99 Bottles of OOP assignment

99bottles.rb

class Bottles
  def verse(number_of_bottles)
    first_line(number_of_bottles) << "\n" << second_line(number_of_bottles) << "\n"
  end

  def verses(number_of_bottles_start, number_of_bottles_end)
    number_of_bottles_start.downto(number_of_bottles_end).map do |number_of_bottles|
      verse(number_of_bottles)
    end.join("\n")
  end

  def song
    verses(99, 0)
  end

  def singular_or_plural_bottles(number_of_bottles)
    return "1 bottle" if number_of_bottles == 1
    return "no more bottles" if number_of_bottles == 0
    "#{number_of_bottles} bottles"
  end

  def first_line(number_of_bottles)
    return "1 bottle of beer on the wall, 1 bottle of beer." if number_of_bottles == 1
    return "No more bottles of beer on the wall, no more bottles of beer." if number_of_bottles == 0
    "#{number_of_bottles} bottles of beer on the wall, #{number_of_bottles} bottles of beer."
  end

  def second_line(number_of_bottles)
    return "Take it down and pass it around, no more bottles of beer on the wall." if number_of_bottles == 1
    return "Go to the store and buy some more, 99 bottles of beer on the wall." if number_of_bottles == 0
    "Take one down and pass it around, #{singular_or_plural_bottles(number_of_bottles -1)} of beer on the wall."
  end
end