"""Offline tests; never opens a WG interface or contacts a gateway."""
import base64
import importlib.util
from pathlib import Path
import tempfile
import unittest
from unittest.mock import patch

spec = importlib.util.spec_from_file_location('wg_agent', Path(__file__).with_name('agent.py'))
agent = importlib.util.module_from_spec(spec)
spec.loader.exec_module(agent)
key = lambda n: base64.b64encode(bytes([n]) * 32).decode()


class AgentTests(unittest.TestCase):
    def setUp(self):
        self.task = dict(id='task-1', publicKey=key(2), oldPublicKey=None, presharedKey=key(3),
                         address='10.203.0.2', desired='active', action='create', version=1)
        self.base = '[Interface]\nPrivateKey = gateway-secret\nAddress = 10.203.0.1/24\nPostUp = preserve firewall\n\n[Peer]\nPublicKey = ' + key(8) + '\nAllowedIPs = 10.203.0.8/32\n'

    def test_merge_preserves_unmanaged_peers_and_interface(self):
        merged = agent.merge_config(self.base, self.task)
        self.assertTrue(merged.startswith(self.base))
        self.assertEqual(agent.merge_config(merged, self.task), merged)
        task = {**self.task, 'desired': 'paused', 'action': 'pause'}
        removed = agent.merge_config(merged, task)
        self.assertNotIn(key(2), removed)
        self.assertIn(key(8), removed)
        self.assertIn('PostUp = preserve firewall', removed)

    def test_conflicts_and_outside_network_are_rejected(self):
        for address in ['8.8.8.8', '10.203.0.1', '10.203.0.255']:
            with self.assertRaises(ValueError):
                agent.merge_config(self.base, {**self.task, 'address': address})
        with self.assertRaises(ValueError):
            agent.merge_config(self.base, {**self.task, 'address': '10.203.0.8'})
        with self.assertRaises(ValueError):
            agent.merge_config(self.base.replace('PostUp = preserve firewall', 'SaveConfig = true'), self.task)

    def test_rotate_removes_old_identity(self):
        old = agent.merge_config(self.base, self.task)
        rotated = agent.merge_config(old, {**self.task, 'publicKey': key(4), 'oldPublicKey': key(2), 'action': 'rotate'})
        self.assertNotIn(key(2), rotated)
        self.assertIn(key(4), rotated)
        self.assertIn(key(8), rotated)

    def test_adoption_is_read_only_and_requires_matching_psk(self):
        config = agent.merge_config(self.base, self.task)
        with tempfile.TemporaryDirectory() as directory:
            file = Path(directory) / 'wg-njcq.conf'
            file.write_text(config)
            with patch.object(agent, 'CONFIG', file), patch.object(agent, 'runtime_peers', return_value=agent.peers(config)), patch.object(agent, 'command') as cmd:
                self.assertEqual(agent.apply_task({**self.task, 'action': 'adopt'}), (True, True))
                self.assertEqual(agent.apply_task({**self.task, 'action': 'adopt', 'presharedKey': key(9)}), (False, False))
                cmd.assert_not_called()
            self.assertEqual(file.read_text(), config)

    def test_pause_persists_and_removes_runtime_peer_before_confirming(self):
        config = agent.merge_config(self.base, self.task)
        runtime = agent.peers(config)
        calls = []
        def command(*args):
            calls.append(args)
            if args[:2] == ('wg', 'showconf'):
                return config
            if args[-1] == 'remove':
                runtime.pop(args[-2], None)
                return ''
            raise AssertionError(args)
        with tempfile.TemporaryDirectory() as directory:
            file = Path(directory) / 'wg-njcq.conf'
            file.write_text(config)
            with patch.object(agent, 'CONFIG', file), patch.object(agent, 'runtime_peers', side_effect=lambda: runtime), patch.object(agent, 'command', side_effect=command):
                task = {**self.task, 'desired': 'paused', 'action': 'pause'}
                self.assertEqual(agent.apply_task(task), (True, True))
                self.assertEqual(agent.apply_task(task), (True, True))
                self.assertNotIn(key(2), file.read_text())
                self.assertIn(key(8), file.read_text())
                self.assertNotIn(key(2), runtime)
                self.assertEqual(len(list((file.parent / 'proxy-station-backups').glob('*.conf'))), 1)
                self.assertEqual(file.stat().st_mode & 0o777, 0o600)


if __name__ == '__main__':
    unittest.main()