import gradio as gr
from PIL import Image, ImageFilter
import numpy as np
import torch
import cv2
from transformers import AutoImageProcessor, AutoModelForDepthEstimation

# Load depth estimation model
image_processor = AutoImageProcessor.from_pretrained("depth-anything/Depth-Anything-V2-Small-hf")
model = AutoModelForDepthEstimation.from_pretrained("depth-anything/Depth-Anything-V2-Small-hf")

def apply_gaussian_blur(image, mask):
    """Applies Gaussian blur to the background based on a user-drawn mask."""
    
    if mask is None:
        return image  # If no mask is provided, return the original image
    
    # Ensure mask is grayscale and resized to match image dimensions
    mask_pil = Image.fromarray(mask).convert("L").resize(image.size)
    mask_array = np.array(mask_pil)

    # Create a blurred background
    blurred_background = image.filter(ImageFilter.GaussianBlur(radius=15))

    # Convert images to NumPy arrays
    img_array = np.array(image)
    blurred_array = np.array(blurred_background)

    # Create a boolean mask (foreground = True, background = False)
    foreground_mask = mask_array > 0
    foreground_mask_3d = np.stack([foreground_mask] * 3, axis=-1)

    # Blend the original image with the blurred background
    final_image_array = np.where(foreground_mask_3d, img_array, blurred_array)
    final_image = Image.fromarray(final_image_array.astype(np.uint8))

    return final_image

def apply_lens_blur(image):
    """Applies depth-based lens blur using a pre-trained model."""
    
    # Resize image to 512x512 for processing
    resized_image = image.resize((512, 512))
    image_np = np.array(resized_image)

    # Prepare image for the model
    inputs = image_processor(images=resized_image, return_tensors="pt")

    with torch.no_grad():
        outputs = model(**inputs)
        predicted_depth = outputs.predicted_depth

    # Interpolate depth map to match the image size
    prediction = torch.nn.functional.interpolate(
        predicted_depth.unsqueeze(1),
        size=resized_image.size[::-1],
        mode="bicubic",
        align_corners=False,
    ).squeeze() 

    # Convert prediction to a NumPy array
    depth_map = prediction.cpu().numpy()

    # Normalize the depth map
    depth_norm = (depth_map - np.min(depth_map)) / (np.max(depth_map) - np.min(depth_map))

    num_blur_levels = 5  
    blurred_layers = []
    for i in range(num_blur_levels):
        sigma = i * 0.5
        if sigma == 0:
            blurred = image_np
        else:
            blurred = cv2.GaussianBlur(image_np, (15, 15), sigmaX=sigma, sigmaY=sigma, borderType=cv2.BORDER_REPLICATE)
        blurred_layers.append(blurred)

    depth_indices = ((1 - depth_norm) * (num_blur_levels - 1)).astype(np.uint8)

    final_blurred_image = np.zeros_like(image_np)
    for y in range(image_np.shape[0]):
        for x in range(image_np.shape[1]):
            depth_index = depth_indices[y, x]
            final_blurred_image[y, x] = blurred_layers[depth_index][y, x]

    # Convert the final blurred image back to a PIL Image
    final_blurred_pil_image = Image.fromarray(final_blurred_image)

    return final_blurred_pil_image

def process_image(image, mask, blur_type):
    """Processes the image based on the selected blur type."""
    if blur_type == "Gaussian Blur":
        return apply_gaussian_blur(image, mask)
    elif blur_type == "Lens Blur":
        return apply_lens_blur(image)
    else:
        return image

interface = gr.Interface(
    fn=process_image,
    inputs=[
        gr.Image(type="pil", label="Upload an Image"),
        gr.Sketchpad(height=256, width=256, label="Draw Mask (Only for Gaussian Blur)"),
        gr.Radio(["Gaussian Blur", "Lens Blur"], label="Choose Blur Effect")
    ],
    outputs=gr.Image(type="pil"),
    title="Gaussian & Lens Blur Effects",
    description="Upload an image and select either Gaussian blur (with mask) or depth-based lens blur."
)


if __name__ == "__main__":
    interface.launch(share=True)