function show(enabled, useSettingsInsteadOfPreferences) {
  if (useSettingsInsteadOfPreferences) {
    document.getElementsByClassName('state-on')[0].innerText =
      'Extension is enabled and ready to use!';
    document.getElementsByClassName('state-off')[0].innerText =
      'Extension is disabled. Enable it in Safari Settings.';
    document.getElementsByClassName('state-unknown')[0].innerText =
      'Enable Mue in Safari Settings to get started.';
    document.getElementsByClassName('open-preferences')[0].innerText = 'Open Safari Settings';
  }

  if (typeof enabled === 'boolean') {
    document.body.classList.toggle(`state-on`, enabled);
    document.body.classList.toggle(`state-off`, !enabled);
  } else {
    document.body.classList.remove(`state-on`);
    document.body.classList.remove(`state-off`);
  }
}

function openPreferences() {
  webkit.messageHandlers.controller.postMessage('open-preferences');
}

document.querySelector('button.open-preferences').addEventListener('click', openPreferences);