moved logic out of SalesWindows.xaml.cs to SaleTransactionServce

PointOfSale/Pos.Ui/Database/PosDbContext.cs

@@ -17,6 +17,16 @@ namespace Database
         public DbSet<SaleLineEntity> SalesLines { get; set; }
         public DbSet<PaymentEntity> Payment { get; set; }
 
+        protected override void OnModelCreating(ModelBuilder modelBuilder)
+        {
+            modelBuilder.Entity<SaleLineEntity>()
+                .Property(saleLine => saleLine.Pieces)
+                .HasConversion<short>()
+                .HasColumnType("smallint");
+
+            base.OnModelCreating(modelBuilder);
+        }
+
         protected override void OnConfiguring(
            DbContextOptionsBuilder optionsBuilder)
         {

PointOfSale/Pos.Ui/Pos/SalesWindow.xaml.cs

@@ -29,7 +29,8 @@ namespace Pos
         private ObservableCollection<ProductGroupEntity> _productGroups;
         private ObservableCollection<SaleGridModel> _saleGridModels;
         private ObservableCollection<AmountGridModel> _paymentGridModels;
-        private List<PriceLineModel> _priceLineModels;
+        private readonly SalesTransactionService _salesTransactionService =
+            new SalesTransactionService();
 
         private ProductEntity _selectedProduct;
         private ProductGroupEntity _selectedProductGroup;
@@ -37,14 +38,10 @@ namespace Pos
         private int _employeeId = -1;
         private int _productGroupId = -1;
         private int _productId = -1;
-        private int _numberOfProducts = 1;
         private int _selectedSaleGridIndex = -1;
 
         private int _maxCharOfName = 0;
         
-        private decimal _price = 0;
-        private decimal _totalPrice = 0;
-
         private Button _prevEmpButton = new Button();
         private Button _prevProductGroupButton = new Button();
         private Button _prevProduct = new Button();
@@ -61,7 +58,6 @@ namespace Pos
             _employees = CacheService.GetEmployee() as ObservableCollection<EmployeeEntity>;
             _productGroups = CacheService.GetProductGroupsIncludeProducts() as ObservableCollection<ProductGroupEntity>;
             _saleGridModels = new ObservableCollection<SaleGridModel>();
-            _priceLineModels = new List<PriceLineModel>();
             _paymentGridModels = new ObservableCollection<AmountGridModel>();
             SaleGrid.ItemsSource = _saleGridModels;
             PaymentGrid.ItemsSource = _paymentGridModels;
@@ -150,11 +146,25 @@ namespace Pos
                 return;
 
             decimal price = Convert.ToDecimal(Price.Text);
-            int number = Convert.ToInt32(NumberOfProducts.Text);
+            int numberOfProducts = Convert.ToInt32(NumberOfProducts.Text);
+
+            try
+            {
+                BuildPrice(numberOfProducts, price);
+            }
+            catch (ArgumentException exception)
+            {
+                MessageBox.Show(
+                    exception.Message,
+                    "Ugyldig salgslinje",
+                    MessageBoxButton.OK,
+                    MessageBoxImage.Error);
+                return;
+            }
+
             NumberOfProducts.Text = "1";
             Price.Text = string.Empty;
             TotalPrice.Content = "0";
-            BuildPrice(false);
             _productId = -1;
             _productGroupId = -1;
             ManipulateBuySection();
@@ -162,16 +172,36 @@ namespace Pos
 
         private void Payment_Click(object sender, RoutedEventArgs e)
         {
-            //bool isValid = ValidateAmountInput();
+            decimal? amount = null;
-            //if (!isValid)
-            //    return;
-            decimal amount = -1;
             if (!string.IsNullOrEmpty(Amount.Text))
+            {
+                bool isValid = ValidateAmountInput();
+                if (!isValid)
+                    return;
+
                 amount = Convert.ToDecimal(Amount.Text);
+            }
 
             Amount.Text = string.Empty;
             Button button = sender as Button;
-            BuildAmuntDataGrid(amount,(string)button.Tag);
+            string paymentMethodName =
+                ((string)button.Tag).Replace("PaymentMethod.", string.Empty);
+
+            if (!Enum.TryParse(paymentMethodName, out PaymentMethod paymentMethod))
+                return;
+
+            try
+            {
+                BuildAmuntDataGrid(amount, paymentMethod);
+            }
+            catch (ArgumentException exception)
+            {
+                MessageBox.Show(
+                    exception.Message,
+                    "Ugyldig betaling",
+                    MessageBoxButton.OK,
+                    MessageBoxImage.Error);
+            }
         }
 
         private void NumberOfProducts_LostFocus(object sender, RoutedEventArgs e)
@@ -249,61 +279,69 @@ namespace Pos
             }
 
