from __future__ import annotations

import os
from pathlib import Path
import subprocess
import sys
import tempfile
import unittest

from cmbuyer_client.core.errors import SingleInstanceError
from cmbuyer_client.localstate.single_instance import NamedMutex


@unittest.skipUnless(os.name == "nt", "named mutex 仅在 Windows 验证")
class NamedMutexTests(unittest.TestCase):
    def test_second_process_for_same_database_is_rejected(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            database = Path(directory) / "state.sqlite3"
            first = NamedMutex(database)
            try:
                with self.assertRaises(SingleInstanceError):
                    NamedMutex(database)
                code = (
                    "from pathlib import Path; "
                    "from cmbuyer_client.localstate.single_instance import NamedMutex; "
                    "from cmbuyer_client.core.errors import SingleInstanceError; "
                    f"p=Path({str(database)!r}); "
                    "\ntry:\n NamedMutex(p)\nexcept SingleInstanceError:\n raise SystemExit(17)\nraise SystemExit(0)"
                )
                environment = dict(os.environ)
                environment["PYTHONPATH"] = str(Path(__file__).resolve().parents[2] / "src")
                result = subprocess.run([sys.executable, "-c", code], env=environment, check=False)
                self.assertEqual(result.returncode, 17)
            finally:
                first.close()

            with NamedMutex(database):
                pass