/**
* Unified `EmailEvent` stream that merges send-side events (queued,
* attempt, success, error) with webhook-side events (delivered, opened,
* clicked, bounced, complained, unsubscribed).
*
* Feeds observability dashboards and audit logs without the consumer
* having to stitch webhook + send sources by hand.
*
* @module
*/
import type { EmailDriver, Middleware } from "../types.mjs";
export type EmailEventType = "send.queued" | "send.attempt" | "send.success" | "send.error" | "delivered" | "opened" | "clicked" | "bounced" | "complained" | "unsubscribed" | "spam_reported";
export interface EmailEvent {
	type: EmailEventType;
	messageId?: string;
	recipient?: string;
	provider: string;
	at: Date;
	meta?: Record<string, unknown>;
}
export interface EventStore {
	append: (event: EmailEvent) => void | Promise<void>;
	list?: (messageId: string) => EmailEvent[] | Promise<EmailEvent[]>;
}
export interface MemoryEventStoreOptions {
	capacity?: number;
}
export declare function memoryEventStore(opts?: MemoryEventStoreOptions): EventStore;
/** Emit `send.*` events around a driver's send call. Pair with webhook
*  ingestion (which already emits delivered/opened/bounced etc.) by
*  piping both into the same store. */
export declare function withEvents(driver: EmailDriver, bus: {
	emit: (event: EmailEvent) => void;
}): EmailDriver;
/** Tiny event bus: emit → listeners. Plug a store as a listener. */
export declare class EventBus {
	private listeners;
	emit(event: EmailEvent): void;
	on(listener: (event: EmailEvent) => void): () => void;
}
/** Observability middleware — wires `EmailMessage` beforeSend/afterSend
*  into a user-supplied event bus. Alternative to `withEvents` when
*  you want a Middleware shape. */
export declare function eventsMiddleware(bus: EventBus): Middleware;