class TrackingNumber
  class UPS < Base
    SEARCH_PATTERN = /(\b1\s*Z\s*(\w\s*){16,16}\b)/
    VERIFY_PATTERN = /^1Z(\w{15,15})(\w)$/
    
    def carrier
      :ups
    end

    def matches
       self.tracking_number.scan(VERIFY_PATTERN).flatten
    end

    def valid_checksum?
      sequence = tracking_number.slice(2...17)
      check_digit = tracking_number.slice(17, 18)

      total = 0
      sequence.chars.each_with_index do |c, i|
        x = if c[/[0-9]/] # numeric
          c.to_i
        else
          (c[0].ord - 3) % 10
        end
        x *= 2 if i.odd?
        total += x
      end

      check = (total % 10)
      check = (10 - check) unless (check.zero?)

      return (check.to_i == check_digit.to_i)
    end

    def decode
      {:shipper_account =>  self.tracking_number.to_s.slice(2...8), 
       :service_type => self.tracking_number.to_s.slice(8...10),
       :package_identifier =>  self.tracking_number.to_s.slice(10...17),
       :check_digit => self.tracking_number.to_s.slice(17, 18)
      }
    end

    def service_type
      case decode[:service_type]
      when "01":
       "UPS United States Next Day Air (Red)"
      when "02":
       "UPS United States Second Day Air (Blue)"
      when "03":
       "UPS United States Ground"
      when "12":
       "UPS United States Third Day Select"
      when "13":
       "UPS United States Next Day Air Saver (Red Saver)"
      when "15":
       "UPS United States Next Day Air Early A.M."
      when "22":
       "UPS United States Ground - Returns Plus - Three Pickup Attempts"
      when "32":
       "UPS United States Next Day Air Early A.M. - COD"
      when "33":
       "UPS United States Next Day Air Early A.M. - Saturday Delivery, COD"
      when "41":
       "UPS United States Next Day Air Early A.M. - Saturday Delivery"
      when "42":
       "UPS United States Ground - Signature Required"
      when "44":
       "UPS United States Next Day Air - Saturday Delivery"
      when "66":
       "UPS United States Worldwide Express"
      when "72":
       "UPS United States Ground - Collect on Delivery"
      when "78":
       "UPS United States Ground - Returns Plus - One Pickup Attempt"
      when "90":
       "UPS United States Ground - Returns - UPS Prints and Mails Label"
      when "A0":
       "UPS United States Next Day Air Early A.M. - Adult Signature Required"
      when "A1":
       "UPS United States Next Day Air Early A.M. - Saturday Delivery, Adult Signature Required"
      when "A2":
       "UPS United States Next Day Air - Adult Signature Required"
      when "A8":
       "UPS United States Ground - Adult Signature Required"
      when "A9":
       "UPS United States Next Day Air Early A.M. - Adult Signature Required, COD"
      when "AA":
       "UPS United States Next Day Air Early A.M. - Saturday Delivery, Adult Signature Required, COD"
     end
    end
  end
end