from fastapi import Request, HTTPException, status, Depends
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select
import redis.asyncio as redis

from database import get_db
from utils.jwt import decode_token
from utils.redis_client import get_redis, check_token_in_redis

security = HTTPBearer()


async def get_current_user(
    request: Request,
    credentials: HTTPAuthorizationCredentials = Depends(security),
    db: AsyncSession = Depends(get_db),
    redis_conn: redis.Redis = Depends(get_redis),
):
    """获取当前用户"""
    token = credentials.credentials

    # 解码令牌
    payload = decode_token(token)
    if not payload:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="无效的认证凭据",
            headers={"WWW-Authenticate": "Bearer"},
        )

    user_id = int(payload.get("sub"))

    # 检查令牌是否在Redis中
    is_valid = await check_token_in_redis(redis_conn, user_id, token)
    if not is_valid:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="令牌已过期或已登出",
            headers={"WWW-Authenticate": "Bearer"},
        )

    # 查找用户
    from models import User

    result = await db.execute(select(User).filter(User.id == user_id))
    user = result.scalar_one_or_none()
    if not user:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="用户不存在")

    return user