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.core.config import settings
from app.core.security import ALGORITHM
from app.db.session import get_db
from app.models.user import User
from app.schemas.token import TokenPayload

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),
) -> User:
    """
    Get current user from JWT token
    """
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        payload = jwt.decode(
            token, settings.SECRET_KEY, algorithms=[ALGORITHM]
        )
        token_data = TokenPayload(**payload)
    except (JWTError, ValidationError):
        raise credentials_exception
    
    user = db.query(User).filter(User.id == token_data.sub).first()
    if not user:
        raise credentials_exception
    if not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Inactive user",
        )
    return user


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