from .utils import fetch


def create_endpoints_dict(endpoints):
    return {
        endpoint["path"]: {
            "assets": {asset["symbol"]: asset["tags"] for asset in endpoint["assets"]},
            "currencies": endpoint["currencies"],
            "resolutions": endpoint["resolutions"],
            "formats": endpoint["formats"],
        }
        for endpoint in endpoints
    }


"""
@pattern Singleton (GoF:127)
"""


class MetaEndpoints(type):
    _instances = {}

    def __call__(cls, *args, **kwargs):
        if cls not in cls._instances:
            instance = super().__call__(*args, **kwargs)
            cls._instances[cls] = instance
        return cls._instances[cls]


class Endpoints(metaclass=MetaEndpoints):
    _endpoints = None

    @property
    def endpoints(self):
        return self._endpoints

    @endpoints.setter
    def endpoints(self, api_key):
        self._endpoints = create_endpoints_dict(
            fetch("/v2/metrics/endpoints", {"api_key": api_key})
        )

    def query(self, path):
        return self._endpoints[path]