Code counts

#!/usr/bin/env ruby

require "pry"

class Grid
  def initialize(data)
    @counts = Hash.new(0)
    @data = data
    @x_size = @data[0].size
    @y_size = @data.size
    raise "Not a rectangle" unless @data.all?{|row| row.size == @x_size}
  end

  def [](x,y)
    @data[y % @y_size][x % @x_size]
  end

  def add!(a,b,c,d)
    @counts[a+b+c+d] += 1
    @counts[d+c+b+a] += 1
  end

  def run!
    @y_size.times do |x|
      @x_size.times do |y|
        # horizontal
        add! self[x,y], self[x+1,y], self[x+2,y], self[x+3,y]
        # vertical
        add! self[x,y], self[x,y+1], self[x,y+2], self[x,y+3]
        # diagonal
        add! self[x,y], self[x+1,y+1], self[x+2,y+2], self[x+3,y+3]
        # reverse diagonal
        add! self[x,y], self[x+1,y-1], self[x+2,y-2], self[x+3,y-3]
      end
    end
    puts @counts.max_by(&:last).join(":")
  end
end


grid = Grid.new(open("grid2.txt").read.split("\n"))
grid.run!