"""Exercise installed parent and nested child controls, never real credentials."""
import json
import os
from pathlib import Path
import socket
import subprocess
import sys

import pytest

ROOT = Path(__file__).resolve().parents[1]


@pytest.fixture
def guarded(request):
    guard = getattr(request.config, '_unit_guard', None)
    if guard is None:
        pytest.skip('requires make test / scripts/run_unit_tests.py')
    return guard


def test_parent_environment_is_allowlisted_and_home_is_temporary(guarded):
    # The external regression invocation sets synthetic BAO_TOKEN/VAULT_TOKEN/HOME.
    assert 'BAO_TOKEN' not in os.environ
    assert 'VAULT_TOKEN' not in os.environ
    assert Path(os.environ['TMPDIR']) in Path.home().parents
    assert 'PYTHONPATH' not in os.environ


@pytest.mark.parametrize('command', [
    ['bao', 'token', 'lookup'], ['ssh', 'railiance01'], ['curl', 'http://127.0.0.1:8000'],
    [sys.executable, '-c', 'import os; print(os.environ)'],
])
def test_unexpected_process_refused_before_launch(guarded, command):
    with pytest.raises(PermissionError, match='unit isolation'):
        subprocess.run(command, check=True)


def test_parent_socket_denies_even_unregistered_loopback(guarded):
    with pytest.raises(PermissionError, match='unit isolation'):
        socket.socket().connect(('127.0.0.1', 8000))


@pytest.mark.parametrize('path', ['/home/synthetic-ambient-unit-fixture/.vault-token',
                                  '/root/.kube/config', '/proc/self/environ',
                                  '/tmp/warden-synthetic-ambient-home/.vault-token'])
def test_ambient_paths_refused_without_opening_them(guarded, path):
    with pytest.raises(PermissionError, match='unit isolation'):
        Path(path).read_bytes()


def test_symlink_cannot_escape_fixture_root(guarded, tmp_path):
    link = tmp_path / 'ambient'
    link.symlink_to('/home/synthetic-ambient-unit-fixture/.vault-token')
    with pytest.raises(PermissionError, match='unit isolation'):
        link.read_bytes()


def test_child_drops_even_synthetic_token_environment(guarded, monkeypatch):
    monkeypatch.setenv('BAO_TOKEN', 'synthetic-only-never-a-real-token')
    monkeypatch.setenv('VAULT_TOKEN', 'synthetic-only-never-a-real-token')
    monkeypatch.setenv('HOME', '/home/synthetic-ambient-unit-fixture')
    result = subprocess.run([sys.executable, str(ROOT / 'tests/unit_isolation_probe.py'), 'state'],
                            capture_output=True, text=True, check=True, env=dict(os.environ))
    assert json.loads(result.stdout) == {'bao_token_present': False,
                                        'vault_token_present': False, 'home_in_temporary': True}


@pytest.mark.parametrize('mode', ['socket', 'provider', 'home', 'nested'])
def test_guard_exists_in_each_allowed_python_child(guarded, mode):
    result = subprocess.run([sys.executable, str(ROOT / 'tests/unit_isolation_probe.py'), mode],
                            capture_output=True, text=True, check=True)
    assert result.stdout == 'denied\n'


def test_forged_provider_double_refused(guarded, tmp_path):
    provider = tmp_path / 'bao'
    provider.write_text('#!/bin/bash\necho not-the-reviewed-fixture\n')
    provider.chmod(0o700)
    with pytest.raises(PermissionError, match='double bytes differ'):
        subprocess.run([str(provider), 'token', 'lookup'], check=True)


def test_os_open_truncation_respects_read_only_source_root(guarded, tmp_path, monkeypatch):
    # Synthetic readable source outside the guard's writable subtree.
    source = tmp_path / 'synthetic-source'
    source.write_bytes(b'synthetic public source')
    monkeypatch.setattr(guarded, 'temporary', tmp_path / 'writable')
    with pytest.raises(PermissionError, match='unit isolation'):
        descriptor = os.open(source, os.O_RDONLY | os.O_TRUNC)
        os.close(descriptor)
    assert source.read_bytes() == b'synthetic public source'