import java.nio.file.Files
import java.io.File
import javax.imageio.ImageIO

def avgDiffSq(file: File): Double = {
  val image = ImageIO.read(file)
  val data = image.getRGB(0, 0, image.getWidth, image.getHeight, null, 0, image.getWidth)
  var i = 0
  var sum = 0.0
  while(i < data.size) {
    val c = data(i)
    val r = (c&0xFF0000)>>16; val g = (c&0xFF00)>>8; val b = c&0xFF
    val d = (math.abs(r-g) + math.abs(r-b)).toDouble
    sum += d*d
    i += 1
  }
  math.sqrt(sum / data.size)
}

var count = 0

new File(".").listFiles.foreach {file =>
  if(file.getName.endsWith(".jpg") || file.getName.endsWith(".jpeg") || file.getName.endsWith(".png")) {
    try {
      val diff = avgDiffSq(file)
      val dir = if(diff < 5) "bw"
                else if(diff < 20) "maybe"
                else "color"
      file.renameTo(new File(dir + "/" + file.getName))
      count += 1
      println(count)
    } catch {
      case e: Exception => println(file.getName); println(e)
    }
  }
}