// Swiping through the feed's pictures (or clips) in the pager is scrolling
// the feed: with four slides or fewer left past the one on screen (six for clips), the
// feed pages on, and the pager grows — past a run of posts with nothing to
// show, too — so the reader never meets the end while there is more.
// Run: bun tools/feed-pager-ahead-test.js
import puppeteer from './puppeteer.js';
import { cacheKeyFor } from '../src/wallet.js';
import { generateSecretKey, getPublicKey, finalizeEvent } from 'nostr-tools/pure';
import { buildHtml } from '../build.js';
const sleep = (ms) => new Promise((r) => setTimeout(r, ms));
let ok = true;
const check = (n, c, d = '') => { console.log(` ${c ? '✓' : '✗'} ${n}${d ? ' — ' + d : ''}`); if (!c) ok = false; };
const png = (size) => Bun.spawnSync(['ffmpeg', '-loglevel', 'error', '-f', 'lavfi', '-i', 'testsrc=size=' + size, '-frames:v', '1', '-f', 'image2', '-c:v', 'png', 'pipe:1']).stdout;
const PIC = png('320x240');

const SK = generateSecretKey(), AUTHOR = getPublicKey(SK);
const now = Math.floor(Date.now() / 1000);
const post = (content, ago) => finalizeEvent({ kind: 1, created_at: now - ago, tags: [], content }, SK);
const html = await buildHtml({ minify: true, pwa: false });
const server = Bun.serve({ port: 0, fetch: (req) => {
  const path = new URL(req.url).pathname;
  if (path.startsWith('/punks')) return new Response(Bun.file('dist' + path));
  if (/^\/p\d+\.png$/.test(path)) return new Response(PIC, { headers: { 'content-type': 'image/png' } });
  return new Response(html, { headers: { 'content-type': 'text/html' } });
} });
const U = (n) => server.url.origin + '/p' + n + '.png';
// 12 picture posts, 15 with only words, then 14 more pictures: 26 in all
const seeded = [];
let ago = 100, pic = 0;
for (let i = 0; i < 12; i++) seeded.push(post('picture number ' + pic + ' ' + U(pic++), ago += 60));
for (let i = 0; i < 15; i++) seeded.push(post('just words ' + i + ' ' + 'lorem ipsum dolor sit amet. '.repeat(i % 3 ? 3 : 90), ago += 60)); // some of them long: rows of very different heights
for (let i = 0; i < 14; i++) seeded.push(post('picture number ' + pic + ' ' + U(pic++), ago += 60));
const TOTAL = pic;

