#!/usr/bin/env node
/**
 * Mirror vai-avatar's live product sources into this Space, same-origin.
 *
 * Why a mirror and not a runtime cross-origin fetch:
 *   huggingface.co serves dataset files with
 *   `Access-Control-Allow-Origin: https://huggingface.co`, and `/resolve` then
 *   302s to a CDN host that sets its own CORS policy. A page on
 *   *.static.hf.space is neither origin, so the browser hides the response
 *   body and the read fails with an opaque "Failed to fetch". Same-origin
 *   cannot be blocked, so the bytes are copied into the Space instead.
 *
 * Freshness therefore depends on this script running, not on a rebuild of any
 * baked data: re-run it (or let the scheduled job run it) and the Space serves
 * whatever vai-avatar has written at that moment.
 *
 *   node scripts/sync-catalogue.mjs
 *
 * Writes public/catalogue/products.json and public/catalogue/promos.json.
 * `public/` is what Vite copies into dist/, so both end up served with the app.
 */

import { mkdir, writeFile } from 'node:fs/promises';
import { realpathSync } from 'node:fs';
import { dirname, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';

const ROOT = resolve(dirname(fileURLToPath(import.meta.url)), '..');
const OUT_DIR = resolve(ROOT, 'public/catalogue');
const REVISION = 'main';
const TIMEOUT_MS = 30_000;

/** Kept byte-identical to the sources declared in src/catalogue.js. */
export const SOURCES = {
  'products.json': {
    repo: 'bep40/grob-products-updated',
    file: 'products_url_added.json',
  },
  'promos.json': {
    repo: 'bep40/vaistudio-data',
    file: 'promos.json',
  },
};

function urlFor({ repo, file }) {
  return `https://huggingface.co/datasets/${repo}/resolve/${REVISION}/${file}?cts=${Date.now()}`;
}

async function fetchSource(name, source) {
  const url = urlFor(source);
  process.stdout.write(`[sync] ${name} <- ${source.repo}/${source.file} ... `);
  const response = await fetch(url, {
    cache: 'no-store',
    signal: AbortSignal.timeout(TIMEOUT_MS),
    headers: process.env.HF_TOKEN ? { Authorization: `Bearer ${process.env.HF_TOKEN}` } : {},
  });
  if (!response.ok) throw new Error(`HTTP ${response.status} for ${url}`);
  const text = await response.text();
  // Validate before writing: a truncated or HTML error body would otherwise be
  // served to the app as if it were a catalogue.
  const parsed = JSON.parse(text);
  const count = Array.isArray(parsed)
    ? `${parsed.length} products`
    : `${Object.keys(parsed?.productEdits ?? {}).length} productEdits`;
  process.stdout.write(`ok (${count})\n`);
  return text;
}

/**
 * Was this file the process entrypoint?
 *
 * Comparing basenames with `endsWith` looks equivalent and is not: any file whose
 * name merely ENDS WITH this one (`my-sync-catalogue.mjs`) also matches, so
 * loading such a file would run main() as a side effect of importing it. Both
 * paths are resolved before comparing.
 */
function isDirectRun() {
  const entry = process.argv[1];
  if (!entry) return false;
  try {
    return realpathSync(entry) === realpathSync(fileURLToPath(import.meta.url));
  } catch {
    return false;
  }
}

async function main() {
  await mkdir(OUT_DIR, { recursive: true });
  let failures = 0;
  for (const [name, source] of Object.entries(SOURCES)) {
    try {
      const text = await fetchSource(name, source);
      await writeFile(resolve(OUT_DIR, name), text, 'utf8');
    } catch (error) {
      // The good file is still written, so one transient error does not throw
      // away a successful fetch. Whether that mixture may be PUBLISHED is
      // decided below.
      failures++;
      console.error(`[sync] FAILED ${name}: ${error.message}`);
    }
  }

  /**
   * ANY failure fails the run, not only a total failure.
   *
   * This matters from the second successful run onward, once public/catalogue is
   * committed: a file that failed to fetch is then still on disk as its previous
   * version, so requireRealFile() and recordCount() in refresh-catalogue.mjs both
   * pass on that stale copy. The caller would then build, commit and print
   * REFRESH_OK, and the Space would serve a fresh products.json beside an old
   * promos.json -- so every Sửa and every Xóa from vai-avatar silently stopped
   * applying, with no error anywhere.
   *
   * On the very first run the mirror is not committed yet, so the failed file is
   * simply absent and the caller's guard already catches it. Failing here makes
   * that behaviour unconditional instead of depending on which run it is.
   *
   * A stale overlay is not a degraded catalogue, it is a wrong one: catalogue.js
   * merges the two files, so old edits resurrect old prices and old tombstones
   * fight the new file. Aborting here is what makes the caller leave the
   * previously committed mirror intact, which is the guarantee both scripts
   * document.
   */
  if (failures > 0) {
    console.error(
      `[sync] ${failures}/${Object.keys(SOURCES).length} source(s) failed — the mirror on disk `
      + 'is now MIXED (fresh file beside last-commit file). Refusing to report success: '
      + 'the caller must abort so the last-good mirror stays live.',
    );
    process.exitCode = 1;
    return;
  }
  console.log(`[sync] wrote ${OUT_DIR}`);
}

if (isDirectRun()) {
  main().catch(error => {
    console.error(`[sync] ${error.stack || error}`);
    process.exitCode = 1;
  });
}