/// <summary>
/// Places a new <c>Order</c>.
/// </summary>
/// <param name="options">Options for creating a new <c>StoreContext</c>.</param>
/// <param name="orderId">The ID of a previously saved <c>Order</c>.</param>
/// <param name="maxQuantity">The maximum amount of <c>Product</c> that may be present in an <c>Order</c>.</param>
/// <returns>A <c>PlaceOrderResult</c> detailing whether the operation completed successfully.</returns>
public static PlaceOrderResult PlaceOrder(this DbContextOptions <StoreContext> options, Guid?orderId, int maxQuantity)
{
if (orderId == null)
{
throw new NullReferenceException("Missing orderId");
}
using (var db = new StoreContext(options))
{
var order = db.GetOrderById(orderId);
if (order == null)
{
return(PlaceOrderResult.OrderNotFound);
}
if (order.OrderLineItems.Count() == 0)
{
return(PlaceOrderResult.NoLineItems);
}
var totalOrderPrice = 0.0;
var totalItemQuantity = 0;
var location = order.Location;
using (var transaction = db.Database.BeginTransaction())
{
foreach (var lineItem in order.OrderLineItems)
{
var locationInventory = db.FindInventoryId(location, lineItem.Product);
if (locationInventory == null)
{
return(PlaceOrderResult.OutOfStock);
}
var newStockQuantity = locationInventory.TryAdjustQuantity(-lineItem.Quantity);
if (newStockQuantity == null)
{
transaction.Rollback();
return(PlaceOrderResult.OutOfStock);
}
var lineItemPrice = lineItem.Quantity * lineItem.Product.Price;
totalOrderPrice += lineItemPrice;
lineItem.AmountCharged = lineItemPrice;
totalItemQuantity += lineItem.Quantity;
db.SaveChanges();
}
if (totalItemQuantity > maxQuantity)
{
return(PlaceOrderResult.HighQuantityRejection);
}
order.AmountPaid = totalOrderPrice;
order.TimeSubmitted = DateTime.Now;
db.SaveChanges();
transaction.Commit();
}
return(PlaceOrderResult.Ok);
}
}