module Authentication
  extend ActiveSupport::Concern

  included do
    has_secure_password
  end

  def User.digest(string)
    cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST : BCrypt::Engine.cost
    BCrypt::Password.create(string, cost: cost)
  end

  def User.new_token
    SecureRandom.urlsafe_base64
  end

  def remember
    self.remember_token = User.new_token
    update_attribute(:remember_digest, User.digest(remember_token))
  end

  def authenticated?(remember_token)
    return false if remember_digest.nil?
    BCrypt::Password.new(remember_digest).is_password?(remember_token)
  end

  def forget
    update_attribute(:remember_digest, nil)
  end
end
