import json
import queue
from typing import Any, Union, Optional

from app.schemas import Notification
from app.utils.singleton import Singleton


class MessageHelper(metaclass=Singleton):
    """
    消息队列管理器，包括系统消息和用户消息
    """
    def __init__(self):
        self.sys_queue = queue.Queue()
        self.user_queue = queue.Queue()

    def put(self, message: Union[str, Notification], role: str = "sys"):
        """
        存消息
        :param message: 消息
        :param role: 消息通道 sys/user
        """
        if role == "sys":
            self.sys_queue.put(message)
        else:
            if isinstance(message, Notification):
                self.user_queue.put(json.dumps(message.dict()))
            else:
                self.user_queue.put(message)

    def get(self, role: str = "sys") -> Optional[str]:
        """
        取消息
        :param role: 消息通道 sys/user
        """
        if role == "sys":
            if not self.sys_queue.empty():
                return self.sys_queue.get(block=False)
        else:
            if not self.user_queue.empty():
                return self.user_queue.get(block=False)
        return None