import io
import os
import select
import signal
import subprocess
import sys
import unittest
from unittest.mock import patch

from car_traker import container_entrypoint


class ContainerEntrypointTests(unittest.TestCase):
    def test_requires_a_command(self):
        with patch("sys.argv", ["entrypoint"]), patch("sys.stderr", new_callable=io.StringIO):
            self.assertEqual(container_entrypoint.main(), 3)


@unittest.skipUnless(os.environ.get("RUN_BROWSER_TESTS") == "1", "Xvfb container tests are opt-in")
class VirtualDisplayTests(unittest.TestCase):
    def test_child_exit_code_is_preserved(self):
        result = subprocess.run([
            sys.executable, "-m", "car_traker.container_entrypoint",
            sys.executable, "-c", "raise SystemExit(7)",
        ], capture_output=True, text=True, timeout=20)
        self.assertEqual(result.returncode, 7, result.stderr)

    def test_sigterm_waits_for_child_finalization(self):
        command = """
import signal, sys, time
def stop(signum, frame):
    print('cleanup-start', flush=True)
    time.sleep(1)
    print('cleanup-done', flush=True)
    sys.exit(130)
signal.signal(signal.SIGTERM, stop)
print('ready', flush=True)
while True:
    signal.pause()
"""
        process = subprocess.Popen([
            sys.executable, "-m", "car_traker.container_entrypoint",
            sys.executable, "-c", command,
        ], stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True)
        try:
            ready, _, _ = select.select([process.stdout], [], [], 15)
            self.assertTrue(ready, "Child did not become ready")
            self.assertEqual(process.stdout.readline().strip(), "ready")
            process.send_signal(signal.SIGTERM)
            stdout, stderr = process.communicate(timeout=15)
            self.assertEqual(process.returncode, 130, stderr)
            self.assertIn("cleanup-start", stdout)
            self.assertIn("cleanup-done", stdout)
        finally:
            if process.poll() is None:
                process.terminate()
                process.communicate(timeout=15)