from fastapi import FastAPI, HTTPException
from pydantic import BaseModel

from .llm import chatgpt

app = FastAPI()


class ChatRequest(BaseModel):
    input: str


class ChatResponse(BaseModel):
    response: str


@app.get("/")
async def root():
    return {"message": "GEN_AI Backend is running 🚀"}


@app.post("/chat", response_model=ChatResponse)
async def chat_endpoint(payload: ChatRequest):
    text = payload.input.strip()
    if not text:
        raise HTTPException(status_code=400, detail="Input cannot be empty")

    reply = chatgpt(text)
    return ChatResponse(response=reply)