BealeEngineering/BealeEngineering/BealeEngineering.Core/Model/Client/PurchaseOrder.cs

using BealeEngineering.Core.Logic.Utilities;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Text;
using System.Linq;
using System.ComponentModel;

namespace BealeEngineering.Core.Model.Client
{
    public class PurchaseOrder : PurchaseOrderHeader
    {
        public int OrderLineCount
        {
            get
            {
                if (OrderLineList == null) { return 0; }
                else { return OrderLineList.Count; }
            }
        }

        public List<PurchaseOrderLine> OrderLineList { get; set; } = new List<PurchaseOrderLine>();

        public class PurchaseOrderLine
        {
            int? clientPurchaseOrderLineId = null;

            public int ClientPurchaseOrderLineID 
            { 
                get { return clientPurchaseOrderLineId.GetValueOrDefault(); }
                set { clientPurchaseOrderLineId = value; }
            }

            public bool ClientPurchaseOrderLineIDIsSet
            {
                get
                {
                    if (clientPurchaseOrderLineId == null || clientPurchaseOrderLineId < 1) { return false; }
                    else { return true; }
                }
            }

            [Required()]
            public int LineNumber { get; set; }

            public string ProjectWorkNumber { get; set; }

            [Required()]
            public string Description { get; set; }

            [Required()]
            public decimal LineNetAmount { get; set; }
        }

        public override IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
        {
            var results = base.Validate(validationContext).ToList();

            if (OrderLineCount == 0)
            {
                var result = new ValidationResult("No order lines set");
                results.Add(result);
            }

            if (OrderTotal != OrderLineList.Sum(x => x.LineNetAmount))
            {
                var result = new ValidationResult("Order total does not equal sum of line list.");
                results.Add(result);
            }
            return results;
        }
    }
}