Add nip 29 room utils

packages/util/src/Room.ts

@@ -0,0 +1,56 @@
+import {randomId, nthNe} from "@welshman/lib"
+import {
+  ROOM_META,
+  ROOM_DELETE,
+  ROOM_CREATE,
+  ROOM_EDIT_META,
+  ROOM_JOIN,
+  ROOM_LEAVE,
+} from "./Kinds.js"
+import {makeEvent, TrustedEvent, getIdentifier} from "./Events.js"
+
+export type RoomMeta = {
+  id: string
+  tags: string[][]
+  event?: TrustedEvent
+}
+
+export type PublishedRoomMeta = Omit<RoomMeta, "event"> & {
+  event: TrustedEvent
+}
+
+export const makeRoomMeta = (room: Partial<RoomMeta> = {}): RoomMeta => ({
+  id: randomId(),
+  tags: [],
+  ...room,
+})
+
+export const readRoomMeta = (event: TrustedEvent): PublishedRoomMeta => {
+  if (event.kind !== ROOM_META) {
+    throw new Error("Invalid group meta event")
+  }
+
+  const id = getIdentifier(event)
+
+  if (!id) {
+    throw new Error("Group meta event had no d tag")
+  }
+
+  const tags = event.tags.filter(nthNe(0, "d"))
+
+  return {id, tags, event}
+}
+
+export const makeRoomCreateEvent = (room: RoomMeta) =>
+  makeEvent(ROOM_CREATE, {tags: [["h", room.id]]})
+
+export const makeRoomDeleteEvent = (room: RoomMeta) =>
+  makeEvent(ROOM_DELETE, {tags: [["h", room.id]]})
+
+export const makeRoomEditEvent = (room: RoomMeta) =>
+  makeEvent(ROOM_EDIT_META, {tags: [["h", room.id], ...room.tags]})
+
+export const makeRoomJoinEvent = (room: RoomMeta) => makeEvent(ROOM_JOIN, {tags: [["h", room.id]]})
+
+export const makeRoomLeaveEvent = (room: RoomMeta) =>
+  makeEvent(ROOM_LEAVE, {tags: [["h", room.id]]})