tic tac toe

game.rb

class Tic
  X = "x"
  O = "o"
  def initialize
  puts "Initialized"
  @board = [
    "-","-","-",
    "-","-","-",
    "-","-","-",
  ]

  @turn = X
  end

  def show_board
    puts "-------"
    @board.each_index do |i|
    print " #{@board[i]}"
    print "\n" if i % 3 == 2
    end
  end

  def show_board_index
    puts "-------"
    @board.each_index do | i  |
     print " #{if @board[i] == "-" then i else "-" end}"
    print "\n" if i % 3 == 2
    end
  end

  def markable? i
    return false unless i > -1 and i < 9
    return false unless @board[i] == "-"
    true
  end 

  def mark i
    @board[i] = @turn
  end

  def change_turn
    if @turn == X
     @turn = O
    else
     @turn = X
    end
  end

  def get_mark_index_and_mark
    puts "type index of board"
    show_board_index
    i = gets.to_i

    while not markable?(i)
      puts "you choosed invalid value"
      i = gets.to_i
    end
    mark i
    puts "-----------"
    show_board
  end

  def start 
    puts "================="
    puts "Start Tic Tac Toe"
    puts "================="
    while true 
      get_mark_index_and_mark
      change_turn
      maybe_winner = who_is_winner? 
      unless maybe_winner == nil
        puts "#{maybe_winner} won"
        break
      end
    end
  end

  def who_is_winner? 
    score_board = [0,0,0,0,0,0,0,0,0]
    @board.each_index do |i|
      if @board[i] == O
       score_board[i] = 1
      elsif @board[i] == X
       score_board[i] = -1
      end
    end

    result = []
    3.times do |i|
      result.push(score_board[i] + score_board[i+1] + score_board[i+2])
      result.push(score_board[i] + score_board[i+3] + score_board[i+6])
    end
    result.push(score_board[0] + score_board[4] + score_board[8])
    result.push(score_board[2] + score_board[4] + score_board[6])
      
    result.each do |i|
      return O if i == 3
      return X if i == -3
    end
    return nil
  end
end

game = Tic.new
game.start