const fs = require('node:fs');
const path = require('node:path');
const vm = require('node:vm');
const test = require('node:test');
const assert = require('node:assert/strict');

async function activateWorker(version, cacheKeys) {
  const listeners = new Map();
  const deleted = [];
  let claimed = false;
  const sandbox = {
    URL,
    self: {
      location: { href: 'http://localhost/sw.js?v=' + encodeURIComponent(version) },
      addEventListener(name, callback) { listeners.set(name, callback); },
      clients: { async claim() { claimed = true; } }
    },
    caches: {
      async keys() { return cacheKeys; },
      async delete(key) { deleted.push(key); return true; }
    }
  };
  const scriptPath = path.join(__dirname, '..', 'src', 'player', 'public', 'sw.js');
  vm.runInNewContext(fs.readFileSync(scriptPath, 'utf8'), sandbox, { filename: scriptPath });
  let activation;
  listeners.get('activate')({ waitUntil(promise) { activation = promise; } });
  await activation;
  assert.equal(claimed, true);
  return deleted;
}

test('player service worker activation preserves caches owned by other applications', async () => {
  const deleted = await activateWorker('2.14.0', ['other-app-assets', 'other-app-pages']);
  assert.deepEqual(deleted, []);
});

test('player service worker retains its active version and the most recently created other generation', async () => {
  const cacheKeys = [
    'other-app-cache',
    'pulse-signage-player-pages-2.10.0',
    'pulse-signage-player-assets-2.10.0',
    'pulse-signage-player-media-2.10.0',
    'pulse-signage-player-playlists-2.10.0',
    'pulse-signage-player-pages-2.9.0',
    'pulse-signage-player-assets-2.11.0',
    'pulse-signage-player-pages-2.11.0'
  ];
  const deleted = await activateWorker('2.10.0', cacheKeys);
  assert.deepEqual(deleted, ['pulse-signage-player-pages-2.9.0']);
});

test('player service worker retention supports opaque versions before active caches exist', async () => {
  const deleted = await activateWorker('current-build', [
    'pulse-signage-player-pages-z-old-build',
    'pulse-signage-player-assets-z-old-build',
    'pulse-signage-player-pages-a-newer-build',
    'pulse-signage-player-playlists-a-newer-build'
  ]);
  assert.deepEqual(deleted, [
    'pulse-signage-player-pages-z-old-build',
    'pulse-signage-player-assets-z-old-build'
  ]);
});

function createFetchWorker({ failure, cachedResponse = null, cacheMatchResponse = null, fetchError = false, networkStatus = 200 } = {}) {
  const networkResponse = new Response('fresh network body', {
    status: networkStatus, headers: { ETag: '"fresh"', 'Content-Type': 'text/plain' }
  });
  const namedCacheResponse = cacheMatchResponse === null ? cachedResponse : cacheMatchResponse;
  const calls = { fetch: 0, writes: [] };
  const listeners = new Map();
  const sandbox = {
    URL,
    Response,
    Request,
    Headers,
    self: {
      location: { href: 'http://localhost/sw.js', origin: 'http://localhost' },
      addEventListener(name, callback) { listeners.set(name, callback); }
    },
    async fetch() {
      calls.fetch += 1;
      if (fetchError) throw new Error('Network unavailable');
      return networkResponse;
    },
    caches: {
      async match() { return cachedResponse; },
      async open() {
        if (failure === 'open') throw new Error('Cache storage unavailable');
        return {
          async match() { return namedCacheResponse; },
          async put(key, response) {
            if (failure === 'put') throw new Error('QuotaExceededError');
            calls.writes.push({ key, response });
          }
        };
      }
    }
  };
  const scriptPath = path.join(__dirname, '..', 'src', 'player', 'public', 'sw.js');
  vm.runInNewContext(fs.readFileSync(scriptPath, 'utf8'), sandbox, { filename: scriptPath });
  return { sandbox, calls, networkResponse, listeners };
}

