From efd378f963fbf7a5bbe724d528b62ee51cd28e5f Mon Sep 17 00:00:00 2001
From: Hazelnoot <acomputerdog@gmail.com>
Date: Sun, 1 Jun 2025 00:25:39 -0400
Subject: [PATCH] return typed relations from MastodonDataService note fetchers

---
 .../api/mastodon/MastodonDataService.ts       | 81 +++++++++++++++++--
 1 file changed, 73 insertions(+), 8 deletions(-)

diff --git a/packages/backend/src/server/api/mastodon/MastodonDataService.ts b/packages/backend/src/server/api/mastodon/MastodonDataService.ts
index db257756de..73cd553b9a 100644
--- a/packages/backend/src/server/api/mastodon/MastodonDataService.ts
+++ b/packages/backend/src/server/api/mastodon/MastodonDataService.ts
@@ -7,8 +7,8 @@ import { Inject, Injectable } from '@nestjs/common';
 import { IsNull } from 'typeorm';
 import { DI } from '@/di-symbols.js';
 import { QueryService } from '@/core/QueryService.js';
-import type { MiNote, NotesRepository } from '@/models/_.js';
-import type { MiLocalUser } from '@/models/User.js';
+import type { MiChannel, MiNote, NotesRepository } from '@/models/_.js';
+import type { MiLocalUser, MiUser } from '@/models/User.js';
 import { ApiError } from '../error.js';
 
 /**
@@ -27,8 +27,8 @@ export class MastodonDataService {
 	/**
 	 * Fetches a note in the context of the current user, and throws an exception if not found.
 	 */
-	public async requireNote(noteId: string, me?: MiLocalUser | null): Promise<MiNote> {
-		const note = await this.getNote(noteId, me);
+	public async requireNote<Rel extends NoteRelations = NoteRelations>(noteId: string, me: MiLocalUser | null | undefined, relations?: Rel): Promise<NoteWithRelations<Rel>> {
+		const note = await this.getNote(noteId, me, relations);
 
 		if (!note) {
 			throw new ApiError({
@@ -46,12 +46,39 @@ export class MastodonDataService {
 	/**
 	 * Fetches a note in the context of the current user.
 	 */
-	public async getNote(noteId: string, me?: MiLocalUser | null): Promise<MiNote | null> {
+	public async getNote<Rel extends NoteRelations = NoteRelations>(noteId: string, me: MiLocalUser | null | undefined, relations?: Rel): Promise<NoteWithRelations<Rel> | null> {
 		// Root query: note + required dependencies
 		const query = this.notesRepository
 			.createQueryBuilder('note')
-			.where('note.id = :noteId', { noteId })
-			.innerJoinAndSelect('note.user', 'user');
+			.where('note.id = :noteId', { noteId });
+
+		// Load relations
+		if (relations) {
+			if (relations.reply) {
+				query.leftJoinAndSelect('note.reply', 'reply');
+				if (typeof(relations.reply) === 'object') {
+					if (relations.reply.reply) query.leftJoinAndSelect('note.reply.reply', 'replyReply');
+					if (relations.reply.renote) query.leftJoinAndSelect('note.reply.renote', 'replyRenote');
+					if (relations.reply.user) query.innerJoinAndSelect('note.reply.user', 'replyUser');
+					if (relations.reply.channel) query.leftJoinAndSelect('note.reply.channel', 'replyChannel');
+				}
+			}
+			if (relations.renote) {
+				query.leftJoinAndSelect('note.renote', 'renote');
+				if (typeof(relations.renote) === 'object') {
+					if (relations.renote.reply) query.leftJoinAndSelect('note.renote.reply', 'renoteReply');
+					if (relations.renote.renote) query.leftJoinAndSelect('note.renote.renote', 'renoteRenote');
+					if (relations.renote.user) query.innerJoinAndSelect('note.renote.user', 'renoteUser');
+					if (relations.renote.channel) query.leftJoinAndSelect('note.renote.channel', 'renoteChannel');
+				}
+			}
+			if (relations.user) {
+				query.innerJoinAndSelect('note.user', 'user');
+			}
+			if (relations.channel) {
+				query.leftJoinAndSelect('note.channel', 'channel');
+			}
+		}
 
 		// Restrict visibility
 		this.queryService.generateVisibilityQuery(query, me);
@@ -59,7 +86,7 @@ export class MastodonDataService {
 			this.queryService.generateBlockedUserQueryForNotes(query, me);
 		}
 
-		return await query.getOne();
+		return await query.getOne() as NoteWithRelations<Rel> | null;
 	}
 
 	/**
@@ -82,3 +109,41 @@ export class MastodonDataService {
 		});
 	}
 }
+
+interface NoteRelations {
+	reply?: boolean | {
+		reply?: boolean;
+		renote?: boolean;
+		user?: boolean;
+		channel?: boolean;
+	};
+	renote?: boolean | {
+		reply?: boolean;
+		renote?: boolean;
+		user?: boolean;
+		channel?: boolean;
+	};
+	user?: boolean;
+	channel?: boolean;
+}
+
+type NoteWithRelations<Rel extends NoteRelations> = MiNote & {
+	reply: Rel extends { reply: false }
+		? null
+		: null | (MiNote & {
+			reply: Rel['reply'] extends { reply: true } ? MiNote | null : null;
+			renote: Rel['reply'] extends { renote: true } ? MiNote | null : null;
+			user: Rel['reply'] extends { user: true } ? MiUser : null;
+			channel: Rel['reply'] extends { channel: true } ? MiChannel | null : null;
+		});
+	renote: Rel extends { renote: false }
+		? null
+		: null | (MiNote & {
+			reply: Rel['renote'] extends { reply: true } ? MiNote | null : null;
+			renote: Rel['renote'] extends { renote: true } ? MiNote | null : null;
+			user: Rel['renote'] extends { user: true } ? MiUser : null;
+			channel: Rel['renote'] extends { channel: true } ? MiChannel | null : null;
+		});
+	user: Rel extends { user: true } ? MiUser : null;
+	channel: Rel extends { channel: true } ? MiChannel | null : null;
+};