"""Connector registry — single source of truth for source_type -> connector."""

from __future__ import annotations

from typing import Any

_CONNECTORS: dict[str, Any] = {}


def register_connector(connector: Any) -> None:
    """Register a SourceConnector instance under its ``source_type``.

    Calling twice with the same ``source_type`` replaces the prior entry —
    useful for tests and hot-reload, but in production each connector
    should be registered exactly once at startup.
    """
    if not getattr(connector, "source_type", None):
        raise ValueError("Connector must declare a non-empty source_type")
    _CONNECTORS[connector.source_type] = connector


def get_connector(source_type: str) -> Any:
    """Return the registered connector for ``source_type`` or raise KeyError."""
    try:
        return _CONNECTORS[source_type]
    except KeyError as exc:
        raise KeyError(f"No connector registered for source_type {source_type!r}") from exc


def _reset_for_tests() -> None:
    """Clear the registry — for use in pytest fixtures only."""
    _CONNECTORS.clear()