backend/app.py

import os
import gradio as gr
from huggingface_hub import InferenceClient
from huggingface_hub.utils import HfHubHTTPError
from dotenv import load_dotenv

# Load environment variables from .env file in parent directory
env_path = os.path.join(os.path.dirname(os.path.dirname(__file__)), '.env')
load_dotenv(dotenv_path=env_path)

api_token = os.getenv("HUGGINGFACE_API_TOKEN")
if not api_token:
    raise ValueError("HUGGINGFACE_API_TOKEN environment variable not set. Please check your .env file.")

client = InferenceClient("HuggingFaceH4/zephyr-7b-beta", token=api_token)

def respond(message, history, system_message, max_tokens, temperature, top_p):
    messages = [{"role": "system", "content": system_message}]
    
    for val in history:
        if val[0]:
            messages.append({"role": "user", "content": val[0]})
        if val[1]:
            messages.append({"role": "assistant", "content": val[1]})
    
    messages.append({"role": "user", "content": message})
    response = ""
    
    try:
        for message in client.chat_completion(
            messages,
            max_tokens=max_tokens,
            stream=True,
            temperature=temperature,
            top_p=top_p,
        ):
            if hasattr(message.choices[0], 'delta') and hasattr(message.choices[0].delta, 'content'):
                token = message.choices[0].delta.content
                response += token
                yield response
    except Exception as e:
        yield f"Error: {str(e)}"

# Create the Gradio interface
demo = gr.ChatInterface(
    fn=respond,
    title="E-commerce Chatbot",
    description="Ask me anything about products!",
    examples=["Tell me about gaming laptops", "What are the best smartphones?"],
    additional_inputs=[
        gr.Textbox(value="You are a friendly E-commerce assistant.", label="System message"),
        gr.Slider(minimum=1, maximum=2048, value=512, step=1, label="Max new tokens"),
        gr.Slider(minimum=0.1, maximum=4.0, value=0.7, step=0.1, label="Temperature"),
        gr.Slider(minimum=0.1, maximum=1.0, value=0.95, step=0.05, label="Top-p")
    ]
)

if __name__ == "__main__":
    try:
        demo.launch(server_name="0.0.0.0", server_port=8000, share=True)
    except Exception as e:
        print(f"Error launching the demo: {e}")