goldprice.dev 點樣用本幣定價黃金

const GRAMS_PER_TROY_OZ = 31.1035;

function localGoldPerGram(usdPerTroyOz, usdToLocalRate) {
  return (usdPerTroyOz / GRAMS_PER_TROY_OZ) * usdToLocalRate;
}

const params = new URLSearchParams({
  from: "XAU",
  to: "IDR",
  amount: "1",
  unit: "gram",
});

const response = await fetch(
  `https://api.goldprice.dev/v1/convert?${params}`,
);

if (!response.ok) {
  throw new Error(`goldprice.dev returned ${response.status}`);
}

const conversion = await response.json();
console.log(conversion.result, conversion.to, conversion.timestamp);

const GRAMS_PER_TROY_OZ = 31.1035;

async function getGoldInCurrencies(currencies) {
  const symbols = currencies.join(",");
  const [spotResponse, fxResponse] = await Promise.all([
    fetch("https://api.goldprice.dev/v1/spot/XAU-USD-SPOT"),
    fetch(`https://api.exchangerate.dev/v1/latest/USD?symbols=${symbols}`),
  ]);

  if (!spotResponse.ok || !fxResponse.ok) {
    throw new Error("A market-data request failed");
  }

  const spot = await spotResponse.json();
  const fx = await fxResponse.json();
  const usdPerGram = Number(spot.price) / GRAMS_PER_TROY_OZ;

  return {
    goldComputedAt: spot.computed_at,
    fxDataUpdatedAt: fx.data_updated_at,
    fxResponseTimestamp: fx.timestamp,
    fxSource: fx.source,
    fxMarketSession: fx.market_session,
    prices: Object.fromEntries(
      currencies.map((currency) => [
        currency,
        usdPerGram * Number(fx.rates[currency]),
      ]),
    ),
  };
}

const result = await getGoldInCurrencies(["EUR", "IDR", "JPY"]);

function formatPrice(amount, currency, locale) {
  return new Intl.NumberFormat(locale, {
    style: "currency",
    currency,
  }).format(amount);
}

console.log(formatPrice(result.prices.IDR, "IDR", "id-ID"));
console.log(formatPrice(result.prices.JPY, "JPY", "ja-JP"));