Import from ERS

/* ===========================================================================
 * Marquee — ERS extractor
 * ---------------------------------------------------------------------------
 * Pulls your catalog, customers and order history out of Event Rental Systems.
 *
 * HOW TO RUN
 *   1. Log in to your ERS control panel (…ourers.com/cp/) as an administrator.
 *   2. Open DevTools -> Console.
 *   3. Paste this whole file and press Enter.
 *
 * It runs entirely inside your own logged-in session. No password, no API key
 * and no cookie ever leaves your browser. When it finishes it will either POST
 * the data straight to your Marquee instance, or — if that is not reachable —
 * save a marquee-ers-export.json file to your Downloads folder for you to
 * upload manually.
 * =========================================================================== */
(async () => {
  const TARGET = window.MARQUEE_URL || 'http://localhost:3000';
  const log = (...a) => console.log('%c[marquee]', 'color:#2a78d6;font-weight:bold', ...a);

  /* ---- helpers ---------------------------------------------------------- */
  const parseDoc = (html) => new DOMParser().parseFromString(html, 'text/html');
  const biggestTable = (doc) =>
    [...doc.querySelectorAll('table')].sort((a, b) => b.rows.length - a.rows.length)[0];

  // Keep newlines: ERS packs multi-line values (order contents, payments)
  // into a single cell as separate child nodes.
  const cellText = (td) =>
    td.innerText.replace(/ /g, ' ').split('\n').map((s) => s.trim()).filter(Boolean).join('\n');

  async function grid(path) {
    const res = await fetch(path, { credentials: 'include' });
    if (!res.ok) throw new Error(`${path} -> ${res.status}`);
    const doc = parseDoc(await res.text());
    const table = biggestTable(doc);
    if (!table) return { headers: [], rows: [], totalRecords: 0 };
    const headers = [...table.rows[0].cells].map((c) => c.innerText.trim().replace(/\s+/g, ' '));
    const rows = [...table.rows].slice(1).map((tr) => {
      const cells = [...tr.cells].map(cellText);
      // ERS serves item photos from a public CDN. Capture the URL so the
      // catalog has real pictures instead of placeholder glyphs.
      const img = tr.querySelector('img[src*="files.sysers.com"]');
      cells.__image = img ? img.src : '';
      return cells;
    });
    const m = doc.body.innerText.match(/of ([\d,]+) records/);
    return { headers, rows, totalRecords: m ? Number(m[1].replace(/,/g, '')) : rows.length };
  }

  /** ERS paginates with ?limit_page=N and 100 rows per page. */
  async function allPages(path, hardCap = 60) {
    const first = await grid(path);
    const per = first.rows.length || 100;
    const pages = Math.min(hardCap, Math.max(1, Math.ceil(first.totalRecords / per)));
    let rows = first.rows;
    for (let p = 2; p <= pages; p++) {
      const sep = path.includes('?') ? '&' : '?';
      const next = await grid(`${path}${sep}limit_page=${p}`);
      rows = rows.concat(next.rows);
      log(`  ${path} page ${p}/${pages} (${rows.length} rows)`);
      await new Promise((r) => setTimeout(r, 120)); // be polite to ERS
    }
    return { headers: first.headers, rows, totalRecords: first.totalRecords };
  }

  /**
   * ERS body rows carry an extra leading cell (the expander icon) plus a
   * trailing action cell, so body index = header index + 1. Verified against
   * the Items, Customer List and Order List grids.
   */
  const objectify = (headers, rows, offset = 1) =>
    rows.map((cells) => {
      const o = {};
      headers.forEach((h, i) => { if (h) o[h] = cells[i + offset] ?? ''; });
      if (cells.__image) o.__image = cells.__image;
      return o;
    }).filter((o) => Object.values(o).some(Boolean));

  /* ---- extract ---------------------------------------------------------- */
  log('Reading catalog…');
  const items = await allPages('/cp/items/');
  log('Reading categories…');
  const cats = await allPages('/cp/categories/');
  log('Reading customers… (this is the slow one)');
  const custs = await allPages('/cp/customer_list/');
  log('Reading orders…');
  const ords = await allPages('/cp/order_list/');

  const payload = {
    source: 'ers',
    extractedAt: new Date().toISOString(),
    company: document.title.replace(/^ERS CP - /, ''),
    items: objectify(items.headers, items.rows),
    categories: objectify(cats.headers, cats.rows),
    customers: objectify(custs.headers, custs.rows),
    orders: objectify(ords.headers, ords.rows),
  };

  log('Extracted:', {
    items: payload.items.length,
    categories: payload.categories.length,
    customers: payload.customers.length,
    orders: payload.orders.length,
  });

  /* ---- deliver ---------------------------------------------------------- */
  try {
    const res = await fetch(`${TARGET}/api/import/ers`, {
      method: 'POST',
      headers: { 'content-type': 'application/json' },
      body: JSON.stringify(payload),
    });
    const out = await res.json();
    log('%cImported into Marquee ✓', 'color:#0ca30c;font-weight:bold', out);
    return out;
  } catch (err) {
    log('Marquee not reachable — saving a file instead.', err.message);
    const blob = new Blob([JSON.stringify(payload, null, 2)], { type: 'application/json' });
    const a = document.createElement('a');
    a.href = URL.createObjectURL(blob);
    a.download = 'marquee-ers-export.json';
    a.click();
    log('Saved marquee-ers-export.json to your Downloads folder.');
  }
})();