import type { Portfolio } from "../api/usePortfolio";

const PERCENT_SCALE = 100;

type Money = Portfolio["totals"];

function formatShare(
	numerator: Money | null,
	denominator: Money | null,
): null | string {
	if (!numerator || !denominator)
		return null;
	const total = Number(denominator.value);
	if (!Number.isFinite(total) || total <= 0)
		return null;
	const percent = (Number(numerator.value) / total) * PERCENT_SCALE;
	if (!Number.isFinite(percent))
		return null;

	const rounded = new Intl.NumberFormat("ru-RU", {
		maximumFractionDigits: 1,
	}).format(percent);

	return `${rounded} %`;
}

export { formatShare };