Various bug fixs and improvements to stock SKU reconciliation

src/bnhtrade.Core/Logic/Stock/StatusBalance.cs

@@ -0,0 +1,111 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace bnhtrade.Core.Logic.Stock
+{
+    public class StatusBalance
+    {
+        private string sqlConnectionString;
+
+        public StatusBalance(string sqlConnectionString)
+        {
+            this.sqlConnectionString = sqlConnectionString;
+        }
+
+        /// <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 new Data.Database.Stock.ReadStatusBalance(sqlConnectionString).BySku(sku, statusId);
+        }
+
+        /// <summary>
+        /// Return the avaliable balance of a status at a specified date and time. Useful for checking availability before
+        /// moving stock/sku retrospectivly
+        /// </summary>
+        /// <param name="sku">SKU number</param>
+        /// <param name="statusId">Status ID</param>
+        /// <param name="atDate">Date and time you would like to know the balance at</param>
+        /// <returns></returns>
+        public Model.Stock.StatusBalance GetBySku(string sku, int statusId)
+        {
+            if (string.IsNullOrWhiteSpace(sku))
+            {
+                throw new Exception("SKU number is null, empty, or whitespace");
+            }
+
+            // get list of transactions for availale stock
+            var stockTransaction = new Data.Database.Stock.ReadStatusTransaction(sqlConnectionString);
+            var transList = stockTransaction.BySku(statusId, sku);
+
+            // create quantity list
+            List<int> qtyList = new List<int>();
+            for (int i = 0; i < transList.TransactionList.Count; i++)
+            {
+                qtyList.Add(transList.TransactionList[i].Quantity);
+            }
+
+            // tally list
+            // loop, in reverse, to find credits to tally with debits
+            for (int iCr = qtyList.Count - 1; iCr > -1; iCr--)
+            {
+                if (qtyList[iCr] < 0)
+                {
+                    int crStockNumber = transList.TransactionList[iCr].StockNumber;
+                    DateTime crDate = transList.TransactionList[iCr].EntryDate;
+
+                    // loop, in reverse, to find debits
+                    for (int iDr = qtyList.Count - 1; iDr > -1; iDr--)
+                    {
+                        // find debits, last in first out (filter by date)
+                        if (transList.TransactionList[iDr].StockNumber == crStockNumber
+                            && transList.TransactionList[iDr].EntryDate <= crDate 
+                            && qtyList[iDr] > 0)
+                        {
+                            // credit fully assigned
+                            if ((qtyList[iCr] + qtyList[iDr]) >= 0)
+                            {
+                                qtyList[iDr] = qtyList[iDr] + qtyList[iCr];
+                                qtyList[iCr] = 0;
+                                break;
+                            }
+                            // credit partially assigned
+                            else
+                            {
+                                qtyList[iCr] = qtyList[iDr] + qtyList[iCr];
+                                qtyList[iDr] = 0;
+                            }
+                        }
+                    }
+                }
+            }
+
+            // build result list from tally results
+            var result = new Model.Stock.StatusBalance();
+            result.Sku = transList.Sku;
+            result.StockStatusId = transList.StockStatusId;
+
+            for (int i = 0; i < qtyList.Count; i++)
+            {
+                if (qtyList[i] != 0)
+                {
+                    result.AddBalanceTransaction(
+                            transList.TransactionList[i].EntryDate,
+                            transList.TransactionList[i].StockNumber,
+                            qtyList[i]);
+                }
+            }
+
+            return result;
+        }
+    }
+}