         }
-        private void BuildPrice(bool returnProduct)
+        private void BuildPrice(int numberOfProducts, decimal price)
         {
-            PriceLineModel pModel = new PriceLineModel();
+            PriceLineModel priceLineModel;
-            pModel.NumberProducts = _numberOfProducts;
-            pModel.Price = _price;
             if (_selectedProduct != null)
             {
-                pModel.Id = _selectedProduct.Id;
+                priceLineModel = _salesTransactionService.AddSaleLine(
-                pModel.Name = _selectedProduct.Name;
+                    _selectedProduct.Id,
-                pModel.IsProductGroup = false;
+                    _selectedProduct.Name,
+                    numberOfProducts,
+                    price,
+                    false);
             }
             else
             {
-                pModel.Id = _selectedProductGroup.Id;
+                priceLineModel = _salesTransactionService.AddSaleLine(
-                pModel.Name = _selectedProductGroup.Name;
+                    _selectedProductGroup.Id,
-                pModel.IsProductGroup = true;
+                    _selectedProductGroup.Name,
+                    numberOfProducts,
+                    price,
+                    true);
             }
 
-            BuildPriceDataGrid(pModel);
+            BuildPriceDataGrid(priceLineModel);
             //BuildEmployee();
             BuildProductGroup();
         }
 
         private void CalculateSubPrice()
         {
-            _price = 0;
+            bool isValid = decimal.TryParse(Price.Text, out decimal price);
-            bool isValid = decimal.TryParse(Price.Text, out _price);
             if (!isValid)
                 return;
 
-            isValid = Int32.TryParse(NumberOfProducts.Text, out _numberOfProducts);
+            isValid = Int32.TryParse(
+                NumberOfProducts.Text,
+                out int numberOfProducts);
             if (!isValid)
                 return;
 
-            TotalPrice.Content = _price * _numberOfProducts;
+            try
+            {
+                TotalPrice.Content =
+                    _salesTransactionService.CalculateLineTotal(
+                        price,
+                        numberOfProducts);
+            }
+            catch (ArgumentOutOfRangeException)
+            {
+                TotalPrice.Content = "0";
+            }
         }
 
         private void CalculateTotalLine()
         {
-            _totalPrice = 0;
+            Total.Content =
-            foreach (PriceLineModel model in _priceLineModels)
+                $"At betale: Kr. {_salesTransactionService.TotalPrice}";
-            {
-                _totalPrice += model.Price * model.NumberProducts;
-            }
-
-            Total.Content = $"At betale: Kr. {_totalPrice}";
         }
 
         private void BuildPriceDataGrid(PriceLineModel priceLineModel)
         {
             _selectedProduct = null;
             _selectedProductGroup = null;
-            _numberOfProducts = 1;
 
-            _priceLineModels.Add(priceLineModel);
             CalculateTotalLine();
 
             SaleGridModel model = new SaleGridModel();
@@ -399,38 +437,14 @@ namespace Pos
             TotalPrice.IsEnabled = enabled;
         }
 
-        private void BuildAmuntDataGrid(decimal amount, string paymentMethod)
+        private void BuildAmuntDataGrid(
+            decimal? amount,
+            PaymentMethod paymentMethod)
         {
-            if (amount == -1)
+            AmountGridModel amountGridModel =
-            {
+                _salesTransactionService.AddPayment(paymentMethod, amount);
-                amount = 0;
-                foreach (PriceLineModel lineModel in _priceLineModels)
-                {
-                    amount += (lineModel.Price * lineModel.NumberProducts);
-                }
-            }
 
