import Immerable from '@Models/GeneralImmer';
import tw from '@Langs/data/tw';
import en from '@Langs/data/en';
import { LangObject, LangList } from './types';

const LANGUAGE_BASE_LIST = [
  {
    lang: 'frontend.global.language.en',
    value: 'en',
  },
  {
    lang: 'frontend.global.language.tw',
    value: 'tw',
  },
];

class I18n extends Immerable {
  public lang: string;

  public langDefault: LangObject;

  public langList: LangList;

  public langBase: LangObject;

  constructor(lang: string) {
    super();
    this.lang = lang;
    this.langDefault = en;
    this.langList = LANGUAGE_BASE_LIST;
    this.langBase = en;
    this.switchLanguage(this.lang);
  }

  t(key: string): string {
    let text = this.langBase[key];
    if (!text) {
      text = this.langDefault[key] || '';
    }
    return text;
  }

  switchLanguage(language: string): void {
    switch (language) {
      case 'en':
        this.langBase = en;
        break;
      case 'tw':
        this.langBase = tw;
        break;
      default:
        this.langBase = en;
        break;
    }
  }

  getSystemLang = (): string => {
    const lang = navigator.language.toLowerCase();
    switch (lang) {
      case 'en':
        return 'en';
      case 'tw':
      case 'zh-tw':
        return 'tw';
      default:
        return 'en';
    }
  };

  get languages(): LangList {
    return this.langList;
  }
}

export default I18n;