namespace EventSubscriber.Application;

/// <summary>
/// Projects inbound NRC notifications into the read projection. Tolerates duplicate and
/// out-of-order deliveries (CLAUDE.md §8.6): the notification log dedups, and the projection
/// upsert is idempotent on the register id. Rebuilds the projection by replaying the log.
/// </summary>
public sealed class NotificationProjector(INotificationLog log, IProjectionStore store, IAclClient acl)
{
    /// <summary>Handle one inbound notification. Reacts to a register record being written to
    /// Objecten (S-19b-2, ADR-0030) and ignores everything else.</summary>
    public async Task HandleAsync(Notification notification, CancellationToken ct = default)
    {
        ArgumentNullException.ThrowIfNull(notification);

        if (!notification.IsRegisterRecordWritten)
            return;

        // S-19b-2: reading the record back through the ACL and projecting it lands with the
        // implementation; today nothing reaches the store.
        await Task.CompletedTask;
    }

    /// <summary>Rebuild the projection from the durable notification log (PRD §8.4).</summary>
    public async Task RebuildAsync(CancellationToken ct = default)
    {
        await store.ClearAsync(ct);
        foreach (var recorded in await log.AllAsync(ct))
            await store.UpsertAsync(ToEntry(recorded), ct);
    }

    /// <summary>The projection row for an accepted notification. The log already holds exactly the
    /// row's fields, so a rebuild needs no mapping rules and no upstream reads. bsn/naam stay
    /// deferred — the register record is public-safe by construction (ADR-0027).</summary>
    private static RegisterEntry ToEntry(RecordedNotification recorded)
        => new(recorded.RegisterId, recorded.Status, recorded.Reference);
}