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 <46447427+samunohito@users.noreply.github.com>
Date: Fri, 11 Oct 2024 20:59:36 +0900
Subject: [PATCH] =?UTF-8?q?feat(backend):=207=E6=97=A5=E9=96=93=E9=81=8B?=
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* feat(backend): 7日間運営のアクティビティがないサーバを自動的に招待制にする

* fix RoleService.

* fix

* fix

* fix

* add test and fix

* fix

* fix CHANGELOG.md

* fix test
---
 CHANGELOG.md                                  |   5 +
 .../core/AbuseReportNotificationService.ts    |  10 +-
 packages/backend/src/core/QueueService.ts     |   7 +
 packages/backend/src/core/RoleService.ts      |  75 ++++--
 .../backend/src/queue/QueueProcessorModule.ts |   3 +
 .../src/queue/QueueProcessorService.ts        |   3 +
 ...CheckModeratorsActivityProcessorService.ts | 127 ++++++++++
 .../server/api/endpoints/admin/show-users.ts  |   4 +-
 packages/backend/test/unit/RoleService.ts     | 150 +++++++++--
 ...CheckModeratorsActivityProcessorService.ts | 235 ++++++++++++++++++
 10 files changed, 575 insertions(+), 44 deletions(-)
 create mode 100644 packages/backend/src/queue/processors/CheckModeratorsActivityProcessorService.ts
 create mode 100644 packages/backend/test/unit/queue/processors/CheckModeratorsActivityProcessorService.ts

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b449a1b91e..030dbfda28 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,10 +1,15 @@
 ## 2024.10.1
+### Note
+- 悪質なユーザからサーバを守る措置の一環として、モデレータ権限を持つユーザの最終アクティブ日時を確認し、 
+7日間活動していない場合は自動的に招待制へと移行(コントロールパネル -> モデレーション -> "誰でも新規登録できるようにする"をオフに変更)するようになりました。  
+詳細な経緯は https://github.com/misskey-dev/misskey/issues/13437 をご確認ください。
 
 ### Client
 - Enhance: l10nの更新
 - Fix: メールアドレス不要でCaptchaが有効な場合にアカウント登録完了後自動でのログインに失敗する問題を修正
 
 ### Server
+- Feat: モデレータ権限を持つユーザが全員7日間活動しなかった場合は自動的に招待制へと移行するように ( #13437 )
 - Fix: `admin/emoji/update`エンドポイントのidのみ指定した時不正なエラーが発生するバグを修正
 
 ## 2024.10.0
diff --git a/packages/backend/src/core/AbuseReportNotificationService.ts b/packages/backend/src/core/AbuseReportNotificationService.ts
index fb7c7bd2c3..7d030f2f16 100644
--- a/packages/backend/src/core/AbuseReportNotificationService.ts
+++ b/packages/backend/src/core/AbuseReportNotificationService.ts
@@ -61,7 +61,10 @@ export class AbuseReportNotificationService implements OnApplicationShutdown {
 			return;
 		}
 
-		const moderatorIds = await this.roleService.getModeratorIds(true, true);
+		const moderatorIds = await this.roleService.getModeratorIds({
+			includeAdmins: true,
+			excludeExpire: true,
+		});
 
 		for (const moderatorId of moderatorIds) {
 			for (const abuseReport of abuseReports) {
@@ -370,7 +373,10 @@ export class AbuseReportNotificationService implements OnApplicationShutdown {
 		}
 
 		// モデレータ権限の有無で通知先設定を振り分ける
-		const authorizedUserIds = await this.roleService.getModeratorIds(true, true);
+		const authorizedUserIds = await this.roleService.getModeratorIds({
+			includeAdmins: true,
+			excludeExpire: true,
+		});
 		const authorizedUserRecipients = Array.of<MiAbuseReportNotificationRecipient>();
 		const unauthorizedUserRecipients = Array.of<MiAbuseReportNotificationRecipient>();
 		for (const recipient of userRecipients) {
diff --git a/packages/backend/src/core/QueueService.ts b/packages/backend/src/core/QueueService.ts
index f35e456556..37028026cc 100644
--- a/packages/backend/src/core/QueueService.ts
+++ b/packages/backend/src/core/QueueService.ts
@@ -93,6 +93,13 @@ export class QueueService {
 			repeat: { pattern: '0 0 * * *' },
 			removeOnComplete: true,
 		});
+
+		this.systemQueue.add('checkModeratorsActivity', {
+		}, {
+			// 毎時30分に起動
+			repeat: { pattern: '30 * * * *' },
+			removeOnComplete: true,
+		});
 	}
 
 	@bindThis
diff --git a/packages/backend/src/core/RoleService.ts b/packages/backend/src/core/RoleService.ts
index 583eea1a34..5af6b05942 100644
--- a/packages/backend/src/core/RoleService.ts
+++ b/packages/backend/src/core/RoleService.ts
@@ -101,6 +101,7 @@ export const DEFAULT_POLICIES: RolePolicies = {
 
