from caching.errors import WorkerCacheError
from caching.worker import Worker


class CacheManager:

    _singleton = None

    def __new__(cls, *args, **kwargs):
        if not cls._singleton:
            cls._singleton = super(CacheManager, cls).__new__(cls, *args, **kwargs)
        return cls._singleton

    def __init__(self):
        """
        The constructor for the CacheManager class.
        """
        self.worker = None

    @property
    def cache_path(self):
        """
        Dynamic property.

        :return: if self.worker => self.worker.base_dir else None
        """
        if self.worker:
            return self.worker.base_dir
        else:
            return None

    def create_cache(self):
        """
        Deletes the old worker and creates a new one.

        :return: None
        """
        del self.worker
        self.worker = Worker()

    def wipe_cache(self):
        """
        Deletes the current worker.

        :return: None
        """
        del self.worker
        self.worker = None

    def __enter__(self):
        self.create_cache()

    def __exit__(self, type, value, traceback):
        self.wipe_cache()