import logging

from PIL import Image, ImageFilter
import scipy.signal
import numpy as np

logging.getLogger(__name__)

sobel_x_kernel = np.array((
    (1, 0, -1),
    (2, 0, -2),
    (1, 0, -1)
))

sobel_y_kernel = np.transpose(sobel_x_kernel)

def difference_of_gaussians(img: Image.Image, blur_strength_1: float | None = 1.0, blur_strength_2: float | None = 1.2) -> Image.Image:
    blur_1 = img.filter(ImageFilter.GaussianBlur(blur_strength_1))
    blur_2 = img.filter(ImageFilter.GaussianBlur(blur_strength_2))

    w, h = img.size

    dog = Image.new(img.mode, img.size)

    for pixel_y in range(h):
        for pixel_x in range(w):

            coords = (pixel_x, pixel_y)

            p1 = blur_1.getpixel(coords)
            p2 = blur_2.getpixel(coords)

            p1 = np.array(p1)
            p2 = np.array(p2)
            new_pixel = p2 - p1

            dog.putpixel(coords, tuple(new_pixel.tolist()))

    return dog

def sobel(img: Image.Image, gradient_threshold: int | None = 20) -> tuple[Image.Image, np.ndarray]:
    logging.debug(img.size)

    img = img.convert('L')
    img.save('debug/test-L.png')

    logging.debug('Sobel Operator')

    logging.debug(img.size)

    pixels = np.array(img)
    logging.debug(f'pixels size: {pixels.size}')

    dx = scipy.signal.correlate(pixels, sobel_x_kernel, mode='same')
    dy = scipy.signal.correlate(pixels, sobel_y_kernel, mode='same')
    logging.debug(f'dx size: {dx.size}')

    edges = np.sqrt(np.square(dx) + np.square(dy))
    edges[edges>255] = 255

    logging.debug(f'edges size: {edges.size}')

    gradient = np.arctan2(dy.flatten(), dx.flatten())
    gradient[gradient > gradient_threshold] = 0

    pil_edges = edges.astype(np.uint8)
    newimg = Image.fromarray(pil_edges, mode='L')
    logging.debug(f'New Img Size: {newimg.size}')

    return (newimg, gradient)