Remove NWC, return a Ln-Invoice header on the zap endpoint

src/controllers/api/statuses.ts

@@ -15,7 +15,7 @@ import { renderReblog, renderStatus } from '@/views/mastodon/statuses.ts';
 import { Storages } from '@/storages.ts';
 import { hydrateEvents } from '@/storages/hydrate.ts';
 import { createEvent, paginationSchema, parseBody, updateListEvent } from '@/utils/api.ts';
-import { getLnurl } from '@/utils/lnurl.ts';
+import { getInvoice, getLnurl } from '@/utils/lnurl.ts';
 import { lookupPubkey } from '@/utils/lookup.ts';
 import { addTag, deleteTag } from '@/utils/tags.ts';
 import { asyncReplaceAll } from '@/utils/text.ts';
@@ -450,15 +450,16 @@ const zapController: AppController = async (c) => {
   const author = target?.author;
   const meta = n.json().pipe(n.metadata()).catch({}).parse(author?.content);
   const lnurl = getLnurl(meta);
+  const amount = params.data.amount;
 
   if (target && lnurl) {
-    await createEvent({
+    const nostr = await createEvent({
       kind: 9734,
       content: params.data.comment ?? '',
       tags: [
         ['e', target.id],
         ['p', target.pubkey],
-        ['amount', params.data.amount.toString()],
+        ['amount', amount.toString()],
         ['relays', Conf.relay],
         ['lnurl', lnurl],
       ],
@@ -467,7 +468,11 @@ const zapController: AppController = async (c) => {
     const status = await renderStatus(target, { viewerPubkey: await c.get('signer')?.getPublicKey() });
     status.zapped = true;
 
-    return c.json(status);
+    return c.json(status, {
+      headers: {
+        'Ln-Invoice': await getInvoice({ amount, nostr, lnurl }, signal),
+      },
+    });
   } else {
     return c.json({ error: 'Event not found.' }, 404);
   }

src/pipeline.ts

@@ -1,5 +1,4 @@
 import { NKinds, NostrEvent, NPolicy, NSchema as n } from '@nostrify/nostrify';
-import { LNURL } from '@nostrify/nostrify/ln';
 import { PipePolicy } from '@nostrify/nostrify/policies';
 import Debug from '@soapbox/stickynotes/debug';
 import { sql } from 'kysely';
@@ -12,15 +11,12 @@ import { DittoEvent } from '@/interfaces/DittoEvent.ts';
 import { DVM } from '@/pipeline/DVM.ts';
 import { MuteListPolicy } from '@/policies/MuteListPolicy.ts';
 import { RelayError } from '@/RelayError.ts';
-import { hydrateEvents, purifyEvent } from '@/storages/hydrate.ts';
+import { hydrateEvents } from '@/storages/hydrate.ts';
 import { Storages } from '@/storages.ts';
-import { eventAge, nostrDate, nostrNow, parseNip05, Time } from '@/utils.ts';
+import { eventAge, nostrDate, parseNip05, Time } from '@/utils.ts';
-import { fetchWorker } from '@/workers/fetch.ts';
 import { policyWorker } from '@/workers/policy.ts';
 import { TrendsWorker } from '@/workers/trends.ts';
 import { verifyEventWorker } from '@/workers/verify.ts';
-import { AdminSigner } from '@/signers/AdminSigner.ts';
-import { lnurlCache } from '@/utils/lnurl.ts';
 import { nip05Cache } from '@/utils/nip05.ts';
 import { updateStats } from '@/utils/stats.ts';
 import { getTagSet } from '@/utils/tags.ts';
@@ -48,7 +44,6 @@ async function handleEvent(event: DittoEvent, signal: AbortSignal): Promise<void
     DVM.event(event),
     trackHashtags(event),
     processMedia(event),
-    payZap(event, signal),
     streamOut(event),
   ]);
 }
@@ -189,53 +184,6 @@ function processMedia({ tags, pubkey, user }: DittoEvent) {
   }
 }
 
-/** Emit Nostr Wallet Connect event from zaps so users may pay. */
-async function payZap(event: DittoEvent, signal: AbortSignal) {
-  if (event.kind !== 9734) return;
-
-  const lnurl = event.tags.find(([name]) => name === 'lnurl')?.[1];
-  const amount = Number(event.tags.find(([name]) => name === 'amount')?.[1]);
-
-  if (!lnurl || !amount) return;
-
-  try {
-    const details = await lnurlCache.fetch(lnurl, { signal });
-
-    if (details.tag !== 'payRequest' || !details.allowsNostr || !details.nostrPubkey) {
-      throw new Error('invalid lnurl');
-    }
-
-    if (amount > details.maxSendable || amount < details.minSendable) {
-      throw new Error('amount out of range');
-    }
-
-    const { pr } = await LNURL.callback(
-      details.callback,
-      { amount, nostr: purifyEvent(event), lnurl },
-      { fetch: fetchWorker, signal },
-    );
-
-    const signer = new AdminSigner();
-
-    const nwcRequestEvent = await signer.signEvent({
-      kind: 23194,
-      content: await signer.nip04.encrypt(
-        event.pubkey,
-        JSON.stringify({ method: 'pay_invoice', params: { invoice: pr } }),
-      ),
-      created_at: nostrNow(),
-      tags: [
-        ['p', event.pubkey],
-        ['e', event.id],
-      ],
-    });
-
-    await handleEvent(nwcRequestEvent, signal);
-  } catch (e) {
-    debug('lnurl error:', e);
-  }
-}
-
 /** Determine if the event is being received in a timely manner. */
 function isFresh(event: NostrEvent): boolean {
   return eventAge(event) < Time.seconds(10);

src/utils/lnurl.ts

@@ -4,6 +4,7 @@ import Debug from '@soapbox/stickynotes/debug';
 import { SimpleLRU } from '@/utils/SimpleLRU.ts';
 import { Time } from '@/utils/time.ts';
 import { fetchWorker } from '@/workers/fetch.ts';
+import { NostrEvent } from '@nostrify/nostrify';
 
 const debug = Debug('ditto:lnurl');
 
@@ -38,4 +39,32 @@ function getLnurl({ lud06, lud16 }: { lud06?: string; lud16?: string }, limit?:
   }
 }
 
-export { getLnurl, lnurlCache };
+interface CallbackParams {
+  amount: number;
+  nostr: NostrEvent;
+  lnurl: string;
+}
+
+async function getInvoice(params: CallbackParams, signal?: AbortSignal): Promise<string> {
+  const { amount, lnurl } = params;
+
+  const details = await lnurlCache.fetch(lnurl, { signal });
+
+  if (details.tag !== 'payRequest' || !details.allowsNostr || !details.nostrPubkey) {
+    throw new Error('invalid lnurl');
+  }
+
+  if (amount > details.maxSendable || amount < details.minSendable) {
+    throw new Error('amount out of range');
+  }
+
+  const { pr } = await LNURL.callback(
+    details.callback,
+    params,
+    { fetch: fetchWorker, signal },
+  );
+
+  return pr;
+}
+
+export { getInvoice, getLnurl, lnurlCache };