declare global {
	interface Window {
		umami?: {
			track: (event: string, data?: Record<string, unknown>) => void;
		};
	}
}

type Pending = { event: string; data?: Record<string, unknown>; onSent?: () => void };

// Events fired during page setup (onMounted) often run before the deferred
// Umami script has loaded; they used to be dropped silently. Queue them and
// flush once the tracker exists. If it never appears (blocked, offline),
// they are discarded after ~10 s without throwing.
const queue: Pending[] = [];
let timer: ReturnType<typeof setInterval> | null = null;
let attempts = 0;
const MAX_ATTEMPTS = 40;
const INTERVAL_MS = 250;

function send(item: Pending) {
	try {
		window.umami!.track(item.event, item.data);
		item.onSent?.();
	} catch {
		// tracking must never break the shop
	}
}

function flush() {
	if (window.umami) {
		while (queue.length) send(queue.shift()!);
	}
	if (window.umami || ++attempts >= MAX_ATTEMPTS) {
		queue.length = 0;
		if (timer) clearInterval(timer);
		timer = null;
		attempts = 0;
	}
}

export const trackEvent = (event: string, data?: Record<string, unknown>, onSent?: () => void) => {
	if (typeof window === "undefined") return;
	const item = { event, data, onSent };
	if (window.umami) return send(item);
	queue.push(item);
	if (!timer) timer = setInterval(flush, INTERVAL_MS);
};

// Test hook: reset module state between cases.
export const __resetTrackQueue = () => {
	queue.length = 0;
	if (timer) clearInterval(timer);
	timer = null;
	attempts = 0;
};