using Big.Domain;

namespace Big.Application;

/// <summary>A zorgprofessional's request to register, in domain language. No ZGW concepts.</summary>
public sealed record SubmitRegistrationCommand(string Bsn);

/// <summary>
/// The submit use case: create the <see cref="Registration"/> aggregate (INGEDIEND), persist it,
/// then start the registratie workflow process and record its instance id. It returns as soon as
/// the process is started — opening the zaak happens later, off the request path, in the external-task
/// worker (ADR-0009). Persisting <em>before</em> starting the process closes the race where the worker
/// acquires the OpenZaakAanmaken job before the aggregate it correlates to exists.
/// </summary>
public sealed class SubmitRegistration(IRegistrationStore store, IWorkflowClient workflow)
{
    public async Task<RegistrationId> HandleAsync(SubmitRegistrationCommand command, CancellationToken ct = default)
    {
        ArgumentNullException.ThrowIfNull(command);

        var registration = Registration.Submit(command.Bsn);

        // Persist before starting the process so the worker can correlate the OpenZaakAanmaken
        // job back to an aggregate that already exists (ADR-0009).
        await store.SaveAsync(registration, ct);

        var processInstanceId = await workflow.StartRegistrationProcessAsync(registration.Id, ct);
        registration.RecordProcessStarted(processInstanceId);
        await store.SaveAsync(registration, ct);

        return registration.Id;
    }
}