import cv2
import numpy as np


def points_in_circle_np(radius, x0=0, y0=0, ):
    x_ = np.arange(x0 - radius - 1, x0 + radius + 1, dtype=int)
    y_ = np.arange(y0 - radius - 1, y0 + radius + 1, dtype=int)
    x, y = np.where((x_[:,np.newaxis] - x0)**2 + (y_ - y0)**2 <= radius**2)
    # x, y = np.where((np.hypot((x_-x0)[:,np.newaxis], y_-y0)<= radius)) # alternative implementation
    for x, y in zip(x_[x], y_[y]):
        yield x, y

def points_mode_value(img, points):
    values = [img[y, x] for y, x in points]
    mode = max(set(values), key=values.count)
    return mode


def main():
  img = cv2.imread('image.png',)
  img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
  _, img = cv2.threshold(img, 240, 255, cv2.THRESH_BINARY)

  circles = cv2.HoughCircles(
      image=img,
      method=cv2.HOUGH_GRADIENT,
      dp=1,
      minDist=22,
      param1=200,
      param2=7,
      minRadius=10,
      maxRadius=12
  )
  print(circles.shape)

  circles = np.round(circles[0, :]).astype("int")
  circles = sorted(circles, key=lambda v: [v[0], v[1]])

  img_colored = cv2.cvtColor(img, cv2.COLOR_GRAY2BGR)

  if circles is not None:
      circles = np.uint16(np.around(circles))
      for cont, i in enumerate(circles, start=1):
          points = points_in_circle_np(x0=i[1], y0=i[0], radius=i[2])
          mode = points_mode_value(img, points)

          if mode == 255:
              cv2.circle(img_colored, (i[0], i[1]), i[2], (0, 0, 255), -1) # cv2.FILLED)
          else:
              cv2.circle(img_colored, (i[0], i[1]), i[2], (0, 255, 0), -1) # cv2.FILLED)

          cv2.putText(img_colored, str(cont), (i[0]-i[2], i[1]+i[2]), cv2.FONT_HERSHEY_SIMPLEX, 0.4, (0,0,0), 1, cv2.LINE_AA)

   cv2.imwrite("out.png", img_colored)


if __name__ == "__main__":
  main()