import cv2
import numpy as np
import scipy as sp
import scipy.sparse.linalg
import gradio as gr

def get_image(img):
    return cv2.cvtColor(img, cv2.COLOR_BGR2RGB).astype('double') / 255.0

def neighbours(i, j, max_i, max_j):
    pairs = []
    for n in [-1, 1]:
        if 0 <= i+n <= max_i:
            pairs.append((i+n, j))
        if 0 <= j+n <= max_j:
            pairs.append((i, j+n))
    return pairs

def poisson_sharpening(img, alpha):
    img_h, img_w = img.shape[:2]
    img_s = img.copy()
    
    im2var = np.arange(img_h * img_w).reshape(img_h, img_w) 
    
    A = sp.sparse.lil_matrix((img_h*img_w*4*2, img_h*img_w))
    b = np.zeros(img_h*img_w*4*2)
    
    e = 0
    for y in range(img_h):
        for x in range(img_w):
            A[e, im2var[y][x]] = 1
            b[e] = img_s[y][x]
            e += 1
            
            for n_y, n_x in neighbours(y, x, img_h-1, img_w-1):
                A[e, im2var[y][x]] = 1
                A[e, im2var[n_y][n_x]] = -1
                
                b[e] = alpha * (img_s[y][x] - img_s[n_y][n_x])
                e += 1
                
    A = sp.sparse.csr_matrix(A)
    v = sp.sparse.linalg.lsqr(A, b)[0]

    return np.clip(v.reshape(img_h, img_w), 0, 1)

def sharpen_image(input_img, alpha):
    img = get_image(input_img)
    
    sharpen_img = np.zeros(img.shape)
    for b in range(3):
        sharpen_img[:,:,b] = poisson_sharpening(img[:,:,b], alpha)
    
    return (sharpen_img * 255).astype(np.uint8)

# Create examples list using the images from the original code
examples = [
    ["img1.jpg", 9.0],
    ["img2.PNG", 7.0],
]

# Create the Gradio interface
iface = gr.Interface(
    fn=sharpen_image,
    inputs=[
        gr.Image(label="Input Image", type="numpy"),
        gr.Slider(minimum=1.0, maximum=15.0, step=0.01, value=9.0, label="Sharpening Strength (alpha)")
    ],
    outputs=gr.Image(label="Sharpened Image"),
    title="Poisson Image Sharpening",
    description="Upload an image or choose from the examples, then adjust the sharpening strength to enhance edges and details.",
    theme='bethecloud/storj_theme',
    examples=examples,
    cache_examples=True
)

iface.launch()