syntax = "proto3";

package coordinator;

option go_package = "server/api";

service Coordinator {
  // Registers a node. User name is auto-generated by server initially.
  rpc RegisterNode(RegisterRequest) returns (RegisterResponse);

  // Updates the display name of the node (allows user to change it later).
  rpc UpdateNodeName(UpdateNameRequest) returns (UpdateNameResponse);

  // Heartbeat to keep the node marked as online in Redis.
  rpc Heartbeat(HeartbeatRequest) returns (HeartbeatResponse);

  // Requests the connection details for a target peer.
  rpc GetPeerEndpoint(PeerRequest) returns (PeerResponse);

  // Notifies the coordinator that a node wants to establish a connection.
  rpc SignalConnection(SignalRequest) returns (SignalResponse);
}

message RegisterRequest {
  string network_key = 1;    // The shared secret for this overlay network
  string node_id = 2;        // Unique hardware/installation ID
  string public_key = 3;     // WireGuard public key for E2EE
  string local_ip = 4;       // Local network IP
}

message RegisterResponse {
  string virtual_ip = 1;     // Assigned IP in the overlay network
  string session_token = 2;  // JWT for subsequent authenticated requests
  string coordinator_address = 3;
  string assigned_name = 4;    // The auto-generated name (e.g., "Node-8a2f")
}

message UpdateNameRequest {
  string node_id = 1;
  string new_name = 2;
  string session_token = 3;
}

message UpdateNameResponse {
  bool success = 1;
  string current_name = 2;
}

message HeartbeatRequest {
  string node_id = 1;
  string session_token = 2;
  string public_endpoint = 3;
}

message HeartbeatResponse {
  bool success = 1;
}

message PeerRequest {
  string target_node_id = 1;
  string session_token = 2;
}

message PeerResponse {
  string peer_public_key = 1;
  string public_endpoint = 2;
  string nat_type = 3;
}

message SignalRequest {
  string source_node_id = 1;
  string target_node_id = 2;
  string session_token = 3;
}

message SignalResponse {
  bool acknowledged = 1;
}