from typing import TYPE_CHECKING, Any

from .GameplayDatabase import GameplayDatabase
from .backend import GameplayBackendBuilder

if TYPE_CHECKING:
  from .EdgeDB import EdgeDB
  from .LocalStorage import LocalStorage

__all__ = (
  "EdgeDB",
  "GameplayBackendBuilder",
  "GameplayDatabase",
  "LocalStorage",
  "StorageLoader",
)

def __getattr__(name:str):
  """Load optional storage backends only when explicitly requested.

  Database maintenance scripts import SQLite backend modules through this
  package. Eagerly importing LocalStorage used to make those scripts require
  unrelated web-storage dependencies such as aiofiles.
  """
  if name == "LocalStorage":
    from .LocalStorage import LocalStorage
    return LocalStorage
  if name == "EdgeDB":
    from .EdgeDB import EdgeDB
    return EdgeDB
  raise AttributeError(f"module {__name__!r} has no attribute {name!r}")

class StorageLoader:
  @classmethod
  def build(cls, selected_storage:str) -> Any:
    storage_module = __import__(
      f"server.database.{selected_storage}", fromlist=[selected_storage],
    )
    storage_class = getattr(storage_module, selected_storage)
    return storage_class