Updates refactoring

utils/windows_update.py

@@ -0,0 +1,54 @@
+"""Windows build selection and executable replacement with rollback."""
+from __future__ import annotations
+
+import ctypes
+import subprocess
+import sys
+import sysconfig
+from contextlib import suppress
+from pathlib import Path
+from typing import Callable, Optional
+
+from utils.update_check import download_asset, relaunch_env
+
+
+def asset_name() -> Optional[str]:
+    # Use the running build, including x86/x64 emulation and renamed executables.
+    target = sysconfig.get_platform()
+    if target == "win-arm64":
+        return "TgWsProxy_windows_arm64.exe"
+    if target == "win32":
+        return "TgWsProxy_windows_7_32bit.exe"
+    if target == "win-amd64":
+        return "TgWsProxy_windows_7_64bit.exe" if sys.version_info < (3, 9) else "TgWsProxy_windows.exe"
+    return None
+
+
+def apply_update(asset: dict, before_restart: Callable[[], None]) -> None:
+    """Verify, replace and launch; keep the old executable if any step fails."""
+    exe = Path(sys.executable)
+    backup = exe.with_name(exe.stem + "_oldtgws.exe")
+    downloaded = download_asset(asset["url"], exe.parent, digest=asset["digest"])
+    try:
+        backup.unlink(missing_ok=True)
+        exe.rename(backup)
+        try:
+            downloaded.replace(exe)
+            before_restart()
+            bundle = getattr(sys, "_MEIPASS", None)
+            if bundle:
+                ctypes.windll.kernel32.SetDllDirectoryW(None)
+            try:
+                subprocess.Popen(
+                    [str(exe), *sys.argv[1:]], env=relaunch_env(),
+                    creationflags=subprocess.DETACHED_PROCESS | subprocess.CREATE_NEW_PROCESS_GROUP,
+                )
+            finally:
+                if bundle:
+                    ctypes.windll.kernel32.SetDllDirectoryW(ctypes.c_wchar_p(bundle))
+        except BaseException:
+            backup.replace(exe)
+            raise
+    finally:
+        with suppress(OSError):
+            downloaded.unlink(missing_ok=True)