"""Address-selection tests (multi-homing) — the core of the reachability fix."""
from mdns_tools import _pick


def test_single_routable_ip_returned():
    assert _pick.pick_best(["192.168.1.17"]) == "192.168.1.17"


def test_only_virtual_ip_returns_none(monkeypatch):
    # libvirt bridge address must be rejected so callers fall back to Tailscale.
    monkeypatch.setattr(_pick, "local_ipv4", lambda: "192.168.1.112")
    assert _pick.pick_best(["192.168.122.1"]) is None


def test_docker_range_rejected(monkeypatch):
    monkeypatch.setattr(_pick, "local_ipv4", lambda: "192.168.1.112")
    assert _pick.pick_best(["172.17.0.1"]) is None


def test_prefers_same_subnet(monkeypatch):
    monkeypatch.setattr(_pick, "local_ipv4", lambda: "192.168.1.112")
    got = _pick.pick_best(["10.8.0.3", "192.168.1.50"])
    assert got == "192.168.1.50"


def test_dedupe_preserves_order():
    assert _pick.pick_best(["10.0.0.9", "10.0.0.9"]) == "10.0.0.9"


def test_ipv6_prefers_global_over_link_local():
    got = _pick.pick_best(["fe80::1", "2800:e2::5"], family="v6")
    assert got == "2800:e2::5"