from fastapi import FastAPI
from pydantic import BaseModel
from ai_engine import generate

app = FastAPI(title="Hello World AI")

# VERY simple in-memory store - now storing tuples (user_msg, assistant_msg)
sessions: dict[str, list[tuple[str, str]]] = {}


class ChatRequest(BaseModel):
    session_id: str
    message: str


class ChatResponse(BaseModel):
    reply: str


@app.post("/chat", response_model=ChatResponse)
def chat(req: ChatRequest):
    history = sessions.setdefault(req.session_id, [])

    reply = generate(req.message, history)

    # Store as tuple (user_msg, assistant_msg)
    history.append((req.message, reply))

    return {"reply": reply}