bigbluebutton-Github/bigbluebutton-html5/imports/api/polls/server/methods/publishVote.js

import RedisPubSub from '/imports/startup/server/redis';
import { check } from 'meteor/check';
import Polls from '/imports/api/polls';
import Logger from '/imports/startup/server/logger';
import { extractCredentials } from '/imports/api/common/server/helpers';

export default function publishVote(pollId, pollAnswerIds) {
  const REDIS_CONFIG = Meteor.settings.private.redis;
  const CHANNEL = REDIS_CONFIG.channels.toAkkaApps;
  const EVENT_NAME = 'RespondToPollReqMsg';
  const { meetingId, requesterUserId } = extractCredentials(this.userId);

  check(pollAnswerIds, Array);
  check(meetingId, String);
  check(requesterUserId, String);
  check(pollId, String);

  const allowedToVote = Polls.findOne({ id: pollId, users: { $in: [requesterUserId] } }, {
    fields: {
      users: 1,
    },
  });

  if (!allowedToVote) {
    Logger.info(`Poll User={${requesterUserId}} has already voted in PollId={${pollId}}`);
    return null;
  }

  const selector = {
    users: requesterUserId,
    meetingId,
    'answers.id': { $all: pollAnswerIds },
  };

  const payload = {
    requesterId: requesterUserId,
    pollId,
    questionId: 0,
    answerIds: pollAnswerIds,
  };

  /*
   We keep an array of people who were in the meeting at the time the poll
   was started. The poll is published to them only.
   Once they vote - their ID is removed and they cannot see the poll anymore
  */
  const modifier = {
    $pull: {
      users: requesterUserId,
    },
  };

  try {
    const numberAffected = Polls.update(selector, modifier);

    if (numberAffected) {
      Logger.info(`Removed responded user=${requesterUserId} from poll (meetingId: ${meetingId}, pollId: ${pollId}!)`);

      RedisPubSub.publishUserMessage(CHANNEL, EVENT_NAME, meetingId, requesterUserId, payload);
    }
  } catch (err) {
    Logger.error(`Removing responded user from Polls collection: ${err}`);
  }
}