/* Baustelle PWA Service Worker
 * Pattern nach claude-db #201 (filemtime-basiert):
 * - Cache-Version kommt aus URL-Query ?v=<mtime>, kein manuelles Hochzählen
 * - Network-First für eigene Assets (immer aktuell, Fallback Cache)
 * - skipWaiting() + clients.claim() damit Updates sofort greifen
 * - Web Share Target via POST → share.html
 */

// Cache-Version dynamisch aus ?v=<mtime> — wird von index.php gesetzt
const SW_VERSION = (new URL(self.location.href)).searchParams.get('v') || 'static';
const CACHE = 'baustelle-' + SW_VERSION;
const SHELL = [
    './',
    './index.php',
    './share.html',
    './icons/icon-192.png',
    './icons/icon-512.png',
    './icons/icon.svg',
    // CSS/JS werden mit ?v=<mtime> geladen und dynamisch gecached
    // beim ersten fetch — nicht in SHELL damit Pre-Cache nicht mit alten v's läuft
];

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

self.addEventListener('activate', (e) => {
    e.waitUntil(
        caches.keys()
            .then(keys => Promise.all(
                keys.filter(k => k.startsWith('baustelle-') && k !== CACHE)
                    .map(k => caches.delete(k))
            ))
            .then(() => self.clients.claim())
    );
});

/* Web Share Target: POST auf share.html abfangen */
async function handleShareTarget(request) {
    const fd = await request.formData();
    let files = [];
    for (const key of ['photos', 'file', 'files', 'image', 'images']) {
        const v = fd.getAll(key);
        if (v && v.length) files = files.concat(v);
    }
    // Fallback: alle File-Entries im FormData durchsuchen
    if (!files.length) {
        for (const [, v] of fd.entries()) {
            if (v && typeof v === 'object' && v.size !== undefined) files.push(v);
        }
    }

    if (files.length) {
        const db = await new Promise((res, rej) => {
            const req = indexedDB.open('baustelle-pwa-v1', 1);
            req.onupgradeneeded = () => {
                const d = req.result;
                if (!d.objectStoreNames.contains('kv')) d.createObjectStore('kv');
                if (!d.objectStoreNames.contains('queue')) d.createObjectStore('queue', { keyPath: 'id', autoIncrement: true });
            };
            req.onsuccess = () => res(req.result);
            req.onerror = () => rej(req.error);
        });
        const tx = db.transaction('kv', 'readwrite');
        tx.objectStore('kv').put(
            files.map(f => ({ name: f.name || 'photo.jpg', type: f.type || 'image/jpeg', data: f })),
            'shared_files'
        );
        await new Promise(res => { tx.oncomplete = res; });
    }
    return Response.redirect('./share.html', 303);
}

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

    // Web Share Target POST → share.html
    if (e.request.method === 'POST' && url.pathname.endsWith('/share.html')) {
        e.respondWith(handleShareTarget(e.request));
        return;
    }

    // API-Requests: nicht cachen, durchreichen
    if (url.pathname.includes('/custom/bericht/api/')) {
        return;
    }

    // Nicht-GETs: durchreichen
    if (e.request.method !== 'GET') {
        return;
    }

    // Eigene Assets: Network-First mit Cache-Fallback
    if (url.origin === location.origin) {
        e.respondWith(
            fetch(e.request)
                .then(response => {
                    // Cache aktualisieren (nur erfolgreiche responses)
                    if (response && response.ok) {
                        const clone = response.clone();
                        caches.open(CACHE).then(c => c.put(e.request, clone)).catch(() => null);
                    }
                    return response;
                })
                .catch(() => caches.match(e.request))
        );
        return;
    }
});

/* Message-Handler: Client kann "SKIP_WAITING" schicken um ein wartenden SW
 * sofort zu aktivieren (für In-App-Update-Button). */
self.addEventListener('message', (e) => {
    if (e.data && e.data.type === 'SKIP_WAITING') {
        self.skipWaiting();
    }
});