/// <reference types="node" />
import EventEmitter from "eventemitter3";
import { SocketFactoryConfig, SocketFactoryStats, SocketFactoryInterface, ClientInterface, WrappedClientInterface } from "pocket-sockets";
export declare const DEFAULT_PING_INTERVAL = 10000;
/** Msg ID length in bytes. */
export declare const MSG_ID_LENGTH = 4;
export declare const PING_ROUTE = "_ping";
export declare const PONG_ROUTE = "_pong";
/**
 * A single message cannot exceed 67 KiB in total for its payload.
 *
 * 67 KiB allows the sender to send a payload of 64 KiB with plenty
 * of space left for its overhead, and 64 KiB is typically a
 * fitting payload to deal with when reading/storing data.
 *
 * Actual data sent comes with some bytes added overhead.
 */
export declare const MESSAGE_MAX_BYTES: number;
export declare type SendReturn = {
    eventEmitter?: EventEmitter;
    msgId: Buffer;
};
export declare type SentMessage = {
    timestamp: number;
    msgId: Buffer;
    timeout: number;
    stream: boolean;
    timeoutStream: number;
    eventEmitter: EventEmitter;
    replyCounter: number;
    isCleared: boolean;
};
export declare enum ExpectingReply {
    NONE = 0,
    SINGLE = 1,
    MULTIPLE = 2
}
/**
 * Bytes:
 * 0 uint8 header version, must be 0
 * 1-4 uint32le total length of message including version byte above
 * 5 uint8 config byte, used for expectingReply flags
 * 6-9 4 bytes msg ID
 * 10 uint8 length of target value
 * 10 x bytes of target value
 * 10+x data bytes
 */
export declare type Header = {
    version: number;
    target: Buffer;
    msgId: Buffer;
    dataLength: number;
    /**
     * Only bit 0+1 are used to signal expectingReply
     */
    config: number;
};
export declare type OutgoingQueue = {
    chunks: Buffer[];
};
export declare type InMessage = {
    target: Buffer;
    msgId: Buffer;
    data: Buffer;
    /**
     * 0 no reply expected
     * 1 one reply expected
     * 2 multiple replies expected
     */
    expectingReply: number;
};
export declare type IncomingQueue = {
    chunks: Buffer[];
    messages: InMessage[];
};
export declare type RouteEvent = {
    target: string;
    fromMsgId: Buffer;
    data: Buffer;
    expectingReply: number;
};
export declare type ReplyEvent = {
    toMsgId: Buffer;
    fromMsgId: Buffer;
    data: Buffer;
    expectingReply: number;
};
export declare type TimeoutEvent = Record<string, never>;
export declare type ErrorEvent = {
    error: string;
};
export declare type AnyEvent = {
    type: EventType;
    event: ReplyEvent | TimeoutEvent | CloseEvent | ErrorEvent;
};
export declare type CloseEvent = {
    hadError: boolean;
};
export declare type PongEvent = {
    roundTripTime: number;
};
export declare enum EventType {
    /**
     * Data event only emitted on main event emitter on new
     * incoming messages (which are not reply messages).
     */
    ROUTE = "route",
    /**
     * Data event only emitted on message specific event emitters as
     * replies on sent message.
     */
    REPLY = "reply",
    /**
     * Socket error event emitted on all event emitters including main.
     */
    ERROR = "error",
    /**
     * Socket close event emitted on all event emitters including main.
     */
    CLOSE = "close",
    /**
     * Message reply timeout event emitted on message specific event emitters
     * who are awaiting replies on sent message.
     */
    TIMEOUT = "timeout",
    /**
     * Any event emitted on message specific event emitters for the events:
     * REPLY,
     * ERROR,
     * CLOSE,
     * TIMEOUT
     * This is useful for having a catch-all event handler when waiting on replies.
     */
    ANY = "any",
    /**
     * Event emitted only on main event emitter when a ping has received its pong message.
     * It provides the round-time in milliseconds as data.
