Created
February 26, 2024 22:15
-
-
Save davidoram/d6adf6cd24a23f3bbac108aaa27c00df to your computer and use it in GitHub Desktop.
Convert a FlyBuys card number to a barcode
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| #!/usr/bin/env ruby | |
| # Convert a FlyBuys card number to a barcode | |
| def get_check_sum_from_thirteen_digit_code(card_number) | |
| evens = 0 | |
| odds = 0 | |
| # Loop over all characters | |
| card_number.chars.each_with_index do |character, index| | |
| # Don't include the last character - 1 | |
| break if index == card_number.length - 1 | |
| # Convert to a number | |
| num = character.to_i | |
| if index.odd? | |
| evens += num | |
| else | |
| odds += num | |
| end | |
| end | |
| (10 - (((evens * 3) + odds) % 10)) % 10 | |
| end | |
| def is_card_number_valid(card_number) | |
| # Implement your validation logic here | |
| true | |
| end | |
| def is_barcode_valid(barcode) | |
| return false unless barcode[0..2] == "264" | |
| return false unless barcode.length == 13 | |
| return false unless barcode.chars.all? { |char| char =~ /[0-9]/ } | |
| return false unless is_checksum_valid(barcode) | |
| true | |
| end | |
| def is_checksum_valid(barcode) | |
| number_one = 0 | |
| number_two = 0 | |
| # Create number one | |
| (11).step(0, -2) do |i| | |
| char = barcode[i] | |
| val = char.to_i | |
| number_one += val | |
| end | |
| number_one *= 3 | |
| # Create number two | |
| (0).step(12, 2) do |i| | |
| char = barcode[i] | |
| val = char.to_i | |
| number_two += val | |
| end | |
| number_two += number_one | |
| # Calculate the check digit | |
| check_digit = (10 - (number_two % 10)) % 10 | |
| # Validate | |
| last_digit = barcode[12].to_i | |
| check_digit == last_digit | |
| end | |
| def convert_card_number_to_barcode(card_number) | |
| raise "Cannot convert an invalid card number to a barcode" unless is_card_number_valid(card_number) | |
| barcode = card_number[0..5].gsub(card_number[0..5], "264") + card_number[6..-1] | |
| check_sum = get_check_sum_from_thirteen_digit_code(barcode) | |
| # Update the last number with the checksum | |
| barcode = barcode[0..-2] + check_sum.to_s | |
| # Post condition validation | |
| raise "An invalid barcode was created from a card number" unless is_barcode_valid(barcode) | |
| barcode | |
| end | |
| puts convert_card_number_to_barcode(ARGV[0]) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment