wip, this turned into a maaaaaahooosive job

src/bnhtrade.Core/Logic/Inventory/StockStatusService.cs

@@ -0,0 +1,39 @@
+using bnhtrade.Core.Data.Database.UnitOfWork;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace bnhtrade.Core.Logic.Inventory
+{
+    public class StockStatusService : UnitOfWorkBase
+    {
+        public StockStatusService() : base() { }
+
+        internal StockStatusService(IUnitOfWork unitOfWork) : base(unitOfWork) { }
+
+        /// <summary>
+        /// Return the avaliable balance of a status. Uses a more efficent sql/code. However, balance requests should
+        /// generally also involve a date/time (i.e. the system does allow a stock transaction in the future, therefore
+        /// this method may give an available quantity, but transfers before that date wouod not be possible).
+        /// </summary>
+        /// <param name="sku">SKU number</param>
+        /// <param name="statusId">Status ID</param>
+        /// <returns>Balance as quantity</returns>
+        private int GetAvailableBalanceBySku(string sku, int statusId)
+        {
+            return WithUnitOfWork(uow =>
+            {
+                if (string.IsNullOrWhiteSpace(sku))
+                {
+                    throw new ArgumentException("SKU number is null, empty, or whitespace", nameof(sku));
+                }
+
+                return uow.StockJournalRepository.ReadStatusBalanceBySku(sku, statusId);
+            });
+        }
+
+
+    }
+}