-            AmountGridModel amountGridModel = new AmountGridModel();
+            amountGridModel.AmountText = $"Kr. {amountGridModel.Amount}";
-            amountGridModel.Amount = amount;
-            amountGridModel.AmountText = $"Kr. {amount}";
-            switch (paymentMethod)
-            {
-                case "PaymentMethod.Card":
-                    amountGridModel.PaymentMethodText = "Kort";
-                    break;
-
-                case "PaymentMethod.Cash":
-                    amountGridModel.PaymentMethodText = "Kontant";
-                    break;
-
-                case "PaymentMethod.GiftCard":
-                    amountGridModel.PaymentMethodText = "Gavekort";
-                    break;
-
-                case "PaymentMethod.MobilePay":
-                    amountGridModel.PaymentMethodText = "MobilePay";
-                    break;
-            }
             _paymentGridModels.Add(amountGridModel);
 
             AmountPayed();
@@ -438,28 +452,25 @@ namespace Pos
 
         private void AmountPayed()
         {
-            decimal amountPayed = 0;
+            if (_salesTransactionService.AmountPaid ==
-            foreach (AmountGridModel paymentGridModel in _paymentGridModels)
+                _salesTransactionService.TotalPrice)
-            {
-                amountPayed += paymentGridModel.Amount;
-            }
-
-            if (amountPayed == _totalPrice)
             {
                 btnFinish_Click(null,null);
                 return;
             }
 
-            if (amountPayed > _totalPrice)
+            if (_salesTransactionService.Change > 0)
             {
-                lblRecived.Content = $"Byttepenge: Kr. {amountPayed - _totalPrice}";
+                lblRecived.Content =
+                    $"Byttepenge: Kr. {_salesTransactionService.Change}";
                 Style style = this.FindResource("BoldLabelWarningNoMargin") as Style;
                 lblRecived.Style = style;
                 btnFinish.IsEnabled = true;
             }
             else
             {
-                lblRecived.Content = $"At betale: Kr. {_totalPrice - amountPayed}";
+                lblRecived.Content =
+                    $"At betale: Kr. {_salesTransactionService.RemainingAmount}";
                 Style style = this.FindResource("BoldLabelNoMargin") as Style;
                 lblRecived.Style = style;
             }
@@ -473,21 +484,37 @@ namespace Pos
                 if (_selectedSaleGridIndex == -1)
                     return;
                 int index = _selectedSaleGridIndex;
-                //_saleGridModels.RemoveAt(_selectedSaleGridIndex);
+                _salesTransactionService.RemoveSaleLineAt(index);
-                _priceLineModels.RemoveAt(index);
+                _saleGridModels.RemoveAt(index);
                 _selectedSaleGridIndex = -1;
                 CalculateTotalLine();
+
+                if (_salesTransactionService.AmountPaid > 0)
+                    AmountPayed();
             }
         }
 
         private void btnFinish_Click(object sender, RoutedEventArgs e)
         {
+            try
+            {
+                _salesTransactionService.EnsureCanComplete();
+            }
+            catch (InvalidOperationException exception)
+            {
+                MessageBox.Show(
+                    exception.Message,
+                    "Salget kan ikke afsluttes",
+                    MessageBoxButton.OK,
+                    MessageBoxImage.Error);
+                return;
+            }
+
             SaleService saleService = new SaleService();
             saleService.Save(_saleGridModels.ToList(),_paymentGridModels.ToList(),_employeeId);
             _paymentGridModels.Clear();
-            _priceLineModels.Clear();
+            _salesTransactionService.Reset();
             UpdateWindowTitle();
-            _totalPrice = 0;
             _saleGridModels.Clear();
             lblRecived.Content = string.Empty;
             _selectedSaleGridIndex = -1;

