(function() {
  'use strict';

  window.utils = window.utils || {};

  window.utils.modal = function(modal) {
    var overlay = document.createElement('div');
    var closer = document.createElement('div');
    var trigger = document.querySelector('#' + modal.dataset.trigger);
    var origParent = modal.parentNode;

    function open(event) {
      // disable modals for narrow screens
      if (event) {
        event.preventDefault();
      }
      modal.classList.add('modal--open');
      overlay.classList.add('modal__overlay');
      document.body.insertBefore(modal, null);
      document.body.insertBefore(overlay, modal);
      overlay.classList.add('modal__overlay--open');

      if (modal.dataset.closeable === 'true') {
        closer.classList.add('modal__closer');
        modal.insertBefore(closer, null);
        closer.addEventListener('click', close, false);
        overlay.addEventListener('click', close, false);
      }
    }

    // open this modal with an event:
    // document.dispatchEvent(new CustomEvent('modal-open', { details: { for: 'modal-13' }}))
    function openOnEvent(event) {
      if (event.detail.for === modal.getAttribute('id')) {
        open();
      }
    }

    function close(event) {
      if (typeof event === 'undefined' || event.target === closer || event.target === overlay) {
        overlay.remove();
        origParent.insertBefore(modal, null);
        modal.classList.remove('modal--open');
        closer.removeEventListener('click', close, false);
      }
    };

    function setup() {
      // every modal can be openend via document-wide event, see openOnEvent
      document.addEventListener('modal-open', openOnEvent, false);
      // if modal has trigger assigned to it open modal on click
      if (trigger) {
        trigger.classList.add('modal__trigger');
        trigger.addEventListener('click', open, false);
      }
      // tell further modals, that this one already got initialized
      modal.classList.add('js-modal-initialized');
    }
    setup();
  };
})();

document.addEventListener('DOMContentLoaded', function() {

  Array.from(document.querySelectorAll('.js-modal:not(.js-modal-initialized)')).map(function(modal) {
    new utils.modal(modal);
  });

}, false);