(function(window) {

  if (!!window.cookieChoices) {
    return window.cookieChoices;
  }

  var document = window.document;
  // IE8 does not support textContent, so we should fallback to innerText.
  var supportsTextContent = 'textContent' in document.body;

  var cookieChoices = (function() {

    var cookieName = 'displayCookieConsent';
    var cookieConsentId = 'cookieChoiceInfo';
    var dismissLinkId = 'cookieChoiceDismiss';

    function _createHeaderElement(cookieText, dismissText, linkText, linkHref) {
      var butterBarStyles = 'position:fixed;width:100%;background-color:#000000;color:#ffffff;' +
          'margin:0; left:0; top:0;padding:4px;z-index:1000;text-align:center;';

      var cookieConsentElement = document.createElement('div');
      cookieConsentElement.id = cookieConsentId;
      cookieConsentElement.style.cssText = butterBarStyles;
      cookieConsentElement.appendChild(_createConsentText(cookieText));

      if (!!linkText && !!linkHref) {
        cookieConsentElement.appendChild(_createInformationLink(linkText, linkHref));
      }
      cookieConsentElement.appendChild(_createDismissLink(dismissText));
      return cookieConsentElement;
    }

    function _createDialogElement(cookieText, dismissText, linkText, linkHref) {
      var glassStyle = 'position:fixed;width:100%;height:100%;z-index:999;' +
          'top:0;left:0;opacity:0.5;filter:alpha(opacity=50);' +
          'background-color:#ccc;';
      var dialogStyle = 'z-index:1000;position:fixed;left:50%;top:50%';
      var contentStyle = 'position:relative;left:-50%;margin-top:-25%;' +
          'background-color:#fff;padding:20px;box-shadow:4px 4px 25px #888;';

      var cookieConsentElement = document.createElement('div');
      cookieConsentElement.id = cookieConsentId;

      var glassPanel = document.createElement('div');
      glassPanel.style.cssText = glassStyle;

      var content = document.createElement('div');
      content.style.cssText = contentStyle;

      var dialog = document.createElement('div');
      dialog.style.cssText = dialogStyle;

      var dismissLink = _createDismissLink(dismissText);
      dismissLink.style.display = 'block';
      dismissLink.style.textAlign = 'right';
      dismissLink.style.marginTop = '8px';

      content.appendChild(_createConsentText(cookieText));
      if (!!linkText && !!linkHref) {
        content.appendChild(_createInformationLink(linkText, linkHref));
      }
      content.appendChild(dismissLink);
      dialog.appendChild(content);
      cookieConsentElement.appendChild(glassPanel);
      cookieConsentElement.appendChild(dialog);
      return cookieConsentElement;
    }

    function _setElementText(element, text) {
      if (supportsTextContent) {
        element.textContent = text;
      } else {
        element.innerText = text;
      }
    }

    function _createConsentText(cookieText) {
      var consentText = document.createElement('span');
      _setElementText(consentText, cookieText);
      return consentText;
    }

    function _createDismissLink(dismissText) {
      var dismissLink = document.createElement('a');
      _setElementText(dismissLink, dismissText);
      dismissLink.id = dismissLinkId;
      dismissLink.href = '#';
      dismissLink.style.marginLeft = '24px';
      return dismissLink;
    }

    function _createInformationLink(linkText, linkHref) {
      var infoLink = document.createElement('a');
      _setElementText(infoLink, linkText);
      infoLink.href = linkHref;
      infoLink.target = '_blank';
      infoLink.style.marginLeft = '8px';
      return infoLink;
    }

    function _dismissLinkClick() {
      _saveUserPreference();
      _removeCookieConsent();
      return false;
    }

    function _showCookieConsent(cookieText, dismissText, linkText, linkHref, isDialog) {
      if (_shouldDisplayConsent()) {
        _removeCookieConsent();
        var consentElement = (isDialog) ?
            _createDialogElement(cookieText, dismissText, linkText, linkHref) :
            _createHeaderElement(cookieText, dismissText, linkText, linkHref);
        var fragment = document.createDocumentFragment();
        fragment.appendChild(consentElement);
        document.body.appendChild(fragment.cloneNode(true));
        document.getElementById(dismissLinkId).onclick = _dismissLinkClick;
      }
    }

    function showCookieConsentBar(cookieText, dismissText, linkText, linkHref) {
      _showCookieConsent(cookieText, dismissText, linkText, linkHref, false);
    }

    function showCookieConsentDialog(cookieText, dismissText, linkText, linkHref) {
      _showCookieConsent(cookieText, dismissText, linkText, linkHref, true);
    }

    function _removeCookieConsent() {
      var cookieChoiceElement = document.getElementById(cookieConsentId);
      if (cookieChoiceElement != null) {
        cookieChoiceElement.parentNode.removeChild(cookieChoiceElement);
      }
    }

    function _saveUserPreference() {
      // Set the cookie expiry to one year after today.
      var expiryDate = new Date();
      expiryDate.setFullYear(expiryDate.getFullYear() + 1);
      document.cookie = cookieName + '=y; path=/; expires=' + expiryDate.toGMTString();
    }

    function _shouldDisplayConsent() {
      // Display the header only if the cookie has not been set.
      return !document.cookie.match(new RegExp(cookieName + '=([^;]+)'));
    }

    var exports = {};
    exports.showCookieConsentBar = showCookieConsentBar;
    exports.showCookieConsentDialog = showCookieConsentDialog;
    return exports;
  })();

  window.cookieChoices = cookieChoices;
  return cookieChoices;
})(this);