 @Injectable()
 export class RoleService implements OnApplicationShutdown, OnModuleInit {
+	private rootUserIdCache: MemorySingleCache<MiUser['id']>;
 	private rolesCache: MemorySingleCache<MiRole[]>;
 	private roleAssignmentByUserIdCache: MemoryKVCache<MiRoleAssignment[]>;
 	private notificationService: NotificationService;
@@ -136,6 +137,7 @@ export class RoleService implements OnApplicationShutdown, OnModuleInit {
 		private moderationLogService: ModerationLogService,
 		private fanoutTimelineService: FanoutTimelineService,
 	) {
+		this.rootUserIdCache = new MemorySingleCache<MiUser['id']>(1000 * 60 * 60 * 24 * 7); // 1week. rootユーザのIDは不変なので長めに
 		this.rolesCache = new MemorySingleCache<MiRole[]>(1000 * 60 * 60); // 1h
 		this.roleAssignmentByUserIdCache = new MemoryKVCache<MiRoleAssignment[]>(1000 * 60 * 5); // 5m
 
@@ -416,49 +418,78 @@ export class RoleService implements OnApplicationShutdown, OnModuleInit {
 	}
 
 	@bindThis
-	public async isExplorable(role: { id: MiRole['id']} | null): Promise<boolean> {
+	public async isExplorable(role: { id: MiRole['id'] } | null): Promise<boolean> {
 		if (role == null) return false;
 		const check = await this.rolesRepository.findOneBy({ id: role.id });
 		if (check == null) return false;
 		return check.isExplorable;
 	}
 
+	/**
+	 * モデレーター権限のロールが割り当てられているユーザID一覧を取得する.
+	 *
+	 * @param opts.includeAdmins 管理者権限も含めるか(デフォルト: true)
+	 * @param opts.includeRoot rootユーザも含めるか(デフォルト: false)
+	 * @param opts.excludeExpire 期限切れのロールを除外するか(デフォルト: false)
+	 */
 	@bindThis
-	public async getModeratorIds(includeAdmins = true, excludeExpire = false): Promise<MiUser['id'][]> {
+	public async getModeratorIds(opts?: {
+		includeAdmins?: boolean,
+		includeRoot?: boolean,
+		excludeExpire?: boolean,
+	}): Promise<MiUser['id'][]> {
+		const includeAdmins = opts?.includeAdmins ?? true;
+		const includeRoot = opts?.includeRoot ?? false;
+		const excludeExpire = opts?.excludeExpire ?? false;
+
 		const roles = await this.rolesCache.fetch(() => this.rolesRepository.findBy({}));
 		const moderatorRoles = includeAdmins
 			? roles.filter(r => r.isModerator || r.isAdministrator)
 			: roles.filter(r => r.isModerator);
 
-		// TODO: isRootなアカウントも含める
 		const assigns = moderatorRoles.length > 0
 			? await this.roleAssignmentsRepository.findBy({ roleId: In(moderatorRoles.map(r => r.id)) })
 			: [];
 
+		// Setを経由して重複を除去(ユーザIDは重複する可能性があるので)
 		const now = Date.now();
-		const result = [
-			// Setを経由して重複を除去(ユーザIDは重複する可能性があるので)
-			...new Set(
-				assigns
-					.filter(it =>
-						(excludeExpire)
-							? (it.expiresAt == null || it.expiresAt.getTime() > now)
-							: true,
-					)
-					.map(a => a.userId),
-			),
-		];
+		const resultSet = new Set(
+			assigns
+				.filter(it =>
+					(excludeExpire)
+						? (it.expiresAt == null || it.expiresAt.getTime() > now)
+						: true,
+				)
+				.map(a => a.userId),
+		);
 
-		return result.sort((x, y) => x.localeCompare(y));
+		if (includeRoot) {
+			const rootUserId = await this.rootUserIdCache.fetch(async () => {
+				const it = await this.usersRepository.createQueryBuilder('users')
+					.select('id')
+					.where({ isRoot: true })
+					.getRawOne<{ id: string }>();
+				// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+				return it!.id;
+			});
+			resultSet.add(rootUserId);
+		}
+
+		return [...resultSet].sort((x, y) => x.localeCompare(y));
 	}
 
 	@bindThis
-	public async getModerators(includeAdmins = true): Promise<MiUser[]> {
-		const ids = await this.getModeratorIds(includeAdmins);
-		const users = ids.length > 0 ? await this.usersRepository.findBy({
-			id: In(ids),
-		}) : [];
-		return users;
+	public async getModerators(opts?: {
+		includeAdmins?: boolean,
+		includeRoot?: boolean,
+		excludeExpire?: boolean,
+	}): Promise<MiUser[]> {
+		const ids = await this.getModeratorIds(opts);
+		return ids.length > 0
+			? await this.usersRepository.findBy({
+				id: In(ids),
+			})
+			: [];
 	}
 
