sase.tr/apps/web/src/lib/i18n.ts

import enMessages from "@/messages/en.json";
import trMessages from "@/messages/tr.json";
import { create } from "zustand";

export type Locale = "tr" | "en";

const messages: Record<Locale, Record<string, unknown>> = {
  tr: trMessages,
  en: enMessages,
};

interface I18nState {
  locale: Locale;
  setLocale: (locale: Locale) => void;
}

export const useI18nStore = create<I18nState>((set) => ({
  locale: "tr",
  setLocale: (locale) => {
    set({ locale });
    if (typeof window !== "undefined") {
      localStorage.setItem("sase-locale", locale);
      document.documentElement.lang = locale;
    }
  },
}));

export function initLocale(): void {
  if (typeof window !== "undefined") {
    const saved = localStorage.getItem("sase-locale") as Locale | null;
    if (saved && (saved === "tr" || saved === "en")) {
      useI18nStore.getState().setLocale(saved);
    }
  }
}

function getNestedValue(obj: unknown, path: string): string {
  const keys = path.split(".");
  let current: unknown = obj;

  for (const key of keys) {
    if (current === null || current === undefined || typeof current !== "object") {
      return path;
    }
    current = (current as Record<string, unknown>)[key];
  }

  if (typeof current === "string") {
    return current;
  }

  return path;
}

export function t(key: string): string {
  const locale = useI18nStore.getState().locale;
  return getNestedValue(messages[locale], key);
}

export function useTranslation() {
  const locale = useI18nStore((state) => state.locale);
  const setLocale = useI18nStore((state) => state.setLocale);

  const translate = (key: string): string => {
    return getNestedValue(messages[locale], key);
  };

  return { t: translate, locale, setLocale };
}