Merge pull request 'Wired up CartDrawel and ProductView to cart service and local storage' (#53) from cart into main

Reviewed-on: #53

MidrandBookshop/Components/Layout/MainLayout.razor

@@ -6,7 +6,7 @@
     <div class="cart-drawer @(IsCartOpen ? "is-open" : "") d-flex flex-column bg-white shadow-lg">
         <div class="cart-header d-flex align-items-center justify-content-between p-4 border-bottom">
             <h5 class="fw-bold m-0 text-dark tracking-tight" style="font-family: 'Inter', sans-serif; font-size: 1.1rem;">
-                YOUR CART (@CartItems.Sum(i => i.Quantity))
+                YOUR CART (@ShoppingCart.Items.Count())
             </h5>
             <button class="btn btn-sm text-dark p-1 border-0" @onclick="ToggleCart" type="button">
                 <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
@@ -17,7 +17,7 @@
         </div>
 
         <div class="cart-body flex-grow-1 overflow-y-auto p-4">
-            @if (!CartItems.Any())
+            @if (!ShoppingCart.Items.Any())
             {
                 <div class="h-100 d-flex flex-column align-items-center justify-content-center text-muted py-5">
                     <svg class="mb-3 opacity-50" width="36" height="36" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.5">
@@ -29,22 +29,29 @@
             else
             {
                 <div class="d-flex flex-column gap-4">
-                    @foreach (var item in CartItems)
+                    @foreach (var item in ShoppingCart.Items)
                     {
                         <div class="cart-item d-flex gap-3 align-items-start pb-3 border-bottom-dashed">
                             <div class="cart-item-thumb bg-dark text-white-50 d-flex align-items-center justify-content-center px-2 text-center" style="width: 54px; height: 74px; font-size: 0.45rem; letter-spacing: 0.5px;">
-                                [ COVER ]
+                                @if (!string.IsNullOrWhiteSpace(item.Product!.ImageUrl))
+                                {
+                                    <img src="@item.Product!.ImageUrl" class="img-fluid book-shadow" style="max-height: 240px; object-fit: contain;" alt="@item.Product.Name" />
+                                }
+                                else
+                                {
+                                    @:[COVER]
+                                }
                             </div>
                             <div class="flex-grow-1">
-                                <h6 class="text-dark small fw-bold mb-0 text-truncate" style="max-width: 180px;">@item.Title</h6>
-                                <p class="text-muted xx-small mb-2">by @item.Author</p>
+                                <h6 class="text-dark small fw-bold mb-0 text-truncate" style="max-width: 180px;">@item.Product!.Name</h6>
+                                <p class="text-muted xx-small mb-2">by @($"{item.Author!.Name} {item.Author.LastName}")</p>
                                 <div class="d-flex align-items-center justify-content-between">
                                     <div class="quantity-picker d-flex align-items-center border rounded-pill bg-light">
                                         <button class="btn btn-sm py-0 px-2 text-dark border-0" @onclick="() => ChangeQuantity(item, -1)" type="button">-</button>
-                                        <span class="px-1 text-dark fw-medium" style="font-size: 0.75rem;">@item.Quantity</span>
+                                        <span class="px-1 text-dark fw-medium" style="font-size: 0.75rem;">@ShoppingCart.Items.FirstOrDefault(i => i.Price!.Id == item.Price!.Id)!.Quantity</span>
                                         <button class="btn btn-sm py-0 px-2 text-dark border-0" @onclick="() => ChangeQuantity(item, 1)" type="button">+</button>
                                     </div>
-                                    <span class="small fw-semibold text-dark">R @(item.Price * item.Quantity)</span>
+                                    <span class="small fw-semibold text-dark">R @(item.Price!.Amount * item.Quantity)</span>
                                 </div>
                             </div>
                             <button class="btn text-muted p-0 border-0 mt-1 align-self-start" style="background: none;" @onclick="() => RemoveFromCart(item)" type="button">
@@ -56,7 +63,7 @@
             }
         </div>
 
