import type { TypedEventTarget } from '@graphql-yoga/typed-event-target';
import { Repeater, type RepeaterBuffer } from '@repeaterjs/repeater';
type PubSubPublishArgsByKey = {
    [key: string]: [] | [any] | [number | string, any];
};
type MapToNull<T> = T extends undefined ? null : T;
export type PubSubEvent<TPubSubPublishArgsByKey extends PubSubPublishArgsByKey, TKey extends Extract<keyof TPubSubPublishArgsByKey, string>> = CustomEvent<TPubSubPublishArgsByKey[TKey][1] extends undefined ? TPubSubPublishArgsByKey[TKey][0] : TPubSubPublishArgsByKey[TKey][1]>;
export type PubSubEventTarget<TPubSubPublishArgsByKey extends PubSubPublishArgsByKey> = TypedEventTarget<PubSubEvent<TPubSubPublishArgsByKey, Extract<keyof TPubSubPublishArgsByKey, string>>>;
export type ChannelPubSubConfig<TPubSubPublishArgsByKey extends PubSubPublishArgsByKey> = {
    /**
     * The event target. If not specified an (in-memory) EventTarget will be created.
     * For multiple server replica or serverless environments a distributed EventTarget is recommended.
     *
     * An event dispatched on the event target MUST have a `data` property.
     */
    eventTarget?: PubSubEventTarget<TPubSubPublishArgsByKey>;
    /**
     * A buffer for the repeater that controls how values are buffered when pushed faster than consumed.
     * By default, no buffer is used and a RepeaterOverflowError is thrown when more than 1024
     * pending pushes accumulate.
     *
     * Available buffers from @repeaterjs/repeater:
     * - FixedBuffer(capacity) - allows N values to be pushed without waiting, throws when full
     * - SlidingBuffer(capacity) - discards oldest values when capacity is exceeded
     * - DroppingBuffer(capacity) - discards newest values when capacity is exceeded
     *
     * @example
     * ```ts
     * import { createPubSub } from '@graphql-yoga/subscription';
     * import { SlidingBuffer } from '@repeaterjs/repeater';
     *
     * const pubSub = createPubSub({
     *   repeaterBuffer: new SlidingBuffer(256)
     * });
     * ```
     */
    repeaterBuffer?: RepeaterBuffer;
};
export type PubSub<TPubSubPublishArgsByKey extends PubSubPublishArgsByKey> = {
    /**
     * Publish a value for a given topic.
     */
    publish<TKey extends Extract<keyof TPubSubPublishArgsByKey, string>>(routingKey: TKey, ...args: TPubSubPublishArgsByKey[TKey]): void;
    /**
     * Subscribe to a topic.
     */
    subscribe<TKey extends Extract<keyof TPubSubPublishArgsByKey, string>>(...[routingKey, id]: TPubSubPublishArgsByKey[TKey][1] extends undefined ? [TKey] : [TKey, TPubSubPublishArgsByKey[TKey][0]]): Repeater<TPubSubPublishArgsByKey[TKey][1] extends undefined ? MapToNull<TPubSubPublishArgsByKey[TKey][0]> : MapToNull<TPubSubPublishArgsByKey[TKey][1]>>;
};
/**
 * Utility for publishing and subscribing to events.
 */
export declare const createPubSub: <TPubSubPublishArgsByKey extends PubSubPublishArgsByKey>(config?: ChannelPubSubConfig<TPubSubPublishArgsByKey>) => PubSub<TPubSubPublishArgsByKey>;
export {};