import type {
	JoinToken,
	MutableAtomToken,
	RegularAtomFamilyToken,
} from "atom.io"
import { atomFamily, join, mutableAtom } from "atom.io"
import type { Hierarchy } from "atom.io/experiments/realms"
import type { RoomKey, Socket, SocketKey, UserKey } from "atom.io/realtime"
import { isSocketKey, isUserKey } from "atom.io/realtime"
import { UList } from "atom.io/transceivers/u-list"

export type SocketSystemHierarchy = Hierarchy<
	[
		{
			above: `root`
			below: [UserKey, SocketKey, RoomKey]
		},
	]
>

export const socketAtoms: RegularAtomFamilyToken<Socket | null, SocketKey> =
	atomFamily({
		key: `socket`,
		default: null,
	})

export const socketKeysAtom: MutableAtomToken<UList<SocketKey>> = mutableAtom({
	key: `socketKeys`,
	class: UList,
})
export const onlineUsersAtom: MutableAtomToken<UList<UserKey>> = mutableAtom({
	key: `onlineUsers`,
	class: UList,
})
export const usersOfSockets: JoinToken<
	`user`,
	UserKey,
	`socket`,
	SocketKey,
	`1:n`
> = join({
	key: `usersOfSockets`,
	between: [`user`, `socket`],
	cardinality: `1:n`,
	isAType: isUserKey,
	isBType: isSocketKey,
})