from collections.abc import Generator

from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from jose import JWTError, jwt
from pydantic import ValidationError
from sqlalchemy.orm import Session

from app import crud
from app.core.config import settings
from app.core.security import ALGORITHM
from app.db.session import SessionLocal
from app.models.user import User
from app.schemas.auth import TokenPayload

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl=f"{settings.API_V1_STR}/auth/login"
)


def get_db() -> Generator:
    try:
        db = SessionLocal()
        yield db
    finally:
        db.close()


def get_current_user(
    db: Session = Depends(get_db), token: str = Depends(oauth2_scheme)
) -> User:
    try:
        payload = jwt.decode(
            token, settings.SECRET_KEY, algorithms=[ALGORITHM]
        )
        token_data = TokenPayload(**payload)
    except (JWTError, ValidationError):
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Could not validate credentials",
        )
    user = crud.get(db, user_id=token_data.sub)
    if not user:
        raise HTTPException(status_code=404, detail="User not found")
    return user


def get_current_active_user(
    current_user: User = Depends(get_current_user),
) -> User:
    if not crud.is_active(current_user):
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user