prs/prs.classes/Entities/Product/ProductPriceComponent.cs

using System;
using System.Linq.Expressions;
using InABox.Core;

namespace Comal.Classes
{
    public class ProductPriceComponentNettCostFormula : IFormula<ProductPriceComponent, double>
    {
        public Expression<Func<ProductPriceComponent, double>> Value => x => x.Quantity;

        public Expression<Func<ProductPriceComponent, double>>[] Modifiers =>
            new Expression<Func<ProductPriceComponent, double>>[] { x => x.Component.NettCost };

        public FormulaOperator Operator => FormulaOperator.Multiply;
        
        public FormulaType Type => FormulaType.Virtual;
    }

    [UserTracking(typeof(Product))]
    public class ProductPriceComponent : Entity, IPersistent, IRemotable, ILicense<ProductManagementLicense>
    {
        [EditorSequence(1)]
        public ProductLink Product { get; set; }

        [EditorSequence(2)]
        public ProductLink Component { get; set; }

        [DoubleEditor(4)]
        [EditorSequence(3)]
        public double Quantity { get; set; }

        [DoubleEditor(Editable = Editable.Disabled, Summary = Summary.Sum)]
        [Formula(typeof(ProductPriceComponentNettCostFormula))]
        [EditorSequence(4)]
        public double NettCost { get; set; }

        protected override void DoPropertyChanged(string name, object? before, object? after)
        {
            base.DoPropertyChanged(name, before, after);
            if (name.Equals("Quantity")) NettCost = (double)after * Component.NettCost;
        }
    }
}