Gilded Rose Exercise

conjured_mana_cake.rb

module Delegates
  class ConjuredManaCake < DefaultItem
    def tick
      unless quality == 0
        if days_remaining > 0
          @quality -= 2
        else
          @quality -= 4
        end
      end

      @days_remaining -= 1
    end
  end
end

Delegates.register('Conjured Mana Cake', Delegates::ConjuredManaCake)

default_item.rb

module Delegates
  class DefaultItem
    attr_reader :name, :days_remaining, :quality, :tick

    def initialize(name:, days_remaining:, quality:)
      @name = name
      @days_remaining = days_remaining
      @quality = quality
    end

    def tick
      if @name != 'Aged Brie' && @name != 'Backstage passes to a TAFKAL80ETC concert'
        if @quality > 0
          if @name != 'Sulfuras, Hand of Ragnaros'
            @quality = @quality - 1
          end
        end
      else
        if @quality < 50
          @quality = @quality + 1
          if @name == 'Backstage passes to a TAFKAL80ETC concert'
            if @days_remaining < 11
              if @quality < 50
                @quality = @quality + 1
              end
            end
            if @days_remaining < 6
              if @quality < 50
                @quality = @quality + 1
              end
            end
          end
        end
      end
      if @name != 'Sulfuras, Hand of Ragnaros'
        @days_remaining = @days_remaining - 1
      end
      if @days_remaining < 0
        if @name != 'Aged Brie'
          if @name != 'Backstage passes to a TAFKAL80ETC concert'
            if @quality > 0
              if @name != 'Sulfuras, Hand of Ragnaros'
                @quality = @quality - 1
              end
            end
          else
            @quality = @quality - @quality
          end
        else
          if @quality < 50
            @quality = @quality + 1
          end
        end
      end
    end
  end
end

delegates.rb

Dir[File.expand_path('delegates/*.rb', File.dirname(__FILE__))].each {|file| require_relative file }

module Delegates
  @@delegates = Hash.new

  def self.get(name)
    @@delegates[name] || DefaultItem
  end

  def self.register(name, item_class)
    @@delegates[name] = item_class
  end
end

gilded_rose.rb

require 'forwardable'
require_relative 'delegates'

class GildedRose
  extend Forwardable
  def_delegators :@delegate, :name, :days_remaining, :quality, :tick

  def initialize(name:, days_remaining:, quality:)
    @delegate = Delegates.get(name).new(name: name, days_remaining: days_remaining, quality: quality)
  end
end