なんかもうめっちゃ変えた

packages/backend/src/core/entities/UserGroupEntityService.ts

@@ -0,0 +1,42 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { DI } from '@/di-symbols.js';
+import { UserGroupJoiningsRepository, UserGroupsRepository } from '@/models/index.js';
+import { awaitAll } from '@/misc/prelude/await-all.js';
+import type { Packed } from '@/misc/schema.js';
+import type { } from '@/models/entities/Blocking.js';
+import type { User } from '@/models/entities/User.js';
+import type { UserGroup } from '@/models/entities/UserGroup.js';
+import { UserEntityService } from './UserEntityService.js';
+
+@Injectable()
+export class UserGroupEntityService {
+	constructor(
+		@Inject(DI.userGroupsRepository)
+		private userGroupsRepository: UserGroupsRepository,
+
+		@Inject(DI.userGroupJoiningsRepository)
+		private userGroupJoiningsRepository: UserGroupJoiningsRepository,
+
+		private userEntityService: UserEntityService,
+	) {
+	}
+
+	public async pack(
+		src: UserGroup['id'] | UserGroup,
+	): Promise<Packed<'UserGroup'>> {
+		const userGroup = typeof src === 'object' ? src : await this.userGroupsRepository.findOneByOrFail({ id: src });
+
+		const users = await this.userGroupJoiningsRepository.findBy({
+			userGroupId: userGroup.id,
+		});
+
+		return {
+			id: userGroup.id,
+			createdAt: userGroup.createdAt.toISOString(),
+			name: userGroup.name,
+			ownerId: userGroup.userId,
+			userIds: users.map(x => x.userId),
+		};
+	}
+}
+