godave

type Callbacks interface {
	// SendMLSKeyPackage sends a MLS Key Package to the voice gateway.
	SendMLSKeyPackage(mlsKeyPackage []byte) error
	// SendMLSCommitWelcome sends a MLS Commit Welcome to the voice gateway.
	SendMLSCommitWelcome(mlsCommitWelcome []byte) error
	// SendReadyForTransition notifies the voice gateway that the client is ready for the transition.
	SendReadyForTransition(transitionID uint16) error
	// SendInvalidCommitWelcome notifies the voice gateway that the commit welcome is invalid.
	SendInvalidCommitWelcome(transitionID uint16) error
}

type ChannelID uint64

type Codec int

type Session interface {
	// MaxSupportedProtocolVersion returns the maximum supported DAVE version for this session.
	MaxSupportedProtocolVersion() int

	// Ready reports whether the session has an active E2EE epoch. Returns false
	// during the MLS handshake window (e.g. right after joining or moving voice
	// channels); returns true once encryption is established or when the session
	// is the sole member of the channel. AudioSenders should hold frames while
	// Ready returns false instead of sending them unencrypted. Encrypt still
	// forwards frames unmodified (passthrough) rather than erroring, so callers
	// that don't gate on Ready continue to work. Sessions that never establish
	// E2EE (such as the noop session) always return true.
	Ready() bool

	// Close releases the session's resources and stops any background work.
	// It is called when the voice connection is discarded (channel move,
	// disconnect). The error return satisfies io.Closer; implementations with
	// nothing to clean up should return nil. Safe to call multiple times.
	Close() error

	// SetChannelID sets the channel ID for this session.
	SetChannelID(channelID ChannelID)

	// AssignSsrcToCodec maps a given SSRC to a specific Codec.
	AssignSsrcToCodec(ssrc uint32, codec Codec)

	// MaxEncryptedFrameSize returns the maximum size of an encrypted OPUS frame given the frame size.
	MaxEncryptedFrameSize(frameSize int) int

	// Encrypt encrypts an OPUS frame.
	Encrypt(ssrc uint32, frame []byte, encryptedFrame []byte) (int, error)

	// MaxDecryptedFrameSize returns the maximum size of a decrypted OPUS frame given the frame size.
	MaxDecryptedFrameSize(userID UserID, frameSize int) int

	// Decrypt decrypts an OPUS frame.
	Decrypt(userID UserID, frame []byte, decryptedFrame []byte) (int, error)

	// AddUser adds a user to the MLS group.
	AddUser(userID UserID)

	// RemoveUser removes a use from the MLS group.
	RemoveUser(userID UserID)

	// OnSelectProtocolAck is to be called when SELECT_PROTOCOL_ACK (4) is received.
	OnSelectProtocolAck(protocolVersion uint16)

	// OnDavePrepareTransition is to be called when DAVE_PROTOCOL_PREPARE_TRANSITION (21) is received.
	OnDavePrepareTransition(transitionID uint16, protocolVersion uint16)

	// OnDaveExecuteTransition is to be called when DAVE_PROTOCOL_EXECUTE_TRANSITION (22) is received.
	OnDaveExecuteTransition(protocolVersion uint16)

	// OnDavePrepareEpoch is to be called when DAVE_PROTOCOL_PREPARE_EPOCH (24) is received.
	OnDavePrepareEpoch(epoch int, protocolVersion uint16)

	// OnDaveMLSExternalSenderPackage is to be called when DAVE_MLS_EXTERNAL_SENDER_PACKAGE (25) is received.
	OnDaveMLSExternalSenderPackage(externalSenderPackage []byte)

	// OnDaveMLSProposals is to be called when DAVE_MLS_PROPOSALS (27) is received.
	OnDaveMLSProposals(proposals []byte)

	// OnDaveMLSPrepareCommitTransition is to be called when DAVE_MLS_ANNOUNCE_COMMIT_TRANSITION (29) is received.
	OnDaveMLSPrepareCommitTransition(transitionID uint16, commitMessage []byte)

	// OnDaveMLSWelcome is to be called when DAVE_MLS_WELCOME (30) is received.
	OnDaveMLSWelcome(transitionID uint16, welcomeMessage []byte)
}

type SessionCreateFunc func(logger *slog.Logger, userID UserID, callbacks Callbacks) Session

type UserID string