-        @if (CartItems.Any())
+        @if (ShoppingCart.Items.Any())
         {
             <div class="cart-footer p-4 bg-light border-top mt-auto">
                 <div class="d-flex align-items-center justify-content-between mb-4">
@@ -156,9 +163,9 @@
                         <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.75">
                             <path d="M6 2L3 6v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2V6l-3-4z M3 6h18 M16 10a4 4 0 0 1-8 0" />
                         </svg>
-                        @if (CartItems.Any())
+                        @if (ShoppingCart.Items.Any())
                         {
-                            <span class="cart-badge">@CartItems.Sum(i => i.Quantity)</span>
+                            <span class="cart-badge">@ShoppingCart.Items.Count</span>
                         }
                     </button>
 

MidrandBookshop/Components/Layout/MainLayout.razor.cs

@@ -1,36 +1,43 @@
-using Microsoft.AspNetCore.Components.Routing;
-using Microsoft.AspNetCore.Components.Web;
-using Microsoft.AspNetCore.WebUtilities;
+using MidrandBookshop.Services.ShoppingCart;
+using MidrandBookshop.Services.ShoppingCart.Models;
 
 namespace MidrandBookshop.Components.Layout;
 
-public partial class MainLayout : IDisposable
+public partial class MainLayout(CartService cartService) : IDisposable
 {
+    [Inject]
+    private AuthenticationStateProvider AuthStateProvider { get; set; } = default!;
+
+    private Cart ShoppingCart => cartService.ShoppingCart;
+
+    private AuthenticationState? AuthState { get; set; }
+    private System.Security.Claims.ClaimsPrincipal? User { get; set; }
+    private bool IsAuthenticated => User?.Identity?.IsAuthenticated ?? false;
+
     private string SearchInputBuffer { get; set; } = string.Empty;
     private string GlobalSearchQuery { get; set; } = string.Empty;
     private bool IsSearchActive { get; set; } = false;
     private bool IsCartOpen { get; set; } = false;
 
-    private List<CartItem> CartItems = new()
+    protected override async Task OnInitializedAsync()
     {
-        new CartItem { Id = 1, Title = "Letters from M/M (Paris)", Author = "M/M Paris", Price = 720, Quantity = 1 },
-        new CartItem { Id = 2, Title = "Daan Paans: Floating Signifiers", Author = "Daan Paans", Price = 540, Quantity = 1 },
-        new CartItem { Id = 3, Title = "Album Architectures, Maputo", Author = "Guedes Archive", Price = 350, Quantity = 1 }
-    };
+        AuthState = await AuthStateProvider.GetAuthenticationStateAsync();
+        User = AuthState!.User;
 
-    private void TriggerHeaderLogout()
-    {
-        // Force tear-down of the active client websocket pipeline safely
-        Navigation.NavigateTo("/logout", forceLoad: true);
-    }
-
-    protected override void OnInitialized()
-    {
         Navigation.LocationChanged += OnLocationChanged;
+        cartService.OnCartChanged += CartService_OnCartChanged;
 
         SyncSearchQueryFromUrl();
     }
 
+    protected override async Task OnAfterRenderAsync(bool firstRender)
+    {
+        if (firstRender) 
+            await cartService.LoadCartFromStorageAsync();
+    }
+
+    private async void CartService_OnCartChanged() => await InvokeAsync(StateHasChanged);
+
     private void OnLocationChanged(object? sender, LocationChangedEventArgs e)
     {
         SyncSearchQueryFromUrl();
@@ -97,17 +104,25 @@ public partial class MainLayout : IDisposable
 
     private void ToggleCart() => IsCartOpen = !IsCartOpen;
 
-    private void ChangeQuantity(CartItem item, int delta)
+    private async void ChangeQuantity(CartItem item, int delta)
     {
-        item.Quantity += delta;
-        if (item.Quantity <= 0)
-        {
-            CartItems.Remove(item);
-        }
+        var peekQuantity = item.Quantity + delta;
+
+        if (peekQuantity < 1) return;
+
+        cartService.UpdateQuantity(item.Price!.Id, delta);
+
+        await cartService.SaveCartToStorageAsync();
     }
 
