// TEMPORARY — the bug this proves: reading a roll used to die the moment the
// catalogue handed the visitor to the studio, because every internal link was a
// full page load and the scan lived in that page's memory. Run it, then delete
// it.
//
//   node scripts/scan-nav-check.mjs
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 SAMPLES = process.env.SAMPLE_DIR ?? path.resolve(FRONTEND, '..');
const APP_PORT = Number(process.env.APP_PORT ?? 4186);
const SAMPLE_PORT = Number(process.env.SAMPLE_PORT ?? 4320);
const DELAY = Number(process.env.SCAN_DELAY ?? 900);
const JPG = 'P1010256.JPG';
const RAW = 'P1010256.RW2';

// Twelve frames: four at the top, four a folder down, four two folders down.
const names = (prefix) => Array.from({ length: 4 }, (_, i) => `${prefix}${i + 1}.JPG`);
const ROLL = {
  files: names('a'),
  dirs: { '2026': { files: names('b'), dirs: { '04': { files: names('c'), dirs: {} } } } },
};
const TOTAL = 12;

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');
  process.exit(0);
}

const sleep = (ms) => new Promise((r) => setTimeout(r, ms));

// One frame at a time, however many the page asks for at once: a roll that reads
// itself in parallel is over before a handover can be timed against it.
let turn = Promise.resolve();
const waitTurn = () => {
  const mine = turn.then(() => sleep(DELAY));
  turn = mine;
  return mine;
};

const sampleServer = createServer(async (req, res) => {
  const name = path.basename(decodeURIComponent((req.url ?? '/').split('?')[0]));
  if (!/\.(jpg|rw2)$/i.test(name)) {
    res.writeHead(404).end();
    return;
  }
  const bytes = await readFile(path.join(SAMPLES, /\.rw2$/i.test(name) ? RAW : JPG));
  await waitTurn();
  res.writeHead(200, {
    'Content-Type': 'application/octet-stream',
    'Content-Length': bytes.length,
    'Access-Control-Allow-Origin': '*',
  });
  res.end(bytes);
});
await new Promise((resolve) => sampleServer.listen(SAMPLE_PORT, '127.0.0.1', resolve));

const app = spawn('npx', ['vite', 'preview', '--port', String(APP_PORT), '--strictPort', '--host', '127.0.0.1'], {
  cwd: FRONTEND,
  stdio: 'ignore',
});
const base = `http://127.0.0.1:${APP_PORT}`;
let up = false;
for (let i = 0; i < 60 && !up; i++) {
  up = await fetch(`${base}/library`).then((r) => r.ok).catch(() => false);
  if (!up) await sleep(500);
}
if (!up) {
  app.kill('SIGTERM');
  sampleServer.close();
  console.log(`FAIL no preview on ${base}`);
  process.exit(1);
}

const browser = await playwright.chromium.launch({
  executablePath: process.env.CHROME || undefined,
  args: ['--no-sandbox', '--enable-unsafe-swiftshader', '--use-gl=angle', '--use-angle=swiftshader'],
});
const context = await browser.newContext();

// Documents this tab has loaded, across navigations: the count only moves when a
// click threw the page away and started a new one.
await context.addInitScript(() => {
  const n = Number(sessionStorage.getItem('docLoads') ?? '0') + 1;
  sessionStorage.setItem('docLoads', String(n));
});

