tablet-checkin/backend/extension-src/content-script.js

// Injects a "Send to Tablet" button into each row of NewBook's "due for
// arrival" list (bookings_lists_checkin), right under the page's own
// Check In button. Only runs on that one page (see manifest.json's
// content_scripts.matches) — the popup covers single-booking pages
// (bookings_view/edit/checkin) already.
//
// Row markup, booking-ID extraction, and the "generic_button_1"-is-not-
// actually-unique gotcha are all confirmed from a real sample row the user
// provided 2026-09-01 (see project_checkin memory) — not guessed. NewBook's
// own Check In button uses a non-unique id (`generic_button_1` repeated
// across every row), so this script never relies on ids from NewBook's own
// markup — only class/attribute selectors scoped per row, and its own
// injected elements get ids built from the booking ID
// (`tcp-btn-<bookingId>`) to stay collision-free and support idempotent
// re-injection checks.
//
// MutationObserver pattern (watching for AJAX-refreshed rows, not just
// initial page load) is the same approach chrome-newbook-assistant already
// had to use for this same NewBook UI (~/laptop-archive) — this system
// clearly refreshes table content via AJAX (see the `via_ajax` tooltip
// classes in the sample row) without a full page reload, so a one-time scan
// on document_idle alone would miss rows added/replaced afterward.

const PROCESSED_ATTR = 'data-tcp-processed';

function extractBookingId(row) {
  const checkbox = row.querySelector('input.booking_id_checkbox');
  if (checkbox?.value) return checkbox.value;
  // Fallback: class name carries it too (`booking_37117`) — confirmed from
  // the sample row, kept as a fallback in case a future NewBook markup
  // change drops the checkbox but keeps the class.
  const match = row.className.match(/\bbooking_(\d+)\b/);
  return match ? match[1] : null;
}

function extractGuestName(row) {
  // The guest/company link's own text node — tooltip content is a sibling
  // element (easytooltip_content), not part of the visible text, so a plain
  // textContent read on the link itself would double up with it. Grab just
  // the first non-empty text child instead.
  const link = row.querySelector('a.easytooltip[class*="booking_"]');
  if (!link) return '';
  for (const node of link.childNodes) {
    if (node.nodeType === Node.TEXT_NODE && node.textContent.trim()) {
      return node.textContent.trim();
    }
  }
  return link.textContent.trim();
}

function findCheckInCell(row) {
  const btn = row.querySelector('button[aria-label="Check In"]');
  return btn ? btn.closest('td') : null;
}

function makeSendButton(bookingId, guestName) {
  const btn = document.createElement('button');
  btn.id = `tcp-btn-${bookingId}`;
  btn.type = 'button';
  btn.textContent = 'Send to Tablet';
  btn.style.cssText = `
    display: block; margin-top: 6px; width: 100%;
    padding: 4px 8px; font-size: 12px; font-weight: 600;
    background: #be123c; color: #fff; border: none; border-radius: 6px;
    cursor: pointer; font-family: -apple-system, BlinkMacSystemFont, sans-serif;
  `;
  btn.addEventListener('click', e => {
    e.preventDefault();
    e.stopPropagation();
    togglePanel(btn, bookingId, guestName);
  });
  return btn;
}

let openPanel = null;

async function togglePanel(anchorBtn, bookingId, guestName) {
  if (openPanel) { openPanel.remove(); openPanel = null; }

  const panel = document.createElement('div');
  panel.style.cssText = `
    margin-top: 6px; padding: 8px; background: #f4f5f7; border: 1px solid #e4e8ee;
    border-radius: 8px; font-family: -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 12px; color: #1e293b;
  `;
  panel.textContent = 'Loading tablets…';
  anchorBtn.insertAdjacentElement('afterend', panel);
  openPanel = panel;

  const res = await chrome.runtime.sendMessage({ action: 'tcpListDevices' });
  if (!res?.ok) {
    panel.textContent = `Could not load tablets: ${res?.error || 'not configured yet — see extension Settings'}`;
    return;
  }
  if (!res.devices.length) {
    panel.textContent = 'No tablets registered yet.';
    return;
  }

  const select = document.createElement('select');
  select.style.cssText = 'width: 100%; margin-bottom: 6px; padding: 4px;';
  select.innerHTML = res.devices.map(d =>
    `<option value="${d.device_id}" ${d.status === 'busy' ? 'disabled' : ''}>${escapeHtml(d.name)}${d.status === 'busy' ? ' (busy)' : ''}</option>`
  ).join('');

  const sendBtn = document.createElement('button');
  sendBtn.textContent = `Send${guestName ? ` — ${guestName}` : ''}`;
  sendBtn.style.cssText = `
    width: 100%; padding: 4px 8px; background: #c9a84c; color: #1a1a2e;
    border: none; border-radius: 6px; font-weight: 600; cursor: pointer;
  `;
  sendBtn.addEventListener('click', async () => {
    sendBtn.disabled = true;
    sendBtn.textContent = 'Sending…';
    const result = await chrome.runtime.sendMessage({
      action: 'tcpPush', bookingId, deviceId: select.value,
    });
    if (result?.ok) {
      panel.textContent = 'Sent — the tablet should navigate now.';
    } else {
      panel.textContent = `Failed: ${result?.error || 'unknown error'}`;
    }
  });

  panel.innerHTML = '';
  panel.appendChild(select);
  panel.appendChild(sendBtn);
}

function escapeHtml(s) {
  const div = document.createElement('div');
  div.textContent = s;
  return div.innerHTML;
}

function processRow(row) {
  if (row.hasAttribute(PROCESSED_ATTR)) return;
  const bookingId = extractBookingId(row);
  const cell = findCheckInCell(row);
  if (!bookingId || !cell) return; // not a real booking row, or no Check In button in it

  row.setAttribute(PROCESSED_ATTR, '1');
  cell.appendChild(makeSendButton(bookingId, extractGuestName(row)));
}

function scanForRows(root = document) {
  root.querySelectorAll('tr.checkbox_row').forEach(processRow);
}

scanForRows();

const observer = new MutationObserver(mutations => {
  for (const m of mutations) {
    for (const node of m.addedNodes) {
      if (node.nodeType !== Node.ELEMENT_NODE) continue;
      if (node.matches?.('tr.checkbox_row')) processRow(node);
      else scanForRows(node);
    }
  }
});
observer.observe(document.body, { childList: true, subtree: true });