// The feed pages to the reader's appetite. Reading at an ordinary pace it
// shows ten more posts at a time, and asks the relays for older ones while
// a page or two is still in hand — never once the reader has run out. A
// reader flying through (five screens in ten seconds, by their own hand)
// gets bigger pages, from further above the foot of the feed; standing
// still a while brings the ordinary page back. A page held still under an
// insert above is not travel.
// Run: bun tools/feed-appetite-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 SK = generateSecretKey(), AUTHOR = getPublicKey(SK);
const now = Math.floor(Date.now() / 1000);
const post = (i) => finalizeEvent({ kind: 1, created_at: now - 60 * i, tags: [], content: 'post number ' + i + ' of the long timeline' }, SK);
const cached = Array.from({ length: 60 }, (_, i) => post(i));           // in the feed cache
const older = Array.from({ length: 300 }, (_, i) => post(60 + i));      // on the relays, for the asks
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));
  return new Response(html, { headers: { 'content-type': 'text/html' } });
} });

const browser = await puppeteer.launch({ executablePath: '/usr/bin/google-chrome', headless: 'new', args: ['--no-sandbox'] });
const page = await browser.newPage();
// The relays, answered in the page: an ask for older posts (a filter with
// `until` for the author) gets the thirty newest at or before it, after a
// moment, then EOSE. Every ask is logged with the feed's state at that moment.
await page.evaluateOnNewDocument((fx) => {
  window.__asks = []; window.__steps = [];
  window.__snap = () => { const f = document.querySelector('.notes-feed'); return { t: Date.now(), shown: +(f?.dataset.shown || 0), held: +(f?.dataset.held || 0), remaining: Math.round(document.documentElement.scrollHeight - window.scrollY - window.innerHeight) }; };
  const Real = window.WebSocket;
  const send1 = (ws, id, ev) => { if (ws.readyState === 1) ws.dispatchEvent(new MessageEvent('message', { data: JSON.stringify(['EVENT', id, ev]) })); };
  const eose = (ws, id) => { if (ws.readyState === 1) ws.dispatchEvent(new MessageEvent('message', { data: JSON.stringify(['EOSE', id]) })); };
  window.WebSocket = function (...a) {
    const ws = new Real(...a);
    const send = ws.send.bind(ws);
    ws.send = (data) => {
      try {
        const m = JSON.parse(data);
        if (m[0] === 'REQ') {
          const f = m.slice(2).find((f) => f.until && (f.kinds || []).includes(1) && (f.authors || []).includes(fx.author));
          if (f) {
            if (!window.__asks.some((a) => a.until === f.until)) window.__asks.push({ ...window.__snap(), until: f.until, limit: f.limit || 0 });
            const evs = fx.older.filter((e) => e.created_at <= f.until).slice(0, f.limit || 30);
            setTimeout(() => { for (const ev of evs) send1(ws, m[1], ev); eose(ws, m[1]); }, 300);
            return;
          }
        }
      } catch {}
      return send(data);
    };
    return ws;
  };
  window.WebSocket.prototype = Real.prototype;
  Object.assign(window.WebSocket, Real);
}, { author: AUTHOR, older });
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, step = 100) => { for (let i = 0; i < ms / step; i++) { if (await page.evaluate(fn, arg)) return true; await sleep(step); } return false; };
const snap = () => page.evaluate(() => window.__snap());
const steps = () => page.evaluate(() => window.__steps);
const asks = () => page.evaluate(() => window.__asks);
// a scroll by the reader's own hand: an input stamp, then the page moves
const handScroll = (dy) => page.evaluate((dy) => { window.dispatchEvent(new PointerEvent('pointerdown', { bubbles: true })); window.scrollBy({ top: dy, behavior: 'instant' }); }, dy);
const H = 500;

