import { isDef } from '../is';
import { reactive } from 'vue';

let locale = reactive({
  lang: localStorage.getItem('v_form_locale') || 'zh-CN'
});

export function createI18n(options) {
  return {
    messages: options.messages,

    $st(path, ...args) {
      const message = get(this.messages[locale.lang], path);
      return typeof message === 'function' ? message(...args) : message !== null ? message : path;
    },

    $st2(path, path2) {
      let messages = this.messages[locale.lang];
      const message = get(messages, path);
      return message !== null ? message : get(messages, path2);
    },

    setLang(lang) {
      locale.lang = lang;
    }
  };
}

// 值存在
// export function isDef(value) {
//   return value !== undefined && value !== null;
// }

// 对象映射 'a.b' {a: {b: 'val'}}
export function get(object, path) {
  const keys = path.split('.');
  let result = object;

  keys.forEach((key) => {
    result = isDef(result) && isDef(result[key]) ? result[key] : null;
  });

  return result;
}

// 是否是对象
export function isObj(x) {
  const type = typeof x;
  return x !== null && (type === 'object' || type === 'function');
}

// 深拷贝
const { hasOwnProperty } = Object.prototype;

function assignKey(to, from, key) {
  const val = from[key];

  if (!isDef(val)) {
    return;
  }

  if (!hasOwnProperty.call(to, key) || !isObj(val)) {
    to[key] = val;
  } else {
    to[key] = deepAssign(Object(to[key]), from[key]);
  }
}

export function deepAssign(to, from) {
  Object.keys(from).forEach((key) => {
    assignKey(to, from, key);
  });

  return to;
}