import type { EventsConstraint, SubscriberEntry } from "./common.ts"

/**
 * @description 表示某一事件名下由订阅者函数到订阅项的内部映射。
 */
export type InternalSubscriberEntryMap<
  Events extends EventsConstraint<Events>,
  K extends keyof Events,
> = Map<Events[K], SubscriberEntry<Events, K>>

/**
 * @description 表示代理订阅项及其所管理的下游订阅集合的内部结构。
 */
export interface InternalProxySubscriberEntry<
  Events extends EventsConstraint<Events>,
  K extends keyof Events,
> {
  managedSubscribers: InternalSubscriberEntryMap<Events, K>
  proxySubscriber: Events[K]
}

/**
 * @description 使用对象而非 Map 来保存事件到代理订阅项的内部映射。
 */
export type InternalProxySubscriberEntryMap<Events extends EventsConstraint<Events>> = {
  [K in keyof Events]?: InternalProxySubscriberEntry<Events, K> | undefined
}