Add i18n

cmd/cbconvert-gui/i18n/detect_windows.go

@@ -0,0 +1,26 @@
+//go:build windows
+
+package i18n
+
+import "syscall"
+
+// primaryLang maps a Windows primary-language id to a two-letter language code.
+var primaryLang = map[uint16]string{
+	0x09: "en",
+	0x16: "pt",
+	0x0a: "es",
+	0x05: "cs",
+	0x19: "ru",
+	0x07: "de",
+	0x0c: "fr",
+	0x04: "zh",
+	0x11: "ja",
+	0x10: "it",
+}
+
+// systemLangCode returns the two-letter code of the user's default UI language, or "".
+func systemLangCode() string {
+	r, _, _ := syscall.NewLazyDLL("kernel32.dll").NewProc("GetUserDefaultUILanguage").Call()
+
+	return primaryLang[uint16(r)&0x3ff]
+}