import { defineConfig, type Plugin } from 'vite'
import vue from '@vitejs/plugin-vue'

// Service Worker als Build-Artefakt: Die Cache-Version ist der Build-Zeitstempel,
// damit Browser nach jedem Deploy den SW aktualisieren und alte Caches räumen.
const SW_SOURCE = `
const VERSION = 'wp-__SW_VERSION__';
const CACHE_NAME = 'wannpassts-' + VERSION;
const PRECACHE = [
  '/',
  '/manifest.webmanifest',
  '/favicon.svg',
  '/icons/icon-192.png',
  '/icons/icon-512.png',
  '/icons/icon-maskable-512.png',
  '/icons/apple-touch-icon.png',
];

self.addEventListener('install', (event) => {
  event.waitUntil((async () => {
    const cache = await caches.open(CACHE_NAME);
    await cache.addAll(PRECACHE).catch(() => {});
    await self.skipWaiting();
  })());
});

self.addEventListener('activate', (event) => {
  event.waitUntil((async () => {
    const keys = await caches.keys();
    await Promise.all(keys.filter((k) => k !== CACHE_NAME).map((k) => caches.delete(k)));
    await self.clients.claim();
  })());
});

self.addEventListener('fetch', (event) => {
  const req = event.request;
  if (req.method !== 'GET') return;
  const url = new URL(req.url);
  if (url.origin !== self.location.origin) return;
  // API-Aufrufe immer live – niemals aus dem Cache bedienen.
  if (url.pathname.startsWith('/api/')) return;

  // Navigation: Netzwerk zuerst, offline App-Shell aus dem Cache.
  if (req.mode === 'navigate') {
    event.respondWith((async () => {
      try {
        const res = await fetch(req);
        const cache = await caches.open(CACHE_NAME);
        cache.put('/', res.clone());
        return res;
      } catch (err) {
        const cached = (await caches.match(req)) || (await caches.match('/'));
        if (cached) return cached;
        return new Response('Offline – bitte Internetverbindung prüfen.', {
          status: 503,
          headers: { 'Content-Type': 'text/plain; charset=utf-8' },
        });
      }
    })());
    return;
  }

  // Statische Assets: Cache zuerst (gehashte Namen sind unveränderlich).
  event.respondWith((async () => {
    const cached = await caches.match(req, { ignoreSearch: true });
    if (cached) return cached;
    const res = await fetch(req);
    if (res.ok) {
      const cache = await caches.open(CACHE_NAME);
      cache.put(req, res.clone());
    }
    return res;
  })());
});
`

function serviceWorkerPlugin(): Plugin {
  return {
    name: 'wannpassts-sw',
    apply: 'build',
    generateBundle() {
      this.emitFile({
        type: 'asset',
        fileName: 'sw.js',
        source: SW_SOURCE.replace('__SW_VERSION__', new Date().toISOString()),
      })
    },
  }
}

export default defineConfig({
  plugins: [vue(), serviceWorkerPlugin()],
  server: {
    port: 5173,
    proxy: {
      '/api': { target: 'http://localhost:8080', changeOrigin: true },
    },
  },
})