"""NAPALM ``get_lldp_neighbors`` from ``HostNetworkSystem.QueryNetworkHint``.

ESXi listens for CDP on standard vSwitches by default and for LLDP where a
vDS enables it. Both answers come back per vmnic in one hint; LLDP is
preferred because it names the switch port the way the switch itself does.
"""

from __future__ import annotations

from typing import Any


def _lldp(info: dict[str, Any]) -> dict[str, str] | None:
    if not info.get("portId"):
        return None
    params = {p.get("key"): p.get("value") for p in info.get("parameter", [])}
    hostname = params.get("System Name") or info.get("chassisId", "")
    return {"hostname": str(hostname), "port": str(info["portId"])}


def _cdp(info: dict[str, Any]) -> dict[str, str] | None:
    if not info.get("portId"):
        return None
    return {"hostname": str(info.get("devId", "")), "port": str(info["portId"])}


def lldp_neighbors(hints: list[dict[str, Any]]) -> dict[str, list[dict[str, str]]]:
    result: dict[str, list[dict[str, str]]] = {}
    for hint in hints:
        neighbor = _lldp(hint.get("lldpInfo") or {}) or _cdp(hint.get("connectedSwitchPort") or {})
        if neighbor:
            result[hint["device"]] = [neighbor]
    return result