War!

war.rb

A = 14

SPADES = :s
DIAMONDS = :d
HEARTS = :h
CLUBS = :c

SUITS = [SPADES, DIAMONDS, HEARTS, CLUBS]

class Card

  attr_reader :rank
  
  def initialize(rank, suit)
    @rank = rank
    @suit = suit #unused
  end
    
end

class Deck

  def initialize(cards)
    @cards = cards
  end
  
  def draw
    return @cards.pop
  end
  
  def collect(stack)
    while(!stack.empty?) do
      @cards.insert(0, stack.shift)
    end
  end
  
  def empty?
    return !@cards.any?
  end

end

class Game
  
  def create_decks
    all_cards = ((2..A).to_a).product(SUITS).map { |x| Card.new(*x) }.shuffle
    return [all_cards[0..(all_cards.count/2 - 1)], all_cards[(all_cards.count/2)..all_cards.count]].map { |x| Deck.new(x) }
  end
  
  def determine_outcome(card1, card2)
    return @deck2 unless card1 #if player 1 can't draw player 2 wins 
    return @deck1 unless card2 #and vice versa
    return war if(card1.rank == card2.rank) 
    return card1.rank > card2.rank ? @deck1 : @deck2
  end
  
  def combat
    @stack << @deck1.draw
    @stack << @deck2.draw	
    winner = determine_outcome(@stack[-2], @stack[-1])	
    winner.collect(@stack)	
    return winner
  end
  
  def war
    @stack << @deck1.draw #facedown
    @stack << @deck1.draw
    @stack << @deck2.draw #facedown
    @stack << @deck2.draw
    return determine_outcome(@stack[-3], @stack[-1])
  end
  
  def initialize
    @deck1, @deck2 = create_decks	
    @stack = []
  end
  
  def play
    turns = 0
    while [@deck1, @deck2].all? { |x| !x.empty? }
      winner = combat	  
      turns += 1
    end
    print "TURNS : #{turns}\n"
    print "WINNER : player#{winner == @deck1 ? 1 : 2}\n"
  end
  
end

Game.new.play