from datetime import datetime, timedelta
from typing import Optional

import jwt
from fastapi import HTTPException, Depends, status
from fastapi.security import OAuth2PasswordBearer
from sqlalchemy.orm import Session
from app.db.database import get_db
from app.models.user import User
from app.schemas.user import UserOut

SECRET_KEY = "supersecretkey"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")

def create_access_token(data: dict):
    to_encode = data.copy()
    expire = datetime.utcnow() + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt

def verify_access_token(token: str, db: Session):
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        user_id: str = payload.get("sub")
        if user_id is None:
            raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid credentials")
        user = db.query(User).filter(User.id == user_id).first()
        if user is None:
            raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED,
                                 detail="User not found")
        return user
    except jwt.PyJWTError:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid credentials")

def get_current_user(token: str = Depends(oauth2_scheme), db: Session = Depends(get_db)):
    return verify_access_token(token, db)