from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
import jwt
from backend.core.config import settings
from backend.core.database import get_database

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="auth/verify-otp")

async def get_current_user(token: str = Depends(oauth2_scheme)):
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        # Decode the JWT token
        payload = jwt.decode(token, settings.JWT_SECRET, algorithms=[settings.JWT_ALGORITHM])
        telegram_id: str = payload.get("sub")
        if telegram_id is None:
            raise credentials_exception
    except jwt.PyJWTError:
        raise credentials_exception
    
    # Check if user exists in MongoDB
    db = get_database()
    user = await db["users"].find_one({"telegram_id": telegram_id})
    if user is None:
        raise credentials_exception
        
    return user

async def get_admin_user(current_user: dict = Depends(get_current_user)):
    """Dependency to enforce admin-only routes."""
    if not current_user.get("is_admin"):
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN, 
            detail="Not enough privileges to access this route"
        )
    return current_user