const browser = await puppeteer.launch({ executablePath: '/usr/bin/google-chrome', headless: 'new', args: ['--no-sandbox'] });
const page = await browser.newPage();
// The relays, in the page: every one holds all the posts (the feed's own
// cache keeps only the newest 30, so the rest have to come from here) and
// answers a REQ by its kinds, authors, since, until and limit.
await page.evaluateOnNewDocument((evs) => {
  const match = (f, e) => (!f.kinds || f.kinds.includes(e.kind)) && (!f.authors || f.authors.includes(e.pubkey)) && (!f.ids || f.ids.includes(e.id))
    && (!f.until || e.created_at <= f.until) && (!f.since || e.created_at >= f.since) && !Object.keys(f).some((k) => k.startsWith('#'));
  class FakeWS {
    constructor(url) { this.url = String(url); this.readyState = 0; setTimeout(() => { this.readyState = 1; this.onopen && this.onopen({}); }, 5); }
    send(raw) {
      const m = JSON.parse(raw);
      const reply = (x) => setTimeout(() => this.readyState === 1 && this.onmessage && this.onmessage({ data: JSON.stringify(x) }), 5);
      if (m[0] === 'REQ') {
        for (const f of m.slice(2)) {
          if (f.cache) continue;
          const hits = evs.filter((e) => match(f, e)).sort((a, b) => b.created_at - a.created_at);
          for (const e of f.limit ? hits.slice(0, f.limit) : hits) reply(['EVENT', m[1], e]);
        }
        reply(['EOSE', m[1]]);
      } else if (m[0] === 'EVENT') reply(['OK', m[1].id, true, '']);
      else if (m[0] === 'COUNT') reply(['COUNT', m[1], { count: 0 }]);
    }
    close() { this.readyState = 3; this.onclose && this.onclose({ code: 1000 }); }
    addEventListener(t, fn) { this['on' + t] = fn; }
    removeEventListener() {}
  }
  FakeWS.CONNECTING = 0; FakeWS.OPEN = 1; FakeWS.CLOSING = 2; FakeWS.CLOSED = 3;
  window.WebSocket = FakeWS;
}, seeded);
const errs = [];
page.on('pageerror', (e) => errs.push(String(e)));
const click = (t) => page.evaluate((x) => { const e = [...document.querySelectorAll('button')].find((n) => n.textContent.trim().toLowerCase().includes(x)); if (e) { e.click(); return true; } return false; }, t);
const waitText = async (x, ms = 25000) => { for (let i = 0; i < ms / 250; i++) { if ((await page.evaluate(() => document.body.innerText)).toLowerCase().includes(x)) return true; await sleep(250); } return false; };
const waitFor = async (fn, arg, ms = 10000) => { for (let i = 0; i < ms / 100; i++) { if (await page.evaluate(fn, arg)) return true; await sleep(100); } return false; };
// the slide the pager rests on, by its picture
const curPic = () => page.evaluate(() => {
  const sc = document.querySelector('.mp-scroll'); if (!sc) return null;
  const s = [...sc.querySelectorAll('.mp-slide')].find((x) => { const r = x.getBoundingClientRect(); return Math.abs(r.top) < 4 && Math.abs(r.left) < 4; });
  return s ? s.getAttribute('data-k').split('|')[1].split('/').pop() : 'between';
});
const resting = async (name) => waitFor((n) => { const sc = document.querySelector('.mp-scroll'); if (!sc) return false; const s = [...sc.querySelectorAll('.mp-slide')].find((x) => { const r = x.getBoundingClientRect(); return Math.abs(r.top) < 4 && Math.abs(r.left) < 4; }); return !!s && s.getAttribute('data-k').endsWith('/' + n); }, name, 4000);
const openPic = async (word) => {
  await page.evaluate((w) => { const r = [...document.querySelectorAll('.notes-feed [data-key]')].find((n) => n.textContent.includes(w)); r.scrollIntoView({ block: 'center' }); }, word);
  await sleep(400);
  const at = await page.evaluate((w) => { const r = [...document.querySelectorAll('.notes-feed [data-key]')].find((n) => n.textContent.includes(w)); const i = r.querySelector('img.note-img').getBoundingClientRect(); return { x: i.x + i.width / 2, y: i.y + i.height / 2, y0: window.scrollY }; }, word);
  await page.mouse.click(at.x, at.y);
  await waitFor(() => !!document.querySelector('.media-pager'), null, 4000);
  return at.y0;
};
const tapPager = async () => { const at = await page.evaluate(() => { const sc = document.querySelector('.mp-scroll'); const s = [...sc.querySelectorAll('.mp-slide')].find((x) => { const r = x.getBoundingClientRect(); return Math.abs(r.top) < 4 && Math.abs(r.left) < 4; }) || sc.firstChild; const r = s.querySelector('img.mp-media').getBoundingClientRect(); return { x: r.x + r.width / 2, y: r.y + r.height / 2 }; }); await page.mouse.click(at.x, at.y); };
const rowTop = (word) => page.evaluate((w) => { const r = [...document.querySelectorAll('.notes-feed [data-key]')].find((n) => n.textContent.includes(w)); return r ? Math.round(r.getBoundingClientRect().top) : null; }, word);

const slides = () => page.evaluate(() => document.querySelectorAll('.mp-scroll .mp-slide').length);
const curIdx = () => page.evaluate(() => { const sc = document.querySelector('.mp-scroll'); if (!sc) return -1; return [...sc.querySelectorAll('.mp-slide')].findIndex((x) => { const r = x.getBoundingClientRect(); return Math.abs(r.top) < 4 && Math.abs(r.left) < 4; }); });
const curName = () => page.evaluate(() => { const sc = document.querySelector('.mp-scroll'); const s = sc && [...sc.querySelectorAll('.mp-slide')].find((x) => { const r = x.getBoundingClientRect(); return Math.abs(r.top) < 4 && Math.abs(r.left) < 4; }); return s ? s.getAttribute('data-k').split('/').pop() : null; });

try {
  await page.setViewport({ width: 390, height: 844 });
  await page.goto(server.url.href, { waitUntil: 'domcontentloaded' });
  await page.evaluate(() => localStorage.setItem('btc-wallet-network', 'regtest'));
  await page.reload({ waitUntil: 'domcontentloaded' });
  await sleep(400);
  await click('create a new wallet'); await sleep(600);
  await page.waitForSelector('.words .w .t');
  const mn = (await page.$$eval('.words .w .t', (l) => l.map((e) => e.textContent.trim()))).join(' ');
  await click('skip verification');
  await waitText('receive', 20000);
  const base = cacheKeyFor(mn + '\n');
  await page.evaluate(([k, pk, ns]) => {
    localStorage.setItem(k + ':follows', JSON.stringify({ tags: [['p', pk]], c: '', at: Math.floor(Date.now() / 1000) }));
    localStorage.setItem(k + ':feedNotes', JSON.stringify(ns));
    localStorage.setItem(k + ':profiles', JSON.stringify({ [pk]: { name: 'Pager Poster', t: Date.now() } }));
    localStorage.setItem('btc-wallet-feed:' + k, 'following');
  }, [base, AUTHOR, seeded]);
  await page.reload({ waitUntil: 'domcontentloaded' });
  await waitText('receive', 20000);
  await page.evaluate(() => document.querySelector('.app-nav-button[aria-label="Feed"]').click());
  check('the pictures are in the feed', await waitFor(() => document.querySelectorAll('.notes-feed img.note-img').length >= 4, null, 20000));

