/**
 * events.ts — A tiny, typed EventEmitter for internal pub/sub.
 * No Node.js dependency — works in any browser.
 */
type EventHandler<T = unknown> = (payload: T) => void;
export declare class EventEmitter<Events extends Record<string, unknown>> {
    private _listeners;
    on<K extends keyof Events>(event: K, handler: EventHandler<Events[K]>): this;
    off<K extends keyof Events>(event: K, handler: EventHandler<Events[K]>): this;
    once<K extends keyof Events>(event: K, handler: EventHandler<Events[K]>): this;
    emit<K extends keyof Events>(event: K, payload: Events[K]): void;
}
/** All events the engine can emit */
export interface EngineEvents extends Record<string, unknown> {
    /** Engine is ready and has determined install status */
    ready: {
        status: string;
        platform: string;
    };
    /** The browser fired beforeinstallprompt — we can now show our UI */
    installable: void;
    /** User clicked "Install" and the outcome was 'accepted' */
    installed: void;
    /** User clicked "Not now" */
    dismissed: void;
    /** An error occurred */
    error: Error;
}
export {};