/// <summary>
/// Calculates Transaction fee - applies Previous (base) fee and Merchant discount if applicable
/// </summary>
/// <param name="transaction">Transaction that requires fee calculation</param>
/// <returns>Calculated transaction fee</returns>
public double GetTransactionFee(Transaction transaction)
{
if (_baseTransactionFeeCalculator == null)
{
throw new ArgumentNullException("Please provide valid baseTransactionFeeCalculator");
}
var baseFee = _baseTransactionFeeCalculator.GetTransactionFee(transaction);
// Check if Merchant has discount - if so, then apply it, otherwise just return base fee
return(_merchantDiscounts != null && _merchantDiscounts.ContainsKey(transaction.MerchantName) ?
baseFee * (100 - _merchantDiscounts[transaction.MerchantName]) / 100
: baseFee);
}
/// <summary>
/// Calculates Transaction fee - applies Previous (base) fee and Monthly fixed fee
/// </summary>
/// <param name="transaction">Transaction that requires fee calculation</param>
/// <returns>Calculated transaction fee</returns>
public double GetTransactionFee(Transaction transaction)
{
if (_baseTransactionFeeCalculator == null)
{
throw new ArgumentNullException("Please provide valid baseTransactionFeeCalculator");
}
var baseFee = _baseTransactionFeeCalculator.GetTransactionFee(transaction);
var merchantNewMonthKey = $"{transaction.MerchantName}_{transaction.TransactionDate.Month}";
// Check if Merchant already paid this month or fee = 0, if so, then only apply base fee
if (_firstTransactionInMonth.ContainsKey(merchantNewMonthKey) || baseFee == 0)
{
return(baseFee);
}
// Mark monthly fee for this merchant and add fixed fee.
_firstTransactionInMonth.Add(merchantNewMonthKey, true);
return(baseFee + _fixedFee);
}