import gradio as gr
import requests
import tempfile
import os

def display_3d_model(url):
    """
    Download a GLB file from a URL and return its path for Model3D.
    """
    if not url:
        return None

    # Validate URL (basic check)
    if not (url.startswith("http://") or url.startswith("https://")):
        return None

    # Optional: check if URL ends with .glb (but not mandatory)
    # Download the file
    try:
        response = requests.get(url, stream=True, timeout=10)
        response.raise_for_status()
        content_type = response.headers.get("content-type", "")
        if "model/gltf-binary" not in content_type and not url.lower().endswith(".glb"):
            print(f"Warning: Unexpected content type {content_type} for {url}")

        # Save to a temporary file
        with tempfile.NamedTemporaryFile(suffix=".glb", delete=False) as tmp:
            for chunk in response.iter_content(chunk_size=8192):
                tmp.write(chunk)
            tmp_path = tmp.name
        return tmp_path
    except Exception as e:
        print(f"Error downloading model: {e}")
        return None

def cleanup(file_path):
    """Delete the temporary file after use."""
    if file_path and os.path.exists(file_path):
        os.unlink(file_path)

# Gradio interface
with gr.Blocks(title="GLB Viewer") as demo:
    gr.Markdown("## 🌐 GLB Model Viewer from URL")
    gr.Markdown("Enter a direct URL to a `.glb` (binary glTF) file. The model will be displayed below.")

    with gr.Row():
        url_input = gr.Textbox(
            label="GLB File URL",
            placeholder="https://example.com/model.glb",
            scale=4
        )
        submit_btn = gr.Button("Load Model", variant="primary", scale=1)

    model_output = gr.Model3D(
        label="3D Model",
        clear_color=[0.2, 0.2, 0.2, 0.8],
        camera_position=(2, 2, 3),
        scale=1.0
    )

    # When the button is clicked, download and display
    submit_btn.click(
        fn=display_3d_model,
        inputs=url_input,
        outputs=model_output,
        queue=False
    )

    # Optional: cleanup temporary files after session ends
    # Gradio doesn't have a built-in session end hook, but we can ignore
    # because files will be deleted when the space restarts or after a while.

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