class ABComputer

# File lib/abcomputer.rb, line 2
def initialize

end

# File lib/abcomputer.rb, line 22
def get_max(depth, alpha, beta)
  iterate_board do |row, column|
    if alpha > beta
      return alpha
    else
      if @board.is_empty_at(row, column)
        @board.move(row, column)
        if @observer.game_over?
         return -@board.player_value if @observer.has_winner?
         return 0
        else
         value = get_min(depth+1, alpha, beta)
         alpha = value if alpha < value
        end
      end
    end
  end
end

# File lib/abcomputer.rb, line 41
def get_min(depth, alpha, beta)
  iterate_board do |row, column|
    if alpha < beta
      return beta
    else
      if @board.is_empty_at(row, column)
        @board.move(row, column)
        if @observer.game_over?
         return -@board.player_value if @observer.has_winner?
         return 0
        else
         value = get_max(depth+1, alpha, beta)
         beta = value if beta > value
        end
      end
    end
  end
end

# File lib/abcomputer.rb, line 6
def make_move
  alpha = (-1.0)/(0.0)
  beta = (1.0)/(0.0)
  best_score = nil
  iterate_board do |row, column|
    @board.make_move(row, column)
    path_score = get_max(1, alpha, beta)
    @board.undo_move
    if best_score.nil? || path_score > best_score
      best_row = row
      best_column = column
      best_score = path_score
    end
  end
end

# File lib/abcomputer.rb, line 62
def iterate_board
  (1..3).each { |row| (1..3).each { |column| yield(row, column) } }
end