class User < ActiveRecord::Base
  attr_protected :friend_list
  
  def following
    self.class.all(:conditions => "id in (#{friend_list})")
  end
  
  def follow(id)
    update_attribute(:friend_list, (friend_list.split(',').map(&:to_i) | [id.to_i]).join(','))
  end
  
  def unfollow(id)
    update_attribute(:friend_list, (friend_list.split(',').map(&:to_i) - [id.to_i]).join(','))
  end
  
  def followers
    self.class.all(:conditions => ['find_in_set(?, friend_list)', id])
  end
end