import { N as NotificationEvent, e as NotificationEventType } from "../packem_shared/types.d-C7l7qdMG.js";
/**
 * An append-only timeline store for notification events.
 */
interface EventStore {
  append: (event: NotificationEvent) => void | Promise<void>;
  timeline: (messageId: string) => NotificationEvent[] | Promise<NotificationEvent[]>;
}
/**
 * In-memory {@link EventStore} keyed by message id.
 */
declare class MemoryEventStore implements EventStore {
  #private;
  append(event: NotificationEvent): void;
  timeline(messageId: string): NotificationEvent[];
}
type NotificationEventListener = (event: NotificationEvent) => void;
/**
 * A tiny synchronous event bus for notification lifecycle events. Listeners can subscribe
 * to a specific {@link NotificationEventType} or to all events with `"*"`.
 */
declare class NotificationEventBus {
  #private;
  /**
   * Subscribes to an event type (or `"*"` for all).
   * @param type A specific {@link NotificationEventType} to listen for, or `"*"` for every event.
   * @param listener The callback invoked with each matching event.
   * @returns An unsubscribe function.
   */
  on(type: "*" | NotificationEventType, listener: NotificationEventListener): () => void;
  /**
   * Emits an event to matching listeners.
   * @param event The event to emit.
   */
  emit(event: NotificationEvent): void;
}
export { type EventStore, MemoryEventStore, NotificationEventBus, NotificationEventListener };