// The wall, checked where it can actually go wrong: in a browser, on a shelf long
// enough that the wall is drawing a few of its rows and standing in for the rest.
//
// One failure is what this guards, and it is the one that has already cost a
// white screen: a window written from the window before it. The wall measures
// itself after every render, writes what it measured, and renders again — so an
// input the measure takes off the window it just wrote feeds itself, pass after
// pass, until React gives up with #185, unmounts the tree, and leaves the reader
// with nothing (there is no error boundary under it).
//
// The trigger is not spelled out — no browser reproduces the reader's own,
// which is the point — so the check drives the *class*: the wall's own box
// reported at two different heights on every pass, plus one scroll to start it.
// That is what any read-back is, and the wall must survive it.
//
//   npm run build && node scripts/wall-check.mjs
//   PLAYWRIGHT_CORE=<path to playwright-core/index.mjs> node scripts/wall-check.mjs
//
// Playwright is not a dependency of this package (a browser run needs it, a
// build does not), so a run without it says SKIP and exits 0.
import { spawn } from 'node:child_process';
import { createServer } from 'node:http';
import { readFile } from 'node:fs/promises';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const FRONTEND = fileURLToPath(new URL('..', import.meta.url));
const SAMPLE_FILE = process.env.SAMPLE_FILE ?? path.resolve(FRONTEND, '../sample/_3279791-develop-check.jpg');
const APP_PORT = Number(process.env.APP_PORT ?? 5033);
const SAMPLE_PORT = Number(process.env.SAMPLE_PORT ?? 5034);
const FRAMES = Number(process.env.FRAMES ?? 300);
const FOLDER = 'WallRoll';
// Every frame is the same bytes under a different name: what is being checked is
// how many cards the wall will draw, not what is on them. The bytes carry no
// EXIF, so a frame's date is its own `lastModified` — spread over the days below,
// because a wall of one day is a wall with one header in it, and the headers are
// half of what this check is for.
const names = Array.from({ length: FRAMES }, (_, i) => `frame-${String(i + 1).padStart(4, '0')}.jpg`);
const DAY_MS = 86400000;
const PER_DAY = Number(process.env.PER_DAY ?? 10);
const DAY0 = Date.UTC(2026, 0, 1);
// The day a frame is filed under, off its own name — the same rule on both sides
// of the wire, so the check reads the wall the way the wall was told to sort it.
const dayOfName = (name) => {
  const n = Number((name.match(/\d+/) ?? ['1'])[0]);
  return DAY0 + Math.floor(Math.max(0, n - 1) / PER_DAY) * DAY_MS;
};

let failures = 0;
function step(name, ok, detail = '') {
  if (!ok) failures++;
  console.log(`${ok ? 'ok  ' : 'FAIL'} ${name}${detail ? ` — ${detail}` : ''}`);
  return ok;
}

const playwright = await import(process.env.PLAYWRIGHT_CORE ?? 'playwright-core').catch(() => null);
if (!playwright) {
  console.log('SKIP playwright-core is not installed — pass PLAYWRIGHT_CORE=<path to its index.mjs>');
  process.exit(0);
}

// --- the roll, off a local server (the page fetches it by CORS) --------------
const jpg = await readFile(SAMPLE_FILE);
const sampleServer = createServer((req, res) => {
  const name = path.basename(decodeURIComponent((req.url ?? '/').split('?')[0]));
  if (!names.includes(name)) {
    res.writeHead(404).end();
    return;
  }
  res.writeHead(200, {
    'Content-Type': 'image/jpeg',
    'Content-Length': jpg.length,
    'Access-Control-Allow-Origin': '*',
  });
  res.end(jpg);
});
await new Promise((resolve) => sampleServer.listen(SAMPLE_PORT, '127.0.0.1', resolve));

// `--host 127.0.0.1`: without it vite's preview binds the name `localhost`, which
// on a dual-stack box can be ::1 alone and every 127.0.0.1 fetch below fails.
// `BASE_URL` points the check at a build already being served instead of at
// `dist/`, which is how the bundle on the box is checked as it stands.
// `detached` so the whole group can be signalled at the end: `npx` spawns a shell
// which spawns vite, and killing only the wrapper leaves vite holding the port.
const app = process.env.BASE_URL
  ? null
  : spawn('npx', ['vite', 'preview', '--port', String(APP_PORT), '--strictPort', '--host', '127.0.0.1'], {
      cwd: FRONTEND,
      stdio: 'ignore',
      detached: true,
    });
const stopApp = () => {
  if (!app?.pid) return;
  try {
    process.kill(-app.pid, 'SIGTERM');
  } catch {}
};
const base = process.env.BASE_URL ?? `http://127.0.0.1:${APP_PORT}`;
let up = !app;
for (let i = 0; i < 60 && !up; i++) {
  up = await fetch(`${base}/library`).then((r) => r.ok).catch(() => false);
  if (!up) await new Promise((r) => setTimeout(r, 500));
}
if (!up) {
  stopApp();
  sampleServer.close();
  console.log(`FAIL no preview on ${base} — run \`npm run build\` first (vite preview serves dist/)`);
  process.exit(1);
}

