import apiFetch from '@wordpress/api-fetch';
import doNotTrack from './doNotTrack';

function handleTracking(
  getUrl: (target: EventTarget | null) => string | undefined,
): (e: Event) => void {
  return function trackingEventHandler(e): void {
    if (!navigator.sendBeacon || !ABTestingForWP.restUrl) return;

    const url = getUrl(e.target);

    if (!url) return;

    navigator.sendBeacon(`${ABTestingForWP.restUrl}ab-testing-for-wp/v1/outbound`, JSON.stringify({ url }));
  };
}

function handleTestTracking(): void {
  if (doNotTrack()) return;

  // listen to anchor navigation
  window.addEventListener('click', handleTracking((target): string | undefined => {
    if (!target || !(target as HTMLAnchorElement).href) return undefined;
    return (target as HTMLAnchorElement).href;
  }));

  // listen to form submits
  window.addEventListener('submit', handleTracking((target): string | undefined => {
    if (!target || !(target as HTMLFormElement).action) return undefined;
    return (target as HTMLFormElement).action;
  }));

  // track every page
  if (ABTestingForWP.postId) {
    apiFetch({ path: `ab-testing-for-wp/v1/track?post=${ABTestingForWP.postId}` });
  }
}

export default handleTestTracking;