export function getTampermonkey() {
  return window.external?.Tampermonkey
}

export function getViolentmonkey() {
  return window.external?.Violentmonkey
}

export function canInstallUserJS() {
  return getTampermonkey() || getViolentmonkey()
}

export async function canInstallUserCSS() {
  if (localStorage.getItem('stylusDetected') == '1') {
    return true;
  }
  postMessage({ type: 'style-version-query', name: "whatever", namespace: "whatever", url: location.href }, location.origin);
  return new Promise(resolve => setTimeout(function() {
    resolve(localStorage.getItem('stylusDetected') == '1')
  }, 200));
}

window.addEventListener("message", function(event) {
  if (event.origin !== location.origin)
    return;

  if (event.data.type != "style-version")
    return;

  localStorage.setItem('stylusDetected', '1')
})