 	@bindThis
diff --git a/packages/backend/src/queue/QueueProcessorModule.ts b/packages/backend/src/queue/QueueProcessorModule.ts
index 0027b5ef3d..9044285bf6 100644
--- a/packages/backend/src/queue/QueueProcessorModule.ts
+++ b/packages/backend/src/queue/QueueProcessorModule.ts
@@ -6,6 +6,7 @@
 import { Module } from '@nestjs/common';
 import { CoreModule } from '@/core/CoreModule.js';
 import { GlobalModule } from '@/GlobalModule.js';
+import { CheckModeratorsActivityProcessorService } from '@/queue/processors/CheckModeratorsActivityProcessorService.js';
 import { QueueLoggerService } from './QueueLoggerService.js';
 import { QueueProcessorService } from './QueueProcessorService.js';
 import { DeliverProcessorService } from './processors/DeliverProcessorService.js';
@@ -80,6 +81,8 @@ import { RelationshipProcessorService } from './processors/RelationshipProcessor
 		DeliverProcessorService,
 		InboxProcessorService,
 		AggregateRetentionProcessorService,
+		CheckExpiredMutingsProcessorService,
+		CheckModeratorsActivityProcessorService,
 		QueueProcessorService,
 	],
 	exports: [
diff --git a/packages/backend/src/queue/QueueProcessorService.ts b/packages/backend/src/queue/QueueProcessorService.ts
index e9e1c45224..85e148e900 100644
--- a/packages/backend/src/queue/QueueProcessorService.ts
+++ b/packages/backend/src/queue/QueueProcessorService.ts
@@ -10,6 +10,7 @@ import type { Config } from '@/config.js';
 import { DI } from '@/di-symbols.js';
 import type Logger from '@/logger.js';
 import { bindThis } from '@/decorators.js';
+import { CheckModeratorsActivityProcessorService } from '@/queue/processors/CheckModeratorsActivityProcessorService.js';
 import { UserWebhookDeliverProcessorService } from './processors/UserWebhookDeliverProcessorService.js';
 import { SystemWebhookDeliverProcessorService } from './processors/SystemWebhookDeliverProcessorService.js';
 import { EndedPollNotificationProcessorService } from './processors/EndedPollNotificationProcessorService.js';
@@ -120,6 +121,7 @@ export class QueueProcessorService implements OnApplicationShutdown {
 		private aggregateRetentionProcessorService: AggregateRetentionProcessorService,
 		private checkExpiredMutingsProcessorService: CheckExpiredMutingsProcessorService,
 		private bakeBufferedReactionsProcessorService: BakeBufferedReactionsProcessorService,
+		private checkModeratorsActivityProcessorService: CheckModeratorsActivityProcessorService,
 		private cleanProcessorService: CleanProcessorService,
 	) {
 		this.logger = this.queueLoggerService.logger;
@@ -150,6 +152,7 @@ export class QueueProcessorService implements OnApplicationShutdown {
 					case 'aggregateRetention': return this.aggregateRetentionProcessorService.process();
 					case 'checkExpiredMutings': return this.checkExpiredMutingsProcessorService.process();
 					case 'bakeBufferedReactions': return this.bakeBufferedReactionsProcessorService.process();
+					case 'checkModeratorsActivity': return this.checkModeratorsActivityProcessorService.process();
 					case 'clean': return this.cleanProcessorService.process();
 					default: throw new Error(`unrecognized job type ${job.name} for system`);
 				}
diff --git a/packages/backend/src/queue/processors/CheckModeratorsActivityProcessorService.ts b/packages/backend/src/queue/processors/CheckModeratorsActivityProcessorService.ts
new file mode 100644
index 0000000000..f2677f8e5c
--- /dev/null
+++ b/packages/backend/src/queue/processors/CheckModeratorsActivityProcessorService.ts
@@ -0,0 +1,127 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { Injectable } from '@nestjs/common';
+import type Logger from '@/logger.js';
+import { bindThis } from '@/decorators.js';
+import { MetaService } from '@/core/MetaService.js';
+import { RoleService } from '@/core/RoleService.js';
+import { QueueLoggerService } from '../QueueLoggerService.js';
+
+// モデレーターが不在と判断する日付の閾値
+const MODERATOR_INACTIVITY_LIMIT_DAYS = 7;
+const ONE_DAY_MILLI_SEC = 1000 * 60 * 60 * 24;
+
+@Injectable()
+export class CheckModeratorsActivityProcessorService {
+	private logger: Logger;
+
+	constructor(
+		private metaService: MetaService,
+		private roleService: RoleService,
+		private queueLoggerService: QueueLoggerService,
+	) {
+		this.logger = this.queueLoggerService.logger.createSubLogger('check-moderators-activity');
+	}
+
+	@bindThis
+	public async process(): Promise<void> {
+		this.logger.info('start.');
+
+		const meta = await this.metaService.fetch(false);
+		if (!meta.disableRegistration) {
+			await this.processImpl();
+		} else {
+			this.logger.info('is already invitation only.');
+		}
+
+		this.logger.succ('finish.');
+	}
+
+	@bindThis
+	private async processImpl() {
+		const { isModeratorsInactive, inactivityLimitCountdown } = await this.evaluateModeratorsInactiveDays();
+		if (isModeratorsInactive) {
+			this.logger.warn(`The moderator has been inactive for ${MODERATOR_INACTIVITY_LIMIT_DAYS} days. We will move to invitation only.`);
