from __future__ import annotations
import uuid
from typing import Optional
from fastapi import Header, HTTPException
from app.core.redis import get_redis


async def get_session_id(x_session_id: Optional[str] = Header(default=None)) -> str:
    if not x_session_id:
        raise HTTPException(status_code=401, detail="No session found. Please upload a resume first.")

    redis = await get_redis()
    exists = await redis.exists(f"session:{x_session_id}:resume")
    if not exists:
        raise HTTPException(status_code=401, detail="Session expired. Please upload your resume again.")

    return x_session_id


def generate_session_id() -> str:
    return str(uuid.uuid4())