hate_brooks.rb

class Grid                                                                         
  attr_reader :coordinate_list                                                     
  def initialize(coordinate_list)                                                  
    @coordinate_list = coordinate_list                                             
  end                                                                              
                                                                                   
  def find_all_matches(x, y)                                                       
    find_target_pixels(x,y).each do |t_x, t_y|                                     
      if eligable_for_painting?([t_x, t_y], [x,y])                                 
        matches << [t_x, t_y]                                                      
        find_all_matches(t_x, t_y)                                                 
      end                                                                          
    end                                                                            
  end                                                                              
                                                                                   
  def eligable_for_painting?(q_coords, coords)                                     
    value_at(q_coords) == value_at(coords) && !matches.include?(q_coords)          
  end                                                                              
                                                                                   
  def find_target_pixels(x, y)                                                     
    [x-1, x, x+1].product([y-1, y, y+1])                                           
  end                                                                              
                                                                                   
  def value_at(coords)                                                             
    coordinate_list[coords[0]][coords[1]]                                          
  end                                                                              
                                                                                   
  def matches                                                                      
    @matches ||= []                                                                
  end                                                                              
                                                                                   
  def update_matches(color)                                                        
    matches.each do |x, y|                                                         
      coordinate_list[x][y] = color                                                
    end                                                                            
  end                                                                              
                                                                                   
  def apply_color(fill_type, x, y, color)                                          
    find_all_matches(x-1, y-1)                                                     
    update_matches(color)                                                          
  end                                                                              
end                                                                                
                                                                                   
class Image                                                                        
  def initialize(width, height, pixels)                                            
    @width = width                                                                 
    @height = height                                                               
    @pixels = pixels                                                               
  end                                                                              
                                                                                   
  def flood_fill(x, y, color)                                                      
    grid.apply_color(:flood, x, y, color)                                          
  end                                                                              
                                                                                   
  def display                                                                      
    grid.coordinate_list                                                           
  end                                                                              
                                                                                   
  private                                                                          
                                                                                   
  def grid                                                                         
    @grid ||= Grid.new(grouped_pixels)                                             
  end                                                                              
                                                                                   
  def grouped_pixels                                                               
    @pixels.each_slice(@width).to_a                                                
  end                                                                              
end                                                                                

Sandi Metz would be proud.