+			await this.changeToInvitationOnly();
+
+			// TODO: モデレータに通知メール+Misskey通知
+			// TODO: SystemWebhook通知
+		} else {
+			if (inactivityLimitCountdown <= 2) {
+				this.logger.warn(`A moderator has been inactive for a period of time. If you are inactive for an additional ${inactivityLimitCountdown} days, it will switch to invitation only.`);
+
+				// TODO: 警告メール
+			}
+		}
+	}
+
+	/**
+	 * モデレーターが不在であるかどうかを確認する。trueの場合はモデレーターが不在である。
+	 * isModerator, isAdministrator, isRootのいずれかがtrueのユーザを対象に、
+	 * {@link MiUser.lastActiveDate}の値が実行日時の{@link MODERATOR_INACTIVITY_LIMIT_DAYS}日前よりも古いユーザがいるかどうかを確認する。
+	 * {@link MiUser.lastActiveDate}がnullの場合は、そのユーザは確認の対象外とする。
+	 *
+	 * -----
+	 *
+	 * ### サンプルパターン
+	 * - 実行日時: 2022-01-30 12:00:00
+	 * - 判定基準: 2022-01-23 12:00:00(実行日時の{@link MODERATOR_INACTIVITY_LIMIT_DAYS}日前)
+	 *
+	 * #### パターン①
+	 * - モデレータA: lastActiveDate = 2022-01-20 00:00:00 ※アウト
+	 * - モデレータB: lastActiveDate = 2022-01-23 12:00:00 ※セーフ(判定基準と同値なのでギリギリ残り0日)
+	 * - モデレータC: lastActiveDate = 2022-01-23 11:59:59 ※アウト(残り-1日)
+	 * - モデレータD: lastActiveDate = null
+	 *
+	 * この場合、モデレータBのアクティビティのみ判定基準日よりも古くないため、モデレーターが在席と判断される。
+	 *
+	 * #### パターン②
+	 * - モデレータA: lastActiveDate = 2022-01-20 00:00:00 ※アウト
+	 * - モデレータB: lastActiveDate = 2022-01-22 12:00:00 ※アウト(残り-1日)
+	 * - モデレータC: lastActiveDate = 2022-01-23 11:59:59 ※アウト(残り-1日)
+	 * - モデレータD: lastActiveDate = null
+	 *
+	 * この場合、モデレータA, B, Cのアクティビティは判定基準日よりも古いため、モデレーターが不在と判断される。
+	 */
+	@bindThis
+	public async evaluateModeratorsInactiveDays() {
+		const today = new Date();
+		const inactivePeriod = new Date(today);
+		inactivePeriod.setDate(today.getDate() - MODERATOR_INACTIVITY_LIMIT_DAYS);
+
+		const moderators = await this.fetchModerators()
+			.then(it => it.filter(it => it.lastActiveDate != null));
+		const inactiveModerators = moderators
+			// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+			.filter(it => it.lastActiveDate!.getTime() < inactivePeriod.getTime());
+
+		// 残りの猶予を示したいので、最終アクティブ日時が一番若いモデレータの日数を基準に猶予を計算する
+		// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+		const newestLastActiveDate = new Date(Math.max(...moderators.map(it => it.lastActiveDate!.getTime())));
+		const inactivityLimitCountdown = Math.floor((newestLastActiveDate.getTime() - inactivePeriod.getTime()) / ONE_DAY_MILLI_SEC);
+
+		return {
+			isModeratorsInactive: inactiveModerators.length === moderators.length,
+			inactiveModerators,
+			inactivityLimitCountdown,
+		};
+	}
+
+	@bindThis
+	private async changeToInvitationOnly() {
+		await this.metaService.update({ disableRegistration: true });
+	}
+
+	@bindThis
+	private async fetchModerators() {
+		// TODO: モデレーター以外にも特別な権限を持つユーザーがいる場合は考慮する
+		return this.roleService.getModerators({
+			includeAdmins: true,
+			includeRoot: true,
+			excludeExpire: true,
+		});
+	}
+}
diff --git a/packages/backend/src/server/api/endpoints/admin/show-users.ts b/packages/backend/src/server/api/endpoints/admin/show-users.ts
index 2fef9abbf9..2b2c8c60ab 100644
--- a/packages/backend/src/server/api/endpoints/admin/show-users.ts
+++ b/packages/backend/src/server/api/endpoints/admin/show-users.ts
@@ -71,13 +71,13 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 					break;
 				}
 				case 'moderator': {
-					const moderatorIds = await this.roleService.getModeratorIds(false);
+					const moderatorIds = await this.roleService.getModeratorIds({ includeAdmins: false });
 					if (moderatorIds.length === 0) return [];
 					query.where('user.id IN (:...moderatorIds)', { moderatorIds: moderatorIds });
 					break;
 				}
 				case 'adminOrModerator': {
-					const adminOrModeratorIds = await this.roleService.getModeratorIds();
+					const adminOrModeratorIds = await this.roleService.getModeratorIds({ includeAdmins: true });
 					if (adminOrModeratorIds.length === 0) return [];
 					query.where('user.id IN (:...adminOrModeratorIds)', { adminOrModeratorIds: adminOrModeratorIds });
 					break;
diff --git a/packages/backend/test/unit/RoleService.ts b/packages/backend/test/unit/RoleService.ts
index ef80d25f81..9c1b1008d6 100644
--- a/packages/backend/test/unit/RoleService.ts
+++ b/packages/backend/test/unit/RoleService.ts
@@ -10,6 +10,8 @@ import { jest } from '@jest/globals';
 import { ModuleMocker } from 'jest-mock';
 import { Test } from '@nestjs/testing';
 import * as lolex from '@sinonjs/fake-timers';
+import type { TestingModule } from '@nestjs/testing';
+import type { MockFunctionMetadata } from 'jest-mock';
 import { GlobalModule } from '@/GlobalModule.js';
 import { RoleService } from '@/core/RoleService.js';
 import {
@@ -31,8 +33,6 @@ import { secureRndstr } from '@/misc/secure-rndstr.js';
 import { NotificationService } from '@/core/NotificationService.js';
 import { RoleCondFormulaValue } from '@/models/Role.js';
 import { UserEntityService } from '@/core/entities/UserEntityService.js';
-import type { TestingModule } from '@nestjs/testing';
-import type { MockFunctionMetadata } from 'jest-mock';
 
