mastodon/app/services/vote_service.rb

# frozen_string_literal: true

class VoteService < BaseService
  include Authorization
  include Payloadable
  include Redisable
  include Lockable

  def call(account, poll, choices)
    return if choices.empty?

    authorize_with account, poll, :vote?

    @account = account
    @poll    = poll
    @choices = choices
    @votes   = []

    already_voted = true

    with_redis_lock("vote:#{@poll.id}:#{@account.id}") do
      already_voted = @poll.votes.exists?(account: @account)

      ApplicationRecord.transaction do
        @choices.each do |choice|
          @votes << @poll.votes.create!(account: @account, choice: Integer(choice))
        end
      end
    end

    increment_voters_count! unless already_voted

    ActivityTracker.increment('activity:interactions')

    if @poll.account.local?
      distribute_poll!
    else
      deliver_votes!
      queue_final_poll_check!
    end
  end

  private

  def distribute_poll!
    return if @poll.hide_totals?

    ActivityPub::DistributePollUpdateWorker.perform_in(3.minutes, @poll.status.id)
  end

  def queue_final_poll_check!
    return unless @poll.expires?

    PollExpirationNotifyWorker.perform_at(@poll.expires_at + 5.minutes, @poll.id)
  end

  def deliver_votes!
    @votes.each do |vote|
      ActivityPub::DeliveryWorker.perform_async(
        build_json(vote),
        @account.id,
        @poll.account.inbox_url
      )
    end
  end

  def build_json(vote)
    Oj.dump(serialize_payload(vote, ActivityPub::VoteSerializer))
  end

  def increment_voters_count!
    unless @poll.voters_count.nil?
      @poll.voters_count = @poll.voters_count + 1
      @poll.save
    end
  rescue ActiveRecord::StaleObjectError
    @poll.reload
    retry
  end
end