syntax = "proto3";

package cmvr.quic_edge.v1;

// Every application message on the edge-opened reliable bidirectional stream
// is carried by this envelope. message_sequence is strictly increasing per
// sender (gaps are allowed) and is independent from the heartbeat sequence used
// for liveness acknowledgement.
message EdgeControlEnvelope {
  uint32 protocol_version = 1;
  uint64 message_sequence = 2;

  oneof payload {
    NodeRegisterRequest node_register_request = 10;
    NodeRegisterResponse node_register_response = 11;
    NodeHeartbeat node_heartbeat = 12;
    NodeHeartbeatAck node_heartbeat_ack = 13;

    MediaSessionOpen media_session_open = 20;
    MediaTrackDescriptor media_track_descriptor = 21;
    MediaSessionClose media_session_close = 22;

    ProtocolError protocol_error = 30;
  }
}

message NetworkInterfaceAddress {
  enum AddressFamily {
    ADDRESS_FAMILY_UNSPECIFIED = 0;
    ADDRESS_FAMILY_IPV4 = 1;
    ADDRESS_FAMILY_IPV6 = 2;
  }

  string interface_name = 1;
  string ip_address = 2;
  AddressFamily family = 3;
  bool loopback = 4;
}

// The existing cmvr-es gRPC server remains the robot-control endpoint. The
// edge advertises its current reachable address through the QUIC control plane.
message GrpcEndpoint {
  string host = 1;
  uint32 port = 2;
  bool tls = 3;
}

message NodeDescriptor {
  string node_id = 1;
  string boot_id = 2;
  string software_version = 3;
  repeated NetworkInterfaceAddress local_interfaces = 4;
  GrpcEndpoint grpc_endpoint = 5;
}

// This must be the first application message sent after each QUIC connection
// is established. A reconnect always creates a new registration session.
message NodeRegisterRequest {
  NodeDescriptor node = 1;
  uint64 sent_at_unix_ms = 2;
}

message NodeRegisterResponse {
  bool accepted = 1;
  string session_id = 2;
  string message = 3;

  // Zero tells the edge to keep its locally configured interval.
  uint32 heartbeat_interval_ms = 4;

  // Derived by the receiver from the authenticated QUIC peer address. It is
  // not copied from a client-supplied local interface.
  string observed_source_ip = 5;
}

// A heartbeat carries a fresh network snapshot so address changes are reported
// without opening a second protocol or connection.
message NodeHeartbeat {
  string node_id = 1;
  string boot_id = 2;
  string session_id = 3;
  uint64 sequence = 4;
  uint64 sent_at_unix_ms = 5;
  string software_version = 6;
  repeated NetworkInterfaceAddress local_interfaces = 7;
  GrpcEndpoint grpc_endpoint = 8;
}

message NodeHeartbeatAck {
  bool accepted = 1;
  uint64 acknowledged_sequence = 2;
  string message = 3;
  uint64 server_time_unix_ms = 4;
  string observed_source_ip = 5;
  string session_id = 6;
}

message MediaSessionOpen {
  string node_id = 1;
  uint64 session_epoch = 2;

  // Binds the media epoch to the accepted node registration on this QUIC
  // connection. Media must not start before this session is assigned.
  string session_id = 3;
}

enum MediaKind {
  MEDIA_KIND_UNSPECIFIED = 0;
  MEDIA_KIND_VIDEO = 1;
  MEDIA_KIND_AUDIO = 2;
}

message MediaTrackDescriptor {
  uint32 track_id = 1;
  MediaKind kind = 2;
  string device_id = 3;
  string codec = 4;
  uint64 codec_generation = 5;

  // The exact MediaSourceHub track and the 32-bit token repeated in every
  // DATAGRAM header. The full generation remains on the reliable stream.
  string source_track_id = 6;
  uint32 codec_generation_token = 7;
  string payload_format = 8;

  // Video fields. They are zero for audio tracks.
  uint32 width = 10;
  uint32 height = 11;
  uint32 frames_per_second = 12;

  // Audio fields. They are zero for video tracks.
  uint32 sample_rate = 20;
  uint32 channels = 21;

  // Decoder initialization bytes, for example AVCC/HVCC or AudioSpecificConfig.
  // Existing cmvr-es sources may leave this empty when configuration NAL units
  // are carried in-band.
  bytes codec_config = 30;
}

message MediaSessionClose {
  string reason = 1;
  string session_id = 2;
  uint64 session_epoch = 3;
}

message ProtocolError {
  uint32 code = 1;
  string message = 2;
  uint64 related_message_sequence = 3;
  bool fatal = 4;
}