import type { Server as HttpServer } from 'http';
import type { LTEvent, LTEventAdapter } from '../../types';
/**
 * Callback to verify a Socket.IO handshake token.
 * Return `true` to allow the connection, `false` to reject.
 */
export type SocketIOAuthenticator = (token: string) => boolean | Promise<boolean>;
/**
 * Socket.IO event adapter for browser clients.
 *
 * Publishes LTEvent payloads to all connected Socket.IO clients
 * on channels following the pattern: `lt.events.{event.type}`
 *
 * The HTTP server must be attached via `attachServer()` before
 * `connect()` is called. The startup flow handles this automatically
 * when Socket.IO is the active event transport.
 *
 * When an `authenticate` callback is provided, Socket.IO middleware
 * rejects handshakes that do not include a valid `auth.token`.
 *
 * Usage:
 * ```typescript
 * import { eventRegistry } from '@hotmeshio/long-tail';
 * import { SocketIOEventAdapter } from '@hotmeshio/long-tail';
 *
 * const adapter = new SocketIOEventAdapter();
 * eventRegistry.register(adapter);
 * // After HTTP server is created:
 * adapter.attachServer(httpServer);
 * await eventRegistry.connect();
 * ```
 */
export declare class SocketIOEventAdapter implements LTEventAdapter {
    private io;
    private httpServer;
    private authenticate;
    private socketPath;
    constructor(options?: {
        authenticate?: SocketIOAuthenticator;
    });
    /** Attach to an HTTP server. Must be called before connect(). */
    attachServer(server: HttpServer): void;
    /** Override the socket.io path (for subpath-mounted deployments). */
    setPath(socketPath: string): void;
    connect(): Promise<void>;
    publish(event: LTEvent): Promise<void>;
    disconnect(): Promise<void>;
}