"""FastAPI dependencies for authentication

供其他模組引用的 dependency injection 函數
"""
from fastapi import Request, HTTPException, status


async def get_current_user(request: Request) -> dict:
    """Get current authenticated user from request state

    Usage in other modules:
        from app.modules.auth import get_current_user

        @router.get("/my-endpoint")
        async def my_endpoint(current_user: dict = Depends(get_current_user)):
            username = current_user["username"]
            display_name = current_user["display_name"]
            ...

    Returns:
        dict: {"id": int, "username": str, "display_name": str}

    Raises:
        HTTPException: If user not authenticated (middleware should prevent this)
    """
    if not hasattr(request.state, "user"):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED, detail="Authentication required"
        )

    return request.state.user