private static string ValidateID(CreateCustomer command, Dictionary <string, Customer> existingCustomers, Source source)
{
//a use case is that when customers are created through the browser an ID is assigned to them
if (source == Source.Web)
{
if (!string.IsNullOrEmpty(command.id))
{
command.LogError(nameof(command.id), "ID can't be set");
}
//simplistic way to create new id
command.id = Guid.NewGuid().ToString().Replace("-", "").Substring(0, 15);
}
else //while when they are created through other means ID is provided to them
{
//often we need to proceed with processing and we can create temporary values to proceed with furter validations
var id = (command.id ?? "TEMP-ID").ToUpperInvariant();
if (string.IsNullOrEmpty(command.id))
{
command.LogError(nameof(command.id), "ID must be provided");
}
else if (existingCustomers.ContainsKey(id))
{
command.LogError(nameof(command.id), "ID already taken");
}
command.id = id;
}
return(command.id);
}
