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

// List of locales approved for use
import activeLocales from '../../../static/locales/activeLocales.json'

const isDev = process.env.NODE_ENV === 'development'

const messages = {}

if (isDev) {
  const { load } = require('js-yaml')
  // Take active locales and load respective YAML file
  activeLocales.forEach((locale) => {
    try {
      // File location when running in dev
      const doc = load(fs.readFileSync(`static/locales/${locale}.yaml`))
      messages[locale] = doc
    } catch (e) {
      console.error(locale, e)
    }
  })
}

class CustomVueI18n extends VueI18n {
  constructor(options) {
    super(options)
    this.allLocales = activeLocales
  }

  async loadLocale(locale) {
    // we only lazy load locales for producation builds
    if (!isDev) {
      // don't need to load it if it's already loaded
      if (this.availableLocales.includes(locale)) {
        return
      }
      if (!this.allLocales.includes(locale)) {
        console.error(`Unable to load unknown locale: "${locale}"`)
      }

      if (process.env.IS_ELECTRON) {
        const { brotliDecompressSync } = require('zlib')
        // locales are only compressed in our production Electron builds
        try {
          // decompress brotli compressed json file and then load it
          // eslint-disable-next-line node/no-path-concat
          const compressed = fs.readFileSync(`${__dirname}/static/locales/${locale}.json.br`)
          const data = JSON.parse(brotliDecompressSync(compressed).toString())
          this.setLocaleMessage(locale, data)
        } catch (err) {
          console.error(locale, err)
        }
      } else {
        const url = new URL(window.location.href)
        url.hash = ''
        if (url.pathname.endsWith('index.html')) {
          url.pathname = url.pathname.replace(/index\.html$/, '')
        }

        if (url.pathname) {
          url.pathname += `${!url.pathname.endsWith('/') ? '/' : ''}static/locales/${locale}.json`
        } else {
          url.pathname = `/static/locales/${locale}.json`
        }

        const response = await fetch(url)
        const data = await response.json()
        this.setLocaleMessage(locale, data)
      }
    }
  }
}

Vue.use(CustomVueI18n)

const i18n = new CustomVueI18n({
  locale: 'en-US',
  fallbackLocale: { default: 'en-US' },
  messages
})

if (!isDev) {
  i18n.loadLocale('en-US')
}

export default i18n