import hashlib
import importlib.util
import tempfile
import unittest
from pathlib import Path

_SPEC = importlib.util.spec_from_file_location(
    "auto_update_service",
    Path("services/auto_update_service.py"),
)
_MODULE = importlib.util.module_from_spec(_SPEC)
_SPEC.loader.exec_module(_MODULE)
AutoUpdateService = _MODULE.AutoUpdateService


class AutoUpdateServiceTests(unittest.TestCase):
    def test_extract_sha256_from_text(self):
        digest = "a" * 64
        text = f"{digest}  AnabasisManager-1.0.0-win.zip\n"
        extracted = AutoUpdateService.extract_sha256_from_text(
            text,
            "AnabasisManager-1.0.0-win.zip",
        )
        self.assertEqual(extracted, digest)

    def test_sha256_file(self):
        with tempfile.TemporaryDirectory() as td:
            path = Path(td) / "payload.bin"
            payload = b"anabasis"
            path.write_bytes(payload)
            expected = hashlib.sha256(payload).hexdigest()
            self.assertEqual(AutoUpdateService.sha256_file(str(path)), expected)

    def test_build_update_script_contains_core_vars(self):
        script = AutoUpdateService.build_update_script(
            app_dir=r"C:\Apps\AnabasisManager",
            source_dir=r"C:\Temp\Extracted",
            exe_name="AnabasisManager.exe",
            target_pid=1234,
        )
        script_text = Path(script).read_text(encoding="utf-8")
        self.assertIn("set \"APP_DIR=", script_text)
        self.assertIn("set \"SRC_DIR=", script_text)
        self.assertIn("set \"EXE_NAME=", script_text)
        self.assertIn("set \"TARGET_PID=", script_text)
        self.assertIn(":rollback", script_text)
        self.assertIn("if not exist \"%SRC_DIR%\\%EXE_NAME%\"", script_text)


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