-    private void RemoveFromCart(CartItem item) => CartItems.Remove(item);
-    private int GetCartTotal() => CartItems.Sum(item => item.Price * item.Quantity);
+    private async void RemoveFromCart(CartItem item)
+    {
+        cartService.RemoveOneItem(item.Price!.Id);
+
+        await cartService.SaveCartToStorageAsync();
+    }
+
+    private decimal GetCartTotal() => ShoppingCart?.TotalPrice ?? 0.00m;
 
     private void RedirectToCart()
     {
@@ -124,14 +139,8 @@ public partial class MainLayout : IDisposable
     public void Dispose()
     {
         Navigation.LocationChanged -= OnLocationChanged;
-    }
+        cartService.OnCartChanged -= CartService_OnCartChanged;
 
-    public class CartItem
-    {
-        public int Id { get; set; }
-        public string Title { get; set; } = string.Empty;
-        public string Author { get; set; } = string.Empty;
-        public int Price { get; set; }
-        public int Quantity { get; set; }
+        GC.SuppressFinalize(this);
     }
 }

MidrandBookshop/Components/Pages/Account.razor

@@ -225,77 +225,4 @@
             </div>
         </div>
     </div>
-</div>
-
-@code {
-    private bool showAddForm = false;
-    private AddressItem? editingAddress = null;
-    private string newAddressName = "";
-    private string newStreetAddress = "";
-    private string newCity = "";
-    private string newPostalCode = "";
-    private bool isBilling, isShipping;
-
-    private List<OrderItem> orderHistory = new()
-    {
-        new OrderItem { OrderId = "#MB-2026-9481", ProductId = "introduction-to-blazor", ProductTitle = "Introduction to Blazor WebAssembly Framework Development", OrderDate = new DateTime(2026, 5, 20), ShippingAddressName = "Home Address", Status = "Shipped", Total = 720.00 },
-        new OrderItem { OrderId = "#MB-2026-8712", ProductId = "mastering-css-isolation", ProductTitle = "Mastering CSS Isolation in Modern .NET Web Applications Architecture", OrderDate = new DateTime(2026, 4, 14), ShippingAddressName = "Midrand Books Warehouse", Status = "Delivered", Total = 890.00 }
-    };
-
-    private List<AddressItem> savedAddresses = new()
-    {
-        new AddressItem { Id = 1, Name = "Home Address", Street = "12 Main Road", City = "Midrand", PostalCode = "1685", IsBilling = true, IsShipping = true, IsPrimary = true },
-        new AddressItem { Id = 2, Name = "Corporate Office", Street = "45 Challink Street", City = "Halfway House", PostalCode = "1682", IsBilling = true, IsShipping = false, IsPrimary = false },
-        new AddressItem { Id = 3, Name = "Midrand Books Warehouse", Street = "Unit 8, Corporate Park North", City = "Randjespark", PostalCode = "1683", IsBilling = false, IsShipping = true, IsPrimary = false }
-    };
-
-    private void TriggerLogout() => Navigation.NavigateTo("/logout", forceLoad: true);
-    private void DownloadInvoice(string orderId) { /* Handle download sequence here */ }
-    private void OpenAddForm() { editingAddress = null; showAddForm = true; }
-
-    private void SaveAddress()
-    {
-        if (!string.IsNullOrWhiteSpace(newAddressName) && !string.IsNullOrWhiteSpace(newStreetAddress))
-        {
-            var nextId = savedAddresses.Any() ? savedAddresses.Max(a => a.Id) + 1 : 1;
-            savedAddresses.Add(new AddressItem
-            {
-                Id = nextId,
-                Name = newAddressName,
-                Street = newStreetAddress,
-                City = newCity,
-                PostalCode = newPostalCode,
-                IsBilling = isBilling,
-                IsShipping = isShipping,
-                IsPrimary = !savedAddresses.Any()
-            });
-            ResetAddForm();
-        }
-    }
-
-    private void ResetAddForm() { newAddressName = ""; newStreetAddress = ""; newCity = ""; newPostalCode = ""; isBilling = isShipping = showAddForm = false; }
-    private void StartEditing(AddressItem addr) { showAddForm = false; editingAddress = new AddressItem { Id = addr.Id, Name = addr.Name, Street = addr.Street, City = addr.City, PostalCode = addr.PostalCode, IsBilling = addr.IsBilling, IsShipping = addr.IsShipping, IsPrimary = addr.IsPrimary }; }
-    private void CancelEditing() => editingAddress = null;
-
-    private void UpdateAddress()
-    {
-        if (editingAddress != null)
-        {
-            var target = savedAddresses.FirstOrDefault(a => a.Id == editingAddress.Id);
-            if (target != null) { target.Name = editingAddress.Name; target.Street = editingAddress.Street; target.City = editingAddress.City; target.PostalCode = editingAddress.PostalCode; target.IsBilling = editingAddress.IsBilling; target.IsShipping = editingAddress.IsShipping; }
-            editingAddress = null;
-        }
-    }
-
-    private void DeleteAddress(AddressItem addr) { if (editingAddress?.Id == addr.Id) editingAddress = null; savedAddresses.Remove(addr); if (addr.IsPrimary && savedAddresses.Any()) savedAddresses.First().IsPrimary = true; }
-
-    private void SetPrimary(AddressItem target, ChangeEventArgs e)
-    {
-        var isChecked = (bool)(e.Value ?? false);
-        if (isChecked) { foreach (var addr in savedAddresses) addr.IsPrimary = (addr.Id == target.Id); }
-        else target.IsPrimary = false;
-    }
-
-    public class AddressItem { public int Id { get; set; } public string Name { get; set; } = ""; public string Street { get; set; } = ""; public string City { get; set; } = ""; public string PostalCode { get; set; } = ""; public bool IsBilling { get; set; } public bool IsShipping { get; set; } public bool IsPrimary { get; set; } }
-    public class OrderItem { public string OrderId { get; set; } = ""; public string ProductId { get; set; } = ""; public string ProductTitle { get; set; } = ""; public DateTime OrderDate { get; set; } public string ShippingAddressName { get; set; } = ""; public string Status { get; set; } = ""; public double Total { get; set; } }
-}
+</div>

