module followable

module Followable
  extend ActiveSupport::Concern
  include ActiveModel::Model

  included do

    has_many :followers_followed, foreign_key: 'followed_id'
    has_many :users, through: :followers_followed
    has_many :messages, foreign_key: 'followable_id'

    after_update do
      message = self.create_message
      self.followers.each do |user|
        MessagesUser.create message: message, user: user
      end
    end

  end

  def create_message
    Message.create content: 'Yay, a message', followable_id: self.id, followable_type_code: self.class.table_name
  end

  def followers
    self.users.where('followers_followed.followable_type_code = ?', self.class.table_name)
  end

  def is_followed?(user)
    return self.followers.include? user if user.class == User
    return self.followers.any? { |follower| follower.id == user } if user.class == Fixnum
    false
  end

end