async Task ICommandHandler <CreateTrip> .HandleAsync(CreateTrip command, CancellationToken cancellationToken)
{
var destinationExists = await _destinationRepository
.DestinationExistsAsync(command.Destination, cancellationToken);
if (!destinationExists)
{
throw new ValidationException($"Destination '{command.Destination}' does not exist.");
}
var user = _userDataProvider.GetUserData();
if (user?.Name is null)
{
throw new ValidationException($"Only known user can create a trip.");
}
var id = Guid.NewGuid();
await _eventPublisher.PublishAsync(
new TripCreated(
id,
command.Destination,
false,
user.Name,
command.CorrelationId,
1),
id,
cancellationToken);
}
async Task ICommandHandler <EditTrip> .HandleAsync(EditTrip command, CancellationToken cancellationToken)
{
var trip = await _entityRepository.GetEntityByIdAsync <Trip>(command.TripId, cancellationToken);
Validate.NotNull(
trip,
$"Trip with ID = {command.TripId} does not exist.");
var user = _userDataProvider.GetUserData();
Validate.UserPermission(
trip.Owner,
user,
$"User {user.Name} does not have permission to edit trip with ID = {trip.Id}");
if (command.Destination != null && command.Destination != trip.Destination)
{
var destinationExists = await _destinationRepository
.DestinationExistsAsync(command.Destination, cancellationToken);
if (!destinationExists)
{
throw new ValidationException($"Destination '{command.Destination}' does not exist.");
}
}
await _eventPublisher.PublishAsync(
new TripUpdated(
command.TripId,
command.Destination,
command.IsCancelled,
command.Owner,
command.CorrelationId,
trip.SequenceNumber + 1),
trip.Id,
cancellationToken);
}