// iPX without a connection (#389): the service worker (web/sw/sw.ts) keeps the page, what it read
// and the pictures in unread items, and holds writes made offline until the connection is back.
// After app.spec.ts, file order being run order: it adds a feed, which that file's counts of
// feeds do not expect.

import type { BrowserContext, Page, Worker } from '@playwright/test';
import { TOKEN } from './global-setup.ts';
import { expect, test } from './coverage.ts';

// The suite blocks the worker, which answers before page.route can; these tests are about it.
test.use({ serviceWorkers: 'allow' });

const call = (page: Page, p: string, init?: RequestInit) =>
  page.evaluate(([p, init]) => fetch(p!, { headers: { 'Content-Type': 'application/json' }, ...(init as RequestInit) })
    .then((r) => r.json().catch(() => null)), [p, init] as const);
const cacheSize = (page: Page, name: string) =>
  page.evaluate(async (name) => (await (await caches.open(name)).keys()).length, name);
const outbox = (page: Page) => cacheSize(page, 'ipx-outbox');

/// The page, under the worker's control.
async function controlled(page: Page) {
  await page.evaluate(() => navigator.serviceWorker.ready);
  await page.reload();
  await expect.poll(() => page.evaluate(() => !!navigator.serviceWorker.controller)).toBe(true);
}
async function worker(context: BrowserContext): Promise<Worker> {
  return context.serviceWorkers()[0] ?? context.waitForEvent('serviceworker');
}

/// The feed these tests read, added once; the tests that follow find it there.
async function offlineBlog(page: Page): Promise<string> {
  const feeds: { id: string, url: string }[] = await call(page, '/api/feeds');
  const had = feeds.find((f) => f.url.endsWith('/offline.xml'));
  if (had) return had.id;
  const added = await call(page, '/api/feeds', { method: 'POST', body: JSON.stringify({ url: 'http://127.0.0.1:8792/offline.xml' }) });
  return added?.id || added?.feed?.id || 'offline-blog';
}

test.beforeEach(async ({ page }) => {
  await page.goto(`/?token=${TOKEN}`);
  await expect(page.locator('#feedlist')).toBeVisible();
  await offlineBlog(page);
});

test('iPX opens offline with what it read and its pictures, and sends a read made offline once back', async ({ page, context }) => {
  const id = await offlineBlog(page);
  // A run before this one read them: both unread again, so the Unread list holds both.
  await expect.poll(async () => (await call(page, `/api/feeds/${encodeURIComponent(id)}/entries?offset=0&limit=50&filter=all`))?.entries?.length ?? 0,
    { timeout: 20_000 }).toBe(2);
  for (const guid of ['offline-1', 'offline-2'])
    await call(page, `/api/entries/${encodeURIComponent(id)}/${guid}/flags`, { method: 'POST', body: JSON.stringify({ read: false }) });
  await controlled(page);
  await page.locator('#feedlist .feed', { hasText: 'Offline Blog' }).click({ timeout: 20_000 });
  await page.locator('#content .tabs button[data-f="unread"]').click();
  await expect(page.locator('.ep', { hasText: 'Read on a Plane' })).toBeVisible();
  // The unread items' four pictures, kept through ipx: no feed names them as artwork, only text.
  await expect.poll(() => cacheSize(page, 'ipx-pics')).toBe(4);

  await context.setOffline(true);
  await page.reload();
  // The page, the feed list and the list kept, with the feed and tab open before.
  await page.locator('.ep', { hasText: 'Read on a Plane' }).click({ timeout: 20_000 });
  await expect(page.locator('#detail .dbody')).toContainText('Read on a plane, with no connection.');
  await expect.poll(() => page.locator('#detail .dbody img').evaluate((i: HTMLImageElement) => i.complete ? i.naturalWidth : 0)).toBeGreaterThan(0);
  // Opening it read it, which waits to be sent.
  await expect.poll(() => outbox(page)).toBe(1);
  // Opened again offline, the Unread list kept no longer has it: read, as the outbox has it.
  await page.reload();
  await expect(page.locator('.ep', { hasText: 'Three Pictures' })).toBeVisible({ timeout: 20_000 });
  await expect(page.locator('.ep', { hasText: 'Read on a Plane' })).toHaveCount(0);

  await context.setOffline(false);
  await expect.poll(() => outbox(page), { timeout: 15_000 }).toBe(0);
  const list = await call(page, `/api/feeds/${encodeURIComponent(id)}/entries?offset=0&limit=50&filter=all`);
  expect(list.entries.find((e: { guid: string }) => e.guid === 'offline-1').read).toBe(true);
});

