Can't add or move correctly :(

[SeanReid]

https://gist.github.com/SeanReid/65739b261d1fd24c6960

require 'io/console'
require 'pry'

@grid = [
  [0, 0, 0, 0],
  [0, 0, 0, 0],
  [4, 0, 0, 0],
  [0, 0, 0, 0]
]

def swap(args)
  position = args[:position]
  destination = args[:destination]

  position_value_before       = value_at(position)
  destination_value_before    = value_at(destination)

  set_value_for_cell(position, destination_value_before)
  set_value_for_cell(destination, position_value_before)

end

def set_value_for_cell(cell, value)
  #[2,0]
  row = cell.first
  column = cell.last
  row = @grid[row]
  row[column] = value
end

def move_d

  columns = [0, 1, 2, 3]
  rows = [3, 2, 1]

  columns.each do |column_number|
    rows.each do |row_number|
      if value_at([row_number, column_number]) == 0
        swap(position: [row_number-1,column_number], destination: [row_number,column_number])
      end
    end
  end
end

def move_t

  columns = [0, 1, 2, 3]
  rows = [0, 1, 2]

  columns.each do |column_number|
    rows.each do |row_number|
      if value_at([row_number, column_number]) == 0
        swap(position: [row_number+1,column_number], destination: [row_number,column_number])
      end
    end
  end
end

def move_l

  columns = [0, 1, 2]
  rows = [0, 1, 2, 3]

  rows.each do |row_number|
    columns.each do |column_number|
      if value_at([row_number, column_number]) == 0
        swap(position: [row_number,column_number+1], destination: [row_number,column_number])
      end
    end
  end
end

def move_r

  columns = [3, 2, 1]
  rows = [0, 1, 2, 3]

  rows.each do |row_number|
    columns.each do |column_number|
      if value_at([row_number, column_number]) == 0
        swap(position: [row_number,column_number-1], destination: [row_number,column_number])
      end
    end
  end
end

def matrix_is_full?
  @grid.flatten.all? do |number|
    number > 0
  end
end

def game_is_over?
  full = matrix_is_full?
  pairs = any_adjacent_pairs?
  # binding.pry
  return full && !pairs
end

def any_adjacent_pairs?
  #for all positions in grid, run any_adjacent?

  found_adjacent = false

  @grid.each_with_index do |row, row_number|

    #4 columns : 0, 1, 2, 3

    row.each_with_index do |column, index|
      if any_adjacent? row_number, index
        found_adjacent = true
        puts [row_number, index].join(',')
      end
    end

  end
  return found_adjacent

end

def add_random_to_grid
  #add either 2 or 4 to a random open square

  value_to_add = [2,4].sample

  chosen_cell = open_cells.sample
  if chosen_cell
    set_value_for_cell(chosen_cell, value_to_add)
  end
end

def open_cells
  cells = []
  @grid.each_with_index do |rows, row_index|
    rows.each_with_index do |columns, column_index|
      if value_at([row_index, column_index]) == 0
        cells << [row_index, column_index]
      end
    end
  end
  cells
end

def any_adjacent?(row, column)
  top = [row-1, column]
  left = [row, column-1]
  down = [row+1, column]
  right = [row, column+1]
  [top, left, down, right].any? do |position|
    does_equal([row, column], position)
  end
end

def does_equal(cell_one, cell_two)

  return false if value_at(cell_one) == 0

  value_at(cell_one) == value_at(cell_two)
end

def value_at(cell)
  x = cell.first
  y = cell.last
  row = @grid[x]

  if row
    value = row[y]
  else
    0
  end
end

def apply_move_to_grid(move)
  acceptable = %w(t d l r)
    if acceptable.include?(move)

    send("move_#{move}".to_sym)
    # case move
    # when 't'
    #   move_up
    # when 'd'
    #   move_down
    # when 'l'
    #   move_left
    # when 'r'
    #   move_right
    # end
    add_random_to_grid

  elsif move == "Q"
    exit()
    else
    puts "Sorry, please enter one of #{acceptable}"
  end
end

def run_game

  until game_is_over?
    system "clear" or system "cls"
    print_grid
    move = STDIN.getch
    apply_move_to_grid(move)
  end
end

def print_grid

  puts "\nEnter Q to quit!\n"
  @grid.each do |row|

    row.each do |i|
      value_to_show = i.to_s
      value_to_show = "" if i == 0
      printf "|%6s|", value_to_show
    end
    print "\n"
  end
end

run_game