public static TaxTable Add(decimal minThreshold,
decimal maxThreshold,
decimal accumulatedTaxFromPreviousBracket,
decimal marginalTaxRate)
{
if (!Validator.IsBetween(minThreshold, maxThreshold))
{
throw new System.Exception("Min value cannot be greater than or equal to max value");
}
var incomeThreshold = CalculateIncomeThreshold(minThreshold);
var taxBracket = new TaxBracket(accumulatedTaxFromPreviousBracket, marginalTaxRate, incomeThreshold);
var taxTableItem = new TaxTable(minThreshold, maxThreshold, taxBracket);
return(taxTableItem);
}
private decimal CalculateMarginalTaxableAmount(decimal annualTaxableIncome, TaxBracket taxBracket)
{
return(annualTaxableIncome - taxBracket.IncomeThreshold);
}
public TaxTable(decimal minThreshold, decimal maxThreshold, TaxBracket incomeTaxBracket)
{
MinThreshold = minThreshold;
MaxThreshold = maxThreshold;
IncomeTaxBracket = incomeTaxBracket;
}
public decimal CalculateMarginalTax(decimal annualTaxableIncome, TaxBracket taxBracket)
{
var marginalTaxableAmount = CalculateMarginalTaxableAmount(annualTaxableIncome, taxBracket);
return(marginalTaxableAmount * taxBracket.MarginalTaxRate);
}