misskey/packages/backend/src/core/PollService.ts

import { Inject, Injectable } from '@nestjs/common';
import { DI } from '@/di-symbols.js';
import type { NotesRepository, UsersRepository, PollsRepository, PollVotesRepository, User } from '@/models/index.js';
import type { Note } from '@/models/entities/Note.js';
import { RelayService } from '@/core/RelayService.js';
import { IdService } from '@/core/IdService.js';
import { GlobalEventService } from '@/core/GlobalEventService.js';
import { ApRendererService } from '@/core/activitypub/ApRendererService.js';
import { UserEntityService } from '@/core/entities/UserEntityService.js';
import { ApDeliverManagerService } from '@/core/activitypub/ApDeliverManagerService.js';
import { bindThis } from '@/decorators.js';
import { UserBlockingService } from '@/core/UserBlockingService.js';

@Injectable()
export class PollService {
	constructor(
		@Inject(DI.usersRepository)
		private usersRepository: UsersRepository,

		@Inject(DI.notesRepository)
		private notesRepository: NotesRepository,

		@Inject(DI.pollsRepository)
		private pollsRepository: PollsRepository,

		@Inject(DI.pollVotesRepository)
		private pollVotesRepository: PollVotesRepository,

		private userEntityService: UserEntityService,
		private idService: IdService,
		private relayService: RelayService,
		private globalEventService: GlobalEventService,
		private userBlockingService: UserBlockingService,
		private apRendererService: ApRendererService,
		private apDeliverManagerService: ApDeliverManagerService,
	) {
	}

	@bindThis
	public async vote(user: User, note: Note, choice: number) {
		const poll = await this.pollsRepository.findOneBy({ noteId: note.id });

		if (poll == null) throw new Error('poll not found');

		// Check whether is valid choice
		if (poll.choices[choice] == null) throw new Error('invalid choice param');

		// Check blocking
		if (note.userId !== user.id) {
			const blocked = await this.userBlockingService.checkBlocked(note.userId, user.id);
			if (blocked) {
				throw new Error('blocked');
			}
		}

		// if already voted
		const exist = await this.pollVotesRepository.findBy({
			noteId: note.id,
			userId: user.id,
		});

		if (poll.multiple) {
			if (exist.some(x => x.choice === choice)) {
				throw new Error('already voted');
			}
		} else if (exist.length !== 0) {
			throw new Error('already voted');
		}

		// Create vote
		await this.pollVotesRepository.insert({
			id: this.idService.genId(),
			createdAt: new Date(),
			noteId: note.id,
			userId: user.id,
			choice: choice,
		});

		// Increment votes count
		const index = choice + 1; // In SQL, array index is 1 based
		await this.pollsRepository.query(`UPDATE poll SET votes[${index}] = votes[${index}] + 1 WHERE "noteId" = '${poll.noteId}'`);

		this.globalEventService.publishNoteStream(note.id, 'pollVoted', {
			choice: choice,
			userId: user.id,
		});
	}

	@bindThis
	public async deliverQuestionUpdate(noteId: Note['id']) {
		const note = await this.notesRepository.findOneBy({ id: noteId });
		if (note == null) throw new Error('note not found');

		const user = await this.usersRepository.findOneBy({ id: note.userId });
		if (user == null) throw new Error('note not found');

		if (this.userEntityService.isLocalUser(user)) {
			const content = this.apRendererService.addContext(this.apRendererService.renderUpdate(await this.apRendererService.renderNote(note, false), user));
			this.apDeliverManagerService.deliverToFollowers(user, content);
			this.relayService.deliverToRelays(user, content);
		}
	}
}