MidrandBookshop/Components/Pages/Account.razor.cs

@@ -0,0 +1,75 @@
+namespace MidrandBookshop.Components.Pages;
+
+public partial class Account
+{
+    private bool showAddForm = false;
+    private AddressItem? editingAddress = null;
+    private string newAddressName = "";
+    private string newStreetAddress = "";
+    private string newCity = "";
+    private string newPostalCode = "";
+    private bool isBilling, isShipping;
+
+    private List<OrderItem> orderHistory = new()
+    {
+        new OrderItem { OrderId = "#MB-2026-9481", ProductId = "introduction-to-blazor", ProductTitle = "Introduction to Blazor WebAssembly Framework Development", OrderDate = new DateTime(2026, 5, 20), ShippingAddressName = "Home Address", Status = "Shipped", Total = 720.00 },
+        new OrderItem { OrderId = "#MB-2026-8712", ProductId = "mastering-css-isolation", ProductTitle = "Mastering CSS Isolation in Modern .NET Web Applications Architecture", OrderDate = new DateTime(2026, 4, 14), ShippingAddressName = "Midrand Books Warehouse", Status = "Delivered", Total = 890.00 }
+    };
+
+    private List<AddressItem> savedAddresses = new()
+    {
+        new AddressItem { Id = 1, Name = "Home Address", Street = "12 Main Road", City = "Midrand", PostalCode = "1685", IsBilling = true, IsShipping = true, IsPrimary = true },
+        new AddressItem { Id = 2, Name = "Corporate Office", Street = "45 Challink Street", City = "Halfway House", PostalCode = "1682", IsBilling = true, IsShipping = false, IsPrimary = false },
+        new AddressItem { Id = 3, Name = "Midrand Books Warehouse", Street = "Unit 8, Corporate Park North", City = "Randjespark", PostalCode = "1683", IsBilling = false, IsShipping = true, IsPrimary = false }
+    };
+
+    private void TriggerLogout() => Navigation.NavigateTo("/logout", forceLoad: true);
+    private void DownloadInvoice(string orderId) { /* Handle download sequence here */ }
+    private void OpenAddForm() { editingAddress = null; showAddForm = true; }
+
+    private void SaveAddress()
+    {
+        if (!string.IsNullOrWhiteSpace(newAddressName) && !string.IsNullOrWhiteSpace(newStreetAddress))
+        {
+            var nextId = savedAddresses.Any() ? savedAddresses.Max(a => a.Id) + 1 : 1;
+            savedAddresses.Add(new AddressItem
+            {
+                Id = nextId,
+                Name = newAddressName,
+                Street = newStreetAddress,
+                City = newCity,
+                PostalCode = newPostalCode,
+                IsBilling = isBilling,
+                IsShipping = isShipping,
+                IsPrimary = !savedAddresses.Any()
+            });
+            ResetAddForm();
+        }
+    }
+
+    private void ResetAddForm() { newAddressName = ""; newStreetAddress = ""; newCity = ""; newPostalCode = ""; isBilling = isShipping = showAddForm = false; }
+    private void StartEditing(AddressItem addr) { showAddForm = false; editingAddress = new AddressItem { Id = addr.Id, Name = addr.Name, Street = addr.Street, City = addr.City, PostalCode = addr.PostalCode, IsBilling = addr.IsBilling, IsShipping = addr.IsShipping, IsPrimary = addr.IsPrimary }; }
+    private void CancelEditing() => editingAddress = null;
+
+    private void UpdateAddress()
+    {
+        if (editingAddress != null)
+        {
+            var target = savedAddresses.FirstOrDefault(a => a.Id == editingAddress.Id);
+            if (target != null) { target.Name = editingAddress.Name; target.Street = editingAddress.Street; target.City = editingAddress.City; target.PostalCode = editingAddress.PostalCode; target.IsBilling = editingAddress.IsBilling; target.IsShipping = editingAddress.IsShipping; }
+            editingAddress = null;
+        }
+    }
+
+    private void DeleteAddress(AddressItem addr) { if (editingAddress?.Id == addr.Id) editingAddress = null; savedAddresses.Remove(addr); if (addr.IsPrimary && savedAddresses.Any()) savedAddresses.First().IsPrimary = true; }
+
+    private void SetPrimary(AddressItem target, ChangeEventArgs e)
+    {
+        var isChecked = (bool)(e.Value ?? false);
+        if (isChecked) { foreach (var addr in savedAddresses) addr.IsPrimary = (addr.Id == target.Id); }
+        else target.IsPrimary = false;
+    }
+
+    public class AddressItem { public int Id { get; set; } public string Name { get; set; } = ""; public string Street { get; set; } = ""; public string City { get; set; } = ""; public string PostalCode { get; set; } = ""; public bool IsBilling { get; set; } public bool IsShipping { get; set; } public bool IsPrimary { get; set; } }
+    public class OrderItem { public string OrderId { get; set; } = ""; public string ProductId { get; set; } = ""; public string ProductTitle { get; set; } = ""; public DateTime OrderDate { get; set; } public string ShippingAddressName { get; set; } = ""; public string Status { get; set; } = ""; public double Total { get; set; } }
+}

MidrandBookshop/Components/Pages/ProductView.razor.cs

@@ -3,6 +3,8 @@ using LiteCharms.Features.MidrandBooks.Authors;
 using LiteCharms.Features.MidrandBooks.Authors.Models;
 using LiteCharms.Features.MidrandBooks.Products;
 using LiteCharms.Features.MidrandBooks.Products.Models;
+using Microsoft.AspNetCore.Cors.Infrastructure;
+using MidrandBookshop.Services.ShoppingCart;
 
 namespace MidrandBookshop.Components.Pages;
 
