syntax = "proto3";

package gossip.v1;

option go_package = "proto/gossip/v1;gossipv1";

message GossipMessage {
  oneof message {
    Heartbeat heartbeat = 1;
    SignedObservation signed_observation = 2;
  }
}

// P2P gossip heartbeats for network introspection purposes.
message Heartbeat {
  // The node's arbitrarily chosen, untrusted nodeName.
  string node_name = 1;
  // A monotonic counter that resets to zero on startup.
  int64 counter = 2;
  // UNIX wall time.
  int64 timestamp = 3;  // TODO: use this

  // Consensus heights on connected networks
  message Network {// TODO: use this
    uint32 id = 1;
    int64 height = 2;
  }
  repeated Network networks = 4;

  // Human-readable representation of the current bridge node release.
  string version = 5;

  // TODO: include statement of gk public key?
}

// A SignedObservation is a signed statement by a given guardian node
// that they observed a given event.
//
// Observations always result from an external, final event being observed.
// Examples are lockups in finalized blocks on a block or guardian set changes
// injected by node operators after reaching off-chain consensus.
//
// The event is uniquely identified by its hashed (tx_hash, nonce, values...) tuple.
//
// Other nodes will verify the signature. Once any node has observed a quorum of
// guardians submitting valid signatures for a given hash, they can be assembled into a VAA.
//
// Messages without valid signature are dropped unceremoniously.
message SignedObservation {
  // Guardian pubkey as truncated eth address.
  bytes addr = 1;
  // The lockup's deterministic, unique hash.
  bytes hash = 2;
  // ECSDA signature of the hash using the node's guardian key.
  bytes signature = 3;
}