/
ShoppingCart.cs
197 lines (153 loc) · 5.5 KB
/
ShoppingCart.cs
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using Carts.Pricing;
using Carts.ShoppingCarts.AddingProduct;
using Carts.ShoppingCarts.CancelingCart;
using Carts.ShoppingCarts.ConfirmingCart;
using Carts.ShoppingCarts.OpeningCart;
using Carts.ShoppingCarts.Products;
using Carts.ShoppingCarts.RemovingProduct;
using Core.Aggregates;
using Core.Extensions;
namespace Carts.ShoppingCarts;
public class ShoppingCart: Aggregate
{
public Guid ClientId { get; private set; }
public ShoppingCartStatus Status { get; private set; }
public IList<PricedProductItem> ProductItems { get; private set; } = default!;
public decimal TotalPrice => ProductItems.Sum(pi => pi.TotalPrice);
public static ShoppingCart Open(
Guid cartId,
Guid clientId)
{
return new ShoppingCart(cartId, clientId);
}
private ShoppingCart(){}
public override void Evolve(object @event)
{
switch (@event)
{
case ShoppingCartOpened cartOpened:
Apply(cartOpened);
return;
case ProductAdded cartOpened:
Apply(cartOpened);
return;
case ProductRemoved cartOpened:
Apply(cartOpened);
return;
case ShoppingCartConfirmed cartOpened:
Apply(cartOpened);
return;
case ShoppingCartCanceled cartCanceled:
Apply(cartCanceled);
return;
}
}
private ShoppingCart(
Guid id,
Guid clientId)
{
var @event = ShoppingCartOpened.Create(
id,
clientId,
ShoppingCartStatus.Pending
);
Enqueue(@event);
Apply(@event);
}
private void Apply(ShoppingCartOpened @event)
{
Version = 0;
Id = @event.CartId;
ClientId = @event.ClientId;
ProductItems = new List<PricedProductItem>();
Status = @event.ShoppingCartStatus;
}
public void AddProduct(
IProductPriceCalculator productPriceCalculator,
ProductItem productItem)
{
if(Status != ShoppingCartStatus.Pending)
throw new InvalidOperationException($"Adding product for the cart in '{Status}' status is not allowed.");
var pricedProductItem = productPriceCalculator.Calculate(productItem).Single();
var @event = ProductAdded.Create(Id, pricedProductItem);
Enqueue(@event);
Apply(@event);
}
private void Apply(ProductAdded @event)
{
Version++;
var newProductItem = @event.ProductItem;
var existingProductItem = FindProductItemMatchingWith(newProductItem);
if (existingProductItem is null)
{
ProductItems.Add(newProductItem);
return;
}
ProductItems.Replace(
existingProductItem,
existingProductItem.MergeWith(newProductItem)
);
}
public void RemoveProduct(
PricedProductItem productItemToBeRemoved)
{
if(Status != ShoppingCartStatus.Pending)
throw new InvalidOperationException($"Removing product from the cart in '{Status}' status is not allowed.");
var existingProductItem = FindProductItemMatchingWith(productItemToBeRemoved);
if (existingProductItem is null)
throw new InvalidOperationException($"Product with id `{productItemToBeRemoved.ProductId}` and price '{productItemToBeRemoved.UnitPrice}' was not found in cart.");
if(!existingProductItem.HasEnough(productItemToBeRemoved.Quantity))
throw new InvalidOperationException($"Cannot remove {productItemToBeRemoved.Quantity} items of Product with id `{productItemToBeRemoved.ProductId}` as there are only ${existingProductItem.Quantity} items in card");
var @event = ProductRemoved.Create(Id, productItemToBeRemoved);
Enqueue(@event);
Apply(@event);
}
private void Apply(ProductRemoved @event)
{
Version++;
var productItemToBeRemoved = @event.ProductItem;
var existingProductItem = FindProductItemMatchingWith(@event.ProductItem);
if (existingProductItem == null)
return;
if (existingProductItem.HasTheSameQuantity(productItemToBeRemoved))
{
ProductItems.Remove(existingProductItem);
return;
}
ProductItems.Replace(
existingProductItem,
existingProductItem.Substract(productItemToBeRemoved)
);
}
public void Confirm()
{
if(Status != ShoppingCartStatus.Pending)
throw new InvalidOperationException($"Confirming cart in '{Status}' status is not allowed.");
var @event = ShoppingCartConfirmed.Create(Id, DateTime.UtcNow);
Enqueue(@event);
Apply(@event);
}
private void Apply(ShoppingCartConfirmed @event)
{
Version++;
Status = ShoppingCartStatus.Confirmed;
}
public void Cancel()
{
if(Status != ShoppingCartStatus.Pending)
throw new InvalidOperationException($"Confirming cart in '{Status}' status is not allowed.");
var @event = ShoppingCartCanceled.Create(Id, DateTime.UtcNow);
Enqueue(@event);
Apply(@event);
}
private void Apply(ShoppingCartCanceled @event)
{
Version++;
Status = ShoppingCartStatus.Canceled;
}
private PricedProductItem? FindProductItemMatchingWith(PricedProductItem productItem)
{
return ProductItems
.SingleOrDefault(pi => pi.MatchesProductAndPrice(productItem));
}
}