import gradio as gr
import mimetypes

def process_video(video, visualize_features):
    if video is None:
        return None, "Error: No video uploaded."

    # Validate video format
    mime_type, _ = mimetypes.guess_type(video)
    if not mime_type or not mime_type.startswith("video"):
        return None, "Error: Unsupported file format. Please upload a valid video file."

    try:
        # Placeholder: In a real app, process the video and visualize features if requested
        msg = "Feature visualization enabled." if visualize_features else "Feature visualization disabled."
        return video, msg
    except Exception as e:
        return None, f"Error: {str(e)}"

with gr.Blocks(theme=gr.themes.Base(), css=".gradio-container {background: #111827; color: #d1d5db;}" ) as demo:
    gr.Markdown(
        """
        # <span style="background: linear-gradient(to right, #2dd4bf, #06b6d4); -webkit-background-clip: text; color: transparent;">DINOv3 Video Tracking</span>
        <span style="color:#94a3b8;">In-browser video tracking powered by Transformers.js</span>
        """,
        elem_id="title"
    )
    with gr.Row():
        video_input = gr.Video(label="Select a video or drag and drop")
    with gr.Row():
        visualize = gr.Checkbox(label="Visualize Dense Features", value=False)
    with gr.Row():
        video_output = gr.Video(label="Preview")
        msg_output = gr.Textbox(label="Status", interactive=False)
    gr.Button("Run").click(
        process_video, 
        inputs=[video_input, visualize], 
        outputs=[video_output, msg_output]
    )

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