(function (root, factory) {
  if (typeof module === 'object' && module.exports) module.exports = factory;
  else root.createLoginController = factory;
}(typeof self !== 'undefined' ? self : this, function createLoginController(options) {
  function validShareContinuation(value) {
    if (typeof value !== 'string' || !value.startsWith('./?') || value.includes('#')) return './';
    const limits = { title: 200, text: 8000, url: 2048 };
    const params = new URLSearchParams(value.slice(3));
    const entries = Array.from(params.entries());
    if (!entries.length) return './';
    const invalid = entries.some(([name, content]) => (
      !Object.prototype.hasOwnProperty.call(limits, name)
      || !content
      || content.length > limits[name]
    ));
    if (invalid) return './';
    return value;
  }

  const form = options.form;
  const status = options.status;
  const button = options.button;
  const fetchImpl = options.fetchImpl;
  const location = options.location;
  const clearPrivateDeviceData = options.clearPrivateDeviceData;
  const continuation = validShareContinuation(options.continuation);
  const setIntervalImpl = options.setIntervalImpl || setInterval;
  const clearIntervalImpl = options.clearIntervalImpl || clearInterval;
  let timer = null;

  if (continuation !== './') status.textContent = 'Sign in to continue your shared capture.';

  async function showReason(reason) {
    if (reason === 'session-expired') {
      status.textContent = 'Your session expired. Private drafts remain on this device. Sign in to continue.';
      return;
    }
    if (reason === 'session-idle') {
      status.textContent = 'Stackchain locked after inactivity. Your drafts and queued work are still on this device. Sign in to resume.';
      return;
    }
    if (reason !== 'session-revoked') return;
    button.disabled = true;
    status.textContent = 'This device was remotely signed out. Clearing Stackchain private data…';
    try {
      if (typeof clearPrivateDeviceData !== 'function') throw new Error('Private data purger unavailable.');
      await clearPrivateDeviceData();
      status.textContent = 'This device was remotely signed out. Stackchain private data was cleared. Sign in to use it again.';
      button.disabled = false;
    } catch (_error) {
      status.textContent = 'This device was remotely signed out, but private data could not be cleared. Close other Stackchain tabs and clear this site’s data before signing in.';
    }
  }

  function showRetryCountdown(seconds) {
    let remaining = Math.max(1, Number.parseInt(seconds, 10) || 1);
    button.disabled = true;
    status.textContent = `Too many attempts. Try again in ${remaining} seconds.`;
    timer = setIntervalImpl(() => {
      remaining -= 1;
      if (remaining <= 0) {
        clearIntervalImpl(timer);
        timer = null;
        button.disabled = false;
        status.textContent = 'You can try signing in again.';
        return;
      }
      status.textContent = `Too many attempts. Try again in ${remaining} seconds.`;
    }, 1000);
  }

  async function submit(accessToken, deviceLabel = 'This device') {
    status.textContent = 'Signing in…';
    let response;
    try {
      response = await fetchImpl('api/v1/session', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ access_token: accessToken, device_label: deviceLabel }),
      });
    } catch (_error) {
      form.reset();
      status.textContent = 'Sign-in failed. Check your connection and try again.';
      return;
    }
    form.reset();
    if (response.ok) {
      location.replace(continuation);
      return;
    }
    if (response.status === 429) {
      showRetryCountdown(response.headers.get('Retry-After'));
      return;
    }
    status.textContent = 'Sign-in failed. Check the token and try again.';
  }

  return { submit, showReason };
}));

if (typeof document !== 'undefined') {
  const form = document.getElementById('sign-in');
  const status = document.getElementById('status');
  const button = document.getElementById('submit-sign-in');
  const loginParams = new URLSearchParams(window.location.search);
  const controller = createLoginController({
    form,
    status,
    button,
    fetchImpl: fetch.bind(window),
    location: window.location,
    continuation: loginParams.get('continue'),
    clearPrivateDeviceData: window.stackchainPrivateDeviceData,
  });
  controller.showReason(loginParams.get('reason'));
  form.addEventListener('submit', event => {
    event.preventDefault();
    const data = new FormData(form);
    const accessToken = data.get('access_token');
    const deviceLabel = data.get('device_label');
    controller.submit(accessToken, deviceLabel);
  });
}