object OpenCVUtils {

  def togglify[A, B, F[_]: Applicative](f: A => B => F[B]): Boolean => A => B => F[B] = {
    toggle =>
      if (toggle)
        f
      else
        a => b => b.pure[F]
  }

  def colorSpace(colorSpace: => Int)(input: Mat): Future[Mat] = {
    delay {
      val colorTransformed = new Mat
      Imgproc.cvtColor(input, colorTransformed, colorSpace)
      colorTransformed
    }
  }

  def blur(size: Size)(input: Mat): Future[Mat] = {
    delay {
      val blurredMat = new Mat
      Imgproc.blur(input, blurredMat, size)
      blurredMat
    }
  }

  def chop(height: => Int, width: => Int)(input: Mat): Future[Mat] = {
    delay {
      new Mat(input, new Range(1, height), new Range(1, width))
    }
  }
}

class ImageSource {

  val videoCapture: VideoCapture = new VideoCapture(0)

  def takeImage: Mat = {
    val image = new Mat()
    while (!videoCapture.read(image)) {}
    image
  }

  def sourceMat: Future[Mat] =
    delay {
      assert(videoCapture.isOpened)
      if (videoCapture.grab) {
        takeImage
      } else
        throw new RuntimeException("Couldn't grab image!")
    }

}