Add trends controller... and it kind of works!

deno.json

@@ -2,7 +2,7 @@
   "$schema": "https://deno.land/x/deno@v1.32.3/cli/schemas/config-file.v1.json",
   "lock": false,
   "tasks": {
-    "dev": "deno run --allow-read --allow-env --allow-net --allow-ffi --unstable --watch src/server.ts",
+    "dev": "deno run --allow-read --allow-write --allow-env --allow-net --allow-ffi --unstable --watch src/server.ts",
     "test": "deno test -A --unstable src"
   },
   "imports": {

src/app.ts

@@ -27,6 +27,7 @@ import {
   statusController,
 } from './controllers/api/statuses.ts';
 import { streamingController } from './controllers/api/streaming.ts';
+import { trendingTagsController } from './controllers/api/trends.ts';
 import { indexController } from './controllers/site.ts';
 import { hostMetaController } from './controllers/well-known/host-meta.ts';
 import { nodeInfoController, nodeInfoSchemaController } from './controllers/well-known/nodeinfo.ts';
@@ -101,6 +102,9 @@ app.get('/api/v2/search', searchController);
 
 app.get('/api/pleroma/frontend_configurations', frontendConfigController);
 
+app.get('/api/v1/trends/tags', trendingTagsController);
+app.get('/api/v1/trends', trendingTagsController);
+
 // Not (yet) implemented.
 app.get('/api/v1/notifications', emptyArrayController);
 app.get('/api/v1/bookmarks', emptyArrayController);

src/controllers/api/trends.ts

@@ -0,0 +1,23 @@
+import { type AppController } from '@/app.ts';
+import { Conf } from '@/config.ts';
+import { trends } from '@/trends.ts';
+import { Time } from '@/utils.ts';
+
+const trendingTagsController: AppController = (c) => {
+  const yesterday = new Date(new Date().getTime() - Time.days(1));
+  const now = new Date();
+
+  const tags = trends.getTrendingTags(yesterday, now);
+
+  return c.json(tags.map(({ name, accounts }) => ({
+    name,
+    url: Conf.local(`/tags/${name}`),
+    history: [{
+      day: String(Math.floor(yesterday.getTime() / 1000)),
+      uses: String(accounts), // Not actually true - we don't collect this
+      accounts: String(accounts),
+    }],
+  })));
+};
+
+export { trendingTagsController };

src/loopback.ts

@@ -1,17 +1,15 @@
 import { Conf } from '@/config.ts';
-import { relayInit, Sqlite } from '@/deps.ts';
-import { TrendsDB } from '@/trends.ts';
-
-const db = new Sqlite('data/trends.sqlite3');
-const trends = new TrendsDB(db);
+import { relayInit } from '@/deps.ts';
+import { trends } from '@/trends.ts';
+import { nostrNow } from '@/utils.ts';
 
 const relay = relayInit(Conf.relay);
 await relay.connect();
 
-const sub = relay.sub([{ kinds: [1] }]);
+const sub = relay.sub([{ kinds: [1], since: nostrNow() }]);
 
-sub.on('eose', sub.unsub);
 sub.on('event', (event) => {
+  console.info('loopback event:', event.id);
   const tags = event.tags
     .filter((tag) => tag[0] === 't')
     .map((tag) => tag[1]);

src/trends.test.ts

@@ -18,7 +18,13 @@ Deno.test('getTrendingTags', () => {
     new Date('2999-01-01T00:00:00'),
   );
 
-  assertEquals(result, ['ditto', 'hello', 'yolo']);
+  const expected = [
+    { name: 'ditto', accounts: 3 },
+    { name: 'hello', accounts: 2 },
+    { name: 'yolo', accounts: 1 },
+  ];
+
+  assertEquals(result, expected);
 
   trends.cleanupTagUsages(new Date('2999-01-01T00:00:00'));
 });

src/trends.ts

@@ -18,7 +18,7 @@ class TrendsDB {
     `);
   }
 
-  getTrendingTags(since: Date, until: Date): string[] {
+  getTrendingTags(since: Date, until: Date) {
     return this.#db.query<string[]>(
       `
       SELECT tag, COUNT(DISTINCT pubkey8)
@@ -29,12 +29,15 @@ class TrendsDB {
         DESC LIMIT 10;
     `,
       [since, until],
-    ).map((row) => row[0]);
+    ).map((row) => ({
+      name: row[0],
+      accounts: Number(row[1]),
+    }));
   }
 
   addTagUsages(pubkey: string, hashtags: string[]): void {
     const pubkey8 = hexIdSchema.parse(pubkey).substring(0, 8);
-    const tags = hashtagSchema.array().parse(hashtags);
+    const tags = hashtagSchema.array().min(1).parse(hashtags);
     const now = new Date();
 
     this.#db.query(
@@ -51,4 +54,8 @@ class TrendsDB {
   }
 }
 
-export { TrendsDB };
+const trends = new TrendsDB(
+  new Sqlite('data/trends.sqlite3'),
+);
+
+export { trends, TrendsDB };