gloom-sim.rb

class Deck
  attr_accessor :needs_shuffle
  def initialize(cards = [%w(x2 miss), %w(2 -2), %w(1 -1) * 5, %w(0) * 6].flatten)
    @orig_cards = cards
    shuffle!
  end

  def add(cards)
    @orig_cards += cards
    self
  end

  def remove(cards)
    cards.each do |card|
      index = @orig_cards.index(card)
      @orig_cards.delete_at(index)
    end
    self
  end

  def replace(removed, added)
    remove(removed)
    add(added)
  end

  def cards
    @orig_cards.sort
  end

  def shuffle!
    @cards = @orig_cards.shuffle
    @needs_shuffle = false
  end

  def draw_normal
    draw = []
    loop do
      draw << @cards.shift
      @needs_shuffle = true if ['x2', 'miss'].include? draw.last
      break if draw.last !~ /r/
    end
    filter(draw)
  end

  def draw_advantage
    draw = []
    draw << @cards.shift
    draw << @cards.shift
    # If all rolling, keep drawing until no rolling
    draw << @cards.shift while draw.all?{|c| c =~ /r/}

    @needs_shuffle = true if draw.include?('x2') || draw.include?('miss')

    # If any rolling, return whole stack
    return filter(draw) if draw.any?{|c| c =~ /r/}

    # If miss, use other
    return filter([draw.first]) if draw.last == "miss"
    return filter([draw.last]) if draw.first == "miss"

    # If double, use that TODO: someknow pass a cutoff where +2 or +3 might be better on low attack
    return ["x2"] if draw.include? "x2"

    # If all numeric, return largest
    if draw.all?{|c| c =~ /^-?\d$/}
      return [draw.map(&:to_i).sort.last]
    end

    # TODO: +1 <thing> beats +1, <thing> vs <thing> is ambiguous
    fail "Ambiguous draw: #{draw.inspect}"
  end

  def filter(draw)
    return ['miss'] if draw.include? "miss"
    draw.sort.map{|card| card == "x2" ? card : card.gsub(/^[r]/,'').to_i }
  end

  def end_turn
    shuffle! if needs_shuffle
  end
end

TRIALS = 1_000_000
def sim(caption, cards, operation)
  deck = Deck.new(cards)
  histogram = Hash.new{|h,k| 0}
  TRIALS.times do
    dmg = ATTACK
    draw = operation.call(deck)
    ddraw = draw.dup # Useful for debugging

    if draw.include? "miss"
      dmg = 0
    else
      while card = draw.shift do
        case card
        when Integer; dmg += card
        when 'x2'   ; dmg *= 2
        else        ; fail "Unknown card: #{card}"
        end
      end
    end

    histogram[dmg] += 1
    deck.end_turn
  end

  puts "#{caption}: (#{cards.size}) #{cards.join(' ')}"
  average = histogram.map{|k,v|k*v}.inject(&:+) / TRIALS.to_f
  puts ">>> expected: %0.2f (+%0.2f)" % [average, average-ATTACK]
  histogram.keys.sort.each do |k|
    freq = (100.0 * histogram[k] / TRIALS)
    puts "[%2d]: %5.2f %% %s" % [k, freq, '#' * freq]
  end
  puts
end

ATTACK = 3
draw_normal = ->(d){d.draw_normal}
draw_advantage = ->(d){d.draw_advantage}
draw_mixed = ->(d){rand(2).zero? ? d.draw_normal : d.draw_advantage}


default = Deck.new.cards
sim 'default', default, draw_normal
sim 'default w/ advantage', default, draw_advantage
# sim 'default 50% advantage', default, draw_mixed
sim 'two 1s', Deck.new.add(%w(1 1)).cards, draw_advantage
sim 'two 1s', Deck.new.add(%w(r1 r1)).cards, draw_advantage

# sunkeeper3a = Deck.new.add(%w(1 1)).remove(%w(-1 -1 -1 -1)).cards
# sunkeeper3b = Deck.new.add(%w(1 1)).remove(%w(-1 -1 0 0 0 0)).cards
# sunkeeper3c = Deck.new.add(%w()).remove(%w(-1 -1 -1 -1 0 0 0 0)).cards
# sunkeeper6 = Deck.new.add(%w(1 1 2)).remove(%w(-2 -1 -1 -1 -1 0 0 0 0)).cards
# sim 'SK3 A', sunkeeper3a, draw_mixed
# sim 'SK3 B', sunkeeper3b, draw_mixed
# sim 'SK3 C', sunkeeper3c, draw_mixed
# sim 'SK6',   sunkeeper6, draw_mixed

ATTACK = 2
soothsinger = Deck.new.remove(%w(-1 -1 -1 -1 -2)).replace(%w(1 1 1 1), %w(4 4)).replace(%w(0 0 0 0 0 0), %w(1 1 2 2 2 3)).replace(%w(-1), %w(0)).add(%w(r1 r1 r1 r0 r0 r0 r0)).cards
soothsinger_slim = Deck.new.remove(%w(-1 -1 -1 -1 -2)).replace(%w(1 1 1 1), %w(4 4)).replace(%w(0 0 0 0 0 0), %w(1 1 2 2 2 3)).replace(%w(-1), %w(0)).cards
sim 'SSMax', soothsinger, draw_normal
sim 'SSSlim', soothsinger_slim, draw_normal