"""carp_virtual_ip: one CARP address as a virtual IP, with its holder in the reading.

CARP differs from vip-manager and keepalived in what the caller can see. The
address is configured on every member, and the interface list of a firewall need
not show it at all -- so the interfaces cannot say who holds it. CARP's own state
can: the member in MASTER holds it, a BACKUP stands by. That is CARP protocol
knowledge, so it lives with the driver that speaks CARP (netOrk #1121), not in
napalm-device-types.
"""

from __future__ import annotations

import pytest

from napalm_opnsense.virtual_ips import carp_virtual_ip


def _entry(**overrides):
    fields = {
        "address": "172.22.8.1",
        "prefix_length": 24,
        "vhid": "108",
        "state": "MASTER",
        "instance": "MGMT",
        "interface": "vtnet0",
    }
    fields.update(overrides)
    return carp_virtual_ip(**fields)


def test_a_master_holds_the_address():
    assert _entry() == {
        "mechanism": "carp",
        "instance": "MGMT",
        "address": "172.22.8.1",
        "prefix_length": 24,
        "interface": "vtnet0",
        "group_key": "vhid:108",
        "running": True,
        "holds": True,
    }


def test_a_backup_stands_by():
    entry = _entry(state="BACKUP")
    assert entry is not None
    assert (entry["running"], entry["holds"]) == (True, False)


@pytest.mark.parametrize("state", ["INIT", "DISABLED"])
def test_a_member_whose_carp_is_not_up_neither_runs_nor_holds(state):
    entry = _entry(state=state)
    assert entry is not None
    assert (entry["running"], entry["holds"]) == (False, False)


@pytest.mark.parametrize("state", [None, "", "SOMETHING-NEW"])
def test_an_unknown_state_says_nothing_about_the_holder(state):
    """None leaves the holder to the interfaces, as for the other mechanisms."""
    entry = _entry(state=state)
    assert entry is not None
    assert (entry["running"], entry["holds"]) == (None, None)


def test_the_state_is_read_case_blind():
    entry = _entry(state=" master ")
    assert entry is not None
    assert entry["holds"] is True


def test_the_address_is_normalised():
    entry = _entry(address="FD00::0001", prefix_length=64)
    assert entry is not None
    assert entry["address"] == "fd00::1"


def test_an_address_written_with_its_prefix_takes_that_prefix():
    entry = _entry(address="10.42.100.1/24", prefix_length=None)
    assert entry is not None
    assert (entry["address"], entry["prefix_length"]) == ("10.42.100.1", 24)


@pytest.mark.parametrize("address", ["", "not-an-address", "10.0.0.300"])
def test_what_is_no_address_is_no_virtual_ip(address):
    assert _entry(address=address) is None


@pytest.mark.parametrize("prefix", [33, -1])
def test_an_impossible_prefix_is_dropped(prefix):
    entry = _entry(prefix_length=prefix)
    assert entry is not None
    assert entry["prefix_length"] is None


@pytest.mark.parametrize("vhid", [None, "", "abc"])
def test_without_a_numeric_vhid_there_is_no_group(vhid):
    entry = _entry(vhid=vhid)
    assert entry is not None
    assert entry["group_key"] is None


def test_a_vhid_given_as_a_number_groups_the_same_way():
    entry = _entry(vhid=108)
    assert entry is not None
    assert entry["group_key"] == "vhid:108"


def test_an_empty_instance_falls_back_to_the_vhid():
    entry = _entry(instance="")
    assert entry is not None
    assert entry["instance"] == "vhid 108"