from langchain_community.chat_message_histories import ChatMessageHistory
from typing import Optional
import logging


logger = logging.getLogger(__name__)


class MemoryStore:
    _instance: Optional['MemoryStore'] = None
    _memory: Optional[ChatMessageHistory] = None

    def __new__(cls):
        if cls._instance is None:
            cls._instance = super(MemoryStore, cls).__new__(cls)
            cls._memory = ChatMessageHistory()
            logger.info("New MemoryStore instance created")
        return cls._instance

    @classmethod
    def get_memory(cls) -> ChatMessageHistory:
        if cls._instance is None:
            cls._instance = cls()
        return cls._memory

    @classmethod
    def clear_memory(cls):
        if cls._memory is not None:
            cls._memory = ChatMessageHistory()
            logger.info("Memory cleared")