some nip29 helpers.

nip29.ts

@@ -1,8 +1,114 @@
-import type { Event } from './pure'
+import { AbstractSimplePool } from './abstract-pool'
+import { Subscription } from './abstract-relay'
+import { decode } from './nip19'
+import type { Event } from './core'
+import { fetchRelayInformation } from './nip11'
+import { normalizeURL } from './utils'
+import { AddressPointer } from './nip19'
+
+export function subscribeRelayGroups(
+  pool: AbstractSimplePool,
+  url: string,
+  params: {
+    ongroups: (_: Group[]) => void
+    onerror: (_: Error) => void
+    onconnect?: () => void
+  },
+): () => void {
+  let normalized = normalizeURL(url)
+  let sub: Subscription
+  let groups: Group[] = []
+
+  fetchRelayInformation(normalized)
+    .then(async info => {
+      let rl = await pool.ensureRelay(normalized)
+      params.onconnect?.()
+      sub = rl.prepareSubscription(
+        [
+          {
+            kinds: [39000],
+            limit: 50,
+            authors: [info.pubkey],
+          },
+        ],
+        {
+          onevent(event: Event) {
+            groups.push(parseGroup(event, normalized))
+          },
+          oneose() {
+            params.ongroups(groups)
+            sub.onevent = (event: Event) => {
+              groups.push(parseGroup(event, normalized))
+              params.ongroups(groups)
+            }
+          },
+        },
+      )
+      sub.fire()
+    })
+    .catch(params.onerror)
+
+  return () => sub.close()
+}
+
+export async function loadGroup(pool: AbstractSimplePool, gr: GroupReference): Promise<Group> {
+  let normalized = normalizeURL(gr.host)
+
+  let info = await fetchRelayInformation(normalized)
+  let event = await pool.get([normalized], {
+    kinds: [39000],
+    authors: [info.pubkey],
+    '#d': [gr.id],
+  })
+  if (!event) throw new Error(`group '${gr.id}' not found on ${gr.host}`)
+  return parseGroup(event, normalized)
+}
+
+export async function loadGroupFromCode(pool: AbstractSimplePool, code: string): Promise<Group> {
+  let gr = parseGroupCode(code)
+  if (!gr) throw new Error(`code "${code}" does not identify a group`)
+  return loadGroup(pool, gr)
+}
+
+export type GroupReference = {
+  id: string
+  host: string
+}
+
+export function parseGroupCode(code: string): null | GroupReference {
+  if (code.startsWith('naddr1')) {
+    try {
+      let { data } = decode(code)
+
+      let { relays, identifier } = data as AddressPointer
+      if (!relays || relays.length === 0) return null
+
+      let host = relays![0]
+      if (host.startsWith('wss://')) {
+        host = host.slice(6)
+      }
+      return { host, id: identifier }
+    } catch (err) {
+      return null
+    }
+  } else if (code.split("'").length === 2) {
+    let spl = code.split("'")
+    return { host: spl[0], id: spl[1] }
+  }
+
+  return null
+}
+
+export function encodeGroupReference(gr: GroupReference): string {
+  if (gr.host.startsWith('https://')) gr.host = gr.host.slice(8)
+  if (gr.host.startsWith('wss://')) gr.host = gr.host.slice(6)
+  return `${gr.host}'${gr.id}`
+}
 
 export type Group = {
   id: string
   relay: string
+  pubkey: string
   name?: string
   picture?: string
   about?: string
@@ -11,7 +117,7 @@ export type Group = {
 }
 
 export function parseGroup(event: Event, relay: string): Group {
-  const group: Partial<Group> = { relay }
+  const group: Partial<Group> = { relay, pubkey: event.pubkey }
   for (let i = 0; i < event.tags.length; i++) {
     const tag = event.tags[i]
     switch (tag[0]) {