💳 คำนวณค่าธรรมเนียม Wise ผ่านบัตรเดบิตไทย (ทุกธนาคาร)

/**
 * Calculates Wise money transfer fees when funded via Thai Debit Card.
 * 
 * @param {number} netAud - The exact net amount the recipient will receive in AUD.
 * @param {number} totalAud - The total amount shown on Wise before checkout in AUD.
 * @param {number} exchangeRate - The base exchange rate before bank markup.
 * @param {number} bankFeePercent - The bank's FX risk fee percentage (e.g. 2.5 for 2.5%, 0 for zero).
 * @returns {object} Calculated fee details formatted to 2 decimal places.
 */
function calculateWiseThaiBankFee(netAud, totalAud, exchangeRate, bankFeePercent = 2.5) {
  const wiseFeeAud = totalAud - netAud;
  const rawThb = totalAud * exchangeRate;
  const bankFeeThb = rawThb * (bankFeePercent / 100);
  const finalThbPay = rawThb + bankFeeThb;
  const totalFeeThb = (wiseFeeAud * exchangeRate) + bankFeeThb;

  return {
    wiseFeeAud: wiseFeeAud.toFixed(2),
    rawThb: rawThb.toFixed(2),
    bankFeeThb: bankFeeThb.toFixed(2),
    finalThbPay: finalThbPay.toFixed(2),
    totalFeeThb: totalFeeThb.toFixed(2),
  };
}

// --- ตัวอย่างการใช้งานแบบระบุธนาคารกสิกรไทย (2.5%) ---
const resultKBank = calculateWiseThaiBankFee(645, 665, 23.4061, 2.5);
console.log(resultKBank);

// --- ตัวอย่างการใช้งานแบบใช้บัตรฟรีค่าธรรมเนียม เช่น JOURNEY หรือ YouTrip (0%) ---
const resultFreeCard = calculateWiseThaiBankFee(645, 665, 23.4061, 0.0);
console.log(resultFreeCard);