 const moduleMocker = new ModuleMocker(global);
 
@@ -277,9 +277,9 @@ describe('RoleService', () => {
 	});
 
 	describe('getModeratorIds', () => {
-		test('includeAdmins = false, excludeExpire = false', async () => {
-			const [adminUser1, adminUser2, modeUser1, modeUser2, normalUser1, normalUser2] = await Promise.all([
-				createUser(), createUser(), createUser(), createUser(), createUser(), createUser(),
+		test('includeAdmins = false, includeRoot = false, excludeExpire = false', async () => {
+			const [adminUser1, adminUser2, modeUser1, modeUser2, normalUser1, normalUser2, rootUser] = await Promise.all([
+				createUser(), createUser(), createUser(), createUser(), createUser(), createUser(), createUser({ isRoot: true }),
 			]);
 
 			const role1 = await createRole({ name: 'admin', isAdministrator: true });
@@ -295,13 +295,17 @@ describe('RoleService', () => {
 				assignRole({ userId: normalUser2.id, roleId: role3.id, expiresAt: new Date(Date.now() - 1000) }),
 			]);
 
-			const result = await roleService.getModeratorIds(false, false);
+			const result = await roleService.getModeratorIds({
+				includeAdmins: false,
+				includeRoot: false,
+				excludeExpire: false,
+			});
 			expect(result).toEqual([modeUser1.id, modeUser2.id]);
 		});
 
-		test('includeAdmins = false, excludeExpire = true', async () => {
-			const [adminUser1, adminUser2, modeUser1, modeUser2, normalUser1, normalUser2] = await Promise.all([
-				createUser(), createUser(), createUser(), createUser(), createUser(), createUser(),
+		test('includeAdmins = false, includeRoot = false, excludeExpire = true', async () => {
+			const [adminUser1, adminUser2, modeUser1, modeUser2, normalUser1, normalUser2, rootUser] = await Promise.all([
+				createUser(), createUser(), createUser(), createUser(), createUser(), createUser(), createUser({ isRoot: true }),
 			]);
 
 			const role1 = await createRole({ name: 'admin', isAdministrator: true });
@@ -317,13 +321,17 @@ describe('RoleService', () => {
 				assignRole({ userId: normalUser2.id, roleId: role3.id, expiresAt: new Date(Date.now() - 1000) }),
 			]);
 
-			const result = await roleService.getModeratorIds(false, true);
+			const result = await roleService.getModeratorIds({
+				includeAdmins: false,
+				includeRoot: false,
+				excludeExpire: true,
+			});
 			expect(result).toEqual([modeUser1.id]);
 		});
 
-		test('includeAdmins = true, excludeExpire = false', async () => {
-			const [adminUser1, adminUser2, modeUser1, modeUser2, normalUser1, normalUser2] = await Promise.all([
-				createUser(), createUser(), createUser(), createUser(), createUser(), createUser(),
+		test('includeAdmins = true, includeRoot = false, excludeExpire = false', async () => {
+			const [adminUser1, adminUser2, modeUser1, modeUser2, normalUser1, normalUser2, rootUser] = await Promise.all([
+				createUser(), createUser(), createUser(), createUser(), createUser(), createUser(), createUser({ isRoot: true }),
 			]);
 
 			const role1 = await createRole({ name: 'admin', isAdministrator: true });
@@ -339,13 +347,17 @@ describe('RoleService', () => {
 				assignRole({ userId: normalUser2.id, roleId: role3.id, expiresAt: new Date(Date.now() - 1000) }),
 			]);
 
-			const result = await roleService.getModeratorIds(true, false);
+			const result = await roleService.getModeratorIds({
+				includeAdmins: true,
+				includeRoot: false,
+				excludeExpire: false,
+			});
 			expect(result).toEqual([adminUser1.id, adminUser2.id, modeUser1.id, modeUser2.id]);
 		});
 
