"""Regression tests for disposable-VM isolation and trustworthy serial evidence."""
import importlib.util
from pathlib import Path
import socket
import subprocess
import tempfile
import threading
import unittest

SCRIPT = Path(__file__).resolve().parents[1] / 'dev/iso-smoke.py'


class SmokeTests(unittest.TestCase):
    def setUp(self):
        self.assertTrue(SCRIPT.is_file(), 'disposable ISO acceptance harness is missing')
        spec = importlib.util.spec_from_file_location('iso_smoke', SCRIPT)
        self.mod = importlib.util.module_from_spec(spec)
        spec.loader.exec_module(self.mod)
        self.temp = tempfile.TemporaryDirectory()
        self.addCleanup(self.temp.cleanup)
        self.root = Path(self.temp.name)
        self.code = self.root / 'code.fd'
        self.variables = self.root / 'vars.fd'
        self.code.write_bytes(b'firmware')
        self.variables.write_bytes(b'fresh vars')

    def test_existing_disk_or_symlink_cannot_be_a_test_drive(self):
        disk = self.root / 'disk.qcow2'
        disk.write_bytes(b'original')
        with self.assertRaises(self.mod.SmokeError):
            self.mod.reserve_disk(disk)
        link = self.root / 'link.qcow2'
        link.symlink_to(disk)
        with self.assertRaises(self.mod.SmokeError):
            self.mod.reserve_disk(link)
        self.assertEqual(disk.read_bytes(), b'original')

    def test_qemu_only_accepts_owned_regular_disk_and_readonly_iso(self):
        disk = self.root / 'disk.qcow2'
        self.mod.reserve_disk(disk)
        iso = self.root / 'trusted.iso'
        iso.write_bytes(b'ISO')
        argv = self.mod.qemu_argv('qemu', self.root, disk, self.code,
                                  self.variables, iso, 2048)
        drives = [argv[i + 1] for i, value in enumerate(argv[:-1]) if value == '-drive']
        self.assertTrue(any('format=qcow2' in item and str(disk) in item for item in drives))
        self.assertTrue(any('media=cdrom' in item and 'readonly=on' in item for item in drives))
        self.assertIn('accel=kvm', ' '.join(argv))
        disk.unlink()
        disk.symlink_to(iso)
        with self.assertRaises(self.mod.SmokeError):
            self.mod.qemu_argv('qemu', self.root, disk, self.code,
                               self.variables, iso, 2048)

    def test_installed_reboot_has_no_optical_medium(self):
        disk = self.root / 'disk.qcow2'
        self.mod.reserve_disk(disk)
        argv = self.mod.qemu_argv('qemu', self.root, disk, self.code,
                                  self.variables, None, 2048)
        self.assertNotIn('media=cdrom', ' '.join(argv))
        self.assertNotIn('-cdrom', argv)

    def test_hardlinked_disk_is_refused(self):
        disk = self.root / 'disk.qcow2'
        self.mod.reserve_disk(disk)
        (self.root / 'alias').hardlink_to(disk)
        with self.assertRaises(self.mod.SmokeError):
            self.mod.qemu_argv('qemu', self.root, disk, self.code,
                               self.variables, None, 2048)

    def test_result_frame_ignores_command_echo_and_preserves_failure(self):
        command = self.mod.frame_command('printf sentinel; false', 'testtoken')
        result = subprocess.run(['/bin/sh', '-c', command], capture_output=True)
        echo = command.encode() + b'\r\n'
        self.assertIsNone(self.mod.parse_frame(echo, 'testtoken'))
        self.assertEqual(self.mod.parse_frame(echo + result.stdout, 'testtoken'),
                         (1, b'sentinel'))

    def test_console_redacts_password_even_when_split_across_reads(self):
        one, two = socket.socketpair()
        self.addCleanup(one.close)
        self.addCleanup(two.close)
        log = self.root / 'serial.log'
        console = self.mod.Console(one, log, ['split-secret'])
        self.addCleanup(console.close)
        two.sendall(b'hello split-')
        console.read(0.1)
        two.sendall(b'secret goodbye')
        console.read(0.1)
        console.close()
        self.assertNotIn(b'split-secret', log.read_bytes())
        self.assertIn(b'[REDACTED]', log.read_bytes())

    def test_console_timeout_is_bounded_and_partial_frame_not_success(self):
        one, two = socket.socketpair()
        self.addCleanup(one.close)
        self.addCleanup(two.close)
        console = self.mod.Console(one, self.root / 'serial.log', [])
        self.addCleanup(console.close)
        two.sendall(b'\\036token:END:0\\037')
        with self.assertRaises(self.mod.SmokeError):
            console.command('true', timeout=0.05)

    def test_frame_real_shell_roundtrip_does_not_accept_sentinel_in_echo(self):
        one, two = socket.socketpair()
        self.addCleanup(one.close)
        self.addCleanup(two.close)
        console = self.mod.Console(one, self.root / 'serial.log', [])
        self.addCleanup(console.close)
        def guest():
            data = b''
            while not data.endswith(b'\n'):
                data += two.recv(65536)
            two.sendall(data)
            result = subprocess.run(['/bin/sh', '-c', data.decode()], capture_output=True)
            two.sendall(result.stdout)
        thread = threading.Thread(target=guest)
        thread.start()
        self.assertEqual(console.command("printf 'persisted-data'", timeout=2), b'persisted-data')
        thread.join(timeout=2)

    def test_firmware_vars_must_be_private_copy_in_scratch(self):
        disk = self.root / 'disk.qcow2'
        self.mod.reserve_disk(disk)
        self.variables.unlink()
        self.variables.symlink_to(self.code)
        with self.assertRaises(self.mod.SmokeError):
            self.mod.qemu_argv('qemu', self.root, disk, self.code,
                               self.variables, None, 2048)

    def test_drive_outside_scratch_and_ambiguous_qemu_paths_are_refused(self):
        disk = self.root / 'disk.qcow2'
        self.mod.reserve_disk(disk)
        other = self.root / 'other'
        other.mkdir()
        with self.assertRaises(self.mod.SmokeError):
            self.mod.qemu_argv('qemu', other, disk, self.code,
                               self.variables, None, 2048)
        comma = self.root / 'disk,cache=unsafe.qcow2'
        self.mod.reserve_disk(comma)
        with self.assertRaises(self.mod.SmokeError):
            self.mod.qemu_argv('qemu', self.root, comma, self.code,
                               self.variables, None, 2048)