tokenizable.rb

module Tokenizable
  extend ActiveSupport::Concern

  module ClassMethods
    def from_token(token)
      row = Rails.cache.read(token).try { |id| find_by_id(id) }
      Rails.cache.write(token, row.id, expires_in: 2.hours.to_i) if row.present?
      row
    end
  end

  def add_access_token
    raise 'cannot add access token if not persisted' unless persisted?
    token = generate_token(Settings.access_token.length)
    Rails.cache.write(token, id, expires_in: 2.hours.to_i)
    token
  end

  private

  def generate_token(size)
    validity = -> (token) { Rails.cache.read(token).nil? }
    begin
      token = SecureRandom.hex(size)[0, size]
    end until validity[token]

    token
  end

end