import Vue from 'vue'
import VueI18n from 'vue-i18n'

Vue.use(VueI18n)
const DEFAULT_LANG = 'zh'
const LOCALE_KEY = 'localeLanguage'

let locales = {
  'zh': require('./langs/zh.json'),
  'en': require('./langs/en.json')
}
// 注册i18n实例并引入语言文件，文件格式等下解析
const i18n = new VueI18n({
  locale: DEFAULT_LANG,
  messages: locales
})

export const setup = lang => {
  if (lang === undefined) {
    lang = window.localStorage.getItem(LOCALE_KEY)
    if (locales[lang] === undefined) {
      lang = DEFAULT_LANG
    }
  }
  window.localStorage.setItem(LOCALE_KEY, lang)

  Object.keys(locales).forEach(lang => {
    document.body.classList.remove(`lang-${lang}`)
  })
  document.body.classList.add(`lang-${lang}`)
  document.body.setAttribute('lang', lang)

  Vue.config.lang = lang
  i18n.locale = lang
}

setup('zh')
export default i18n