-		test('includeAdmins = true, excludeExpire = true', async () => {
-			const [adminUser1, adminUser2, modeUser1, modeUser2, normalUser1, normalUser2] = await Promise.all([
-				createUser(), createUser(), createUser(), createUser(), createUser(), createUser(),
+		test('includeAdmins = true, includeRoot = false, excludeExpire = true', async () => {
+			const [adminUser1, adminUser2, modeUser1, modeUser2, normalUser1, normalUser2, rootUser] = await Promise.all([
+				createUser(), createUser(), createUser(), createUser(), createUser(), createUser(), createUser({ isRoot: true }),
 			]);
 
 			const role1 = await createRole({ name: 'admin', isAdministrator: true });
@@ -361,9 +373,111 @@ describe('RoleService', () => {
 				assignRole({ userId: normalUser2.id, roleId: role3.id, expiresAt: new Date(Date.now() - 1000) }),
 			]);
 
-			const result = await roleService.getModeratorIds(true, true);
+			const result = await roleService.getModeratorIds({
+				includeAdmins: true,
+				includeRoot: false,
+				excludeExpire: true,
+			});
 			expect(result).toEqual([adminUser1.id, modeUser1.id]);
 		});
+
+		test('includeAdmins = false, includeRoot = true, excludeExpire = false', async () => {
+			const [adminUser1, adminUser2, modeUser1, modeUser2, normalUser1, normalUser2, rootUser] = await Promise.all([
+				createUser(), createUser(), createUser(), createUser(), createUser(), createUser(), createUser({ isRoot: true }),
+			]);
+
+			const role1 = await createRole({ name: 'admin', isAdministrator: true });
+			const role2 = await createRole({ name: 'moderator', isModerator: true });
+			const role3 = await createRole({ name: 'normal' });
+
+			await Promise.all([
+				assignRole({ userId: adminUser1.id, roleId: role1.id }),
+				assignRole({ userId: adminUser2.id, roleId: role1.id, expiresAt: new Date(Date.now() - 1000) }),
+				assignRole({ userId: modeUser1.id, roleId: role2.id }),
+				assignRole({ userId: modeUser2.id, roleId: role2.id, expiresAt: new Date(Date.now() - 1000) }),
+				assignRole({ userId: normalUser1.id, roleId: role3.id }),
+				assignRole({ userId: normalUser2.id, roleId: role3.id, expiresAt: new Date(Date.now() - 1000) }),
+			]);
+
+			const result = await roleService.getModeratorIds({
+				includeAdmins: false,
+				includeRoot: true,
+				excludeExpire: false,
+			});
+			expect(result).toEqual([modeUser1.id, modeUser2.id, rootUser.id]);
+		});
+
+		test('root has moderator role', async () => {
+			const [adminUser1, modeUser1, normalUser1, rootUser] = await Promise.all([
+				createUser(), createUser(), createUser(), createUser({ isRoot: true }),
+			]);
+
+			const role1 = await createRole({ name: 'admin', isAdministrator: true });
+			const role2 = await createRole({ name: 'moderator', isModerator: true });
+			const role3 = await createRole({ name: 'normal' });
+
+			await Promise.all([
+				assignRole({ userId: adminUser1.id, roleId: role1.id }),
+				assignRole({ userId: modeUser1.id, roleId: role2.id }),
+				assignRole({ userId: rootUser.id, roleId: role2.id }),
+				assignRole({ userId: normalUser1.id, roleId: role3.id }),
+			]);
+
+			const result = await roleService.getModeratorIds({
+				includeAdmins: false,
+				includeRoot: true,
+				excludeExpire: false,
+			});
+			expect(result).toEqual([modeUser1.id, rootUser.id]);
+		});
+
+		test('root has administrator role', async () => {
+			const [adminUser1, modeUser1, normalUser1, rootUser] = await Promise.all([
+				createUser(), createUser(), createUser(), createUser({ isRoot: true }),
+			]);
+
+			const role1 = await createRole({ name: 'admin', isAdministrator: true });
+			const role2 = await createRole({ name: 'moderator', isModerator: true });
+			const role3 = await createRole({ name: 'normal' });
+
+			await Promise.all([
+				assignRole({ userId: adminUser1.id, roleId: role1.id }),
+				assignRole({ userId: rootUser.id, roleId: role1.id }),
+				assignRole({ userId: modeUser1.id, roleId: role2.id }),
+				assignRole({ userId: normalUser1.id, roleId: role3.id }),
+			]);
+
+			const result = await roleService.getModeratorIds({
+				includeAdmins: true,
+				includeRoot: true,
+				excludeExpire: false,
+			});
+			expect(result).toEqual([adminUser1.id, modeUser1.id, rootUser.id]);
+		});
+
+		test('root has moderator role(expire)', async () => {
+			const [adminUser1, modeUser1, normalUser1, rootUser] = await Promise.all([
+				createUser(), createUser(), createUser(), createUser({ isRoot: true }),
+			]);
+
+			const role1 = await createRole({ name: 'admin', isAdministrator: true });
+			const role2 = await createRole({ name: 'moderator', isModerator: true });
+			const role3 = await createRole({ name: 'normal' });
+
+			await Promise.all([
+				assignRole({ userId: adminUser1.id, roleId: role1.id }),
+				assignRole({ userId: modeUser1.id, roleId: role2.id, expiresAt: new Date(Date.now() - 1000) }),
+				assignRole({ userId: rootUser.id, roleId: role2.id, expiresAt: new Date(Date.now() - 1000) }),
+				assignRole({ userId: normalUser1.id, roleId: role3.id }),
+			]);
+
+			const result = await roleService.getModeratorIds({
+				includeAdmins: false,
+				includeRoot: true,
+				excludeExpire: true,
+			});
+			expect(result).toEqual([rootUser.id]);
+		});
 	});
 
