"""Loader for installed BASALT-compatible VIO runtime packages."""

from collections.abc import Mapping
from importlib import import_module
from typing import Any

from vio_adapter.interfaces import NativeVioRunner, VioBackendError
from vio_adapter.types import VioBackendEstimate


class BasaltNativeRunner:
    """Adapts an installed BASALT binding to the VIO runner protocol."""

    def __init__(
        self,
        module_name: str = "basalt_vio",
        factory_name: str = "create_runner",
        config: Mapping[str, object] | None = None,
    ) -> None:
        self._module_name = module_name
        self._factory_name = factory_name
        self._config = dict(config or {})
        self._runner: NativeVioRunner | None = None

    def initialize(self) -> None:
        try:
            module = import_module(self._module_name)
            factory = getattr(module, self._factory_name)
            runner = factory(**self._config)
        except Exception as exc:
            raise VioBackendError(
                f"unable to load BASALT runtime {self._module_name}:{self._factory_name}"
            ) from exc

        if not isinstance(runner, NativeVioRunner):
            raise VioBackendError(
                f"BASALT runtime {self._module_name}:{self._factory_name} "
                "does not implement NativeVioRunner"
            )

        self._runner = runner
        self._runner.initialize()

    def estimate(self, frame: Any, telemetry_window: tuple[Any, ...]) -> VioBackendEstimate:
        if self._runner is None:
            raise VioBackendError("BASALT runtime is not initialized")
        return self._runner.estimate(frame, telemetry_window)