/*
===========================================================================
traffic.mjs - port-only first-touch attribution with a 30-day first-party cookie.
Storage refusal keeps this landing's values in memory. Never stores full URLs.
===========================================================================
*/
const KEYS = [ "utm_source", "utm_medium", "utm_campaign", "ref" ];
const MAX_AGE = 30 * 86400;
const COOKIE = "varkand_traffic";
/*
================
sanitizeTraffic
================
*/
export function sanitizeTraffic( value ) {
	const result = {};
	for ( const key of KEYS ) {
		const text = typeof value?.[key] === "string" ? value[key].trim() : "";
		if ( /^[A-Za-z0-9_.-]{1,40}$/.test( text ) ) result[key] = text;
	}
	return result;
}
/*
================
captureTraffic
================
*/
export function captureTraffic( location, document, now = Date.now() ) {
	let saved;
	try {
		const cookie = document.cookie.split( ";" ).map( value => value.trim() ).find( value =>
			value.startsWith( COOKIE + "=" )
		);
		if ( cookie ) saved = JSON.parse( decodeURIComponent( cookie.slice( COOKIE.length + 1 ) ) );
	} catch {}
	if ( saved && Number.isFinite( saved.expires ) && saved.expires > now && saved.expires <= now + MAX_AGE * 1000 ) {
		return sanitizeTraffic( saved.values );
	}
	const params = new URLSearchParams( location.search );
	const values = sanitizeTraffic( Object.fromEntries( params ) );
	if ( !values.utm_source && !values.ref ) values.utm_source = "direct";
	try {
		document.cookie = COOKIE + "=" +
			encodeURIComponent( JSON.stringify( { expires: now + MAX_AGE * 1000, values } ) ) +
			"; Max-Age=" + MAX_AGE + "; Path=/; SameSite=Lax; Secure";
	} catch {}
	return values;
}
/*
================
appendTraffic
================
*/
export function appendTraffic( href, base, values ) {
	const url = new URL( href, base );
	if (
		url.hostname !== "play.varkand.com" &&
		!(url.origin === new URL( base ).origin && /^\/play(?:\/|$)/.test( url.pathname ))
	) return href;
	if ( url.hostname !== "play.varkand.com" ) {
		url.hostname = "play.varkand.com";
		url.protocol = "https:";
		url.port = "";
		url.pathname = url.pathname.replace( /^\/play/, "" ) || "/";
	}
	for ( const [key, value] of Object.entries( sanitizeTraffic( values ) ) ) url.searchParams.set( key, value );
	return url.href;
}
/*
================
landingTraffic
================
*/
export const landingTraffic = typeof document === "undefined" ? {} : captureTraffic( globalThis.location, document );
if ( typeof document !== "undefined" ) {
	for ( const link of document.querySelectorAll( "a[href]" ) ) {
		if ( link instanceof HTMLAnchorElement ) {
			link.href = appendTraffic( link.href, globalThis.location.href, landingTraffic );
		}
	}
}