99bottles.rb

99bottles.rb

class Bottles
  def song
    verses(99, 0)
  end

  def verse(n)
    "#{start(n)} #{pluralization(n)} of beer on the wall, "\
    "#{start(n).downcase} #{pluralization(n)} of beer.\n" + beer_chore(n)
  end

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

  def pluralization(n)
    n == 1 ? 'bottle' : 'bottles'
  end

  def pronoun(n)
    n == 1 ? 'it' : 'one'
  end

  def remaining(n)
    (n - 1).zero? ? 'no more' : n - 1
  end

  def start(n)
    n.zero? ? 'No more' : n.to_s
  end

  def beer_chore(n)
    if remaining(n) == -1
      "Go to the store and buy some more, 99 bottles of beer on the wall.\n"
    else
      "Take #{pronoun(n)} down and pass it around, #{remaining(n)} "\
      "#{pluralization(n - 1)} of beer on the wall.\n"
    end
  end
end