import gradio as gr
from PIL import Image, ImageDraw

def halftone_effect(img, dot_size=10):
    """
    Apply a halftone effect to the input image.
    
    Parameters:
    - img: PIL.Image object (input image)
    - dot_size: int, spacing and maximum cell size for dot placement
    
    Returns:
    - PIL.Image object with halftone effect
    """
    # Convert to grayscale
    grayscale = img.convert('L')
    width, height = grayscale.size

    # Create a new white image for the halftone effect
    halftone_image = Image.new('L', (width, height), color=255)
    draw = ImageDraw.Draw(halftone_image)

    # Loop through the image in steps of dot_size
    for x in range(0, width, dot_size):
        for y in range(0, height, dot_size):
            # Determine the size of the current block (to handle image edges)
            block_width = min(dot_size, width - x)
            block_height = min(dot_size, height - y)

            # Extract the region of interest and calculate its average brightness
            region = grayscale.crop((x, y, x + block_width, y + block_height))
            avg_brightness = sum(region.getdata()) / (block_width * block_height)

            # Calculate radius based on brightness (brighter = smaller dot)
            max_radius = dot_size // 2
            radius = int((255 - avg_brightness) / 255 * max_radius)
            radius = max(0, min(radius, max_radius))  # Clamp radius between 0 and max_radius

            # Draw the circle at the center of the current cell
            center_x = x + dot_size // 2
            center_y = y + dot_size // 2
            draw.ellipse(
                (
                    center_x - radius,
                    center_y - radius,
                    center_x + radius,
                    center_y + radius
                ),
                fill=0  # Black dot
            )

    return halftone_image

# Gradio Interface
interface = gr.Interface(
    fn=halftone_effect,
    inputs=[
        gr.Image(type="pil", label="Upload an Image"),
        gr.Slider(minimum=5, maximum=20, step=1, value=10, label="Dot Size")
    ],
    outputs=gr.Image(label="Halftone Image"),
    title="Halftone Image Generator",
    description="Convert any image into a stylized halftone effect using black dots.",
    allow_flagging="never"
)

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