namespace EventSubscriber.Application;

/// <summary>
/// The durable log of notifications the subscriber has accepted. It is both the idempotency
/// guard (a replayed notification is recognised and dropped) and the rebuild source: the
/// projection is a derived artefact (PRD §8.4) regenerated by replaying this log, so a rebuild
/// needs no access to OpenZaak (CLAUDE.md §8.1). Implemented in Infrastructure over Postgres.
/// </summary>
public interface INotificationLog
{
    /// <summary>
    /// Record a notification. Returns <c>true</c> if it was newly recorded, <c>false</c> if an
    /// entry with the same key already existed (a duplicate delivery). Must be atomic so that
    /// concurrent duplicate deliveries cannot both observe <c>true</c>.
    /// </summary>
    Task<bool> TryRecordAsync(RecordedNotification notification, CancellationToken ct = default);

    /// <summary>Every accepted notification, for rebuilding the projection.</summary>
    Task<IReadOnlyList<RecordedNotification>> AllAsync(CancellationToken ct = default);
}

/// <summary>A notification that has been accepted, retaining what a rebuild needs to recompute its
/// projection row — including the ZGW <c>resource</c>, which distinguishes a zaak-create (INGEDIEND)
/// from a status-set (INGESCHREVEN) so a rebuild reproduces the right status.</summary>
public sealed record RecordedNotification(string Key, string Actie, string ZaakId, string Resource);

/// <summary>The read projection store. Owned by the projection bounded context (ADR-0008); the
/// subscriber writes to it and the projection-api reads it.</summary>
public interface IProjectionStore
{
    /// <summary>Insert or update the row for <see cref="RegisterEntry.Id"/>. Idempotent on the id.</summary>
    Task UpsertAsync(RegisterEntry entry, CancellationToken ct = default);

    /// <summary>Remove every row — the first step of a rebuild.</summary>
    Task ClearAsync(CancellationToken ct = default);

    /// <summary>Every projection row (used by tests and the rebuild verification).</summary>
    Task<IReadOnlyList<RegisterEntry>> AllAsync(CancellationToken ct = default);
}