import type { ShopCurrency } from "@/lib/shopCatalog";

/**
 * Rough USD notional for cart/checkout when only BTC spot is loaded from API.
 * ETH/XMR are pegged off BTC for display totals (sim storefront).
 */
export function estimateUsdForCryptoAmount(
  amount: number,
  currency: ShopCurrency,
  btcUsd: number,
): number {
  if (currency === "USD") return Math.round(amount * 100) / 100;
  if (!(btcUsd > 0)) return 0;
  const ethUsd = btcUsd / 28;
  const xmrUsd = btcUsd / 520;
  switch (currency) {
    case "BTC":
      return Math.round(amount * btcUsd * 100) / 100;
    case "ETH":
      return Math.round(amount * ethUsd * 100) / 100;
    case "XMR":
      return Math.round(amount * xmrUsd * 100) / 100;
    default:
      return 0;
  }
}