feat: add backend Mac support (#913)

Adds a Mac localplatform based on the Linux one

Signed-off-by: Gianni Spadoni <me@gio.blue>

backend/decky_loader/localplatform/localplatform.py

@@ -1,11 +1,15 @@
 import platform, os
 
 ON_WINDOWS = platform.system() == "Windows"
-ON_LINUX = not ON_WINDOWS
+ON_MAC = platform.system() == "Darwin"
+ON_LINUX = not ON_WINDOWS and not ON_MAC
 
 if ON_WINDOWS:
     from .localplatformwin import *
     from . import localplatformwin as localplatform
+elif ON_MAC:
+    from .localplatformmac import *
+    from . import localplatformmac as localplatform
 else:
     from .localplatformlinux import *
     from . import localplatformlinux as localplatform

backend/decky_loader/localplatform/localplatformmac.py

@@ -0,0 +1,59 @@
+from ..enums import UserType
+import os, sys
+from . import localplatformlinux
+
+# this should be public
+def _get_effective_user_id() -> int:
+    return os.geteuid()
+
+def chown(path : str,  user : UserType = UserType.HOST_USER, recursive : bool = True) -> bool:
+    return localplatformlinux.chown(path, user, recursive)
+
+def chmod(path : str, permissions : int, recursive : bool = True) -> bool:
+    return localplatformlinux.chmod(path, permissions, recursive)
+
+def file_owner(path : str) -> UserType|None:
+    return localplatformlinux.file_owner(path)
+
+def get_home_path(user : UserType = UserType.HOST_USER) -> str:
+    return localplatformlinux.get_home_path(user)
+
+def setgid(user : UserType = UserType.HOST_USER):
+    return localplatformlinux.setgid(user)
+
+def setuid(user : UserType = UserType.HOST_USER):
+    return localplatformlinux.setuid(user)
+
+async def service_active(service_name : str) -> bool:
+    return True # Stubbed
+
+async def service_stop(service_name : str) -> bool:
+    return True # Stubbed
+
+async def service_start(service_name : str) -> bool:
+    return True # Stubbed
+
+async def service_restart(service_name : str, block : bool = True) -> bool:
+    return True # Stubbed
+
+def get_effective_username() -> str:
+    return localplatformlinux.get_effective_username()
+
+def get_username() -> str:
+    return localplatformlinux.get_username()
+
+def get_privileged_path() -> str:
+    '''On Mac, privileged_path is equal to unprivileged_path'''
+    return get_unprivileged_path()
+
+def get_unprivileged_path() -> str:
+    return localplatformlinux.get_unprivileged_path()
+
+def get_unprivileged_user() -> str:
+    return localplatformlinux.get_unprivileged_user()
+
+async def restart_webhelper() -> bool:
+    return await localplatformlinux.restart_webhelper()
+
+async def close_cef_socket():
+    return # Stubbed