#! /usr/bin/ruby
require 'chunky_png'

image1 = ChunkyPNG::Image.from_file(ARGV[0])
keyR = ARGV[1]
keyG = ARGV[2]
keyB = ARGV[3]

def go(r, g, b, image)
  range = 2
  if (r.to_i > 255) || (r.to_i < 0) || (g.to_i > 255) || (g.to_i < 0) || (b.to_i > 255) || (b.to_i < 0)
    puts 'Invalid arguments. Syntax is ./findColorin [IMAGE] [R VALUE] [G VALUE] [B VALUE]'
    return 0
  end
  (0..image.dimension.width - 1).each do |x|
    (0..image.dimension.height - 1).each do |y|
      if (image[x, y] > ChunkyPNG::Color.rgb(r.to_i - range, g.to_i - range, b.to_i - range)) && (image[x, y] < ChunkyPNG::Color.rgb(r.to_i + range, g.to_i + range, b.to_i + range))
        image[x, y] = ChunkyPNG::Color.rgb(0, 0, 0)
      else
        image[x, y] = ChunkyPNG::Color.rgb(255, 255, 255)
            end
    end
  end
  puts 'Saving to output.png'
  image.save('output.png')
end

go keyR, keyG, keyB, image1