from __future__ import annotations

from govoplan_core.core.registry import PlatformRegistry


_registry: PlatformRegistry | None = None
_service: object | None = None


def configure_runtime(*, registry: object) -> None:
    global _registry, _service
    if not isinstance(registry, PlatformRegistry):
        raise RuntimeError("Postbox requires a platform registry")
    if registry is not _registry:
        _registry = registry
        _service = None


def get_registry() -> PlatformRegistry:
    if _registry is None:
        raise RuntimeError("Postbox runtime has not been configured")
    return _registry


def get_service():
    global _service
    if _service is None:
        from govoplan_postbox.backend.service import PostboxService

        _service = PostboxService.from_registry(get_registry())
    return _service