import { i18n } from "@lingui/core";

import type { Locale } from "~/locales";
import { defaultLocale } from "~/locales";
import { messages as enMessages } from "~/locales/en/messages";
import { messages as zhCNMessages } from "~/locales/zh-CN/messages";

const loadMessages = async (locale: Locale) => {
  switch (locale) {
    case "en":
      return enMessages;
    case "fr":
      return (await import("~/locales/fr/messages")).messages;
    case "de":
      return (await import("~/locales/de/messages")).messages;
    case "es":
      return (await import("~/locales/es/messages")).messages;
    case "it":
      return (await import("~/locales/it/messages")).messages;
    case "nl":
      return (await import("~/locales/nl/messages")).messages;
    case "ru":
      return (await import("~/locales/ru/messages")).messages;
    case "pl":
      return (await import("~/locales/pl/messages")).messages;
    case "ptbr":
      return (await import("~/locales/ptbr/messages")).messages;
    case "zh-CN":
      return (await import("~/locales/zh-CN/messages")).messages;
    default:
      return enMessages;
  }
};

let isInitialized = false;
const loadedLocales = new Set<string>();

export function initializeI18n() {
  if (!isInitialized) {
    // 首屏同步加载中英文，避免默认语言激活前出现中英混排。
    i18n.load("en", enMessages);
    i18n.load("zh-CN", zhCNMessages);
    i18n.activate(defaultLocale);
    loadedLocales.add(defaultLocale);
    loadedLocales.add("en");
    loadedLocales.add("zh-CN");
    isInitialized = true;
  }

  return i18n;
}

export async function activateLocale(locale: Locale) {
  if (!loadedLocales.has(locale)) {
    const messages = await loadMessages(locale);
    i18n.load(locale, messages);
    loadedLocales.add(locale);
  }

  i18n.activate(locale);
  return i18n;
}

initializeI18n();

export { i18n };