import gradio as gr
from PIL import Image

def composite_images(bg_image, overlay_image, x, y, scale, transparency, flip, grayscale):
    if bg_image is None or overlay_image is None:
        return None

    bg = bg_image.convert("RGBA")
    overlay = overlay_image.convert("RGBA")

    # Apply optional effects
    if flip:
        overlay = overlay.transpose(Image.FLIP_LEFT_RIGHT)

    if grayscale:
        overlay = overlay.convert("L").convert("RGBA")

    # Resize overlay
    new_size = (int(overlay.width * scale), int(overlay.height * scale))
    overlay = overlay.resize(new_size, resample=Image.LANCZOS)  # ✅ FIXED here

    # Adjust transparency
    alpha = int(255 * transparency)
    r, g, b, a = overlay.split()
    a = a.point(lambda p: alpha)
    overlay = Image.merge("RGBA", (r, g, b, a))

    # Create composite image
    composed = bg.copy()
    composed.paste(overlay, (int(x), int(y)), overlay)

    return composed

with gr.Blocks() as demo:
    gr.Markdown("### 🖼️ Overlay Image Composer with Transparency & Effects")

    with gr.Row():
        bg_input = gr.Image(label="Background Image", type="pil")
        overlay_input = gr.Image(label="Overlay Image", type="pil")

    with gr.Row():
        x = gr.Slider(0, 1024, value=100, step=1, label="X Position")
        y = gr.Slider(0, 1024, value=100, step=1, label="Y Position")

    with gr.Row():
        scale = gr.Slider(0.1, 3.0, value=1.0, step=0.1, label="Overlay Scale")
        transparency = gr.Slider(0, 1, value=1.0, step=0.01, label="Overlay Transparency")

    with gr.Row():
        flip = gr.Checkbox(label="Flip Overlay Horizontally")
        grayscale = gr.Checkbox(label="Convert Overlay to Grayscale")

    output_image = gr.Image(label="Composed Image", type="pil")

    run_btn = gr.Button("Generate Composite")
    download_btn = gr.Button("Download")

    run_btn.click(
        composite_images,
        inputs=[bg_input, overlay_input, x, y, scale, transparency, flip, grayscale],
        outputs=output_image
    )

    def download_image(img):
        if img is not None:
            img.save("composed_output.png")
            return "composed_output.png"
        return None

    download_btn.click(download_image, inputs=output_image, outputs=gr.File(label="Download Link"))

demo.launch()