from typing import Generator, Optional

from fastapi import Depends, HTTPException, status
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from sqlalchemy.orm import Session

from app.db.session import get_db
from app.models.user import User
from app.services.auth import verify_token, get_user_by_username

# Security scheme
security = HTTPBearer()


def get_current_user(
    db: Session = Depends(get_db),
    credentials: HTTPAuthorizationCredentials = Depends(security),
) -> User:
    """Get current authenticated user."""
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    
    # Verify token
    username = verify_token(credentials.credentials)
    if username is None:
        raise credentials_exception
    
    # Get user from database
    user = get_user_by_username(db, username=username)
    if user is None:
        raise credentials_exception
    
    if not user.is_active:
        raise HTTPException(status_code=400, 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=400, detail="Inactive user")
    return current_user


def get_current_active_superuser(
    current_user: User = Depends(get_current_user),
) -> User:
    """Get current active superuser."""
    if not current_user.is_superuser:
        raise HTTPException(
            status_code=400, detail="The user doesn't have enough privileges"
        )
    return current_user