import importlib.util
from pathlib import Path
import socket
import subprocess
import unittest
from unittest.mock import patch


spec = importlib.util.spec_from_file_location(
    "relay", Path(__file__).parents[1] / "roles/common/files/k3s-control-plane-relay.py"
)
relay = importlib.util.module_from_spec(spec)
spec.loader.exec_module(relay)
BASE = (Path(__file__).parents[1] / "roles/common/templates/control-plane-relay.nft.j2").read_text()


class ControlPlaneRelayTest(unittest.TestCase):
    @patch.object(relay.subprocess, "run")
    @patch.object(relay.socket, "getaddrinfo")
    def test_all_dns_addresses_are_deduplicated_and_checked_before_apply(self, resolve, run):
        resolve.return_value = [
            (socket.AF_INET, 0, 0, "", ("192.0.2.1", 0)),
            (socket.AF_INET6, 0, 0, "", ("2001:db8::1", 0, 0, 0)),
            (socket.AF_INET, 0, 0, "", ("192.0.2.1", 0)),
        ]
        relay.apply_rules(["tthk.node.dev.cm"], BASE)
        rules = run.call_args_list[0].kwargs["input"]
        self.assertEqual(rules.count("peers4 { 192.0.2.1 }"), 1)
        self.assertIn("peers6 { 2001:db8::1 }", rules)
        self.assertIn("--check", run.call_args_list[0].args[0])
        self.assertEqual(run.call_args_list[1].kwargs["input"], rules)

    @patch.object(relay.subprocess, "run")
    @patch.object(relay.socket, "getaddrinfo")
    def test_any_dns_failure_preserves_existing_rules(self, resolve, run):
        resolve.side_effect = [
            [(socket.AF_INET, 0, 0, "", ("192.0.2.1", 0))],
            socket.gaierror("temporary failure"),
        ]
        with self.assertRaises(socket.gaierror):
            relay.apply_rules(["tthk.node.dev.cm", "other.node.dev.cm"], BASE)
        run.assert_not_called()

    @patch.object(relay.subprocess, "run", side_effect=subprocess.CalledProcessError(1, "nft"))
    def test_invalid_rules_are_not_applied(self, run):
        with self.assertRaises(subprocess.CalledProcessError):
            relay.apply_rules([], BASE)
        self.assertEqual(run.call_count, 1)

    @patch.object(relay.subprocess, "run")
    def test_empty_list_clears_only_the_owned_table(self, run):
        relay.apply_rules([], BASE)
        rules = run.call_args.kwargs["input"]
        self.assertIn("delete table inet k3s_control_plane_relay", rules)
        self.assertNotIn("add element", rules)
        self.assertNotIn("flush ruleset", rules)