  console.log('\n[the pager starts with the feed\'s first page]');
  await page.evaluate(() => { const r = [...document.querySelectorAll('.notes-feed [data-key]')].find((n) => n.textContent.includes('picture number 0 ')); r.scrollIntoView({ block: 'center' }); });
  await sleep(400);
  const at = await page.evaluate(() => { const r = [...document.querySelectorAll('.notes-feed [data-key]')].find((n) => n.textContent.includes('picture number 0 ')); const i = r.querySelector('img.note-img').getBoundingClientRect(); return { x: i.x + i.width / 2, y: i.y + i.height / 2 }; });
  await page.mouse.click(at.x, at.y);
  check('the pager opens', await waitFor(() => !!document.querySelector('.media-pager'), null, 4000));
  const first = await slides();
  check('it holds the first page\'s pictures, not all of them', first >= 1 && first < TOTAL, first + ' of ' + TOTAL);

  console.log('\n[nearing the end pages the feed on]');
  let grew = false, maxSlides = first;
  for (let step = 0; step < TOTAL + 4; step++) {
    const n = await slides(), i = await curIdx();
    maxSlides = Math.max(maxSlides, n);
    if (i >= 0 && n - 1 - i <= 4) {
      // give the look-ahead a moment: it should get past three ahead again (or the feed's end)
      await waitFor((k) => { const sc = document.querySelector('.mp-scroll'); const j = [...sc.querySelectorAll('.mp-slide')].findIndex((x) => { const r = x.getBoundingClientRect(); return Math.abs(r.top) < 4 && Math.abs(r.left) < 4; }); return sc.querySelectorAll('.mp-slide').length - 1 - j > 4 || sc.querySelectorAll('.mp-slide').length >= k; }, TOTAL, 6000);
    }
    const before = await curIdx();
    await page.keyboard.press('ArrowDown');
    await waitFor((b) => { const sc = document.querySelector('.mp-scroll'); return [...sc.querySelectorAll('.mp-slide')].findIndex((x) => { const r = x.getBoundingClientRect(); return Math.abs(r.top) < 4 && Math.abs(r.left) < 4; }) > b; }, before, 2000);
  }
  // past the last picture is the pager's end (its loading screen): back up onto the last
  if (await page.evaluate(() => { const sc = document.querySelector('.mp-scroll'); const t = sc.querySelector('.mp-tail'); return t && Math.abs(t.offsetTop - sc.scrollTop) < 4; })) { await page.keyboard.press('ArrowUp'); await sleep(800); }
  grew = (await slides()) > first;
  check('the pager grew as the end came near', grew, first + ' → ' + (await slides()));
  check('every picture in the feed became reachable', (await slides()) === TOTAL, (await slides()) + ' of ' + TOTAL);
  check('…past fifteen posts with none', (await curName()) === 'p' + (TOTAL - 1) + '.png', await curName());
  check('…in the feed\'s order', await page.evaluate((t) => [...document.querySelectorAll('.mp-scroll .mp-slide')].every((s, i) => s.getAttribute('data-k').endsWith('/p' + i + '.png')), TOTAL));

  console.log('\n[closing lands the feed on the last picture\'s post]');
  await page.keyboard.press('ArrowUp');
  await waitFor((n) => { const sc = document.querySelector('.mp-scroll'); const s = [...sc.querySelectorAll('.mp-slide')].find((x) => { const r = x.getBoundingClientRect(); return Math.abs(r.top) < 4 && Math.abs(r.left) < 4; }); return s && s.getAttribute('data-k').endsWith('/p' + n + '.png'); }, TOTAL - 2, 3000);
  const want = 'picture number ' + (TOTAL - 2) + ' ';
  await page.keyboard.press('Escape');
  check('the pager closes', await waitFor(() => !document.querySelector('.media-pager') && !!document.querySelector('.notes-feed'), null, 3000));
  const top = () => page.evaluate((w) => { const r = [...document.querySelectorAll('.notes-feed > [data-key]')].find((n) => n.textContent.includes(w)); return r ? Math.round(r.getBoundingClientRect().top) : null; }, want);
  await sleep(2500); // the pictures above it load meanwhile
  const t = await top();
  check('…the feed sits on the post of the picture last looked at', t !== null && t >= -10 && t < 120, 'row top ' + t);
  check('no page errors', errs.length === 0, errs.slice(0, 2).join(' | '));
} finally { await browser.close(); server.stop(true); }
console.log(ok ? '\n✅ the pager pages the feed on ahead of the reader' : '\n❌ failed');
process.exit(ok ? 0 : 1);