import bcrypt
from datetime import datetime, timedelta, timezone
from fastapi import Depends, HTTPException
from fastapi.security import OAuth2PasswordBearer
from jose import JWTError, jwt
from sqlalchemy.orm import Session
from app.core.config import settings
from app.core.database import get_db

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/auth/login")


def hash_password(password: str) -> str:
    return bcrypt.hashpw(password[:72].encode(), bcrypt.gensalt()).decode()

def verify_password(plain: str, hashed: str) -> bool:
    return bcrypt.checkpw(plain[:72].encode(), hashed.encode())

def create_access_token(data: dict) -> str:
    expire = datetime.now(timezone.utc) + timedelta(
        minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES
    )
    return jwt.encode({**data, "exp": expire}, settings.SECRET_KEY, algorithm="HS256")

def get_current_user(
    token: str = Depends(oauth2_scheme),
    db: Session = Depends(get_db)
):
    from app.models import User
    try:
        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=["HS256"])
        user_id = payload.get("sub")
        if not user_id:
            raise HTTPException(401, "Ugyldig token")
    except JWTError:
        raise HTTPException(401, "Ugyldig token")
    user = db.query(User).filter(User.id == user_id).first()
    if not user:
        raise HTTPException(401, "Bruger ikke fundet")
    return user