 	describe('conditional role', () => {
diff --git a/packages/backend/test/unit/queue/processors/CheckModeratorsActivityProcessorService.ts b/packages/backend/test/unit/queue/processors/CheckModeratorsActivityProcessorService.ts
new file mode 100644
index 0000000000..b783320aa0
--- /dev/null
+++ b/packages/backend/test/unit/queue/processors/CheckModeratorsActivityProcessorService.ts
@@ -0,0 +1,235 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { jest } from '@jest/globals';
+import { Test, TestingModule } from '@nestjs/testing';
+import * as lolex from '@sinonjs/fake-timers';
+import { addHours, addSeconds, subDays, subHours, subSeconds } from 'date-fns';
+import { CheckModeratorsActivityProcessorService } from '@/queue/processors/CheckModeratorsActivityProcessorService.js';
+import { MiUser, UserProfilesRepository, UsersRepository } from '@/models/_.js';
+import { IdService } from '@/core/IdService.js';
+import { RoleService } from '@/core/RoleService.js';
+import { GlobalModule } from '@/GlobalModule.js';
+import { MetaService } from '@/core/MetaService.js';
+import { DI } from '@/di-symbols.js';
+import { QueueLoggerService } from '@/queue/QueueLoggerService.js';
+
+const baseDate = new Date(Date.UTC(2000, 11, 15, 12, 0, 0));
+
+describe('CheckModeratorsActivityProcessorService', () => {
+	let app: TestingModule;
+	let clock: lolex.InstalledClock;
+	let service: CheckModeratorsActivityProcessorService;
+
+	// --------------------------------------------------------------------------------------
+
+	let usersRepository: UsersRepository;
+	let userProfilesRepository: UserProfilesRepository;
+	let idService: IdService;
+	let roleService: jest.Mocked<RoleService>;
+
+	// --------------------------------------------------------------------------------------
+
+	async function createUser(data: Partial<MiUser> = {}) {
+		const id = idService.gen();
+		const user = await usersRepository
+			.insert({
+				id: id,
+				username: `user_${id}`,
+				usernameLower: `user_${id}`.toLowerCase(),
+				...data,
+			})
+			.then(x => usersRepository.findOneByOrFail(x.identifiers[0]));
+
+		await userProfilesRepository.insert({
+			userId: user.id,
+		});
+
+		return user;
+	}
+
+	function mockModeratorRole(users: MiUser[]) {
+		roleService.getModerators.mockReset();
+		roleService.getModerators.mockResolvedValue(users);
+	}
+
+	// --------------------------------------------------------------------------------------
+
+	beforeAll(async () => {
+		app = await Test
+			.createTestingModule({
+				imports: [
+					GlobalModule,
+				],
+				providers: [
+					CheckModeratorsActivityProcessorService,
+					IdService,
+					{
+						provide: RoleService, useFactory: () => ({ getModerators: jest.fn() }),
+					},
+					{
+						provide: MetaService, useFactory: () => ({ fetch: jest.fn() }),
+					},
+					{
+						provide: QueueLoggerService, useFactory: () => ({
+							logger: ({
+								createSubLogger: () => ({
+									info: jest.fn(),
+									warn: jest.fn(),
+									succ: jest.fn(),
+								}),
+							}),
+						}),
+					},
+				],
+			})
+			.compile();
+
+		usersRepository = app.get(DI.usersRepository);
+		userProfilesRepository = app.get(DI.userProfilesRepository);
+
+		service = app.get(CheckModeratorsActivityProcessorService);
+		idService = app.get(IdService);
+		roleService = app.get(RoleService) as jest.Mocked<RoleService>;
+
+		app.enableShutdownHooks();
+	});
+
+	beforeEach(async () => {
+		clock = lolex.install({
+			now: new Date(baseDate),
+			shouldClearNativeTimers: true,
+		});
+	});
+
+	afterEach(async () => {
+		clock.uninstall();
+		await usersRepository.delete({});
+		await userProfilesRepository.delete({});
+		roleService.getModerators.mockReset();
+	});
+
+	afterAll(async () => {
+		await app.close();
+	});
+
+	// --------------------------------------------------------------------------------------
+
+	describe('evaluateModeratorsInactiveDays', () => {
+		test('[isModeratorsInactive] inactiveなモデレーターがいても他のモデレーターがアクティブなら"運営が非アクティブ"としてみなされない', async () => {
+			const [user1, user2, user3, user4] = await Promise.all([
