from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from sqlalchemy.orm import Session
from typing import Optional
from ..core.database import get_db
from ..core.security import decode_token
from ..models.models import User, UserRole
from ..schemas import TokenData

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/v1/auth/login")


async def get_current_user(
    token: str = Depends(oauth2_scheme),
    db: Session = Depends(get_db)
) -> User:
    """Get current authenticated user"""
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    
    user_id = decode_token(token)
    if user_id is None:
        raise credentials_exception
    
    user = db.query(User).filter(User.id == int(user_id)).first()
    if user is None:
        raise credentials_exception
    
    if not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Inactive user"
        )
    
    return user


async def get_current_active_user(
    current_user: User = Depends(get_current_user)
) -> User:
    """Get current active user"""
    return current_user


async def get_admin_user(
    current_user: User = Depends(get_current_user)
) -> User:
    """Verify user has admin privileges"""
    if current_user.role not in [UserRole.ADMIN, UserRole.SUPER_ADMIN]:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Not enough permissions"
        )
    return current_user


async def get_super_admin_user(
    current_user: User = Depends(get_current_user)
) -> User:
    """Verify user has super admin privileges"""
    if current_user.role != UserRole.SUPER_ADMIN:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Super admin access required"
        )
    return current_user