     */
    PONG = "ping"
}
export declare type HandshakeResult = {
    longtermPk: Buffer;
    peerLongtermPk: Buffer;
    clientToServerKey: Buffer;
    clientNonce: Buffer;
    serverToClientKey: Buffer;
    serverNonce: Buffer;
    clockDiff: number;
    peerData: Buffer;
};
export declare type KeyPair = {
    publicKey: Buffer;
    secretKey: Buffer;
};
export declare type ClientValidatorFunctionInterface = (clientLongTermPk: Buffer) => boolean;
export declare type PeerDataGeneratorFunctionInterface = (isServer: boolean) => Buffer;
export declare type HandshakeFactoryConfig = {
    socketFactoryConfig: SocketFactoryConfig;
    socketFactoryStats?: SocketFactoryStats;
    /** The keypair to use in the cryptographic handshake. */
    keyPair: KeyPair;
    /** The discriminator which must match the peer's discriminator when handshaking. */
    discriminator: Buffer;
    /**
     * Arbitrary data sent to the other peer.
     * If a function then call it to get the peerData buffer.
     */
    peerData?: Buffer | PeerDataGeneratorFunctionInterface;
    /** If connecting as client the public key of the server must be set. */
    serverPublicKey?: Buffer;
    /**
     * If opening a server we can discriminate on peers public keys in the handshake.
     * If set as array the client public key must be in the array to accept to client.
     * If set as function the function must return boolean true to accept the client.
     * If not set (undefined) then all clients are accepted.
     * */
    allowedClients?: Buffer[] | ClientValidatorFunctionInterface;
    /** If set, the maximum no of connections each cryptographically handshaked publicKey is allowed. */
    maxConnectionsPerClient?: number;
    /**
     * If set, the maximum no of connections per connected client pair.
     * This is useful for peer-to-peer clients who both have client and server sockets
     * and we only desire a single connection between the client pair.
     * When setting maxConnectionsPerClient=1 there can still be two connections open,
     * but when setting maxConnectionsPerClientPair=1 we can cap the no of connectio to one per pair of clients.
     */
    maxConnectionsPerClientPair?: number;
    /**
     * If set > 0 then the Messaging instances will be configured to
     * frequently send pings to detect silent disconnects of the underlying socket.
     * Unit is milliseconds.
     */
    pingInterval?: number;
};
export declare const EVENT_HANDSHAKEFACTORY_HANDSHAKE = "HANDSHAKE";
export declare const EVENT_HANDSHAKEFACTORY_HANDSHAKE_ERROR = "HANDSHAKE_ERROR";
export declare const EVENT_HANDSHAKEFACTORY_PUBLICKEY_OVERFLOW = "PUBLICKEY_OVERFLOW";
export declare type HandshakeFactoryPublicKeyOverflowCallback = (publicKey: Buffer) => void;
/**
 * Event emitted when client is successfully handshaked and setup for encryption.
 * The client returned is the original client socket.
 * The wrappedClient is prepared for being used with encryption but it must be called
 * with await init() before using, if wanting to the encrypted client.
 */
export declare type HandshakeFactoryHandshakeCallback = (isServer: boolean, client: ClientInterface, wrappedClient: WrappedClientInterface, handshakeResult: HandshakeResult) => void;
/**
 * Event emitted when client could not handshake.
 * An error occurred in the handshake process (the Error provided).
 */
export declare type HandshakeFactoryHandshakeErrorCallback = (error: Error) => void;
export interface HandshakeFactoryInterface extends SocketFactoryInterface {
    getHandshakeFactoryConfig(): HandshakeFactoryConfig;
    /** A successful handshake. */
    onHandshake(callback: HandshakeFactoryHandshakeCallback): void;
    /** An error in the handshake process, could be wrong key, wrong protocol format, etc. Unrecoverable. */
    onHandshakeError(callback: HandshakeFactoryHandshakeErrorCallback): void;
    /**
     * Too many connections detected for specific connected peer public key.
     * The connection is closed and this event triggered.
     */
    onPublicKeyOverflow(callback: HandshakeFactoryPublicKeyOverflowCallback): void;
}