACHE_URLS))
            .catch((error) => {
                console.error('[SW] Failed to precache static assets:', error);
            })
            .then(() => self.skipWaiting())
    );
});

/**
 * Событие активации Service Worker
 */
self.addEventListener('activate', (event) => {
    console.log('[SW] Service Worker activated, version:', SW_VERSION);
    event.waitUntil(
        caches.keys().then((cacheKeys) =>
            Promise.all(
                cacheKeys.map((cacheKey) => {
                    if (cacheKey !== STATIC_CACHE && cacheKey.startsWith('eusrr-static-')) {
                        return caches.delete(cacheKey);
                    }
                    return Promise.resolve(false);
                })
            )
        ).then(() => self.clients.claim())
    );
});

self.addEventListener('fetch', (event) => {
    const { request } = event;

    if (request.method !== 'GET') {
        return;
    }

    const url = new URL(request.url);
    if (url.origin !== self.location.origin) {
        return;
    }

    const isApiRequest = url.pathname.startsWith('/api/');
    const isStaticAsset =
        url.pathname.startsWith('/_next/static/') ||
        PRECACHE_URLS.includes(url.pathname) ||
        ['image', 'style', 'script', 'font', 'worker'].includes(request.destination);

    if (isApiRequest || !isStaticAsset) {
        return;
    }

    event.respondWith(
        caches.open(STATIC_CACHE).then(async (cache) => {
            const cachedResponse = await cache.match(request);
            if (cachedResponse) {
                return cachedResponse;
            }

            const networkResponse = await fetch(request);
            if (networkResponse.ok) {
                cache.put(request, networkResponse.clone()).catch(() => undefined);
            }
            return networkResponse;
        })
    );
});

/**
 * Обработка входящих push-уведомлений
 * 
 * Формат данных с сервера:
 * {
 *   "title": "Заголовок уведомления",
 *   "body": "Текст уведомления",
 *   "icon": "/logo.png",
 *   "badge": "/logo.png",
 *   "tag": "notification-id",
 *   "data": {
 *     "url": "/path/to/page",
 *     "notification_id": 123,
 *     "category": "requests",
 *   }
 * }
 */
self.addEventListener('push', (event) => {
    console.log('[SW] Push received:', event);
    
    let notificationData = {
        title: 'Новое уведомление',
        body: '',
        ...DEFAULT_NOTIFICATION_OPTIONS,
        data: {}
    };
    
    if (event.data) {
        try {
            const payload = event.data.json();
            console.log('[SW] Push payload:', payload);
            
            notificationData = {
                ...notificationData,
                title: payload.title || payload.head || notificationData.title,
                body: payload.body || payload.message || '',
                icon: payload.icon || notificationData.icon,
                badge: payload.badge || notificationData.badge,
                tag: payload.tag || `notification-${Date.now()}`,
                data: {
                    ...(payload.data || {}),
                    url:
                        payload.data?.url ||
                        payload.url ||
                        payload.action_url ||
                        notificationData.data?.url ||
                        '/',
                }
            };
            
            // Дополнительные опции
            if (payload.image) {
                notificationData.image = payload.image;
            }
            if (payload.actions) {
                notificationData.actions = payload.actions;
            }
            if (payload.requireInteraction !== undefined) {
                notificationData.requireInteraction = payload.requireInteraction;
            }
            
        } catch (e) {
            console.log('[SW] Push data is not JSON, using as text');
            notificationData.body = event.data.text();
        }
    }
    
    // Показываем уведомление
    const { title, ...options } = notificationData;
    
    event.waitUntil(
        self.registration.showNotification(title, options)
            .then(() => {
                console.log('[SW] Notification shown:', title);
            })
            .catch((error) => {
                console.error('[SW] Failed to show notification:', error);
            })
    );
});

/**
 * Обработка клика по уведомлению
 */
self.addEventListener('notificationclick', (event) => {
    console.log('[SW] Notification clicked:', event.notification.tag);
    
    event.notification.close();
    
    // Получаем URL из данных уведомления
    const urlToOpen = new URL(
        event.notification.data?.url || '/',
        self.location.origin,
    ).toString();
    
    // Для установленного PWA даём браузеру самому решить, открыть app window
    // или вкладку. Не фокусируем произвольную already-open same-origin вкладку.
    event.waitUntil(
        clients.matchAll({ type: 'window', includeUncontrolled: true })
            .then(async (windowClients) => {
                const exactClient = windowClients.find(
                    (client) => client.url === urlToOpen && 'focus' in client,
                );
                if (exactClient) {
                    return exactClient.focus();
                }

                if (clients.openWindow) {
                    return clients.openWindow(urlToOpen);
                }

                const sameOriginClient = windowClients.find(
                    (client) =>
                        client.url.startsWith(self.location.origin) &&
                        'focus' in client,
                );
                if (sameOriginClient) {
                    return sameOriginClient.focus().then((client) => {
                        if ('navigate' in client) {
                            return client.navigate(urlToOpen);
                        }
                        return client.postMessage({
                            type: 'NOTIFICATION_CLICK',
                            url: urlToOpen,
                            notificationId: event.notification.data?.notification_id
                        });
                    });
                }
            })
    );
});

/**
 * Обработка закрытия уведомления
 */
self.addEventListener('notificationclose', (event) => {
    console.log('[SW] Notification closed:', event.notification.tag);
    
    // Можно отправить статистику на сервер
    if (event.notification.data?.notification_id) {
        // fetch('/api/v1/notifications/stats/closed/', {
        //     method: 'POST',
        //     body: JSON.stringify({ id: event.notification.data.notification_id })
        // });
    }
});

console.log('[SW] Service Worker loaded, version:', SW_VERSION);