package pqkem

// CallbackHandler is implemented by the host and invoked by the library. The
// library only reports events; the host owns the reaction. Keeping this an
// interface — rather than touching the transport or keying directly — is what lets
// the KEM code be extracted as a standalone library.
type CallbackHandler interface {
	// OnNewPSKReady fires when a fresh post-quantum PSK has been derived for a peer
	// and must be programmed into the consumer's secure channel. It is invoked at
	// the commit point of each side: the initiator on receiving the answer, the
	// responder on receiving the confirm.
	OnNewPSKReady(remoteID RemoteID, psk PSK) error

	// OnRekeyFailed fires when an exchange fails to converge within the allotted
	// time. The host should tear the peer connection down so it re-establishes, and
	// log a WARN. The library reports the event; it does not dictate the reaction.
	OnRekeyFailed(remoteID RemoteID) error
}