99 Bottles of Beer

# title: 99 Bottles of Beer
# source: https://rosettacode.org/wiki/99_bottles_of_beer
# category: Rosetta Code
# difficulty: beginner
# summary: Generate the full 99 Bottles of Beer song from 99 down to 0.
# tags: rosetta-code, popular, strings, loops, conditionals
# vibe: 0.2

def bottle_phrase(count)
  if count == 0
    "no more bottles of beer"
  elsif count == 1
    "1 bottle of beer"
  else
    count + " bottles of beer"
  end
end

def action_line(count)
  if count == 0
    "Go to the store and buy some more"
  elsif count == 1
    "Take it down and pass it around"
  else
    "Take one down and pass it around"
  end
end

def next_count(count)
  if count == 0
    99
  else
    count - 1
  end
end

def verse(count)
  current = bottle_phrase(count)
  upcoming = bottle_phrase(next_count(count))
  text = current.capitalize + " on the wall, " + current + ".\n"
  text = text + action_line(count) + ", " + upcoming + " on the wall.\n"
  text
end

def sing(start)
  song = ""
  for count in start..0
    if song == ""
      song = verse(count)
    else
      song = song + "\n" + verse(count)
    end
  end
  song
end

def run
  sing(99)
end