From 6748e13a36231a6a3d25ebf8a23fac8ce2aa3e5d Mon Sep 17 00:00:00 2001
From: Alex Gleason <alex@alexgleason.me>
Date: Sat, 18 Mar 2023 14:49:44 -0500
Subject: [PATCH] Make Home feed kind of work

---
 src/api/home.ts | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/app.ts      |  4 +++-
 src/client.ts   | 37 +++++++++++++++++++++++++++++--------
 src/event.ts    | 22 ++++------------------
 4 files changed, 84 insertions(+), 27 deletions(-)
 create mode 100644 src/api/home.ts

diff --git a/src/api/home.ts b/src/api/home.ts
new file mode 100644
index 00000000..81995bf5
--- /dev/null
+++ b/src/api/home.ts
@@ -0,0 +1,48 @@
+import { fetchFeed, fetchFollows } from '../client.ts';
+import { getKeys } from '../utils.ts';
+
+import type { Context } from '@/deps.ts';
+import type { SignedEvent } from '../event.ts';
+
+async function homeController(c: Context) {
+  const keys = getKeys(c);
+  if (!keys) {
+    return c.json({ error: 'Unauthorized' }, 401);
+  }
+
+  const follows = await fetchFollows(keys.pubkey);
+  if (!follows) {
+    return c.json([]);
+  }
+
+  const events = await fetchFeed(follows);
+  const statuses = events.map(toStatus);
+
+  return c.json(statuses);
+}
+
+interface Account {
+  id: string;
+  acct: string;
+  username: string;
+}
+
+interface Status {
+  id: string;
+  content: string;
+  account: Account;
+}
+
+function toStatus(event: SignedEvent<1>): Status {
+  return {
+    id: event.id,
+    content: event.content,
+    account: {
+      id: event.pubkey,
+      acct: event.pubkey,
+      username: event.pubkey,
+    },
+  };
+}
+
+export default homeController;
diff --git a/src/app.ts b/src/app.ts
index 19dbb11c..58feba45 100644
--- a/src/app.ts
+++ b/src/app.ts
@@ -3,6 +3,7 @@ import { cors, Hono } from '@/deps.ts';
 import { credentialsController } from './api/accounts.ts';
 import { appCredentialsController, createAppController } from './api/apps.ts';
 import { emptyArrayController, emptyObjectController } from './api/fallback.ts';
+import homeController from './api/home.ts';
 import instanceController from './api/instance.ts';
 import { createTokenController } from './api/oauth.ts';
 import { createStatusController } from './api/statuses.ts';
@@ -23,8 +24,9 @@ app.get('/api/v1/accounts/verify_credentials', credentialsController);
 
 app.post('/api/v1/statuses', createStatusController);
 
+app.get('/api/v1/timelines/home', homeController);
+
 // Not (yet) implemented.
-app.get('/api/v1/timelines/*', emptyArrayController);
 app.get('/api/v1/notifications', emptyArrayController);
 app.get('/api/v1/accounts/:id/statuses', emptyArrayController);
 app.get('/api/v1/bookmarks', emptyArrayController);
diff --git a/src/client.ts b/src/client.ts
index 19268e34..287fbcaf 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -2,30 +2,30 @@ import { Author, RelayPool } from '@/deps.ts';
 
 import { poolRelays } from './config.ts';
 
-import type { Event } from './event.ts';
+import type { Event, SignedEvent } from './event.ts';
 
 const pool = new RelayPool(poolRelays);
 
 /** Fetch a Nostr event by its ID. */
-const fetchEvent = async (id: string): Promise<Event | null> => {
-  const event = await (pool.getEventById(id, poolRelays, 0) as Promise<Event>);
+const fetchEvent = async (id: string): Promise<SignedEvent | null> => {
+  const event = await (pool.getEventById(id, poolRelays, 0) as Promise<SignedEvent>);
   return event?.id === id ? event : null;
 };
 
 /** Fetch a Nostr `set_medatadata` event for a user's pubkey. */
-const fetchUser = async (pubkey: string): Promise<Event<0> | null> => {
+const fetchUser = async (pubkey: string): Promise<SignedEvent<0> | null> => {
   const author = new Author(pool, poolRelays, pubkey);
-  const event: Event<0> | null = await new Promise((resolve) => author.metaData(resolve, 0));
+  const event: SignedEvent<0> | null = await new Promise((resolve) => author.metaData(resolve, 0));
   return event?.pubkey === pubkey ? event : null;
 };
 
 /** Fetch users the given pubkey follows. */
-const fetchFollows = (pubkey: string): Promise<Event<3> | null> => {
+const fetchFollows = (pubkey: string): Promise<SignedEvent<3> | null> => {
   return new Promise((resolve) => {
     pool.subscribe(
       [{ authors: [pubkey], kinds: [3] }],
       poolRelays,
-      (event: Event<3> | null) => {
+      (event: SignedEvent<3> | null) => {
         resolve(event?.pubkey === pubkey ? event : null);
       },
       undefined,
@@ -34,4 +34,25 @@ const fetchFollows = (pubkey: string): Promise<Event<3> | null> => {
   });
 };
 
-export { fetchEvent, fetchFollows, fetchUser, pool };
+/** Fetch 20 events from people the user follows. */
+function fetchFeed(event3: Event<3>): Promise<SignedEvent<1>[]> {
+  const authors = event3.tags.filter((tag) => tag[0] === 'p').map((tag) => tag[1]);
+  const results: SignedEvent<1>[] = [];
+
+  return new Promise((resolve) => {
+    pool.subscribe(
+      [{ authors, kinds: [1], limit: 20 }],
+      poolRelays,
+      (event: SignedEvent<1> | null) => {
+        if (event) {
+          results.push(event);
+        }
+      },
+      void 0,
+      () => resolve(results),
+      { unsubscribeOnEose: true },
+    );
+  });
+}
+
+export { fetchEvent, fetchFeed, fetchFollows, fetchUser, pool };
diff --git a/src/event.ts b/src/event.ts
index 14e47a7d..2b4ff62b 100644
--- a/src/event.ts
+++ b/src/event.ts
@@ -1,20 +1,4 @@
-enum Kind {
-  Metadata = 0,
-  Text = 1,
-  RecommendRelay = 2,
-  Contacts = 3,
-  EncryptedDirectMessage = 4,
-  EventDeletion = 5,
-  DeprecatedRepost = 6,
-  Reaction = 7,
-  ChannelCreation = 40,
-  ChannelMetadata = 41,
-  ChannelMessage = 42,
-  ChannelHideMessage = 43,
-  ChannelMuteUser = 44,
-}
-
-interface Event<K = Kind> {
+interface Event<K extends number = number> {
   id?: string;
   sig?: string;
   kind: K;
@@ -24,4 +8,6 @@ interface Event<K = Kind> {
   created_at: number;
 }
 
-export type { Event, Kind };
+type SignedEvent<K extends number = number> = Event<K> & { id: string; sig: string };
+
+export type { Event, SignedEvent };