@@ -13,9 +15,13 @@ public partial class ProductView : ComponentBase
     [Inject] private ProductService ProductService { get; set; } = default!;
     [Inject] private AuthorService AuthorService { get; set; } = default!;
     [Inject] private NavigationManager Navigation { get; set; } = default!;
+    [Inject] private CartService CartService { get; set; } = default!;
+
+    protected Services.ShoppingCart.Models.Cart ShoppingCart => CartService?.ShoppingCart!;
 
     protected bool IsLoading { get; private set; } = true;
     protected Product? CurrentProduct { get; private set; }
+    protected ProductPrice? CurrentPrice { get; private set; }
     protected decimal LivePrice { get; private set; } = 0.00m;
     protected string AuthorName { get; private set; } = "Unknown Author";
     protected string PrimaryCategory { get; private set; } = "General";
@@ -26,6 +32,9 @@ public partial class ProductView : ComponentBase
 
     protected Author? CurrentAuthor { get; private set; }
 
+    private static Func<Services.ShoppingCart.Models.Cart, long, int> getCartItemQuantity = (shoppingCart, productPriceId) => 
+        shoppingCart.Items.FirstOrDefault(p => p.Price!.Id == productPriceId)?.Quantity ?? 1;
+
     protected override async Task OnParametersSetAsync()
     {
         try
@@ -44,6 +53,7 @@ public partial class ProductView : ComponentBase
 
                 var priceResult = await ProductService.GetProductPriceAsync(BookId);
                 LivePrice = priceResult.IsSuccess ? priceResult.Value.Amount : 0m;
+                CurrentPrice = priceResult.IsSuccess ? priceResult.Value : null;
 
                 var categoryResult = await ProductService.GetProductCategoriesAsync(BookId);
                 if (categoryResult.IsSuccess && categoryResult.Value.Length > 0)
@@ -73,6 +83,7 @@ public partial class ProductView : ComponentBase
         catch (Exception)
         {
             CurrentProduct = null;
+            CurrentPrice = null;
         }
         finally
         {
@@ -80,14 +91,52 @@ public partial class ProductView : ComponentBase
         }
     }
 
-    protected void IncreaseQty() => Quantity++;
-    protected void DecreaseQty() { if (Quantity > 1) Quantity--; }
+    protected async void IncreaseQty()
+    {
+        if (CurrentPrice is not null)
+        {
+            CartService.UpdateQuantity(CurrentPrice!.Id, 1);
+                        
+            Quantity = getCartItemQuantity(ShoppingCart, CurrentPrice.Id);
 
-    protected void HandleAddToCart()
+            await CartService.SaveCartToStorageAsync();
+        }
+    }
+    protected async void DecreaseQty() 
+    {
+        if (Quantity >= 1)
+        {
+            CartService.UpdateQuantity(CurrentPrice!.Id, -1);
+
+            Quantity = getCartItemQuantity(ShoppingCart, CurrentPrice.Id);
+
+            await CartService.SaveCartToStorageAsync();
+        }
+    }
+
+    protected async void HandleAddToCart()
     {
         if (CurrentProduct == null) return;
+
+        if (CurrentPrice is not null)
+        {
+            if(ShoppingCart.Items.Any(p => p.Price!.Id == CurrentPrice.Id))
+            {
+                CartService.UpdateQuantity(CurrentPrice.Id, 1);
+
+                await CartService.SaveCartToStorageAsync();
+
+                return;
+            }
+
+            CartService.AddItem(CurrentPrice, CurrentProduct, CurrentAuthor!);
+
+            Quantity = getCartItemQuantity(ShoppingCart, CurrentPrice.Id);
+
+            await CartService.SaveCartToStorageAsync();
+        }
     }
-        
+
     protected void ViewAllAuthorBooks()
     {
         if (CurrentAuthor is not null)

MidrandBookshop/MidrandBookshop.csproj

@@ -18,13 +18,13 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="LiteCharms.Features" Version="1.98.0" />
+    <PackageReference Include="LiteCharms.Features" Version="1.101.0" />
   </ItemGroup>
 