await context.addInitScript(
  ({ origin, roll, folder }) => {
    const bytes = new Map();
    const load = async (name) => {
      if (!bytes.has(name)) bytes.set(name, fetch(`${origin}/${name}`).then((r) => r.arrayBuffer()));
      return bytes.get(name);
    };
    // A second scan of the same roll reads the same names again; dropping what the
    // stand-in already holds makes it go back to the server for each of them, so
    // a re-reading roll has the same minutes in it a first one does.
    window.__forget = () => bytes.clear();
    const fileHandle = (name) => {
      const handle = { kind: 'file', name, __fake: true };
      Object.defineProperty(handle, 'getFile', {
        value: async () => new File([await load(name)], name, { type: 'image/jpeg' }),
      });
      return handle;
    };
    const dirHandle = (label, node) => {
      // `__fake` on a folder too: the catalogue reads its folders back out of the
      // store after every remount, and a handle that does not say what it is comes
      // back as a plain object with no `queryPermission` — a folder it cannot ask
      // about is a folder it offers to reconnect.
      const handle = { kind: 'directory', name: label, __fake: true };
      Object.defineProperties(handle, {
        values: {
          value: () =>
            [
              ...(node.files ?? []).map(fileHandle),
              ...Object.entries(node.dirs ?? {}).map(([name, kid]) => dirHandle(name, kid)),
            ][Symbol.iterator](),
        },
        queryPermission: { value: async () => 'granted' },
        requestPermission: { value: async () => 'granted' },
      });
      return handle;
    };
    const root = () => dirHandle(folder, roll);
    window.showDirectoryPicker = async () => root();
    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}`, roll: ROLL, folder: 'SlowRoll' }
);

const page = await context.newPage();
const indexed = () =>
  page.evaluate(async () => {
    const db = await new Promise((resolve, reject) => {
      const req = indexedDB.open('recipescam-library');
      req.onsuccess = () => resolve(req.result);
      req.onerror = () => reject(req.error);
    });
    return new Promise((resolve, reject) => {
      const req = db.transaction('photos').objectStore('photos').count();
      req.onsuccess = () => resolve(req.result);
      req.onerror = () => reject(req.error);
    });
  });

await page.goto(`${base}/library`);
await page.click('[data-key="lib-add"]');
await page.waitForSelector('[data-key="lib-stop"]', { timeout: 15_000 });
step('the scan is running', true);

// The rows only reach IndexedDB in one batch at the end of the scan, so the
// toolbar's own line is what says how far the reading is.
const progressText = (timeout) =>
  page
    .waitForFunction(() => document.querySelector('[data-key="lib-progress"]')?.textContent?.trim() || null, null, {
      timeout,
      polling: 100,
    })
    .then((h) => h.jsonValue())
    .catch(() => null);

const docs = () => page.evaluate(() => Number(sessionStorage.getItem('docLoads') ?? '0'));
const tiles = () => page.$$eval('[data-key^="lib-thumb-"]', (els) => els.length);
// The count of documents standing when the page was last settled: every step that
// follows a link or a frame asserts against this, because a link followed with no
// scan in flight is *meant* to load the page again.
let seen = await docs();
const noReload = async () => (await docs()) === seen;

// Hand over to the studio while the roll is still being read, which is the whole
// point: part of it in, the rest still to come.
const midway = await progressText(15_000);
step('the roll is half read when the studio is opened', !!midway, String(midway));

await page.click('[data-key="lib-studio"]');
await page.waitForSelector('[data-key="nav-library"]', { timeout: 15_000 });
step('the handover stays in the page, it does not reload it', await noReload(), `${await docs()} document load(s)`);
step('and it lands in the studio', new URL(page.url()).pathname === '/app', page.url());

// Back to the catalogue mid-scan: the screen that started the scan is gone and
// back, and the roll is still being read — the reading belongs to the tab.
await page.click('[data-key="nav-library"]');
await page.waitForSelector('[data-key="lib-frame"]', { timeout: 15_000 });
step('coming back stays in the page too', await noReload(), `${await docs()} document load(s)`);
const progress = await progressText(15_000);
step('the catalogue comes back showing the scan it missed', !!progress, String(progress));
await page.waitForSelector('[data-key^="lib-node-"]', { timeout: 15_000 });
const tree = await page.$$eval('[data-key^="lib-node-"]', (els) => els.map((e) => e.dataset.key));
step('the tree is there, from the scan that outlived its screen', tree.includes('lib-node-SlowRoll'), JSON.stringify(tree));