// --- the browser ------------------------------------------------------------
const browser = await playwright.chromium.launch({
  executablePath: process.env.CHROME || undefined,
  args: ['--no-sandbox', '--enable-unsafe-swiftshader'],
});
const context = await browser.newContext({ viewport: { width: 1500, height: 950 } });

// The account the shelf belongs to. `vite preview` has no backend, and the app
// reads a shape off every one of these calls, so the check answers them: an
// empty account is all the wall needs.
await context.route('**/api/**', (route) => {
  const url = route.request().url();
  const json = (body) => route.fulfill({ status: 200, contentType: 'application/json', body: JSON.stringify(body) });
  if (url.includes('/auth/me')) return json({ user: { id: 1, email: 'check@example.com', name: 'check', verified: true, pro: true, admin: false } });
  if (url.includes('/photos')) return json({ photos: [] });
  if (url.includes('/place')) return json({ place: 'Hanoi' });
  if (url.includes('/ratings')) return json({ ratings: [] });
  if (url.includes('/highlights')) return json({ highlights: { day: [], week: [], ever: [] } });
  if (url.includes('/recipes')) return json({ recipes: [] });
  return json({});
});

// Only a person can answer a folder picker; the check stands in for one. The
// stand-in handles carry their methods as *non-enumerable* properties, which is
// what lets them through IndexedDB's structured clone at all (a clone copies
// enumerable own keys, and a function anywhere else is a DataCloneError), and
// they are put back where the catalogue reads them, because a cloned handle is a
// plain object with no `getFile`.
await context.addInitScript(
  ({ origin, names, folder, days }) => {
    // `days` is the day of each frame, index-aligned with `names`: the init
    // script is cloned into the page and cannot close over the check's own scope.
    const dayOfNameIn = (name) => days[names.indexOf(name)] ?? Date.UTC(2026, 0, 1);
    const fileHandle = (name) => {
      const handle = { kind: 'file', name, __fake: true };
      Object.defineProperty(handle, 'getFile', {
        value: async () =>
          new File([await (await fetch(`${origin}/${name}`)).arrayBuffer()], name, {
            type: 'image/jpeg',
            lastModified: dayOfNameIn(name),
          }),
      });
      return handle;
    };
    const dirHandle = (label, node) => {
      const handle = { kind: 'directory', name: label, __fake: true };
      Object.defineProperties(handle, {
        values: { value: () => [...node.files.map(fileHandle)][Symbol.iterator]() },
        queryPermission: { value: async () => 'granted' },
        requestPermission: { value: async () => 'granted' },
        getDirectoryHandle: { value: async () => { throw new Error('no such folder'); } },
        getFileHandle: {
          value: async (name) => {
            if (!node.files.includes(name)) throw new Error(`no frame named ${name}`);
            return fileHandle(name);
          },
        },
      });
      return handle;
    };
    const root = () => dirHandle(folder, { files: names });
    window.showDirectoryPicker = async () => root();
    // The day each frame was given, for the header audit below: the page's own
    // clock reads the label, so the day is read back here the same way.
    window.__dayOf = (name) => dayOfNameIn(name);

    const revive = (row) => {
      if (row?.handle?.__fake && !Object.getOwnPropertyDescriptor(row.handle, 'getFile')) {
        row.handle = row.handle.kind === 'directory' ? root() : fileHandle(row.handle.name);
      }
      return row;
    };
    for (const method of ['get', 'getAll']) {
      const original = IDBObjectStore.prototype[method];
      IDBObjectStore.prototype[method] = function (...args) {
        const request = original.apply(this, args);
        const descriptor = Object.getOwnPropertyDescriptor(IDBRequest.prototype, 'result');
        Object.defineProperty(request, 'result', {
          configurable: true,
          get() {
            const value = descriptor.get.call(this);
            return Array.isArray(value) ? value.map(revive) : revive(value);
          },
        });
        return request;
      };
    }
  },
  { origin: `http://127.0.0.1:${SAMPLE_PORT}`, names, folder: FOLDER, days: names.map(dayOfName) }
);

const page = await context.newPage();
const errors = [];
page.on('pageerror', (e) => errors.push(String(e.message).slice(0, 200)));
const read = () =>
  page.evaluate(() => {
    const el = document.querySelector('.adm-grid');
    return {
      cards: el ? el.querySelectorAll('.adm-card').length : 0,
      wall: el ? el.scrollHeight > el.clientHeight : false,
      // The white screen itself: no rail, no words, nothing drawn.
      blank: document.body.innerText.trim().length < 40 && !document.querySelector('nav.rail'),
    };
  });