   <!-- UI -->
   <ItemGroup>
     <PackageReference Include="ANM.Blazored.Toast" Version="0.1.1" />
-    <PackageReference Include="LiteCharms.Features.MidrandBooks" Version="1.98.0" />
+    <PackageReference Include="LiteCharms.Features.MidrandBooks" Version="1.101.0" />
     
     <!-- Global Usings -->
     <Using Include="Blazored.Toast.Services" />
@@ -51,6 +51,10 @@
   <!-- Shared Global Usings -->
   <ItemGroup>
     <Using Include="Blazored.Toast" />
+    <Using Include="Microsoft.AspNetCore.Components.Authorization" />
+    <Using Include="Microsoft.AspNetCore.Components.Routing" />
+    <Using Include="Microsoft.AspNetCore.Components.Web" />
+    <Using Include="Microsoft.AspNetCore.WebUtilities" />
     <Using Include="Microsoft.AspNetCore.Components" />
   </ItemGroup>
 

MidrandBookshop/Program.cs

@@ -3,6 +3,7 @@ using LiteCharms.Features.Mediator;
 using LiteCharms.Features.MidrandBooks.Extensions;
 using Microsoft.AspNetCore.HttpOverrides;
 using MidrandBookshop.Components;
+using MidrandBookshop.Services.ShoppingCart;
 using static LiteCharms.Features.Extensions.Quartz;
 
 var builder = WebApplication.CreateBuilder(args);
@@ -26,6 +27,7 @@ builder.Services.AddEmailServiceBus();
 
 builder.Services.AddHttpClient();
 builder.Services.AddShopServices();
+builder.Services.AddScoped<CartService>();
 builder.Services.AddHashServices(builder.Configuration);
 builder.Services.AddMidrandShopDatabase(builder.Configuration);
 

