feat: account migration (#10507)

* add Move activity

* add endpoint to move from local to remote

* follow move activity coming to inbox

* fix move endpoint

* add known-as endpoint to create account alias

* add migration page

* add route to migration page

* add move and known-as endpoints

* fix dependnecies error

* fix new endpoints

* fix move activity id

* fix refollow

* add movedToUri and alsoKnownAs to api

* fix moveToUri indicator

* fix missing context

* add chengelog

* rename MkMoved to MkAccountMoved

* add missing semicolon

* fix targetUri

* fix followings query

* remove redundant null check

1 files changed, 114 insertions, 0 deletions

diff --git a/packages/backend/src/core/AccountMoveService.ts b/packages/backend/src/core/AccountMoveService.ts
new file mode 100644
index 0000000000..6a7727c57a
--- /dev/null
+++ b/packages/backend/src/core/AccountMoveService.ts
@@ -0,0 +1,114 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { IsNull } from 'typeorm';
+
+import { bindThis } from '@/decorators.js';
+import { DI } from '@/di-symbols.js';
+import type { LocalUser } from '@/models/entities/User.js';
+import { User } from '@/models/entities/User.js';
+import type { FollowingsRepository, UsersRepository } from '@/models/index.js';
+
+import { GlobalEventService } from '@/core/GlobalEventService.js';
+import { UserFollowingService } from '@/core/UserFollowingService.js';
+import { ApDeliverManagerService } from '@/core/activitypub/ApDeliverManagerService.js';
+import { ApRendererService } from '@/core/activitypub/ApRendererService.js';
+import { UserEntityService } from '@/core/entities/UserEntityService.js';
+import { AccountUpdateService } from '@/core/AccountUpdateService.js';
+import { RelayService } from '@/core/RelayService.js';
+
+@Injectable()
+export class AccountMoveService {
+	constructor(
+		@Inject(DI.usersRepository)
+		private usersRepository: UsersRepository,
+
+		@Inject(DI.followingsRepository)
+		private followingsRepository: FollowingsRepository,
+
+		private userEntityService: UserEntityService,
+		private apRendererService: ApRendererService,
+		private apDeliverManagerService: ApDeliverManagerService,
+		private globalEventService: GlobalEventService,
+		private userFollowingService: UserFollowingService,
+		private accountUpdateService: AccountUpdateService,
+		private relayService: RelayService,
+	) {
+	}
+
+	/**
+	 * Move a local account to a remote account.
+	 *
+	 * After delivering Move activity, its local followers unfollow the old account and then follow the new one.
+	 */
+	@bindThis
+	public async moveToRemote(src: LocalUser, dst: User): Promise<unknown> {
+		// Make sure that the destination is a remote account.
+		if (this.userEntityService.isLocalUser(dst)) throw new Error('move destiantion is not remote');
+		if (!dst.uri) throw new Error('destination uri is empty');
+
+		// add movedToUri to indicate that the user has moved
+		const update = {} as Partial<User>;
+		update.alsoKnownAs = src.alsoKnownAs?.concat([dst.uri]) ?? [dst.uri];
+		update.movedToUri = dst.uri;
+		await this.usersRepository.update(src.id, update);
+
+		const srcPerson = await this.apRendererService.renderPerson(src);
+		const updateAct = this.apRendererService.addContext(this.apRendererService.renderUpdate(srcPerson, src));
+		await this.apDeliverManagerService.deliverToFollowers(src, updateAct);
+		this.relayService.deliverToRelays(src, updateAct);
+
+		// Deliver Move activity to the followers of the old account
+		const moveAct = this.apRendererService.addContext(this.apRendererService.renderMove(src, dst));
+		await this.apDeliverManagerService.deliverToFollowers(src, moveAct);
+
+		// Publish meUpdated event
+		const iObj = await this.userEntityService.pack<true, true>(src.id, src, { detail: true, includeSecrets: true });
+		this.globalEventService.publishMainStream(src.id, 'meUpdated', iObj);
+
+		// follow the new account and unfollow the old one
+		const followings = await this.followingsRepository.find({
+			relations: {
+				follower: true,
+			},
+			where: {
+				followeeId: src.id,
+				followerHost: IsNull(), // follower is local
+			}
+		});
+		followings.forEach(async (following) => {
+			if (!following.follower) return;
+			try {
+				await this.userFollowingService.follow(following.follower, dst);
+				await this.userFollowingService.unfollow(following.follower, src);
+			} catch {
+				/* empty */
+			}
+		});
+
+		return iObj;
+	}
+
+	/**
+	 * Create an alias of an old remote account.
+	 *
+	 * The user's new profile will be published to the followers.
+	 */
+	@bindThis
+	public async createAlias(me: LocalUser, updates: Partial<User>): Promise<unknown> {
+		await this.usersRepository.update(me.id, updates);
+
+		// Publish meUpdated event
+		const iObj = await this.userEntityService.pack<true, true>(me.id, me, {
+			detail: true,
+			includeSecrets: true,
+		});
+		this.globalEventService.publishMainStream(me.id, 'meUpdated', iObj);
+
+		if (me.isLocked === false) {
+			await this.userFollowingService.acceptAllFollowRequests(me);
+		}
+
+		this.accountUpdateService.publishToFollowers(me.id);
+
+		return iObj;
+	}
+}