RobAndDansBottlesOfBeer

class Bottles

	def initialize
		@verses = Hash.new { |h, num_bottles| Verse.new(num_bottles) }
		@verses[6] = SixPackVerse.new(6)
		@verses[7] = SixPackVerse.new(7)
	end

	def song
		verses(99,0)
	end

	def verses(from, to)
		from.downto(to).map { |v| verse(v) }.join("\n")
	end

	def verse(number_of_bottles)
		@verses[number_of_bottles].first_line + "\n" + @verses[number_of_bottles].second_line + "\n"
	end

	class Verse

		def initialize(number_of_bottles)
			@number_of_bottles = number_of_bottles
		end

		def first_line
			"#{format_bottles(@number_of_bottles)} of beer on the wall, #{format_bottles(@number_of_bottles)} of beer.".capitalize
		end

		def second_line
			if (@number_of_bottles == 0)
				"Go to the store and buy some more, 99 bottles of beer on the wall."
			else
				"Take #{one_or_it} down and pass it around, #{format_bottles(@number_of_bottles - 1)} of beer on the wall."
			end 
		end

		def one_or_it
			if (@number_of_bottles == 1)
				"it"
			else
				"one"
			end
		end

		def format_bottles(n)
			if (n == 1) 
				"1 bottle"
			elsif (n == 0)
				"no more bottles"
			else
				"#{n} bottles"
			end
		end
	end

	class SixPackVerse < Verse

		def format_bottles(n)
			if (n == 6) 
				"1 six-pack"
			else
				"#{n} bottles"
			end
		end
	end
	
end