Batch coupon generation

gistfile1.rb

class Coupon::BatchGenerator
  def self.generate(options = {})
    new(options).generate
  end

  private_class_method :new

  def initialize(options)
    @options = defaults.merge(options)
  end

  def generate
    Array.new(@options[:count]).map do
      create_coupon.tap do |coupon|
        coupon.code = coupon_code_with_prefix while !coupon.save
      end
    end
  end

  private

  def defaults
    {
      :name => "Not set",
      :expiry => 1.week.from_now,
      :discount => 0,
      :count => 1,
      :coupon_length => 4,
      :one_time_use => true,
      :prefix => ""
    }
  end

  def create_coupon
    Coupon.new(:name => @options[:name],
               :description => @options[:description],
               :expiry => @options[:expiry],
               :code => coupon_code_with_prefix,
               :discount_percentage => @options[:discount],
               :one_time_use => @options[:one_time_use])
  end

  def coupon_code
    random_code.first(@options[:coupon_length])
  end

  def coupon_code_with_prefix
    @options[:prefix] + coupon_code
  end

  def random_code
    SecureRandom.urlsafe_base64.tr('^A-Za-z0-9','')
  end
end