// Tells knotless-serve a page was drawn, for its operator's counts: the
// route that drew it, and the site the visitor came from if another. Sent
// once the page runs, so a crawler that reads the HTML alone sends none,
// and never when the browser asks not to be followed (Global Privacy
// Control). No cookie, and nothing about the visitor but what every
// request carries.

import type { afterNavigate } from '$app/navigation';

/** What `afterNavigate` hands its callback. */
type Navigated = Parameters<Parameters<typeof afterNavigate>[0]>[0];

export function hit({ to, type }: Navigated): void {
	const route = to?.route.id;
	const gpc = (navigator as Navigator & { globalPrivacyControl?: boolean }).globalPrivacyControl;
	if (!route || gpc) return;
	// Where the visitor came from counts only on arriving, from elsewhere.
	const from = type === 'enter' ? document.referrer : '';
	const referrer = from && new URL(from).origin !== location.origin ? from : '';
	navigator.sendBeacon('/_hit', JSON.stringify({ route, referrer }));
}