/// <summary>
/// Calculate Tax and Surcharge
/// </summary>
/// <param name="amount"></param>
/// <param name="taxIncluded">if true tax is calculated from gross otherwise from net </param>
/// <param name="scale"></param>
/// <returns>tax amount</returns>
public Decimal CalculateSurcharge(Decimal amount, Boolean taxIncluded, int scale, out Decimal SurchargeAmt)
{
// Null Tax
SurchargeAmt = Env.ZERO;
Decimal TaxAmt = Env.ZERO;
if (IsZeroTax())
{
return(Env.ZERO);
}
Decimal multiplier = Env.ZERO;
Decimal taxBase = amount;
Decimal taxRate = GetRate();
MTax surTax = MTax.Get(GetCtx(), GetSurcharge_Tax_ID());
Decimal surRate = surTax.GetRate();
// for Surcharge Calculation type - Line Amount + Tax Amount
if (GetSurchargeType() == MTax.SURCHARGETYPE_LineAmountPlusTax)
{
if (!taxIncluded) // $100 * 6 / 100 == $6 == $100 * 0.06
{
// Calculate Tax Amount on Line Amount
multiplier = Decimal.Round(Decimal.Divide(taxRate, 100), 12, MidpointRounding.AwayFromZero);
TaxAmt = Decimal.Multiply(amount, multiplier);
// Calculate Surcharge Tax Amount on Line Amount + Tax Amount
amount = amount + TaxAmt;
multiplier = Decimal.Round(Decimal.Divide(surRate, 100), 12, MidpointRounding.AwayFromZero);
SurchargeAmt = Decimal.Multiply(amount, multiplier);
TaxAmt = Decimal.Round(TaxAmt, scale, MidpointRounding.AwayFromZero);
SurchargeAmt = Decimal.Round(SurchargeAmt, scale, MidpointRounding.AwayFromZero);
}
else // $106 - ($106 / (100+6)/100) == $6 == $106 - ($106/1.06)
{
multiplier = Decimal.Round(Decimal.Divide(surRate, 100), 12, MidpointRounding.AwayFromZero);
multiplier = Decimal.Add(multiplier, Env.ONE);
taxBase = Decimal.Divide(amount, multiplier);
taxBase = Decimal.Round(taxBase, 12, MidpointRounding.AwayFromZero);
amount = taxBase;
multiplier = Decimal.Round(Decimal.Divide(taxRate, 100), 12, MidpointRounding.AwayFromZero);
multiplier = Decimal.Add(multiplier, Env.ONE);
taxBase = Decimal.Divide(amount, multiplier);
TaxAmt = CalculateTax(taxBase, false, scale);
SurchargeAmt = surTax.CalculateTax(Decimal.Add(taxBase, TaxAmt), false, scale);
}
}
// for Surcharge Calculation type - Line Amount
else if (GetSurchargeType() == MTax.SURCHARGETYPE_LineAmount)
{
if (!taxIncluded) // $100 * 6 / 100 == $6 == $100 * 0.06
{
// Calculate Tax Amount on Line Amount
multiplier = Decimal.Round(Decimal.Divide(taxRate, 100), 12, MidpointRounding.AwayFromZero);
TaxAmt = Decimal.Multiply(amount, multiplier);
TaxAmt = Decimal.Round(TaxAmt, scale, MidpointRounding.AwayFromZero);
// Calculate Surcharge Tax Amount on Line Amount
multiplier = Decimal.Round(Decimal.Divide(surRate, 100), 12, MidpointRounding.AwayFromZero);
SurchargeAmt = Decimal.Multiply(amount, multiplier);
SurchargeAmt = Decimal.Round(SurchargeAmt, scale, MidpointRounding.AwayFromZero);
}
else // $106 - ($106 / (100+6)/100) == $6 == $106 - ($106/1.06)
{
multiplier = Decimal.Round(Decimal.Divide(Decimal.Add(taxRate, surRate), 100), 12, MidpointRounding.AwayFromZero);
multiplier = Decimal.Add(multiplier, Env.ONE);
taxBase = Decimal.Divide(amount, multiplier);
taxBase = Decimal.Round(taxBase, 12, MidpointRounding.AwayFromZero);
TaxAmt = CalculateTax(taxBase, false, scale);
SurchargeAmt = surTax.CalculateTax(taxBase, false, scale);
}
}
// for Surcharge Calculation type - Tax Amount
else
{
if (!taxIncluded) // $100 * 6 / 100 == $6 == $100 * 0.06
{
// Calculate Tax Amount on Line Amount
multiplier = Decimal.Round(Decimal.Divide(taxRate, 100), 12, MidpointRounding.AwayFromZero);
TaxAmt = Decimal.Multiply(amount, multiplier);
// Calculate Surcharge Tax Amount on Line Amount + Tax Amount
multiplier = Decimal.Round(Decimal.Divide(surRate, 100), 12, MidpointRounding.AwayFromZero);
SurchargeAmt = Decimal.Multiply(TaxAmt, multiplier);
TaxAmt = Decimal.Round(TaxAmt, scale, MidpointRounding.AwayFromZero);
SurchargeAmt = Decimal.Round(SurchargeAmt, scale, MidpointRounding.AwayFromZero);
}
else // $106 - ($106 / (100+6)/100) == $6 == $106 - ($106/1.06)
{
multiplier = Decimal.Round(Decimal.Divide(surRate, 100), 12, MidpointRounding.AwayFromZero);
multiplier = Decimal.Multiply(taxRate, multiplier);
multiplier = Decimal.Add(taxRate, multiplier);
multiplier = Decimal.Round(Decimal.Divide(multiplier, 100), 12, MidpointRounding.AwayFromZero);
multiplier = Decimal.Add(multiplier, Env.ONE);
taxBase = Decimal.Divide(amount, multiplier);
taxBase = Decimal.Round(taxBase, 12, MidpointRounding.AwayFromZero);
TaxAmt = CalculateTax(taxBase, false, scale);
SurchargeAmt = surTax.CalculateTax(TaxAmt, false, scale);
}
}
return(TaxAmt);
}
