chore: move toApiLang util to hotel trpc folder

server/routers/hotels/utils.ts

@@ -0,0 +1,22 @@
+import { Lang } from "@/constants/languages"
+
+const langMap: { [key in Lang]: string } = {
+  [Lang.en]: "En",
+  [Lang.sv]: "Sv",
+  [Lang.no]: "No",
+  [Lang.fi]: "Fi",
+  [Lang.da]: "Da",
+  [Lang.de]: "De",
+}
+
+/**
+ * Helper function to convert Lang enum to uppercase
+ * Needed for the Hotel endpoint.
+ */
+export const toApiLang = (lang: Lang): string => {
+  const result = langMap[lang]
+  if (!result) {
+    throw new Error("Invalid language")
+  }
+  return result
+}