try {
  await page.setViewport({ width: 390, height: H, hasTouch: true });
  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: 'Long Timeline', t: Date.now() } }));
    localStorage.setItem('btc-wallet-feed:' + k, 'following');
  }, [base, AUTHOR, cached]);
  await page.reload({ waitUntil: 'domcontentloaded' });
  await waitText('receive', 20000);
  await page.evaluate(() => document.querySelector('.app-nav-button[aria-label="Feed"]').click());
  check('the cached posts are in the feed', await waitFor(() => document.querySelectorAll('.notes-feed [data-key]').length >= 5, null, 20000));
  // every change of the page count, with the feed's state at that moment
  await page.evaluate(() => {
    const f = document.querySelector('.notes-feed');
    let last = +f.dataset.shown;
    new MutationObserver(() => { const n = +(document.querySelector('.notes-feed')?.dataset.shown || 0); if (n !== last) { window.__steps.push({ ...window.__snap(), from: last }); last = n; } })
      .observe(document.querySelector('#app') || document.body, { attributes: true, subtree: true, attributeFilter: ['data-shown'] });
  });
  const s0 = await snap();
  check('it opens on a page of ten, with the cached posts in hand', s0.shown === 10 && s0.held >= 30, JSON.stringify(s0)); // (the feed cache keeps thirty)

  console.log('\n[reading at an ordinary pace]');
  // a few posts every so often, no hand on it (the browser's own scroll: the
  // trail counts only travel within a moment of an input)
  for (let i = 0; i < 60; i++) {
    await page.evaluate(() => window.scrollBy({ top: 300, behavior: 'instant' }));
    await sleep(600);
    const s = await snap();
    if (s.shown >= 60) break;
  }
  await waitFor(() => +(document.querySelector('.notes-feed')?.dataset.shown || 0) >= 60, null, 8000);
  const slow = await steps();
  check('pages of ten', slow.length >= 3 && slow.every((s) => s.shown - s.from <= 10), slow.map((s) => s.from + '→' + s.shown).join(' '));
  const a = await asks();
  check('the relays were asked for older posts while posts were still in hand', a.length >= 1 && a[0].shown < a[0].held, JSON.stringify(a[0]));
  const at60 = slow.find((s) => s.shown >= 60);
  check('…so reaching the end of what was held found more already there', !!at60 && at60.held > at60.shown, JSON.stringify(at60));
  check('the ordinary pace never asked for more than a page at a time', slow.every((s) => s.shown - s.from <= 10));

  console.log('\n[flying through]');
  await sleep(10_500); // the trail forgets the slow spell
  await page.evaluate(() => window.scrollTo({ top: 0, behavior: 'instant' })); await sleep(600);
  const before = await steps();
  const sB = await snap();
  // eleven screens in half a second, by hand; a breath; eleven more
  for (let i = 0; i < 11; i++) { await handScroll(H); await sleep(45); }
  await sleep(1500);
  for (let i = 0; i < 11; i++) { await handScroll(H); await sleep(45); }
  await waitFor((n) => window.__steps.length > n && window.__steps.slice(n).some((s) => s.shown - s.from >= 30), before.length, 6000);
  await sleep(1500);
  const fast = (await steps()).slice(before.length);
  const big = fast.find((s) => s.shown - s.from >= 20);
  check('a bigger page at once', !!big, fast.map((s) => s.from + '→' + s.shown).join(' ') || 'no page');
  // (a page begun mid-flight is sized to the screens flown so far; the ones after are the full three)
  check('…growing to three pages\' worth', fast.some((s) => s.shown - s.from >= 30), fast.map((s) => s.shown - s.from).join(' '));
  check('…asked for from further above the foot than the ordinary lead', !!big && big.remaining > Math.max(3000, 4 * H), big ? big.remaining + ' px left below' : '');
  const a2 = (await asks()).slice(a.length);
  check('…and the relays asked for more per round trip', a2.some((x) => x.limit >= 60), a2.map((x) => x.limit).join(' ') || 'no ask');

  console.log('\n[standing still again]');
  await sleep(10_500);
  const before3 = await steps();
  for (let i = 0; i < 30; i++) {
    await page.evaluate(() => window.scrollBy({ top: 300, behavior: 'instant' }));
    await sleep(600);
    if ((await steps()).length > before3.length) break;
  }
  await sleep(500);
  const calm = (await steps()).slice(before3.length);
  check('the ordinary page is back', calm.length >= 1 && calm.every((s) => s.shown - s.from <= 10), calm.map((s) => s.from + '→' + s.shown).join(' ') || 'no page');
  check('no page errors', errs.length === 0, errs.slice(0, 2).join(' | '));
} catch (e) { console.error(e); ok = false; } finally { await browser.close(); server.stop(true); }
console.log(ok ? '\n✅ the feed pages to the reader\'s appetite' : '\n❌ failed');
process.exit(ok ? 0 : 1);