syntax = "proto3";

package mpc.router.v1;

option go_package = "github.com/rwadurian/mpc-system/api/grpc/router/v1;router";

// MessageRouter service handles MPC message routing
service MessageRouter {
  // RouteMessage routes a message from one party to others
  rpc RouteMessage(RouteMessageRequest) returns (RouteMessageResponse);

  // SubscribeMessages subscribes to messages for a party (streaming)
  rpc SubscribeMessages(SubscribeMessagesRequest) returns (stream MPCMessage);

  // GetPendingMessages retrieves pending messages (polling alternative)
  rpc GetPendingMessages(GetPendingMessagesRequest) returns (GetPendingMessagesResponse);
}

// RouteMessageRequest routes an MPC message
message RouteMessageRequest {
  string session_id = 1;
  string from_party = 2;
  repeated string to_parties = 3;        // Empty for broadcast
  int32 round_number = 4;
  string message_type = 5;
  bytes payload = 6;                     // Encrypted MPC message
}

// RouteMessageResponse confirms message routing
message RouteMessageResponse {
  bool success = 1;
  string message_id = 2;
}

// SubscribeMessagesRequest subscribes to messages for a party
message SubscribeMessagesRequest {
  string session_id = 1;
  string party_id = 2;
}

// MPCMessage represents an MPC protocol message
message MPCMessage {
  string message_id = 1;
  string session_id = 2;
  string from_party = 3;
  bool is_broadcast = 4;
  int32 round_number = 5;
  string message_type = 6;
  bytes payload = 7;
  int64 created_at = 8;                  // Unix timestamp milliseconds
}

// GetPendingMessagesRequest retrieves pending messages
message GetPendingMessagesRequest {
  string session_id = 1;
  string party_id = 2;
  int64 after_timestamp = 3;             // Get messages after this timestamp
}

// GetPendingMessagesResponse contains pending messages
message GetPendingMessagesResponse {
  repeated MPCMessage messages = 1;
}