import { IConnection } from "./IConnection";
import { IHttpConnectionOptions } from "./IHttpConnectionOptions";
import { HttpTransportType, ITransport, TransferFormat } from "./ITransport";
/** @private */
export interface INegotiateResponse {
    connectionId?: string;
    connectionToken?: string;
    negotiateVersion?: number;
    availableTransports?: IAvailableTransport[];
    url?: string;
    accessToken?: string;
    error?: string;
}
/** @private */
export interface IAvailableTransport {
    transport: keyof typeof HttpTransportType;
    transferFormats: (keyof typeof TransferFormat)[];
}
/** @private */
export declare class HttpConnection implements IConnection {
    private _connectionState;
    private _connectionStarted;
    private readonly _httpClient;
    private readonly _logger;
    private readonly _options;
    private transport?;
    private _startInternalPromise?;
    private _stopPromise?;
    private _stopPromiseResolver;
    private _stopError?;
    private _accessTokenFactory?;
    private _sendQueue?;
    readonly features: any;
    baseUrl: string;
    connectionId?: string;
    onreceive: ((data: string | ArrayBuffer) => void) | null;
    onclose: ((e?: Error) => void) | null;
    private readonly _negotiateVersion;
    constructor(url: string, options?: IHttpConnectionOptions);
    start(): Promise<void>;
    start(transferFormat: TransferFormat): Promise<void>;
    send(data: string | ArrayBuffer): Promise<void>;
    stop(error?: Error): Promise<void>;
    private _stopInternal;
    private _startInternal;
    private _getNegotiationResponse;
    private _createConnectUrl;
    private _createTransport;
    private _constructTransport;
    private _startTransport;
    private _resolveTransportOrError;
    private _isITransport;
    private _stopConnection;
    private _resolveUrl;
    private _resolveNegotiateUrl;
}
/** @private */
export declare class TransportSendQueue {
    private readonly _transport;
    private _buffer;
    private _sendBufferedData;
    private _executing;
    private _transportResult?;
    private _sendLoopPromise;
    constructor(_transport: ITransport);
    send(data: string | ArrayBuffer): Promise<void>;
    stop(): Promise<void>;
    private _bufferData;
    private _sendLoop;
    private static _concatBuffers;
}