mastodon/app/models/concerns/account_counters.rb

# frozen_string_literal: true

module AccountCounters
  extend ActiveSupport::Concern

  included do
    has_one :account_stat, inverse_of: :account
    after_save :save_account_stat
  end

  delegate :statuses_count,
           :statuses_count=,
           :following_count,
           :following_count=,
           :followers_count,
           :followers_count=,
           :increment_count!,
           :decrement_count!,
           :last_status_at,
           to: :account_stat

  def account_stat
    super || build_account_stat
  end

  private

  def save_account_stat
    return unless account_stat&.changed?
    account_stat.save
  end
end