import { APP_NAME, STORAGE_KEY_LANG } from '~/constants'

export function setupPageHeader() {
  const isDev = process.dev
  const isPreview = useRuntimeConfig().public.env === 'staging'

  const i18n = useI18n()

  useHeadFixed({
    htmlAttrs: {
      lang: () => i18n.locale.value,
    },
    titleTemplate: title => `${title ? `${title} | ` : ''}${APP_NAME}${isDev ? ' (dev)' : isPreview ? ' (preview)' : ''}`,
  })

  // eslint-disable-next-line no-unused-expressions
  isDark.value
}

export async function setupI18n() {
  const { locale, setLocale, locales } = useI18n()
  const isFirstVisit = !window.localStorage.getItem(STORAGE_KEY_LANG)
  const localeStorage = useLocalStorage(STORAGE_KEY_LANG, locale.value)

  if (isFirstVisit) {
    const userLang = (navigator.language || 'en-US').toLowerCase()
    // cause vue-i18n not explicit export LocaleObject type
    const supportLocales = unref(locales) as { code: string }[]
    const lang = supportLocales.find(locale => userLang.startsWith(locale.code.toLowerCase()))?.code
      || supportLocales.find(locale => userLang.startsWith(locale.code.split('-')[0]))?.code
    localeStorage.value = lang || 'en-US'
  }

  if (localeStorage.value !== locale.value)
    await setLocale(localeStorage.value)

  watchEffect(() => {
    localeStorage.value = locale.value
  })
}