from protosim_py import TychoDB


class TychoDBSingleton:
    """
    A singleton wrapper around the TychoDB class.

    This class ensures that there is only one instance of TychoDB throughout the lifetime of the program,
    avoiding the overhead of creating multiple instances.
    """

    _instance = None

    @classmethod
    def initialize(cls, tycho_http_url: str):
        """
        Initialize the TychoDB instance with the given URLs.

        Parameters
        ----------
        tycho_http_url : str
            The URL of the Tycho HTTP server.

        """
        cls._instance = TychoDB(tycho_http_url=tycho_http_url)

    @classmethod
    def get_instance(cls) -> TychoDB:
        """
        Retrieve the singleton instance of TychoDB.

        If the TychoDB instance does not exist, it creates a new one.
        If it already exists, it returns the existing instance.

        Returns
        -------
        TychoDB
            The singleton instance of TychoDB.
        """
        if cls._instance is None:
            raise ValueError(
                "TychoDB instance not initialized. Call initialize() first."
            )
        return cls._instance

    @classmethod
    def clear_instance(cls):
        cls._instance = None