test('successful network responses survive cache open and write failures', async () => {
  for (const failure of ['open', 'put']) {
    for (const strategy of ['networkFirst', 'cacheFirst', 'staleWhileRevalidate']) {
      for (const cached of strategy === 'networkFirst' ? [false, true] : [false]) {
        const cachedResponse = cached ? new Response('stale body') : null;
        const { sandbox, networkResponse } = createFetchWorker({ failure, cachedResponse });
        const response = await sandbox[strategy]({ url: 'http://localhost/screen/test' }, 'cache');
        assert.equal(response, networkResponse, strategy + ', failure=' + failure + ', cached=' + cached);
        assert.equal(response.status, 200);
        assert.equal(response.headers.get('ETag'), '"fresh"');
        assert.equal(await response.text(), 'fresh network body');
      }
    }
  }
});

test('successful cache writes retain the normalized key and do not consume the network body', async () => {
  const { sandbox, calls, networkResponse } = createFetchWorker();
  const request = { url: 'http://localhost/api/screens/test/playlist?ts=1' };
  const normalizedKey = { url: 'http://localhost/api/screens/test/playlist' };
  const response = await sandbox.networkFirst(request, 'cache', normalizedKey);
  assert.equal(response, networkResponse);
  assert.equal(calls.writes.length, 1);
  assert.equal(calls.writes[0].key, normalizedKey);
  assert.notEqual(calls.writes[0].response, networkResponse);
  assert.equal(await calls.writes[0].response.text(), 'fresh network body');
  assert.equal(await response.text(), 'fresh network body');
});

test('asset cache hits do not fetch and offline pages still fall back to cached responses', async () => {
  const cachedResponse = new Response('cached body');
  const cacheHit = createFetchWorker({ cachedResponse });
  assert.equal(await cacheHit.sandbox.cacheFirst({}, 'cache'), cachedResponse);
  assert.equal(cacheHit.calls.fetch, 0);
  const offlineHit = createFetchWorker({ cachedResponse, fetchError: true });
  assert.equal(await offlineHit.sandbox.networkFirst({}, 'cache'), cachedResponse);
  const offlineMiss = createFetchWorker({ fetchError: true });
  assert.equal((await offlineMiss.sandbox.networkFirst({}, 'cache')).status, 504);
});

test('player script assets refresh from network and retain offline cache fallback', async () => {
  const cachedResponse = new Response('old script body');
  const online = createFetchWorker({ cachedResponse });
  let onlineResponsePromise;
  online.listeners.get('fetch')({
    request: new Request('http://localhost/assets/player-script/rendering.js?v=2.14.0'),
    respondWith(promise) { onlineResponsePromise = promise; }
  });
  assert.equal(await onlineResponsePromise, online.networkResponse);
  assert.equal(online.calls.fetch, 1);

  const offline = createFetchWorker({ cachedResponse: cachedResponse, fetchError: true });
  let offlineResponsePromise;
  offline.listeners.get('fetch')({
    request: new Request('http://localhost/assets/player-script/rendering.js?v=2.14.0'),
    respondWith(promise) { offlineResponsePromise = promise; }
  });
  assert.equal(await offlineResponsePromise, cachedResponse);
});

test('playlist HTTP errors are not hidden by a stale cached playlist', async () => {
  const cachedResponse = new Response('stale playlist body', { status: 200 });
  const worker = createFetchWorker({ cachedResponse, networkStatus: 403 });
  const request = new Request('http://localhost/api/screens/test/playlist?ts=2');
  const response = await worker.sandbox.networkFirst(
    request,
    'playlists',
    { url: 'http://localhost/api/screens/test/playlist' },
    false
  );

  assert.equal(response.status, 403);
  assert.equal(await response.text(), 'fresh network body');
});

test('playlist offline fallback does not read an older cache generation', async () => {
  const staleResponse = new Response('stale QR playlist', { status: 200 });
  const currentResponse = new Response('current Video playlist', { status: 200 });
  const worker = createFetchWorker({
    cachedResponse: staleResponse,
    cacheMatchResponse: currentResponse,
    fetchError: true
  });
  const request = new Request('http://localhost/api/screens/test/playlist?ts=3');
  const response = await worker.sandbox.networkFirst(
    request,
    'playlists-current',
    { url: 'http://localhost/api/screens/test/playlist' },
    false
  );

  assert.equal(response, currentResponse);
  assert.equal(await response.text(), 'current Video playlist');
});