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1.5 KiB
C#

namespace Distribution.Features.Grn;
public record LineAmounts(decimal Gross, decimal Discount, decimal Nbt, decimal Vat, decimal Total);
/// <summary>
/// GRN costing. Per line: gross = accepted qty x unit cost; discount = gross x disc%;
/// NBT = (gross - discount) x NBT%; VAT = (gross - discount + NBT) x VAT%;
/// total = gross - discount + NBT + VAT. Rejected units are never costed.
/// Each amount is rounded to 2 dp per line so the GRN totals equal the sum of what the lines show.
/// </summary>
public static class GrnPricing
{
public static decimal Round(decimal value) => Math.Round(value, 2, MidpointRounding.AwayFromZero);
public static LineAmounts Line(
int acceptedQty, decimal unitCost, decimal discountPercent, decimal nbtPercent, decimal vatPercent)
{
var gross = Round(acceptedQty * unitCost);
var discount = Round(gross * discountPercent / 100m);
var net = gross - discount;
var nbt = Round(net * nbtPercent / 100m);
var vat = Round((net + nbt) * vatPercent / 100m);
return new LineAmounts(gross, discount, nbt, vat, net + nbt + vat);
}
public static void ValidatePercent(decimal value, string label)
{
if (value < 0 || value > 100)
throw new InvalidOperationException($"{label} must be between 0 and 100.");
}
public static void ValidateCost(decimal value, string label)
{
if (value < 0)
throw new InvalidOperationException($"{label} cannot be negative.");
}
}