syntax = "proto3";

package uns;

service UnsGateway {
  rpc Publish (PublishRequest) returns (Ack);
  rpc Subscribe (SubscribeRequest) returns (stream MqttMessage);
  rpc RegisterApiGet (RegisterApiGetRequest) returns (Ack);
  rpc UnregisterApiGet (UnregisterApiGetRequest) returns (Ack);
  rpc ApiEventStream (stream ApiEventResponse) returns (stream ApiEvent);
  rpc Ready (ReadyRequest) returns (Ack);
}

message PublishRequest {
  string topic = 1;
  string attribute = 2;
  string description = 3;
  repeated string tags = 4;
  bool attribute_needs_persistence = 5;
  oneof content {
    Data data = 6;
    Table table = 7;
  }
  // Deprecated: producer-side delta calculation loses previous-value state
  // across service restarts. Publish raw cumulative counter values and request
  // delta/rate from Datahub history APIs.
  bool value_is_cumulative = 8;
}

message Data {
  string time = 1;
  double value_number = 2;
  string value_string = 3;
  string uom = 4;
  string data_group = 5;
  string foreign_event_key = 6;
}

message TableValue {
  string name = 1;
  string type = 2;          // QuestDB column type (e.g., int, double, geohash(5c))
  string uom = 3;           // Optional unit of measure
  double value_number = 4;
  string value_string = 5;
}

message Table {
  string time = 1;
  repeated TableValue columns = 2;
  string data_group = 3;
}

message SubscribeRequest {
  repeated string topics = 1;
}

message MqttMessage {
  string topic = 1;
  string payload = 2; // UNS packet JSON
}

message Ack {
  bool ok = 1;
  string error = 2;
}

message ReadyRequest {
  int32 timeout_ms = 1;              // default 15000
  bool wait_output = 2;              // wait for publisher active (output)
  bool wait_input = 3;               // wait for subscriber active (input)
  bool wait_api = 4;                 // wait for API server (optional)
}

message ApiQueryParam {
  string name = 1;
  string type = 2; // string | number | boolean
  bool required = 3;
  string description = 4;
}

message RegisterApiGetRequest {
  string topic = 1;
  string attribute = 2;
  string api_description = 3;
  repeated string tags = 4;
  repeated ApiQueryParam query_params = 5;
}

message UnregisterApiGetRequest {
  string topic = 1;
  string attribute = 2;
}

message ApiEvent {
  string id = 1;
  string method = 2; // GET only for now
  string path = 3;   // /{topic}{attribute}
  map<string, string> query = 4;
  string bearer = 5; // access token (optional)
}

message ApiEventResponse {
  string id = 1;          // correlation
  int32 status = 2;       // HTTP status
  string body = 3;        // response body as string (JSON string if needed)
  map<string, string> headers = 4; // optional extra headers
}