from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select
from app.core.database import get_db
from app.core.security import decode_access_token
from app.models.user import User

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


async def get_current_user(
    token: str = Depends(oauth2_scheme),
    db: AsyncSession = Depends(get_db),
) -> User:
    payload = decode_access_token(token)
    if payload is None:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="无效的认证凭据")
    user_id = payload.get("sub")
    if user_id is None:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="无效的认证凭据")
    result = await db.execute(select(User).where(User.id == int(user_id)))
    user = result.scalar_one_or_none()
    if user is None or not user.is_active:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="用户不存在或已禁用")
    return user


def require_roles(*roles: str):
    async def checker(user: User = Depends(get_current_user)):
        if user.role not in roles:
            raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="权限不足")
        return user
    return checker