MidrandBookshop/Services/ShoppingCart/CartService.cs

@@ -0,0 +1,150 @@
+using LiteCharms.Features.Browser;
+using LiteCharms.Features.Hasher;
+using LiteCharms.Features.MidrandBooks.Authors.Models;
+using LiteCharms.Features.MidrandBooks.Products.Models;
+using MidrandBookshop.Services.ShoppingCart.Models;
+
+namespace MidrandBookshop.Services.ShoppingCart;
+
+public sealed class CartService(LocalStorageService localStorage)
+{
+    private readonly string CartStorageKey = HashService.ToMd5Hash(nameof(Cart)).Value;
+
+    public Cart ShoppingCart { get; private set; } = new();
+
+    public event Action? OnCartChanged;
+
+    public Cart GetCart() => ShoppingCart;
+
+    public void NotifyStateChanged() => OnCartChanged?.Invoke();
+
+    public async Task LoadCartFromStorageAsync()
+    {
+        var loadResult = await localStorage.GetAsync<Cart>(CartStorageKey);
+
+        if (loadResult.IsFailed) await localStorage.SaveAsync(CartStorageKey, ShoppingCart);
+
+        if (loadResult.IsSuccess) ShoppingCart = loadResult.Value;
+
+        NotifyStateChanged();
+    }
+
+    public async Task SaveCartToStorageAsync() => await localStorage.SaveAsync(CartStorageKey, ShoppingCart);
+
+    public void AddItem(ProductPrice productPrice, Product product, Author author)
+    {
+        var itemExists = false;
+
+        for (var i = 0; i < ShoppingCart.Items.Count; i++)
+        {
+            if (ShoppingCart.Items[i].Price!.Id == productPrice.Id)
+            {
+                ShoppingCart.Items[i].Quantity++;
+                ShoppingCart.Items[i].Amount += productPrice.Amount;
+
+                itemExists = true;
+
+                break;
+            }
+        }
+
+        if (!itemExists)
+            ShoppingCart.Items.Add(new CartItem
+            {
+                Product = product,
+                Author = author,
+                Price = productPrice,
+                Amount = productPrice.Amount,
+                Quantity = 1,
+            });
+
+        CalculateTotalPrice();
+        NotifyStateChanged();
+    }
+
+    public void UpdateQuantity(long productPriceId, int delta)
+    {
+        for (var i = 0; i < ShoppingCart.Items.Count; i++)
+        {
+            if (ShoppingCart.Items[i].Price!.Id == productPriceId)
+            {
+                var oldQuantity = ShoppingCart.Items[i].Quantity;
+                var pricePerUnit = ShoppingCart.Items[i].Price!.Amount;
+
+                ShoppingCart.Items[i].Quantity += delta;
+                ShoppingCart.Items[i].Amount = pricePerUnit * ShoppingCart.Items[i].Quantity;
+                break;
+            }
+        }
+
+        CalculateTotalPrice();
+        NotifyStateChanged();
+    }
+
+    public void RemoveOneItem(long productPriceId)
+    {
