WMTheme: add support for WIndows

CMakeLists.txt

@@ -317,7 +317,7 @@ if(WIN_MSYS)
         src/detection/displayserver/displayserver_windows.c
         src/detection/terminalfont/terminalfont_linux.c
         src/detection/media/media_linux.c
-        src/detection/wmtheme/wmtheme_linux.c
+        src/detection/wmtheme/wmtheme_windows.c
         src/detection/font/font_linux.c
         src/detection/opengl/opengl_windows.c
         src/util/windows/wmi.cpp

src/detection/wmtheme/wmtheme_windows.c

@@ -0,0 +1,41 @@
+#include "fastfetch.h"
+#include "wmtheme.h"
+
+#define WIN32_LEAN_AND_MEAN 1
+#include <Windows.h>
+
+bool ffDetectWmTheme(FFinstance* instance, FFstrbuf* themeOrError)
+{
+    FF_UNUSED(instance);
+
+    HKEY hKey;
+    if(RegOpenKeyExW(HKEY_CURRENT_USER, L"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize", 0, KEY_READ, &hKey) != ERROR_SUCCESS)
+    {
+        ffStrbufAppendS(themeOrError, "RegOpenKeyExW() failed");
+        return false;
+    }
+
+    bool result = true;
+    int SystemUsesLightTheme = 1;
+    DWORD bufSize = sizeof(SystemUsesLightTheme);
+
+    if(RegQueryValueExW(hKey, L"SystemUsesLightTheme", NULL, NULL, (LPBYTE)&SystemUsesLightTheme, &bufSize) != ERROR_SUCCESS)
+    {
+        ffStrbufAppendS(themeOrError, "RegOpenKeyExW(SystemUsesLightTheme) failed");
+        goto exit;
+    }
+
+    int AppsUsesLightTheme = 1;
+    bufSize = sizeof(AppsUsesLightTheme);
+    if(RegQueryValueExW(hKey, L"AppsUseLightTheme", NULL, NULL, (LPBYTE)&AppsUsesLightTheme, &bufSize) != ERROR_SUCCESS)
+    {
+        ffStrbufAppendS(themeOrError, "RegOpenKeyExW(AppsUseLightTheme) failed");
+        goto exit;
+    }
+
+    ffStrbufAppendF(themeOrError, "System - %s, Apps - %s", SystemUsesLightTheme ? "Light" : "Dark", AppsUsesLightTheme ? "Light" : "Dark");
+
+exit:
+    RegCloseKey(hKey);
+    return result;
+}