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

bearer = HTTPBearer(auto_error=True)


async def get_current_user(
    credentials: HTTPAuthorizationCredentials = Depends(bearer),
    db: AsyncSession = Depends(get_db),
) -> User:
    token = credentials.credentials
    payload = decode_token(token)

    if payload is None or payload.get("type") != "access":
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Token 无效或已过期",
        )

    user_id = int(payload["sub"])
    result = await db.execute(select(User).where(User.id == 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="用户不存在或已被禁用",
        )

    return user