Files
silver-octo-spoon/wolverine/a-frame-architecture/FinancialApi.Application/TransferFundsHandler.cs
T

63 lines
2.1 KiB
C#

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using FinancialApi.Domain;
using Wolverine.Persistence;
namespace FinancialApi.Application;
public interface IAccountQuery
{
Task<Account?> FindByIdAsync(int id);
}
public record TransferFundsCommand(int SourceAccountId, int DestinationAccountId, decimal Amount);
public record FundsTransferredEvent(int SourceAccountId, int DestinationAccountId, decimal Amount);
public record TransferPair(Account Source, Account Destination, DateTimeOffset TimeStamp);
public static class TransferFundsHandler
{
public static async Task<TransferPair?> LoadAsync(TransferFundsCommand cmd, IAccountQuery query,
TimeProvider timeProvider)
{
var source = await query.FindByIdAsync(cmd.SourceAccountId);
var dest = await query.FindByIdAsync(cmd.DestinationAccountId);
if (source == null || dest == null) return null;
return new TransferPair(source, dest, timeProvider.GetUtcNow());
}
public static (
IStorageAction<Account> SourceWrite,
IStorageAction<Account> DestWrite,
IStorageAction<JournalEntry> JournalWrite,
FundsTransferredEvent Event
) Handle(TransferFundsCommand cmd, TransferPair pair)
{
var updatedSource = pair.Source.Debit(cmd.Amount);
var updatedDest = pair.Destination.Credit(cmd.Amount);
var lines = new List<JournalLine>
{
new(pair.Source.Id, cmd.Amount, EntryType.Debit),
new(pair.Destination.Id, cmd.Amount, EntryType.Credit)
};
var journalEntry =
BalancedJournal.Create(Guid.NewGuid(),
$"Transfer: {cmd.Amount} from {cmd.SourceAccountId} to {cmd.DestinationAccountId}",
pair.TimeStamp, lines);
var @event = new FundsTransferredEvent(cmd.SourceAccountId, cmd.DestinationAccountId, cmd.Amount);
return (
Storage.Update(updatedSource),
Storage.Update(updatedDest),
Storage.Insert(journalEntry.Entry),
@event
);
}
}