99bottles.rb

class Bottles

  def song
    verses(99, 0)
  end

  def verses(first, last)
    first.downto(last).map { |n| verse(n) }.join("\n")
  end

  def verse(n)
    "#{bottles(n, :capitalize)} of beer on the wall, #{bottles(n)} of beer.\n" +
    case n
    when 0; then "Go to the store and buy some more, 99 bottles of beer on the wall.\n"
    when 1; then "Take it down and pass it around, no more bottles of beer on the wall.\n"
    else         "Take one down and pass it around, #{bottles(n-1)} of beer on the wall.\n"
    end
  end

  def bottles(n, capitalize = false)
    case(n)
    when 0; then (capitalize ? "No more bottles" : "no more bottles")
    when 1; then "1 bottle"
    else         "#{n} bottles"
    end
  end

end