/// <reference types="ws" />
import WebSocket from 'isomorphic-ws';
import { MempoolOptions, Transaction } from './interfaces';
export declare enum ConnectionState {
    connected = 0,
    connecting = 1,
    offline = 2
}
export declare enum AddressTxEvent {
    removed = "removed",
    mempool = "mempool",
    confirmed = "confirmed"
}
export type WebsocketEvent = AddressTxEvent | 'disconnected' | 'connected' | 'error';
export declare class MempoolSocket {
    private options;
    private wsUrl;
    private heartbeatTimer;
    private lastResponseTime;
    private websocketState;
    private ws;
    private eventCallbacks;
    private outQueue;
    constructor(options?: MempoolOptions);
    private init;
    private reconnect;
    private heartbeat;
    private handleOpen;
    private handleClose;
    private handleResponse;
    private handleMultiAddressTransactions;
    private send;
    isConnected(): boolean;
    connect(): Promise<WebSocket>;
    disconnect(): void;
    on(event: WebsocketEvent, callback: (args: {
        address?: string;
        tx?: Transaction;
        error?: any;
    }) => void): void;
    off(event: WebsocketEvent): void;
    trackAddresses(addresses: string[]): Promise<void>;
}