negareh-admin/src/locale/index.ts

import { fa } from "./fa";

export type LocaleKey = "fa";
export interface TranslationsType {
  [key: string]: string | TranslationsType;
}

const locales: Record<LocaleKey, TranslationsType> = { fa };

let currentLang: LocaleKey = "fa";

export const setLang = (lang: LocaleKey) => {
  currentLang = lang;
};

export const getLang = (): LocaleKey => currentLang;

const cache = new Map<string, string>();

export const t = (key: string, fallback?: string): string => {
  const cacheKey = `${currentLang}:${key}`;
  if (cache.has(cacheKey)) return cache.get(cacheKey)!;

  const keys = key.split(".");
  let value: string | TranslationsType | undefined = locales[currentLang];

  for (const k of keys) {
    if (typeof value === "object" && value !== null) {
      value = value[k];
    } else {
      value = undefined;
      break;
    }
  }

  const result = typeof value === "string" ? value : fallback || key;
  cache.set(cacheKey, result);
  return result;
};