syntax = "proto3";

package trading;

service TradingService {
  rpc SendOrder(Order) returns (OrderAck);
  rpc StreamMarketData(MarketRequest) returns (stream MarketData);
}

enum Side {
  SIDE_UNSPECIFIED = 0;
  BUY = 1;
  SELL = 2;
}

message Order {
  string symbol = 1;
  int32 quantity = 2;
  double price = 3;
  Side side = 4; // "buy" or "sell"
}

message OrderAck {
  bool success = 1;
  string message = 2;
}

message MarketRequest {
  string symbol = 1;
}

message MarketData {
  string symbol = 1;
  double price = 2;
  int64 timestamp = 3;
}