bj.rb

# Interactive command line blackjack game


def calculate_total(cards) 
  # [['H', '3'], ['S', 'Q'], ... ]
  arr = cards.map{|e| e[1] }

  total = 0
  arr.each do |value|
    if value == "A"
      total += 11
    elsif value.to_i == 0 # J, Q, K
      total += 10
    else
      total += value.to_i
    end
  end

  #correct for Aces
  arr.select{|e| e == "A"}.count.times do
    total -= 10 if total > 21
  end

  total
end

# Start Game
def play_game
  first_game = false
  puts "Welcome to Blackjack!"

  suits = ['H', 'D', 'S', 'C']
  cards = ['2', '3', '4', '5', '6', '7', '8', '9', '10', 'J', 'Q', 'K', 'A']

  deck = suits.product(cards)
  deck.shuffle!

  # Deal Cards

  mycards = []
  dealercards = []

  mycards << deck.pop
  dealercards << deck.pop
  mycards << deck.pop
  dealercards << deck.pop

  dealertotal = calculate_total(dealercards)
  mytotal = calculate_total(mycards)

  # Show Cards

  puts "Dealer has: #{dealercards[0]} and #{dealercards[1]}, for a total of #{dealertotal}"
  puts "You have: #{mycards[0]} and #{mycards[1]}, for a total of: #{mytotal}"
  puts ""

  # Player turn
  if mytotal == 21
    puts "Congratulations, you hit blackjack! You win!"
    play_again
  end

  while mytotal < 21
    puts "What would you like to do? 1) hit 2) stay"
    hit_or_stay = gets.chomp

    if !['1', '2'].include?(hit_or_stay)
      puts "Error: you must enter 1 or 2"
      next
    end

    if hit_or_stay == "2"
      puts "You chose to stay."
      break
    end

    #hit
    new_card = deck.pop
    puts "Dealing card to player: #{new_card}"
    mycards << new_card
    mytotal = calculate_total(mycards)
    puts "Your total is now: #{mytotal}"

    if mytotal == 21
      puts "Congratulations, you hit blackjack! You win!"
      play_again
    elsif mytotal > 21
      puts "Sorry, it looks like you busted!"
      play_again
    end
  end

  # Dealer turn

  if dealertotal == 21
    puts "Sorry, dealer hit blackjack. You lose."
    play_again
  end

  while dealertotal < 17
    #hit
    new_card = deck.pop
    puts "Dealing new card for dealer: #{new_card}"
    dealercards << new_card
    dealertotal = calculate_total(dealercards)
    puts "Dealer total is now: #{dealertotal}"

    if dealertotal == 21
      puts "Sorry, dealer hit blackjack. You lose."
      play_again
    elsif dealertotal > 21
      puts "Congratulations, dealer busted! You win!"
      play_again
    end
  end

  # Compare hands

  puts "Dealer's cards: "
  dealercards.each do |card|
    puts "=> #{card}"
  end
  puts ""

  puts "Your cards:"
  mycards.each do |card|
    puts "=> #{card}"
  end
  puts ""

  if dealertotal > mytotal
    puts "Sorry, dealer wins."
  elsif dealertotal < mytotal
    puts "Congratulations, you win!"
  else
    puts "It's a tie!"
  end

  play_again
end

def play_again
  puts "Play again? Y/N"
  if gets.chomp.downcase == "n"
    exit
  else
    play_game
  end
end

play_game