app.py

from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel
from huggingface_hub import InferenceClient
import os


HF_TOKEN = os.getenv("HF_TOKEN")
MODEL_ID = "google/gemma-2b-it"
client = InferenceClient(token=HF_TOKEN)

app = FastAPI()

# Allow CORS for all origins (for development and Netlify)
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # For production, specify frontend domain
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

class ChatRequest(BaseModel):
    message: str

@app.get("/")
def root():
    return {"message": "Gemma Chat API is running 🚀. Use POST /chat to send messages."}


@app.post("/chat")
async def chat(req: ChatRequest):
    try:
        messages = [{"role": "user", "content": req.message}]
        response = client.chat_completion(
            model=MODEL_ID,
            messages=messages,
            temperature=0.7,
        )
        return {"response": response.choices[0].message.content}
    except Exception as e:
        return {"error": str(e)}