require 'debug'

module FileHandler
  def self.read_lines(file_path)
    File.readlines(file_path, chomp: true).map do |line|
      yield(line)
    end
  end

  def self.read_file(file_path)
    File.read(file_path)
  end
end

class JoltageCalculator
  def initialize(file_path, debug: false)
    @file_path = file_path
    @debug = debug
  end

  def calculate_total_joltage
    total = 0
    FileHandler.read_lines(@file_path) do |line|
      int_array = line.split('').map(&:to_i)
      length = int_array.length
      first_digit = int_array.slice(0, length - 1).max
      first_pos = int_array.find_index(first_digit)
      second_digit = int_array.slice(first_pos + 1, length).max
      total += "#{first_digit}#{second_digit}".to_i
    end
    total
  end
end

if ARGV[0].nil? || ARGV[0].empty?
  puts "Usage: ruby part1.rb <file_name> [debug]"
  exit 1
end

debug = (ARGV[1] == "debug")
calculator = JoltageCalculator.new(ARGV[0], debug:)
puts "The answer is: #{calculator.calculate_total_joltage}"

# The answer is: 17166

# real	0m0,256s
# user	0m0,207s
# sys	0m0,049s