/**
 * @module ServerSentEvents
 * SSE client that dispatches received events as DOM events.
 * Uses the browser's built-in EventSource reconnection.
 *
 * @example
 * const sse = new SSEClient('/api/events', {
 *     eventTypes: ['user-updated', 'order-created']
 * });
 * sse.connect();
 *
 * document.addEventListener('user-updated', (e: SSEDataEvent) => {
 *     console.log('User updated:', e.data);
 * });
 */
/**
 * Event dispatched when an SSE message is received.
 * The event name matches the SSE event type.
 */
export declare class SSEDataEvent extends Event {
    data: unknown;
    constructor(eventName: string, data: unknown, eventInit?: EventInit);
}
/**
 * Factory function for creating custom event instances.
 *
 * @example
 * const factory: SSEEventFactory = (eventName, data) => {
 *     switch (eventName) {
 *         case 'user-updated':
 *             return new UserUpdatedEvent(data as User);
 *         default:
 *             return new SSEDataEvent(eventName, data);
 *     }
 * };
 */
export type SSEEventFactory = (eventName: string, data: unknown) => Event;
/**
 * Configuration options for SSEClient.
 */
export interface SSEOptions {
    /**
     * Target element or CSS selector for event dispatching.
     * Defaults to document.
     */
    target?: string | Element;
    /**
     * Whether to send credentials with the request (default: false).
     */
    withCredentials?: boolean;
    /**
     * Specific SSE event types to listen for.
     * If not specified, listens to the default 'message' event.
     *
     * @example
     * eventTypes: ['user-updated', 'order-created']
     */
    eventTypes?: string[];
    /**
     * Factory function for creating custom event instances.
     * If not provided, SSEDataEvent is used.
     *
     * @example
     * eventFactory: (name, data) => new MyCustomEvent(name, data)
     */
    eventFactory?: SSEEventFactory;
    /**
     * Callback when connection is established.
     */
    onConnect?: (client: SSEClient) => void;
    /**
     * Callback when an error occurs.
     * Note: EventSource automatically reconnects on errors.
     */
    onError?: (client: SSEClient, error: Event) => void;
}
/**
 * Server-Sent Events client that dispatches received events as DOM events.
 * Uses the browser's built-in EventSource with automatic reconnection.
 *
 * @example
 * const sse = new SSEClient('/api/events', {
 *     target: '#notifications',
 *     eventTypes: ['notification', 'alert']
 * });
 *
 * sse.connect();
 *
 * document.querySelector('#notifications')
 *     .addEventListener('notification', (e: SSEDataEvent) => {
 *         showNotification(e.data);
 *     });
 *
 * sse.disconnect();
 */
export declare class SSEClient {
    private url;
    private options?;
    private eventSource?;
    private target;
    /**
     * Whether the client is currently connected.
     */
    get connected(): boolean;
    constructor(url: string, options?: SSEOptions);
    /**
     * Establish connection to the SSE endpoint.
     */
    connect(): void;
    /**
     * Close the connection.
     */
    disconnect(): void;
    private resolveTarget;
    private dispatchEvent;
}