/**
 * Simplified version
 * https://github.com/ElemeFE/element/blob/dev/src/locale/index.js
 */
import Vue from "vue";
import deepmerge from "deepmerge";
import defaultLang from "./lang/zh-CN";

let lang = defaultLang;
let merged = false;
let i18nHandler = function (...args) {
  const vuei18n = Object.getPrototypeOf(this || Vue).$t;

  // @ts-ignore
  if (typeof vuei18n === "function" && !!Vue.locale) {
    if (!merged) {
      merged = true;
      // @ts-ignore
      Vue.locale(
        // @ts-ignore
        Vue.config.lang,
        // @ts-ignore
        deepmerge(lang, Vue.locale(Vue.config.lang) || {}, { clone: true })
      );
    }
    return vuei18n.apply(this, args);
  }
};

export const t = function (...args) {
  let value = i18nHandler.apply(this, args);
  if (value !== null && typeof value !== "undefined") {
    return value;
  }

  const array = args[0].split(".");
  let current = lang;

  for (let i = 0, len = array.length; i < len; i++) {
    const property = array[i];
    value = current[property];

    if (i === len - 1) {
      return value;
    } else if (!value) {
      return "";
    }

    current = value;
  }

  return "";
};

export const use = function (l) {
  lang = l || lang;
};

export const i18n = function (fn) {
  i18nHandler = fn || i18nHandler;
};

export function currentLang(): String {
  // @ts-ignore
  return lang;
}

export default { use, t, i18n, currentLang };