Trends: track based on the event's created_at date, instead of whenever the row was inserted

src/loopback.ts

@@ -1,7 +1,7 @@
 import { Conf } from '@/config.ts';
 import { relayInit } from '@/deps.ts';
 import { trends } from '@/trends.ts';
-import { nostrNow } from '@/utils.ts';
+import { nostrDate, nostrNow } from '@/utils.ts';
 
 import type { Event } from '@/event.ts';
 
@@ -23,12 +23,14 @@ function handleEvent(event: Event): void {
 
 /** Track whenever a hashtag is used, for processing trending tags. */
 function trackHashtags(event: Event): void {
+  const date = nostrDate(event.created_at);
+
   const tags = event.tags
     .filter((tag) => tag[0] === 't')
     .map((tag) => tag[1]);
 
   try {
-    trends.addTagUsages(event.pubkey, tags);
+    trends.addTagUsages(event.pubkey, tags, date);
   } catch (_e) {
     // do nothing
   }

src/trends.ts

@@ -54,14 +54,13 @@ class TrendsDB {
     }));
   }
 
-  addTagUsages(pubkey: string, hashtags: string[]): void {
+  addTagUsages(pubkey: string, hashtags: string[], date = new Date()): void {
     const pubkey8 = hexIdSchema.parse(pubkey).substring(0, 8);
     const tags = hashtagSchema.array().min(1).parse(hashtags);
-    const now = new Date();
 
     this.#db.query(
       'INSERT INTO tag_usages (tag, pubkey8, inserted_at) VALUES ' + tags.map(() => '(?, ?, ?)').join(', '),
-      tags.map((tag) => [tag, pubkey8, now]).flat(),
+      tags.map((tag) => [tag, pubkey8, date]).flat(),
     );
   }