cs50_pset_1_bad_credit

#!/usr/bin/ruby
# CS50 Harvard PSET 1 - Bad Credit in Ruby.
prompt = "Please enter a valid CC number : "
input = nil # initialize the variable so you can invoke methods on it
input_array = Array.new
input_add = Array.new
type_of_card = nil

loop do
  puts "#{prompt}"
  input =  Integer(gets) rescue nil
  if input.to_s.length < 13 || input.to_s.length > 16 || input.is_a?(String)
    puts "input wrong -> minimum 13 and max 16 digits only"
  else
    puts "validating your input : #{input}"
    if input.to_s =~ /^4/
      type_of_card = "VISA"
    elsif input.to_s =~ /^5[0-5]/
      type_of_card = "MASTERCARD"
    elsif input.to_s =~ /^34|^37/
      type_of_card = "AMEX"
    else
      type_of_card = "INVALID"
    end
    break
   end
end

#add the input into an array
input_array = input.to_s.split('')
#Multiply every other digit by 2, starting with the number’s second-to-last digit, and then add those products' digits together.
input_every_other = (0... input_array.length).select{ |x| x%2 == 2-1 }.map { |y| input_array[y] }

input_add = input_every_other.collect { |x| x.to_i*2 }
# split every integer into a new array index
#input_add = input_add.to_s.split(',')
input_add = input_add.join.chars.map(&:to_i)


input_sum = input_add.inject(:+)

#Now let’s add that sum (27) to the sum of the digits that weren’t multiplied by 2:
input_the_rest = (0... input_array.length).select{ |x| x%2 == 1-1 }.map { |y| input_array[y] }

input_the_rest << input_sum

#convert to integer
input_the_rest = input_the_rest.map(&:to_i)

if input_the_rest.inject(:+)%10 == 0
  puts "#{type_of_card}"
else
  puts "#{type_of_card = 'INVALID'}"
end