"""Resolver that inherits a candidate from another entity's resolution.

Used by BGP events to pick up the location of their owning collector. The
``source_lookup`` callable is the only domain coupling — it receives the
incoming :class:`LocationQuery` and returns either an already-resolved
:class:`LocationCandidate` (typically by querying another pipeline) or
``None`` to signal "no parent location available".
"""

from __future__ import annotations

from typing import Callable

from ..models import LocationCandidate, LocationQuery, ResolverOutput


class InheritFromAnotherEntityResolver:
    def __init__(
        self,
        *,
        source_lookup: Callable[[LocationQuery], LocationCandidate | None],
        name: str = "inherited",
    ) -> None:
        self.name = name
        self._lookup = source_lookup

    def resolve(self, query: LocationQuery) -> ResolverOutput:
        result = self._lookup(query)
        if result is None:
            return ResolverOutput()
        return ResolverOutput(candidates=(result,))