from skimage import io
from skimage.measure import label, regionprops
from skimage.filters import threshold_otsu
from skimage.color import rgb2gray


from skimage import io
from skimage.color import rgb2gray
from skimage.filters import threshold_sauvola
from skimage.exposure import equalize_adapthist
from skimage.measure import label, regionprops
from skimage.morphology import closing, square

def get_heights(filename: str) -> list:
    """Open an image and return a list of the bar heights."""
    # Load image and convert to grayscale
    image = io.imread(filename)
    im = rgb2gray(image)

    # Apply adaptive histogram equalization to enhance contrast
    im_eq = equalize_adapthist(im, clip_limit=0.03)

    # Adaptive thresholding using Sauvola method
    window_size = 25  # Adjust window size if needed
    thresh_sauvola = threshold_sauvola(im_eq, window_size=window_size)
    binary_im = im_eq > thresh_sauvola

    # Morphological closing to fill gaps and clean noise
    binary_im = closing(binary_im, square(3))

    # Label connected components
    labeled = label(binary_im)

    # Get bounding boxes for each detected object
    bar_dimensions = [r.bbox for r in regionprops(labeled)]

    # Sort bounding boxes by horizontal position (xmin)
    bar_dimensions.sort(key=lambda x: x[1])

    # Use the first detected object (logo) as max height reference
    logo = bar_dimensions[0]
    max_height = logo[2] - logo[0]

    sequence = []
    for bar in bar_dimensions[1:]:
        height = bar[2] - bar[0]
        ratio = height / max_height
        ratio *= 8
        ratio = int(ratio)  # truncate decimal part
        sequence.append(ratio - 1)

    return sequence