Class: Gambler::Game::Blackjack

Inherits:
BasicGame show all
Defined in:
lib/gambler/game/blackjack.rb

Overview

The Game of Blackjack.

Constant Summary collapse

BUST =

The hand_value in which the Player busts.

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INITIAL_CARDS = 
2
FACE_VALUES =

These are used instead of Card::FACE_VALUES to accommodate Blackjack.

{
  'A' => 11,
  'K' => 10,
  'Q' => 10,
  'J' => 10,
  'T' => 10,
  '9' => 9,
  '8' => 8,
  '7' => 7,
  '6' => 6,
  '5' => 5,
  '4' => 4,
  '3' => 3,
  '2' => 2,
  'L' => 1 # Magic low Ace.
}

Constants inherited from BasicGame

Gambler::Game::BasicGame::INITIAL_ANTE, Gambler::Game::BasicGame::INITIAL_POT

Instance Attribute Summary collapse

Attributes inherited from BasicGame

#ante, #deck, #players, #pot

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Blackjack

Returns a new instance of Blackjack.

Raises:



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# File 'lib/gambler/game/blackjack.rb', line 31

def initialize(options = {})
  raise Exceptions::InvalidPlayerSize unless options[:players].size >= 2
  super(options)
  @players.each { |player| player.empty_hand! }
  @players_in_round = Array.new
  @players_in_round.replace(@players)
  @round_winner = nil
end

Instance Attribute Details

#players_in_round ⇒ Object (readonly)

Returns the value of attribute players_in_round.



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# File 'lib/gambler/game/blackjack.rb', line 28

def players_in_round
  @players_in_round
end

#round_winner ⇒ Object (readonly)

Returns the value of attribute round_winner.



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# File 'lib/gambler/game/blackjack.rb', line 29

def round_winner
  @round_winner
end

Instance Method Details

#ante_up! ⇒ Object

Forces each Player to put ante in the pot.



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# File 'lib/gambler/game/blackjack.rb', line 41

def ante_up!
  @players_in_round.each { |player| place_bet(player, @ante) }
end

#finish_round! ⇒ Object

This should be called after all players bust or stay. Sets the @round_winner variable to the Player object who won and gives them the pot.

Raises:



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# File 'lib/gambler/game/blackjack.rb', line 106

def finish_round!
  raise Exceptions::NoWinner if @players_in_round.nil?
  # The winner is the Player with the highest hand_value.
  @round_winner = @players_in_round.sort_by do |player|
    hand_value(player.hand)
  end.reverse.first
  @round_winner.chips += @pot
  @pot = INITIAL_POT
end

#hand_value(hand) ⇒ Object

Calculates the integer value for a Blackjack hand. Aces are converted to their lower value if the total hand value will bust the Player (and there are aces in the hand, of course).



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# File 'lib/gambler/game/blackjack.rb', line 48

def hand_value(hand)
  return 0 if hand.empty?
  value = 0

  # Add up the face values
  hand.each do |card|
    value += FACE_VALUES[card.face]
  end

  # Handle any needed Ace changes.
  while value > BUST
    hand.each do |card|
      if card.face == 'A'
        # Subtract the difference between high and low ace (10).
        value -= (FACE_VALUES['A'] - FACE_VALUES['L'])
      end
    end
    break # no aces to change, bail
  end

  return value
end

#hit(player) ⇒ Object

Give player a Card.



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# File 'lib/gambler/game/blackjack.rb', line 72

def hit(player)
  @deck.deal_to player
  if player_bust?(player)
    @players_in_round.delete(player)
    raise Exceptions::PlayerBust
  end
end

#place_bet(player, amount) ⇒ Object

Allows player to place a bet for amount which will be added to the current hand’s pot.

Raises:



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# File 'lib/gambler/game/blackjack.rb', line 82

def place_bet(player, amount)
  raise Exceptions::NotEnoughChips if player.chips < amount
  @pot += amount
  player.chips -= amount
end

#player_bust?(player) ⇒ Boolean

Returns true of the Player’s hand has a value above BUST.

Returns:

  • (Boolean) 


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# File 'lib/gambler/game/blackjack.rb', line 89

def player_bust?(player)
  hand_value(player.hand) > BUST
end

#start_round! ⇒ Object

This should be called at the beginning of every round (not game), and sets up things like the ante and dealing initial hands.



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# File 'lib/gambler/game/blackjack.rb', line 95

def start_round!
  @players.each { |player| player.empty_hand! }
  @players_in_round.replace(@players)
  @round_winner = nil
  ante_up!
  deal_initial_hands
end