from fastapi import Header, HTTPException
import os
import jwt
from dotenv import load_dotenv

load_dotenv()

secret_token = os.getenv("AUTH_TOKEN")

async def authenticate_token(authorization: str = Header(...)):
    token_type, token = authorization.split()
    if token_type != "Bearer":
        raise HTTPException(status_code=401, detail="Unauthorized")
    try:
        return jwt.decode(token, secret_token, algorithms=["HS256"])
    except jwt.ExpiredSignatureError:
        raise HTTPException(status_code=401, detail="Token has expired") from None
    except (jwt.InvalidTokenError, IndexError):
        raise HTTPException(status_code=401, detail="Invalid token") from None