from __future__ import annotations

from datetime import datetime, timezone
from typing import TYPE_CHECKING

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

from app import models, schemas
from app.core.config import settings
from app.core import security
from app.db.session import get_db

if TYPE_CHECKING:
    from sqlalchemy.orm import Session

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


def get_current_user(
    db: Session = Depends(get_db), token: str = Depends(oauth2_scheme)
) -> models.User:
    """
    Validate access token and return current user.
    """
    try:
        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM])
        token_data = schemas.TokenPayload(**payload)

        if datetime.fromtimestamp(token_data.exp, tz=timezone.utc) < datetime.now(tz=timezone.utc):
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Token expired",
                headers={"WWW-Authenticate": "Bearer"},
            )
    except (JWTError, ValidationError) as e:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Could not validate credentials",
            headers={"WWW-Authenticate": "Bearer"},
        ) from e

    user = db.query(models.User).filter(models.User.id == token_data.sub).first()

    if not user:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="User not found")

    return user


def get_current_active_user(
    current_user: models.User = Depends(get_current_user),
) -> models.User:
    """
    Get current active user.
    """
    if not current_user.is_active:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Inactive user")
    return current_user


def get_current_active_superuser(
    current_user: models.User = Depends(get_current_user),
) -> models.User:
    """
    Get current active superuser.
    """
    if not current_user.is_superuser:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN, detail="The user doesn't have enough privileges"
        )
    return current_user