natsdotnet/src/NATS.Server/JetStream/Models/StreamConfig.cs

namespace NATS.Server.JetStream.Models;

public sealed class StreamConfig
{
    public string Name { get; set; } = string.Empty;
    public string Description { get; set; } = string.Empty;
    public List<string> Subjects { get; set; } = [];
    public int MaxMsgs { get; set; }
    public long MaxBytes { get; set; }
    public int MaxMsgsPer { get; set; }
    [System.Text.Json.Serialization.JsonIgnore]
    public int MaxAgeMs { get; set; }

    /// <summary>
    /// MaxAge in nanoseconds for JSON wire compatibility with Go server.
    /// Go reference: StreamConfig.MaxAge is a time.Duration (nanoseconds in JSON).
    /// </summary>
    public long MaxAge
    {
        get => (long)MaxAgeMs * 1_000_000L;
        set => MaxAgeMs = (int)(value / 1_000_000);
    }
    public int MaxMsgSize { get; set; }
    public int MaxConsumers { get; set; }
    public int DuplicateWindowMs { get; set; }
    public bool Sealed { get; set; }
    public bool DenyDelete { get; set; }
    public bool DenyPurge { get; set; }
    public bool AllowDirect { get; set; }
    // Go: StreamConfig.AllowMsgTTL — per-message TTL header support
    public bool AllowMsgTtl { get; set; }
    // Go: StreamConfig.FirstSeq — initial sequence number for the stream
    public ulong FirstSeq { get; set; }
    public RetentionPolicy Retention { get; set; } = RetentionPolicy.Limits;
    public DiscardPolicy Discard { get; set; } = DiscardPolicy.Old;
    public StorageType Storage { get; set; } = StorageType.Memory;
    public int Replicas { get; set; } = 1;
    public string? Mirror { get; set; }
    public string? Source { get; set; }
    public List<StreamSourceConfig> Sources { get; set; } = [];

    // Go: StreamConfig.SubjectTransform — transforms inbound message subjects on store.
    // Source and Dest follow the same token-wildcard rules as NATS subject transforms.
    // Go reference: server/stream.go:352 (SubjectTransform field in StreamConfig)
    public string? SubjectTransformSource { get; set; }
    public string? SubjectTransformDest { get; set; }

    // Go: StreamConfig.RePublish — re-publish stored messages on a separate subject.
    // Source is the filter (empty = match all); Dest is the target subject pattern.
    // Go reference: server/stream.go:356 (RePublish field in StreamConfig)
    public string? RePublishSource { get; set; }
    public string? RePublishDest { get; set; }
    // Go: RePublish.HeadersOnly — republished copy omits message body.
    public bool RePublishHeadersOnly { get; set; }

    // Go: StreamConfig.SubjectDeleteMarkerTTL — duration to retain delete markers.
    // When > 0 and AllowMsgTTL is true, expired messages emit a delete-marker msg.
    // Incompatible with Mirror config.
    // Go reference: server/stream.go:361 (SubjectDeleteMarkerTTL field)
    public int SubjectDeleteMarkerTtlMs { get; set; }

    // Go: StreamConfig.AllowMsgSchedules — enables scheduled publish headers.
    // Incompatible with Mirror and Sources.
    // Go reference: server/stream.go:369 (AllowMsgSchedules field)
    public bool AllowMsgSchedules { get; set; }

    // Go: StreamConfig.AllowMsgCounter — enables CRDT counter semantics on messages.
    // Added in v2.12, requires API level 2.
    // Go reference: server/stream.go:365 (AllowMsgCounter field)
    public bool AllowMsgCounter { get; set; }

    // Go: StreamConfig.AllowAtomicPublish — enables atomic batch publishing.
    // Added in v2.12, requires API level 2.
    // Go reference: server/stream.go:367 (AllowAtomicPublish field)
    public bool AllowAtomicPublish { get; set; }

    // Go: StreamConfig.PersistMode — async vs sync storage persistence.
    // AsyncPersistMode requires API level 2.
    // Go reference: server/stream.go:375 (PersistMode field)
    public PersistMode PersistMode { get; set; } = PersistMode.Sync;

    // Go: StreamConfig.Metadata — user-supplied and server-managed key/value metadata.
    // The server automatically sets _nats.req.level, _nats.ver, _nats.level.
    // Go reference: server/stream.go:380 (Metadata field)
    public Dictionary<string, string>? Metadata { get; set; }
}

/// <summary>
/// Persistence mode for the stream.
/// Go reference: server/stream.go — AsyncPersistMode constant.
/// </summary>
public enum PersistMode
{
    Sync = 0,
    Async = 1,
}

public enum StorageType
{
    Memory,
    File,
}

public sealed class StreamSourceConfig
{
    public string Name { get; set; } = string.Empty;
    public string? SubjectTransformPrefix { get; set; }
    public string? SourceAccount { get; set; }

    // Go: StreamSource.FilterSubject — only forward messages matching this subject filter.
    public string? FilterSubject { get; set; }

    // Deduplication window in milliseconds for Nats-Msg-Id header-based dedup.
    // Defaults to 0 (disabled). When > 0, duplicate messages with the same Nats-Msg-Id
    // within this window are silently dropped.
    public int DuplicateWindowMs { get; set; }

    // Go: StreamSource.SubjectTransforms — per-source subject transforms.
    // Reference: golang/nats-server/server/stream.go — SubjectTransforms field.
    public List<SubjectTransformConfig> SubjectTransforms { get; set; } = [];
}

// Go: SubjectTransformConfig — source/destination subject transform pair.
// Reference: golang/nats-server/server/stream.go — SubjectTransformConfig struct.
public sealed class SubjectTransformConfig
{
    public string Source { get; set; } = string.Empty;
    public string Destination { get; set; } = string.Empty;
}