From 42b555e5e429b42aea8ed9ae129722191b349fd1 Mon Sep 17 00:00:00 2001
From: Johann150 <johann.galle@protonmail.com>
Date: Fri, 2 Jun 2023 15:47:13 +0200
Subject: [PATCH] activitypub: handle incoming Update Note activities

Changelog: Added
---
 .../remote/activitypub/kernel/update/index.ts |  5 +-
 .../remote/activitypub/kernel/update/note.ts  | 50 +++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 packages/backend/src/remote/activitypub/kernel/update/note.ts

diff --git a/packages/backend/src/remote/activitypub/kernel/update/index.ts b/packages/backend/src/remote/activitypub/kernel/update/index.ts
index d34965db2..96367af0a 100644
--- a/packages/backend/src/remote/activitypub/kernel/update/index.ts
+++ b/packages/backend/src/remote/activitypub/kernel/update/index.ts
@@ -1,9 +1,10 @@
 import { IRemoteUser } from '@/models/entities/user.js';
-import { getApId, getApType, IUpdate, isActor } from '@/remote/activitypub/type.js';
+import { getApId, getOneApId, getApType, IUpdate, isActor, isPost } from '@/remote/activitypub/type.js';
 import { apLogger } from '@/remote/activitypub/logger.js';
 import { updateQuestion } from '@/remote/activitypub/models/question.js';
 import { Resolver } from '@/remote/activitypub/resolver.js';
 import { updatePerson } from '@/remote/activitypub/models/person.js';
+import { update as updateNote } from '@/remote/activitypub/kernel/update/note.js';
 
 /**
  * Updateアクティビティを捌きます
@@ -30,6 +31,8 @@ export default async (actor: IRemoteUser, activity: IUpdate, resolver: Resolver)
 	} else if (getApType(object) === 'Question') {
 		await updateQuestion(object, resolver).catch(e => console.log(e));
 		return 'ok: Question updated';
+	} else if (isPost(object)) {
+		return await updateNote(actor, object, resolver);
 	} else {
 		return `skip: Unknown type: ${getApType(object)}`;
 	}
diff --git a/packages/backend/src/remote/activitypub/kernel/update/note.ts b/packages/backend/src/remote/activitypub/kernel/update/note.ts
new file mode 100644
index 000000000..1c1140241
--- /dev/null
+++ b/packages/backend/src/remote/activitypub/kernel/update/note.ts
@@ -0,0 +1,50 @@
+import { IRemoteUser } from '@/models/entities/user.js';
+import { getApId } from '@/remote/activitypub/type.js';
+import { Resolver } from '@/remote/activitypub/resolver.js';
+import { Notes } from '@/models/index.js';
+import createNote from '@/remote/activitypub/kernel/create/note.js';
+import { getApLock } from '@/misc/app-lock.js';
+import { updateNote } from '@/remote/activitypub/models/note.js';
+
+export async function update(actor: IRemoteUser, note: IObject, resolver: Resolver): Promise<string> {
+	// check whether note exists
+	const uri = getApId(note);
+	const exists = await Notes.findOneBy({ uri });
+
+	if (exists == null) {
+		// does not yet exist, handle as if this was a create activity
+		// and since this is not a direct creation, handle it silently
+		createNote(resolver, actor, note, true);
+
+		const unlock = await getApLock(uri);
+		try {
+			// if creating was successful...
+			const existsNow = await Notes.findOneByOrFail({ uri });
+			// set the updatedAt timestamp since the note was changed
+			await Notes.update(existsNow.id, { updatedAt: new Date() });
+			return 'ok: unknown note created and marked as updated';
+		} catch (e) {
+			return `skip: updated note unknown and creating rejected: ${e.message}`;
+		} finally {
+			unlock();
+		}
+	} else {
+		// check that actor is authorized to update this note
+		if (actor.id !== exists.userId) {
+			return 'skip: actor not authorized to update Note';
+		}
+		// this does not redo the checks from the Create Note kernel
+		// since if the note made it into the database, we assume
+		// those checks must have been passed before.
+
+		const unlock = await getApLock(uri);
+		try {
+			await updateNote(note, actor, resolver);
+			return 'ok: note updated';
+		} catch (e) {
+			return `skip: update note rejected: ${e.message}`;
+		} finally {
+			unlock();
+		}
+	}
+}