app.py

#pip install gradio==4.43.0
#pip install gradio-client==1.3.0
#pip install huggingface_hub>=0.24.0

import os
import gradio as gr
from gradio_client import Client, handle_file
import zipfile
import time

BACKEND_URL = os.getenv("BACKEND_URL")
HF_TOKEN = os.environ["HF_TOKEN"]  # set in Space Secrets

# Client is created on the server; token never goes to the browser.
client = Client(BACKEND_URL, hf_token=HF_TOKEN)

def proxy_transcribe(audio_path):
    if not audio_path:
        return "No audio provided.", None, None
    try:
        # Send file server-side to the private backend
        out = client.predict(audio_path=handle_file(audio_path), api_name="/transcribe")
        transcript = out[0] if isinstance(out, (list, tuple)) else out

        # Create zip
        timestamp = int(time.time())
        zip_path = f"/tmp/results_{timestamp}.zip"
        with zipfile.ZipFile(zip_path, "w") as zf:
            zf.write(audio_path, arcname=os.path.basename(audio_path))
            transcript_path = audio_path.rsplit(".", 1)[0] + ".txt"
            with open(transcript_path, "w", encoding="utf-8") as f:
                f.write(transcript)
            zf.write(transcript_path, arcname=os.path.basename(transcript_path))

        return transcript, audio_path, zip_path
    except Exception as e:
        # Never echo secrets; keep errors generic
        return f"Backend error: {type(e).__name__}",None ,audio_path

with gr.Blocks() as demo:
    gr.Markdown("## ASR Demo (frontend proxy)")
    a = gr.Audio(sources=["upload", "microphone"], type="filepath", label="Audio")
    t = gr.Textbox(label="Transcription",lines=7, interactive=False) #,elem_classes="auto-height")
    audio_file_output = gr.File(label="Download Audio")
    zip_output = gr.File(label="Download ZIP")
    
    a.change(proxy_transcribe, inputs=a, outputs=[t,audio_file_output, zip_output])

# demo.css = """
# .auto-height textarea {
#     height: auto !important;
#     min-height: 40px;
#     max-height: 150px;
#     overflow-y: auto;
# }
# """
# demo.queue(concurrency_count=2, max_size=8)

if __name__ == "__main__":
    demo.launch(server_name="0.0.0.0", server_port=7860, share=True)