PointOfSale/Pos.Ui/Pos/Service/SalesTransactionService.cs

@@ -0,0 +1,171 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Pos.Models;
+
+namespace Pos.Service
+{
+    /// <summary>
+    /// Holder styr på den igangværende handel og dens beregninger.
+    /// Servicen har ingen afhængighed til WPF eller web.
+    /// </summary>
+    public class SalesTransactionService
+    {
+        private readonly List<PriceLineModel> _saleLines = new List<PriceLineModel>();
+        private readonly List<AmountGridModel> _payments = new List<AmountGridModel>();
+
+        public IReadOnlyList<PriceLineModel> SaleLines => _saleLines;
+        public IReadOnlyList<AmountGridModel> Payments => _payments;
+
+        public decimal TotalPrice =>
+            _saleLines.Sum(line =>
+                CalculateLineTotal(line.Price, line.NumberProducts));
+
+        public decimal AmountPaid =>
+            _payments.Sum(payment => payment.Amount);
+
+        public decimal RemainingAmount =>
+            Math.Max(TotalPrice - AmountPaid, 0);
+
+        public decimal Change =>
+            Math.Max(AmountPaid - TotalPrice, 0);
+
+        public bool IsFullyPaid =>
+            TotalPrice > 0 && AmountPaid >= TotalPrice;
+
+        /// <summary>
+        /// Beregner totalen for en enkelt salgslinje.
+        /// Parsing og visning af resultatet er fortsat UI-ansvar.
+        /// </summary>
+        public decimal CalculateLineTotal(decimal price, int numberOfProducts)
+        {
+            ValidatePriceAndQuantity(price, numberOfProducts);
+            return price * numberOfProducts;
+        }
+
+        public PriceLineModel AddSaleLine(
+            int id,
+            string name,
+            int numberOfProducts,
+            decimal price,
+            bool isProductGroup)
+        {
+            if (id <= 0)
+                throw new ArgumentOutOfRangeException(
+                    nameof(id),
+                    "Id skal være større end 0.");
+
+            if (string.IsNullOrWhiteSpace(name))
+                throw new ArgumentException(
+                    "Navn skal være udfyldt.",
+                    nameof(name));
+
+            ValidatePriceAndQuantity(price, numberOfProducts);
+
+            PriceLineModel saleLine = new PriceLineModel
+            {
+                Id = id,
+                Name = name,
+                NumberProducts = numberOfProducts,
+                Price = price,
+                IsProductGroup = isProductGroup
+            };
+
+            _saleLines.Add(saleLine);
+            return saleLine;
+        }
+
+        public void RemoveSaleLineAt(int index)
+        {
+            if (index < 0 || index >= _saleLines.Count)
+                throw new ArgumentOutOfRangeException(nameof(index));
+
+            _saleLines.RemoveAt(index);
+        }
+
+        /// <summary>
+        /// Registrerer en betaling. Hvis amount er null, betales restbeløbet.
+        /// </summary>
+        public AmountGridModel AddPayment(
+            PaymentMethod paymentMethod,
+            decimal? amount = null)
+        {
+            if (_saleLines.Count == 0)
+                throw new InvalidOperationException(
+                    "Der kan ikke registreres betaling på et tomt salg.");
+
+            decimal paymentAmount = amount ?? RemainingAmount;
+
+            if (paymentAmount <= 0)
+                throw new ArgumentOutOfRangeException(
+                    nameof(amount),
+                    "Betalingsbeløbet skal være større end 0.");
+
+            AmountGridModel payment = new AmountGridModel
+            {
+                Amount = paymentAmount,
+                PaymentMethodText = GetPaymentMethodText(paymentMethod)
+            };
+
+            _payments.Add(payment);
+            return payment;
+        }
+
+        public void RemovePaymentAt(int index)
+        {
+            if (index < 0 || index >= _payments.Count)
+                throw new ArgumentOutOfRangeException(nameof(index));
+
+            _payments.RemoveAt(index);
+        }
+
+        public void EnsureCanComplete()
+        {
+            if (_saleLines.Count == 0)
+                throw new InvalidOperationException(
+                    "Et tomt salg kan ikke afsluttes.");
+
+            if (!IsFullyPaid)
+                throw new InvalidOperationException(
+                    "Salget er ikke fuldt betalt.");
+        }
+
+        public void Reset()
+        {
+            _saleLines.Clear();
+            _payments.Clear();
+        }
+
+        private static void ValidatePriceAndQuantity(
+            decimal price,
+            int numberOfProducts)
+        {
+            if (price < 0)
+                throw new ArgumentOutOfRangeException(
+                    nameof(price),
+                    "Prisen må ikke være negativ.");
+
+            if (numberOfProducts <= 0)
+                throw new ArgumentOutOfRangeException(
+                    nameof(numberOfProducts),
+                    "Antal skal være større end 0.");
+        }
+
+        private static string GetPaymentMethodText(PaymentMethod paymentMethod)
+        {
+            switch (paymentMethod)
+            {
+                case PaymentMethod.Card:
+                    return "Kort";
+                case PaymentMethod.Cash:
+                    return "Kontant";
+                case PaymentMethod.GiftCard:
+                    return "Gavekort";
+                case PaymentMethod.MobilePay:
+                    return "MobilePay";
+                default:
+                    throw new ArgumentOutOfRangeException(nameof(paymentMethod));
+            }
+        }
+    }
+}