/**
 * Event Emitter for NotebookLM MCP
 *
 * Central event bus for system-wide events.
 * Events can trigger webhook notifications, logging, or other actions.
 */
import type { SystemEvent, EventType } from "./event-types.js";
export type EventHandler = (event: SystemEvent) => void | Promise<void>;
declare class EventEmitter {
    private handlers;
    private eventHistory;
    private maxHistorySize;
    private handlerTimeoutMs;
    private maxHandlersPerType;
    private leakWarned;
    /**
     * Subscribe to an event type
     */
    on(eventType: EventType | "*", handler: EventHandler): () => void;
    /**
     * Subscribe to an event type (one-time only)
     */
    once(eventType: EventType | "*", handler: EventHandler): () => void;
    /**
     * Emit an event
     */
    emit(event: SystemEvent): Promise<void>;
    /**
     * Run a single handler with a timeout, catching and logging any error so
     * a rejected/hung handler can never produce an unhandled rejection or hang
     * emit() indefinitely.
     */
    private runHandler;
    /**
     * Get recent events
     */
    getHistory(limit?: number): SystemEvent[];
    /**
     * Get events by type
     */
    getEventsByType(eventType: EventType, limit?: number): SystemEvent[];
    /**
     * Clear event history
     */
    clearHistory(): void;
    /**
     * Get handler count for debugging
     */
    getHandlerCount(): Record<string, number>;
}
declare const eventEmitter: EventEmitter;
export { eventEmitter };
export default eventEmitter;