register-referentie/services/domain/Big.Application/WithdrawRegistration.cs

using Big.Domain;

namespace Big.Application;

/// <summary>A zorgprofessional's request to withdraw their own registration ("trek aanvraag in").</summary>
public sealed record WithdrawRegistrationCommand(RegistrationId RegistrationId);

/// <summary>
/// The withdrawal use case (S-11): a zorgprofessional pulls a still-open registration back. It
/// advances the aggregate to INGETROKKEN and persists it. Idempotent — a repeated or redelivered
/// withdrawal of an already-withdrawn registration is a no-op (the aggregate is not persisted again).
/// Cancelling the running Flowable process (so the case leaves the behandelaar's werkbak) is a later
/// sub-slice (S-11b, via a BPMN message event); this sub-slice owns the domain transition only —
/// mirroring how the beoordeling's rejection deferred its zaak propagation.
/// </summary>
public sealed class WithdrawRegistration(IRegistrationStore store)
{
    public async Task HandleAsync(WithdrawRegistrationCommand command, CancellationToken ct = default)
    {
        ArgumentNullException.ThrowIfNull(command);

        var registration = await store.GetAsync(command.RegistrationId, ct)
            ?? throw new InvalidOperationException($"No registration {command.RegistrationId} to withdraw.");

        // A repeated withdrawal is a no-op: don't persist the already-withdrawn aggregate again.
        if (registration.Status == RegistrationStatus.Ingetrokken)
            return;

        registration.Withdraw();
        await store.SaveAsync(registration, ct);
    }
}