await page.goto(`${base}/library`);
await page.click('[data-key="lib-add"]');
await page.waitForSelector(`[data-key="lib-node-${FOLDER}"]`, { timeout: 60_000 });
await page
  .waitForFunction(
    (n) => (document.querySelector('[data-key="lib-count"]')?.textContent ?? '').includes(String(n)),
    FRAMES,
    { timeout: 240_000, polling: 250 }
  )
  .catch(() => {});
const counted = await page.$eval('[data-key="lib-count"]', (e) => e.textContent?.trim() ?? '');
step('the roll is read whole', counted.includes(String(FRAMES)), counted);

// The day the header of a card stands under, read off the sections themselves:
// every header must name the day of every card filed under it. A day whose first
// rows are above the window still gets its header where the eye lands (see
// `dayRuns`), so the rule is "a header names its own cards" and not "one header
// per day in the shelf".
const dayAudit = () =>
  page.evaluate(() => {
    const key = (ts) => {
      const d = new Date(ts);
      return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
    };
    const out = { sections: 0, cards: 0, labelled: 0, bad: [] };
    for (const section of document.querySelectorAll('.adm-day')) {
      out.sections++;
      const own = (section.getAttribute('data-key') ?? '').replace('lib-day-', '');
      const head = section.querySelector('.adm-day-head')?.textContent?.trim() ?? '';
      if (head) out.labelled++;
      const names = [...section.querySelectorAll('[data-key^="lib-photo-"]')].map(
        (el) => (el.getAttribute('data-key') ?? '').split('/').pop()
      );
      const days = new Set(names.map((name) => key(window.__dayOf(name))));
      if (!names.length || days.size !== 1 || !days.has(own)) out.bad.push({ own, head, days: [...days], names: names.slice(0, 2) });
    }
    out.cards = document.querySelectorAll('.adm-card').length;
    return out;
  });

await page.click('[data-key="lib-view-grid"]');
await page.waitForSelector('.adm-grid', { timeout: 15_000 });
await page.waitForFunction(() => document.querySelectorAll('.adm-card').length > 0, null, { timeout: 30_000 });
await page.waitForTimeout(2000);
const wall = await read();
step('the wall draws a screenful of the shelf', wall.cards > 0 && wall.cards < FRAMES, `${wall.cards} of ${FRAMES} cards drawn`);
step('and stands in for the rows it is not drawing', wall.wall, 'the shelf scrolls');

const days1 = await dayAudit();
step('the wall is cut into the days its frames were shot', days1.sections > 1, `${days1.sections} headers over ${days1.cards} cards`);
step('every header names the day of the cards under it', days1.bad.length === 0, JSON.stringify(days1.bad.slice(0, 2)));
step('and every header carries its day in words', days1.labelled === days1.sections, `${days1.labelled} of ${days1.sections}`);

// The same wall, scrolled to where no day starts at the fold: the headers have to
// move with it, which is the whole risk of cutting a virtualised wall into days.
await page.evaluate(() => {
  const el = document.querySelector('.adm-grid');
  el.scrollTop = Math.round(el.scrollHeight * 0.7);
  el.dispatchEvent(new Event('scroll'));
});
await page.waitForTimeout(1500);
const days2 = await dayAudit();
step('a scrolled wall still files every card under its own day', days2.sections > 0 && days2.bad.length === 0, JSON.stringify(days2.bad.slice(0, 2)));

// The class of trigger, made to happen: one input the wall reads back off itself,
// moving on every pass.
await page.evaluate(() => {
  const el = document.querySelector('.adm-grid');
  const h = el.clientHeight;
  let n = 0;
  Object.defineProperty(el, 'clientHeight', { configurable: true, get: () => (n++ % 2 ? h : h + 300) });
  el.dispatchEvent(new Event('scroll'));
});
await page.waitForTimeout(8000);
const after = await read();
const looped = errors.filter((e) => e.includes('185') || e.includes('update depth'));
step(
  'a wall fed its own window does not take the screen down',
  !after.blank && after.cards > 0 && looped.length === 0,
  `blank=${after.blank}, cards=${after.cards}, errors=${looped.length ? looped[0] : 'none'}`
);
step('the wall is still the wall', after.cards > 0, `${after.cards} cards after the feed`);

await page.screenshot({ path: process.env.SHOT ?? '/tmp/wall-check.png' }).catch(() => {});
if (errors.length) console.log('page errors:', errors.slice(0, 6).join(' // '));

await browser.close();
stopApp();
sampleServer.close();
console.log(failures ? `\n${failures} FAILED` : '\nall ok');
process.exit(failures ? 1 : 0);