(function () {
  'use strict';

  var modalEl = null;
  var iframeEl = null;
  var titleEl = null;
  var modalReady = false;

  function ensureModal() {
    if (modalEl) {
      return;
    }

    modalEl = document.createElement('div');
    modalEl.className = 'modal fade eventup-registration-modal';
    modalEl.id = 'eventupRegistrationModal';
    modalEl.setAttribute('tabindex', '-1');
    modalEl.setAttribute('role', 'dialog');
    modalEl.setAttribute('aria-labelledby', 'eventupRegistrationModalTitle');
    modalEl.setAttribute('aria-hidden', 'true');
    modalEl.innerHTML =
      '<div class="modal-dialog modal-dialog-centered modal-lg" role="document">' +
        '<div class="modal-content">' +
          '<div class="modal-header">' +
            '<h5 class="modal-title" id="eventupRegistrationModalTitle">Register</h5>' +
            '<button type="button" class="close" data-dismiss="modal" aria-label="Close">' +
              '<span aria-hidden="true">&times;</span>' +
            '</button>' +
          '</div>' +
          '<div class="modal-body eventup-registration-modal__body">' +
            '<iframe class="eventup-registration-modal__frame" title="Event registration form" src="about:blank"></iframe>' +
          '</div>' +
        '</div>' +
      '</div>';

    document.body.appendChild(modalEl);
    iframeEl = modalEl.querySelector('.eventup-registration-modal__frame');
    titleEl = modalEl.querySelector('#eventupRegistrationModalTitle');

    if (window.jQuery) {
      window.jQuery(modalEl).on('hidden.bs.modal', function () {
        if (iframeEl) {
          iframeEl.src = 'about:blank';
        }
      });
    }

    modalReady = true;
  }

  function buildEmbedUrl(url) {
    if (!url) {
      return '';
    }

    try {
      var parsed = new URL(url, window.location.href);
      parsed.searchParams.set('embed', '1');
      return parsed.toString();
    } catch (error) {
      var joiner = url.indexOf('?') >= 0 ? '&' : '?';
      return url + joiner + 'embed=1';
    }
  }

  function resolveRegistrationUrl(cta, config) {
    if (cta && cta.url) {
      return cta.url;
    }

    var meta = (config && config.meta) || {};
    var eventId = meta.eventId;
    var webBase = meta.webBaseUrl;

    if (eventId && webBase) {
      return String(webBase).replace(/\/$/, '') + '/event/' + eventId + '/register';
    }

    return '';
  }

  function openModal(url, title) {
    ensureModal();

    if (!url) {
      console.warn('[registration-modal] No registration URL configured.');
      return;
    }

    if (titleEl) {
      titleEl.textContent = title || 'Register';
    }

    if (iframeEl) {
      iframeEl.src = buildEmbedUrl(url);
    }

    if (window.jQuery) {
      window.jQuery(modalEl).modal('show');
    } else {
      modalEl.classList.add('show');
      modalEl.style.display = 'block';
      modalEl.removeAttribute('aria-hidden');
    }
  }

  function bindLink(link, cta, config) {
    if (!link || link.getAttribute('data-registration-modal-bound') === 'true') {
      return;
    }

    link.setAttribute('data-registration-modal-bound', 'true');
    link.setAttribute('data-cta-target', 'modal');
    link.href = '#';

    link.addEventListener('click', function (event) {
      event.preventDefault();
      openModal(resolveRegistrationUrl(cta, config), cta && cta.text ? cta.text : 'Register');
    });
  }

  window.EventUpRegistrationModal = {
    bindLink: bindLink,
    open: openModal,
    resolveUrl: resolveRegistrationUrl,
    isReady: function () {
      return modalReady;
    },
  };
})();