Cocktail "Recursive": 20% of alcohol, 30% of water and 50% of cocktail "Recursive"...

recursive_cocktail.rb

require "faker"                                                                                                                                                                                      [35/39]

class RecursiveCocktail
  def initialize(ingredients: {}, capacity: 500) # default capacity - 500 ml
    validate_ingredients!(ingredients)
    @ingredients = {}
    ingredients.each do |ingredient, percentage|
      @ingredients[ingredient] = { percentage: percentage / 100.0, used: 0 }
    end
    @cocktail_name = generate_cocktail_name
    @capacity = capacity
    @iteration = 0
  end

  def mix!
    return if cocktail_ready?

    run_logger
    add_ingredients!
    mix!
  end

  def to_s
    <<~COCKTAIL

      [ #{current_capacity} ml | #{@iteration} iterations ]

      \\      /
       |____|
       |    |
        \\  /
         ||
        ----

      #{@ingredients.map do |ingredient, info|
        "#{ingredient}: #{info[:used]} ml"
      end.join("\n")}
    COCKTAIL
  end

  private

  def run_logger
    if @iteration.zero?
      print "Preparing cocktail \"#{@cocktail_name}\""
    else
      print "."
    end
    @iteration += 1
  end
  
  def add_ingredients!
    capacity_left = @capacity - current_capacity
    @ingredients.each do |_ingredient, info|
      info[:used] += (capacity_left * info[:percentage]).ceil
    end
  end

  def current_capacity
    @ingredients.map { |_ingredient, info| info[:used] }.inject(:+)
  end

  def cocktail_ready?
    current_capacity >= @capacity
  end

  def validate_ingredients!(ingredients)
    abort "Wrong ingredients list!" if ingredients.empty? || ingredients.size <= 1
    percentage =
      begin
        ingredients.map { |_ingredient, info| info }.inject(:+)
      rescue TypeError
        0
      end
    abort "Wrong proportions!" unless (1..100).include?(percentage)
  end

  def generate_cocktail_name
    Faker::Verb.past_participle.capitalize + " " + Faker::Creature::Animal.name.capitalize
  end
end

rc = RecursiveCocktail.new(ingredients: { water: rand(1..50), alcohol: rand(1..50) })
rc.mix!
puts rc