+				// 期限よりも1秒新しいタイミングでアクティブ化(セーフ)
+				createUser({ lastActiveDate: subDays(addSeconds(baseDate, 1), 7) }),
+				// 期限ちょうどにアクティブ化(セーフ)
+				createUser({ lastActiveDate: subDays(baseDate, 7) }),
+				// 期限よりも1秒古いタイミングでアクティブ化(アウト)
+				createUser({ lastActiveDate: subDays(subSeconds(baseDate, 1), 7) }),
+				// 対象外
+				createUser({ lastActiveDate: null }),
+			]);
+
+			mockModeratorRole([user1, user2, user3, user4]);
+
+			const result = await service.evaluateModeratorsInactiveDays();
+			expect(result.isModeratorsInactive).toBe(false);
+			expect(result.inactiveModerators).toEqual([user3]);
+		});
+
+		test('[isModeratorsInactive] 全員非アクティブなら"運営が非アクティブ"としてみなされる', async () => {
+			const [user1, user2] = await Promise.all([
+				// 期限よりも1秒古いタイミングでアクティブ化(アウト)
+				createUser({ lastActiveDate: subDays(subSeconds(baseDate, 1), 7) }),
+				// 対象外
+				createUser({ lastActiveDate: null }),
+			]);
+
+			mockModeratorRole([user1, user2]);
+
+			const result = await service.evaluateModeratorsInactiveDays();
+			expect(result.isModeratorsInactive).toBe(true);
+			expect(result.inactiveModerators).toEqual([user1]);
+		});
+
+		test('[countdown] 猶予まで24時間ある場合、猶予1日として計算される', async () => {
+			const [user1, user2] = await Promise.all([
+				createUser({ lastActiveDate: subDays(baseDate, 8) }),
+				// 猶予はこのユーザ基準で計算される想定。
+				// 期限まで残り24時間->猶予1日として計算されるはずである
+				createUser({ lastActiveDate: subDays(baseDate, 6) }),
+			]);
+
+			mockModeratorRole([user1, user2]);
+
+			const result = await service.evaluateModeratorsInactiveDays();
+			expect(result.isModeratorsInactive).toBe(false);
+			expect(result.inactiveModerators).toEqual([user1]);
+			expect(result.inactivityLimitCountdown).toBe(1);
+		});
+
+		test('[countdown] 猶予まで25時間ある場合、猶予1日として計算される', async () => {
+			const [user1, user2] = await Promise.all([
+				createUser({ lastActiveDate: subDays(baseDate, 8) }),
+				// 猶予はこのユーザ基準で計算される想定。
+				// 期限まで残り25時間->猶予1日として計算されるはずである
+				createUser({ lastActiveDate: subDays(addHours(baseDate, 1), 6) }),
+			]);
+
+			mockModeratorRole([user1, user2]);
+
+			const result = await service.evaluateModeratorsInactiveDays();
+			expect(result.isModeratorsInactive).toBe(false);
+			expect(result.inactiveModerators).toEqual([user1]);
+			expect(result.inactivityLimitCountdown).toBe(1);
+		});
+
+		test('[countdown] 猶予まで23時間ある場合、猶予0日として計算される', async () => {
+			const [user1, user2] = await Promise.all([
+				createUser({ lastActiveDate: subDays(baseDate, 8) }),
+				// 猶予はこのユーザ基準で計算される想定。
+				// 期限まで残り23時間->猶予0日として計算されるはずである
+				createUser({ lastActiveDate: subDays(subHours(baseDate, 1), 6) }),
+			]);
+
+			mockModeratorRole([user1, user2]);
+
+			const result = await service.evaluateModeratorsInactiveDays();
+			expect(result.isModeratorsInactive).toBe(false);
+			expect(result.inactiveModerators).toEqual([user1]);
+			expect(result.inactivityLimitCountdown).toBe(0);
+		});
+
+		test('[countdown] 期限ちょうどの場合、猶予0日として計算される', async () => {
+			const [user1, user2] = await Promise.all([
+				createUser({ lastActiveDate: subDays(baseDate, 8) }),
+				// 猶予はこのユーザ基準で計算される想定。
+				// 期限ちょうど->猶予0日として計算されるはずである
+				createUser({ lastActiveDate: subDays(baseDate, 7) }),
+			]);
+
+			mockModeratorRole([user1, user2]);
+
+			const result = await service.evaluateModeratorsInactiveDays();
+			expect(result.isModeratorsInactive).toBe(false);
+			expect(result.inactiveModerators).toEqual([user1]);
+			expect(result.inactivityLimitCountdown).toBe(0);
+		});
+
+		test('[countdown] 期限より1時間超過している場合、猶予-1日として計算される', async () => {
+			const [user1, user2] = await Promise.all([
+				createUser({ lastActiveDate: subDays(baseDate, 8) }),
+				// 猶予はこのユーザ基準で計算される想定。
+				// 期限より1時間超過->猶予-1日として計算されるはずである
+				createUser({ lastActiveDate: subDays(subHours(baseDate, 1), 7) }),
+			]);
+
+			mockModeratorRole([user1, user2]);
+
+			const result = await service.evaluateModeratorsInactiveDays();
+			expect(result.isModeratorsInactive).toBe(true);
+			expect(result.inactiveModerators).toEqual([user1, user2]);
+			expect(result.inactivityLimitCountdown).toBe(-1);
+		});
+	});
+});