text: /* globals __webpack_hash__ */
  import fetch from 'unfetch'
  import EventSourcePolyfill from './event-source-polyfill'
  import { getEventSourceWrapper } from './dev-error-overlay/eventsource'
  import { setupPing } from './on-demand-entries-utils'
  
  if (!window.EventSource) {
    window.EventSource = EventSourcePolyfill
  }
  
  const data = JSON.parse(document.getElementById('__NEXT_DATA__').textContent)
  let { assetPrefix, page } = data
  assetPrefix = assetPrefix || ''
  let mostRecentHash = null
  /* eslint-disable-next-line */
  let curHash = __webpack_hash__
  const hotUpdatePath = assetPrefix + (assetPrefix.endsWith('/') ? '' : '/') + '_next/static/webpack/'
  
  // Is there a newer version of this code available?
  function isUpdateAvailable () {
    // __webpack_hash__ is the hash of the current compilation.
    // It's a global variable injected by Webpack.
    /* eslint-disable-next-line */
    return mostRecentHash !== __webpack_hash__
  }
  
  // Webpack disallows updates in other states.
  function canApplyUpdates () {
    return module.hot.status() === 'idle'
  }
  
  // This function reads code updates on the fly and hard
  // reloads the page when it has changed.
  async function tryApplyUpdates () {
    if (!isUpdateAvailable() || !canApplyUpdates()) {
      return
    }
    try {
      const res = await fetch(`${hotUpdatePath}${curHash}.hot-update.json`)
      const data = await res.json()
      const curPage = page === '/' ? 'index' : page
      const pageUpdated = Object.keys(data.c)
        .some(mod => {
          return (
            mod.indexOf(`pages${curPage.substr(0, 1) === '/' ? curPage : `/${curPage}`}`) !== -1 ||
            mod.indexOf(`pages${curPage.substr(0, 1) === '/' ? curPage : `/${curPage}`}`.replace(/\//g, '\\')) !== -1
          )
        })
  
      if (pageUpdated) {
        document.location.reload(true)
      } else {
        curHash = mostRecentHash
      }
    } catch (err) {
      console.error('Error occurred checking for update', err)
      document.location.reload(true)
    }
  }
  
  getEventSourceWrapper({
    path: `${assetPrefix}/_next/webpack-hmr`
  }).addMessageListener(event => {
    if (event.data === '\uD83D\uDC93') {
      return
    }
  
    try {
      const message = JSON.parse(event.data)
  
      if (message.action === 'sync' || message.action === 'built') {
        if (!message.hash) {
          return
        }
        mostRecentHash = message.hash
        tryApplyUpdates()
      } else if (message.action === 'reloadPage') {
        document.location.reload(true)
      }
    } catch (ex) {
      console.warn('Invalid HMR message: ' + event.data + '\n' + ex)
    }
  })
  
  setupPing(assetPrefix, () => page)
  