import { type RemoteInfo } from "node:dgram";
import { EventEmitter } from "node:events";
export type UdpDatagram = {
    data: Buffer;
    remote: RemoteInfo;
};
export type UdpTransportOptions = {
    host?: string;
    port?: number;
};
/**
 * A consumer that wants first dibs on inbound datagrams that look like
 * STUN/TURN (RFC 5389 magic cookie at offset 4). ICE agents and TURN
 * clients register here so net_crypto/DHT never sees their control
 * packets, and so TURN DATA-INDICATIONs get unwrapped before the inner
 * app packet is re-emitted as a normal datagram.
 *
 * Return true if the datagram was consumed (stop further dispatch).
 */
export type StunInterceptor = (data: Buffer, remote: RemoteInfo) => boolean;
/**
 * A TURN route: outbound datagrams addressed to `${host}:${port}` are
 * handed to `send` instead of going out the raw socket. Used to tunnel
 * net_crypto traffic through a TURN relay transparently — net_crypto
 * sets session.remote to the peer's relay address and is none the wiser.
 */
export type TurnRoute = {
    send: (data: Buffer) => void;
};
export declare class UdpTransport extends EventEmitter {
    #private;
    constructor();
    get bound(): boolean;
    start(opts?: UdpTransportOptions): Promise<void>;
    stop(): Promise<void>;
    /**
     * The OS-assigned local UDP port (after bind). Useful so the peer layer
     * can recognize and skip its own address in friend endpoint candidates
     * (some toxcore peers echo our address back inside DHT-PK extras).
     */
    localPort(): number | undefined;
    send(data: Buffer, host: string, port: number): Promise<void>;
    /** Direct socket send, bypassing TURN routes. ICE/TURN use this so
     *  their own control packets (SEND-INDICATION, binding checks) don't
     *  recurse back through the route table. */
    sendDirect(data: Buffer, host: string, port: number): Promise<void>;
    /** Synchronous fire-and-forget direct send (for hot TURN data path). */
    sendDirectSync(data: Buffer, host: string, port: number): void;
    addStunInterceptor(fn: StunInterceptor): void;
    removeStunInterceptor(fn: StunInterceptor): void;
    registerTurnRoute(host: string, port: number, route: TurnRoute): void;
    unregisterTurnRoute(host: string, port: number): void;
}