test('a place in an episode saved offline waits, and is saved once back', async ({ page, context }) => {
  await controlled(page);
  const at = '/api/entries/offline-blog/offline-2/position';
  await context.setOffline(true);
  const answer = await page.evaluate((at) => fetch(at, {
    method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ secs: 321, duration: 600 }),
  }).then((r) => `${r.status} ${r.headers.get('X-Ipx-Queued')}`), at);
  // Answered for the server, so the player carries on, and kept.
  expect(answer).toBe('204 1');
  expect(await outbox(page)).toBe(1);

  await context.setOffline(false);
  await page.evaluate(() => window.dispatchEvent(new Event('online')));
  await expect.poll(() => outbox(page), { timeout: 15_000 }).toBe(0);
  expect((await call(page, '/api/entries/offline-blog/offline-2')).position).toBe(321);
});

test('online, a picture in an item\'s text still comes from its publisher, through the worker', async ({ page }) => {
  await controlled(page);
  await page.locator('#feedlist .feed', { hasText: 'Offline Blog' }).click({ timeout: 20_000 });
  await page.locator('#content .tabs button[data-f="all"]').click();
  await page.locator('.ep', { hasText: 'Read on a Plane' }).click();
  const img = page.locator('#detail .dbody img');
  await expect.poll(() => img.evaluate((i: HTMLImageElement) => i.complete ? i.naturalWidth : 0)).toBeGreaterThan(0);
  // Past the worker, not round it: what it passes on online is what it would keep.
  expect(await page.evaluate(() =>
    ((performance.getEntriesByName('http://127.0.0.1:8792/pic.png')[0] as PerformanceResourceTiming | undefined)?.workerStart ?? 0) > 0)).toBe(true);
});

test('kept pictures past the budget go oldest first', async ({ page, context }) => {
  const pic = (n: number) => `http://127.0.0.1:8792/pic.png?n=${n}`;
  // ipx serves only pictures it has sent in item text: the list names them, once scanned.
  await expect.poll(async () => (await call(page, '/api/feeds/offline-blog/entries?offset=0&limit=50&filter=all'))?.entries?.length ?? 0,
    { timeout: 20_000 }).toBe(2);
  // Read, so the page asks the worker to keep none of them itself while this test does.
  for (const guid of ['offline-1', 'offline-2'])
    await call(page, `/api/entries/offline-blog/${guid}/flags`, { method: 'POST', body: JSON.stringify({ read: true }) });
  await controlled(page);
  const sw = await worker(context);
  const kept = await sw.evaluate(async ([a, b, c]) => {
    await caches.delete('ipx-pics');
    // One at a time, so which is oldest is known; the third goes over two pictures' budget.
    await keepPictures([a!]);
    await keepPictures([b!]);
    const one = Number((await (await caches.open('ipx-pics')).match(`/api/art?u=${encodeURIComponent(a!)}`))?.headers.get('X-Size'));
    await keepPictures([c!], one * 2.5);
    return (await (await caches.open('ipx-pics')).keys()).map((k) => decodeURIComponent(new URL(k.url).searchParams.get('u')!));
  }, [pic(1), pic(2), pic(3)]);
  expect(kept).toEqual([pic(2), pic(3)]);
});

test('another account signing in on the device clears what the last one kept', async ({ page }) => {
  await controlled(page);
  // What an account before this one left, and the page last opened as that account.
  await page.evaluate(async () => {
    await (await caches.open('ipx-api')).put('/api/left-by-someone-else', new Response('{}'));
    localStorage.setItem('ipx.owner', 'someone else');
  });
  await page.reload();
  await expect.poll(() => page.evaluate(async () =>
    !!(await (await caches.open('ipx-api')).match('/api/left-by-someone-else')))).toBe(false);
  // This account is the owner now, and what it keeps from here stays.
  expect(await page.evaluate(() => localStorage.getItem('ipx.owner'))).not.toBe('someone else');
});

test('signing out leaves nothing kept for offline on the device', async ({ page }) => {
  await controlled(page);
  await expect.poll(() => page.evaluate(async () => (await caches.keys()).filter((k) => k.startsWith('ipx-')).length)).toBeGreaterThan(0);
  await page.locator('#signout').evaluate((b: HTMLButtonElement) => b.click());
  await page.waitForURL((u) => u.pathname !== '/');
  // What was read, its pictures and unsent writes. The sign-in page's own script and styles are
  // kept again as it loads: the same files for everyone, nothing of the account's.
  expect(await page.evaluate(async () => (await caches.keys()).filter((k) => k.startsWith('ipx-') && k !== 'ipx-page'))).toEqual([]);
});

// The worker's own functions, called in it by the test above; declared for the type check.
declare function keepPictures(srcs: string[], budget?: number): Promise<void>;