import os
from logging import Logger
from typing import Any, Tuple, Union

from apollo_utils.core.utils.ext_enum import ExtEnum
from apollo_utils.core.utils.singleton import SingleValue

NO_DATA = SingleValue()

LOADED_ATTRS = ("host", "apikey")
LOADED_DEFAULT_ATTRS = ("schema", "timeout", "retry_count", "retry_delay")


class BaseConfig:
    service: ExtEnum = None
    logger: Logger = None
    _loaded_attrs: Tuple = LOADED_ATTRS
    _loaded_default_attrs: Tuple = LOADED_DEFAULT_ATTRS
    _api: str = "api"
    _auth_name: str = "Authorization"
    _schema: str = "https"
    _timeout: int = 60
    _retry_count: int = 3
    _retry_delay: int = 1

    def _get_names(self, item: Union[str, tuple, list, set]) -> Tuple[str, str]:
        if isinstance(item, str):
            return item, item
        elif isinstance(item, (tuple, list, set)) and len(item) == 2:
            return item

    def _get_attr(self, name: str) -> Any:
        return os.environ.get(f"{self.service.value.upper()}{self._api.upper()}_{name.upper()}", NO_DATA)

    def _set_attr(self, name: str, value: Any):
        setattr(self, f"_{name}", value)

    def _load_attr(self, item: Union[str, tuple, list, set], try_load_orig: bool = False):
        source_attr, dest_attr = self._get_names(item)
        v = self._get_attr(source_attr)
        if v is NO_DATA:
            if try_load_orig:
                v = os.environ.get(source_attr.upper(), NO_DATA)
            else:
                raise RuntimeError(f"{self.service.value}{self._api.upper()}: {source_attr.upper()} is not set.")
        if v is not NO_DATA:
            self._set_attr(dest_attr, v)

    def _load_attrs(self):
        for item in self._loaded_attrs:
            self._load_attr(item, try_load_orig=False)

        for item in self._loaded_default_attrs:
            self._load_attr(item, try_load_orig=True)