TicTacToe

tic-tac-toe.rb

PLAYER_SYMBOL = "X"
COMPUTER_SYMBOL = "O"

WINNING_COMBINATION =
  {
    0 => [[0, 1, 2], [0, 3, 6], [0, 4, 8]],
    1 => [[0, 1, 2], [1, 4, 7]],
    2 => [[0, 1, 2], [2, 5, 8], [2, 4, 6]],
    3 => [[0, 3, 6], [3, 4, 5]],
    4 => [[0, 4, 8], [3, 4, 5], [2, 4, 6], [1, 4, 7]],
    5 => [[3, 4, 5], [2, 5, 8]],
    6 => [[0, 3, 6], [2, 4, 6], [6, 7, 8]],
    7 => [[1, 4, 7], [6, 7, 8]],
    8 => [[0, 4, 8], [6, 7, 8], [2, 5, 8]]
  }

def computer(boxes)
  b = boxes.find {|b| b.text.length == 0}
  if b
    b.text = COMPUTER_SYMBOL
  end
end

def game_over?(boxes)
  has_winner?(boxes) || all_filled?(boxes)
end

def has_winner?(boxes)
  winning_symbol(boxes)
end

def all_filled?(boxes)
  boxes.all? {|b| b.text.length > 0}
end

def announce_winner(boxes)
  s = winning_symbol(boxes)
  if s == COMPUTER_SYMBOL
    alert('COMPUTER WINS;')
  elsif s == PLAYER_SYMBOL
    alert('YOU WIN!')
  else
    alert('DRAW')
  end
end

def winning_symbol(boxes)
  s = WINNING_COMBINATION.find do |idx, combinations|
    combinations.find do |combination|
      x = combination.collect do |i|
        boxes[i].text
      end
      x.uniq.length == 1 && x.uniq.first != ''
    end
  end
  if s
    boxes[s.flatten.first].text
  end
end

def all_clear(boxes)
  boxes.each do |box|
    box.text = ''
  end
end

def button_clicked(boxes, i)
  if boxes[i].text.length == 0
    boxes[i].text = PLAYER_SYMBOL
  end
  computer(boxes)
  if game_over?(boxes)
    announce_winner(boxes)
    all_clear(boxes)
  end
end

Shoes.app(:title => 'TicTacToe') do
  boxes = []
  buttons = []
  9.times do
    boxes << edit_box()
  end
  9.times do |i|
    buttons << button("X", :width => 200)
  end

  buttons.each_with_index do |button, index|
    button.click do
      button_clicked(boxes, index)
    end
  end
end