+        for (var i = 0; i < ShoppingCart.Items.Count; i++)
+        {
+            if (ShoppingCart.Items[i].Price!.Id == productPriceId)
+            {
+                if (ShoppingCart.Items[i].Quantity <= 1)
+                {
+                    ShoppingCart.Items.Remove(ShoppingCart.Items[i]);
+
+                    break;
+                }
+                else
+                {
+                    ShoppingCart.Items[i].Quantity--;
+                    ShoppingCart.Items[i].Amount -= ShoppingCart.Items[i].Price!.Amount;
+                }
+
+                break;
+            }
+        }
+
+        CalculateTotalPrice();
+        NotifyStateChanged();
+    }
+
+    public void RemoveAllSameItem(long productPriceId)
+    {
+        if (ShoppingCart.Items.Count == 0) return;
+
+        var item = ShoppingCart.Items.FirstOrDefault(i => i.Price?.Id == productPriceId);
+
+        if (item is not null) ShoppingCart.Items.Remove(item);
+
+        CalculateTotalPrice();
+        NotifyStateChanged();
+    }
+
+    public void Clear()
+    {
+        if(ShoppingCart.CustomerId is not null || ShoppingCart.OrderId is not null)
+        {
+            ShoppingCart.TotalPrice = 0;
+            ShoppingCart.TotalVat = 0;
+            ShoppingCart.Items.Clear();
+
+            return;
+        }
+
+        ShoppingCart = new Cart();
+
+        NotifyStateChanged();
+    }
+
+    public decimal CalculateTotalPrice()
+    {
+        if (ShoppingCart.Items.Count == 0) return 0;
+
+        var gross = ShoppingCart.Items.Sum(i => i.Amount);
+
+        if (!ShoppingCart.IsVatInclusive) ShoppingCart.TotalVat = gross * ShoppingCart.VatRate;
+
+        ShoppingCart.TotalPrice = gross + ShoppingCart.TotalVat;
+
+        return ShoppingCart.TotalPrice;
+    }
+}

MidrandBookshop/Services/ShoppingCart/Models/Cart.cs

@@ -0,0 +1,18 @@
+namespace MidrandBookshop.Services.ShoppingCart.Models;
+
+public sealed class Cart
+{
+    public long? CustomerId { get; set; }
+
+    public long? OrderId { get; set; }
+
+    public decimal TotalPrice { get; set; }
+
+    public decimal TotalVat { get; set; }
+
+    public decimal VatRate { get; set; } = 0.15m;
+
+    public bool IsVatInclusive { get; set; } = true;
+
+    public IList<CartItem> Items { get; set; } = [];
+}

MidrandBookshop/Services/ShoppingCart/Models/CartItem.cs

@@ -0,0 +1,17 @@
+using LiteCharms.Features.MidrandBooks.Authors.Models;
+using LiteCharms.Features.MidrandBooks.Products.Models;
+
+namespace MidrandBookshop.Services.ShoppingCart.Models;
+
+public sealed class CartItem
+{
+    public Author? Author { get; set; }
+
+    public Product? Product { get; set; }
+
+    public ProductPrice? Price { get; set; }
+
+    public int Quantity { get; set; }
+
+    public decimal Amount { get; set; }
+}