from typing import AsyncGenerator

from fastapi import Depends, HTTPException, Request, status
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.user import User
from app.services.auth import get_user_by_id
from app.services.database import AsyncSessionLocal


async def get_db() -> AsyncGenerator[AsyncSession, None]:
    async with AsyncSessionLocal() as session:
        async with session.begin():
            yield session


async def get_current_user(request: Request, db: AsyncSession = Depends(get_db)) -> User:
    user_id = getattr(request.state, "user_id", None)
    if user_id is None:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Not authenticated")
    user = await get_user_by_id(db, user_id)
    if user is None:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="User not found or inactive")
    return user


async def require_admin(current_user: User = Depends(get_current_user)) -> User:
    if current_user.role != "admin":
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Admin access required")
    return current_user