public async Task HandleAsync(AddReservationsCommand command, CancellationToken cancellationToken)
{
using (var context = dbContextFactory.CreateDbContext())
{
var productIds = command.Items.Select(i => i.ProductId).ToList();
var productLookup = await GetProductLookupAsync(context, productIds, cancellationToken).ConfigureAwait(false);
requestValidator.ValidateAndThrow(command, productLookup);
// This is for idempotence. We check only the TransactionId because we assume that if one item in a transaction is reserved then so are the others.
var alreadyReserved = await context.ProductReservations.AnyAsync(r => r.TransactionId == command.TransactionId, cancellationToken).ConfigureAwait(false);
if (alreadyReserved)
{
return;
}
foreach (var addedReservation in command.Items)
{
context.ProductReservations.Add(new ProductReservation
{
ProductId = addedReservation.ProductId,
Quantity = addedReservation.Quantity,
TransactionId = command.TransactionId
});
}
await context.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
}
}
public async Task HandleAsync(RemoveStocksCommand command, CancellationToken cancellationToken)
{
using (var context = dbContextFactory.CreateDbContext())
{
var productIds = command.Items.Select(i => i.ProductId).ToList();
var productLookup = await GetProductLookupAsync(context, productIds, cancellationToken).ConfigureAwait(false);
var availableCountLookup = await GetAvailabileCountLookupAsync(context, productIds, cancellationToken).ConfigureAwait(false);
requestValidator.ValidateAndThrow(command, productLookup, availableCountLookup);
// This is for idempotence. We check only the TransactionId because we assume that if stocks for one product in a transaction is removed then so are the others.
var stocksAlreadyRemoved = await context.ProductStockRemovedEvents.AnyAsync(evt => evt.TransactionId == command.TransactionId, cancellationToken).ConfigureAwait(false);
if (stocksAlreadyRemoved)
{
return;
}
foreach (var removedStock in command.Items)
{
context.ProductStockRemovedEvents.Add(new ProductStockRemovedEvent
{
ProductId = removedStock.ProductId,
Quantity = removedStock.Quantity,
TransactionId = command.TransactionId
});
}
await context.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
}
}
public async Task HandleAsync(TakeoutItemsCommand command, CancellationToken cancellationToken)
{
using (var context = dbContextFactory.CreateDbContext())
{
var productIds = command.Items.Select(i => i.ProductId).ToList();
var productLookup = await GetProductLookupAsync(context, productIds, cancellationToken).ConfigureAwait(false);
var reservationLookup = await GetReservationLookupAsync(context, command.TransactionId, cancellationToken).ConfigureAwait(false);
var availableCountLookup = await GetAvailabileCountLookupAsync(context, productIds, cancellationToken).ConfigureAwait(false);
requestValidator.ValidateAndThrow(command, productLookup, reservationLookup, availableCountLookup);
// This is for idempotence. We check only the TransactionId because we assume that if one item in a transaction is taken out then so are the others.
var itemsAlreadyTakenOut = await context.ProductTakenOutEvents.AnyAsync(evt => evt.TransactionId == command.TransactionId, cancellationToken).ConfigureAwait(false);
if (itemsAlreadyTakenOut)
{
return;
}
foreach (var takenOutItem in command.Items)
{
context.ProductTakenOutEvents.Add(new ProductTakenOutEvent
{
ProductId = takenOutItem.ProductId,
Quantity = takenOutItem.Quantity,
TransactionId = command.TransactionId
});
}
await context.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
}
}
public async Task <GetProductByIdResponse> HandleAsync(GetProductByIdRequest request, CancellationToken cancellationToken)
{
using (var context = dbContextFactory.CreateDbContext())
{
var product = await context.Products.FindAsync(new[] { request.ProductId }, cancellationToken).ConfigureAwait(false);
if (product == null)
{
return(null);
}
return(new GetProductByIdResponse
{
Name = product.Name,
ProductId = product.Id,
PointsCost = product.PointsCost
});
}
}
public async Task HandleAsync(CancelReservationsCommand command, CancellationToken cancellationToken)
{
using (var context = dbContextFactory.CreateDbContext())
{
requestValidator.ValidateAndThrow(command);
var productReservations = await context
.ProductReservations
.Where(evt => evt.TransactionId == command.TransactionId)
.ToListAsync(cancellationToken)
.ConfigureAwait(false);
if (productReservations.Count == 0)
{
return;
}
context.ProductReservations.RemoveRange(productReservations);
await context.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
}
}
public async Task HandleAsync(BringbackItemsCommand command, CancellationToken cancellationToken)
{
using (var context = dbContextFactory.CreateDbContext())
{
requestValidator.ValidateAndThrow(command);
// This is for idempotence. We check only the TransactionId because we assume that if one item in a transaction is brought back then so are the others.
var itemsAlreadyBroughtBack = await context.ProductBroughtBackEvents.AnyAsync(evt => evt.TransactionId == command.TransactionId, cancellationToken).ConfigureAwait(false);
if (itemsAlreadyBroughtBack)
{
return;
}
var correspondingTakeoutEvents = await context
.ProductTakenOutEvents
.AsNoTracking()
.Where(evt => evt.TransactionId == command.TransactionId)
.ToListAsync(cancellationToken)
.ConfigureAwait(false);
if (correspondingTakeoutEvents.Count == 0)
{
return;
}
foreach (var takeoutEvent in correspondingTakeoutEvents)
{
context.ProductBroughtBackEvents.Add(new ProductBroughtBackEvent
{
ProductId = takeoutEvent.ProductId,
Quantity = takeoutEvent.Quantity,
TransactionId = command.TransactionId
});
}
await context.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
}
}
public async Task <CreateProductResponse> HandleAsync(CreateProductCommand command, CancellationToken cancellationToken)
{
requestValidator.ValidateAndThrow(command);
using (var context = dbContextFactory.CreateDbContext())
{
var product = new Product
{
Name = command.Name,
PointsCost = command.PointsCost
};
context.Products.Add(product);
await context.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
return(new CreateProductResponse
{
PointsCost = product.PointsCost,
ProductId = product.Id,
Name = product.Name
});
}
}