/**
 * @file transport-stack.ts
 * @description Composes ICE -> DTLS -> SCTP -> DCEP into one transport, the
 * real WebRTC data-channel pipeline.
 * @module transport-stack
 *
 * Wiring:
 *   IceAgent  emits 'data' (non-STUN datagrams) -> DtlsConnection.handlePacket
 *   DtlsConnection.output                        -> IceAgent.send
 *   DtlsConnection 'data' (app records)          -> SctpAssociation.receivePacket
 *   SctpAssociation 'output'                     -> DtlsConnection.send
 *   SctpAssociation + DataChannelManager         -> RTCDataChannel
 *
 * The DTLS client/server role follows the negotiated a=setup; the SCTP client
 * (INIT initiator) is the DTLS client, per RFC 8832.
 */
import { EventEmitter } from 'events';
import { IceAgent } from './ice/ice-agent';
import { DtlsConnection } from './dtls/connection';
import { SctpAssociation } from './sctp/association';
import { DataChannelManager, OpenRequestInfo } from './sctp/datachannel-manager';
import type { RTCDataChannel, RTCDataChannelInit } from './datachannel/RTCDataChannel';
import type { KeyObject } from 'crypto';
export interface TransportStackOptions {
    /** ICE controlling vs controlled (offerer is controlling). */
    iceRole: 'controlling' | 'controlled';
    /** DTLS role from a=setup (active=client). */
    dtlsRole: 'client' | 'server';
    localUfrag: string;
    localPwd: string;
    certDer: Buffer;
    privateKey: KeyObject;
    verifyFingerprint?: (fp: {
        algorithm: string;
        value: string;
    }) => boolean;
}
export declare class TransportStack extends EventEmitter {
    #private;
    ice: IceAgent;
    dtls: DtlsConnection | null;
    sctp: SctpAssociation | null;
    dcm: DataChannelManager | null;
    constructor(opts: TransportStackOptions);
    /**
     * Begin gathering local candidates.
     * @param opts - { iceServers, iceTransportPolicy } forwarded to ICE.
     */
    gather(opts?: {
        iceServers?: unknown[];
        iceTransportPolicy?: 'all' | 'relay';
    }): Promise<void>;
    getLocalCandidates(): ReturnType<IceAgent['getLocalCandidates']>;
    /** Provide the peer's ICE credentials and start checks when ready. */
    setRemote(ufrag: string, pwd: string): void;
    addRemoteCandidate(cand: {
        address: string;
        port: number;
        type?: string;
        priority?: number;
    }): void;
    /** Open a locally-initiated data channel once SCTP is established. */
    openChannel(channel: RTCDataChannel, init: RTCDataChannelInit): void;
    /** Accept an inbound channel created from a 'datachannel-request'. */
    acceptChannel(channel: RTCDataChannel, info: OpenRequestInfo): void;
    isReady(): boolean;
    close(): void;
}