bill.rb

#!/usr/bin/ruby
# encoding: utf-8
# Barmanov účet

class Bill
	def initialize
		@items = []
		@total = 0.0
	end

	def add_item name, price, quantity = 1
		item = @items.find{|i| i["name"] == name}
		if item.nil? 
			item = {"name" => name, "price" => price, "quantity" => quantity.to_i, "total" => price*quantity }
			@items << item
		else
			item["quantity"] += 1
			item["total"] = item["quantity"]*item["price"]
		end
	end

	def display
		@items.each do |i|
			printf "%15s %.2fx%i -> %.2f\n", i["name"], i["price"], i["quantity"], i["total"]
		end

		puts "==============================================="
		printf "%15s : \e[31m %.2f\e[0m\n", "Celkom", total
	end

	private
	def total
		@items.inject(0){| sum, i| sum + i["total"] }
	end
end

u = Bill.new
u.add_item "Káva", 1.8
u.add_item "Soletky", 0.5
u.add_item "Minerálka", 1.1
u.add_item "Káva", 1.8
u.add_item "Lupienky", 0.8, 3
u.add_item "Kavenka", 0.3
u.add_item "Kavenka", 0.3
u.add_item "Kavenka", 0.3
u.display