// Now leave it alone in the studio and let it finish: nothing up there reads the
// roll, so every frame that lands from here on landed for a screen that is gone.
await page.click('[data-key="lib-studio"]');
await page.waitForSelector('[data-key="nav-library"]', { timeout: 15_000 });
let indexed_to = 0;
for (let i = 0; i < 300 && indexed_to < TOTAL; i++) {
  indexed_to = await indexed().catch(() => indexed_to);
  if (indexed_to < TOTAL) await sleep(200);
}
step('the whole roll is read with the studio up', indexed_to === TOTAL, `${indexed_to}/${TOTAL} indexed`);
step('and the studio is still the page it was', await noReload(), `${await docs()} document load(s)`);

await page.click('[data-key="nav-library"]');
await page.waitForFunction(
  (n) => document.querySelectorAll('[data-key^="lib-thumb-"]').length === n,
  TOTAL,
  { timeout: 60_000, polling: 200 }
).catch(() => {});
step('every frame ends up as a thumbnail', (await tiles()) === TOTAL, `${await tiles()} tiles`);
const grown = await page.$$eval('[data-key^="lib-node-"]', (els) => els.map((e) => e.dataset.key));
step('the tree ends up holding the deepest folder of the roll', grown.includes('lib-node-SlowRoll/2026/04'), JSON.stringify(grown));
// Nothing was scanning at that last click, so that one did load the page again —
// which is the whole point of the guard. Everything below counts from here.
seen = await docs();

// Now the reader's own way into the studio, and the noisiest one for this page: a
// frame opened from a roll that is being read again. The rows are drawn from the
// catalogue it already has, so this is the one route out of here that the browser
// could take with no link anywhere in sight.
const rows = () => page.$eval('[data-key="lib-node-SlowRoll"] .adm-album-count', (el) => Number(el.textContent));
await page.evaluate(() => window.__forget());
await page.click('[data-key="lib-node-SlowRoll"]', { button: 'right' });
await page.waitForSelector('[data-key="lib-menu"]', { timeout: 10_000 });
const menu = await page.$$eval('[data-key="lib-menu"] button', (els) => els.map((b) => b.dataset.key));
const rescan = menu.find((k) => /^lib-(rescan|reconnect)-/.test(k));
step('the roll can be read again from its own menu', !!rescan, JSON.stringify(menu));
await page.click(`[data-key="${rescan}"]`);
await page.waitForSelector('[data-key="lib-stop"]', { timeout: 15_000 });
await sleep(DELAY);
const early = await rows();
await sleep(DELAY * 2);
const later = await rows();
step('the row counts the reading as it comes, not the catalogue standing still', later !== early, `${early} → ${later} of ${TOTAL}`);
step('the strip is still the catalogue the roll left behind', (await tiles()) === TOTAL, `${await tiles()} tiles`);

await page.click('[data-key="lib-open"]');
await page.waitForSelector('[data-key="nav-library"]', { timeout: 30_000 });
step('opening a frame stays in the page, it does not reload it', await noReload(), `${await docs()} document load(s)`);
// The studio takes the frame out of the address as soon as it has it, so the
// route is what is left to say the handover arrived.
step('and it lands in the studio', new URL(page.url()).pathname === '/app', page.url());

await page.click('[data-key="nav-library"]');
await page.waitForSelector('[data-key="lib-frame"]', { timeout: 15_000 });
step('and the scan it interrupted is still the scan in hand', await noReload(), `${await docs()} document load(s)`);
const steady = await progressText(15_000);
step('the catalogue is still reading the roll it was reading', !!steady, String(steady));

await browser.close();
app.kill('SIGTERM');
sampleServer.close();
console.log(failures ? `\n${failures} step(s) failed` : '\nall steps passed');
process.exit(failures ? 1 : 0);