text: const fs = require('fs')
  const path = require('path')
  const pump = require('pump')
  const querystring = require('querystring')
  const LocalMessageDuplexStream = require('post-message-stream')
  const PongStream = require('ping-pong-stream/pong')
  const ObjectMultiplex = require('obj-multiplex')
  const extension = require('extensionizer')
  const PortStream = require('extension-port-stream')
  
  const inpageContent = fs.readFileSync(path.join(__dirname, '..', '..', 'dist', 'chrome', 'inpage.js'), 'utf8').toString()
  const inpageSuffix = '//# sourceURL=' + extension.extension.getURL('inpage.js') + '\n'
  const inpageBundle = inpageContent + inpageSuffix
  
  // Eventually this streaming injection could be replaced with:
  // https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XPCOM/Language_Bindings/Components.utils.exportFunction
  //
  // But for now that is only Firefox
  // If we create a FireFox-only code path using that API,
  // MetaMask will be much faster loading and performant on Firefox.
  
  if (shouldInjectWeb3()) {
    setupInjection()
    setupStreams()
  }
  
  /**
   * Creates a script tag that injects inpage.js
   */
  function setupInjection () {
    try {
      // inject in-page script
      const scriptTag = document.createElement('script')
      scriptTag.textContent = inpageBundle
      scriptTag.onload = function () { this.parentNode.removeChild(this) }
      const container = document.head || document.documentElement
      // append as first child
      container.insertBefore(scriptTag, container.children[0])
    } catch (e) {
      console.error('Nifty Wallet injection failed.', e)
    }
  }
  
  /**
   * Sets up two-way communication streams between the
   * browser extension and local per-page browser context
   */
  function setupStreams () {
    // setup communication to page and plugin
    const pageStream = new LocalMessageDuplexStream({
      name: 'nifty-contentscript',
      target: 'nifty-inpage',
    })
    const pluginPort = extension.runtime.connect({ name: 'contentscript' })
    const pluginStream = new PortStream(pluginPort)
  
    // forward communication plugin->inpage
    pump(
      pageStream,
      pluginStream,
      pageStream,
      (err) => logStreamDisconnectWarning('Nifty Wallet Contentscript Forwarding', err),
    )
  
    // setup local multistream channels
    const mux = new ObjectMultiplex()
    mux.setMaxListeners(25)
  
    pump(
      mux,
      pageStream,
      mux,
      (err) => logStreamDisconnectWarning('Nifty Wallet Inpage', err),
    )
    pump(
      mux,
      pluginStream,
      mux,
      (err) => logStreamDisconnectWarning('Nifty Wallet Background', err),
    )
  
    // connect ping stream
    const pongStream = new PongStream({ objectMode: true })
    pump(
      mux,
      pongStream,
      mux,
      (err) => logStreamDisconnectWarning('Nifty Wallet PingPongStream', err),
    )
  
    // connect phishing warning stream
    const phishingStream = mux.createStream('phishing')
    phishingStream.once('data', redirectToPhishingWarning)
  
    // ignore unused channels (handled by background, inpage)
    mux.ignoreStream('provider')
    mux.ignoreStream('publicConfig')
  }
  
  
  /**
   * Error handler for page to plugin stream disconnections
   *
   * @param {string} remoteLabel Remote stream name
   * @param {Error} err Stream connection error
   */
  function logStreamDisconnectWarning (remoteLabel, err) {
    let warningMsg = `MetamaskContentscript - lost connection to ${remoteLabel}`
    if (err) warningMsg += '\n' + err.stack
    console.warn(warningMsg)
  }
  
  /**
   * Determines if Web3 should be injected
   *
   * @returns {boolean} {@code true} if Web3 should be injected
   */
  function shouldInjectWeb3 () {
    return doctypeCheck() && suffixCheck() &&
      documentElementCheck() && !blacklistedDomainCheck()
  }
  
  /**
   * Checks the doctype of the current document if it exists
   *
   * @returns {boolean} {@code true} if the doctype is html or if none exists
   */
  function doctypeCheck () {
    const doctype = window.document.doctype
    if (doctype) {
      return doctype.name === 'html'
    } else {
      return true
    }
  }
  
  /**
   * Returns whether or not the extension (suffix) of the current document is prohibited
   *
   * This checks {@code window.location.pathname} against a set of file extensions
   * that should not have web3 injected into them. This check is indifferent of query parameters
   * in the location.
   *
   * @returns {boolean} whether or not the extension of the current document is prohibited
   */
  function suffixCheck () {
    const prohibitedTypes = [
      /\.xml$/,
      /\.pdf$/,
    ]
    const currentUrl = window.location.pathname
    for (let i = 0; i < prohibitedTypes.length; i++) {
      if (prohibitedTypes[i].test(currentUrl)) {
        return false
      }
    }
    return true
  }
  
  /**
   * Checks the documentElement of the current document
   *
   * @returns {boolean} {@code true} if the documentElement is an html node or if none exists
   */
  function documentElementCheck () {
    const documentElement = document.documentElement.nodeName
    if (documentElement) {
      return documentElement.toLowerCase() === 'html'
    }
    return true
  }
  
  /**
   * Checks if the current domain is blacklisted
   *
   * @returns {boolean} {@code true} if the current domain is blacklisted
   */
  function blacklistedDomainCheck () {
    const blacklistedDomains = [
      'uscourts.gov',
      'dropbox.com',
      'webbyawards.com',
      'cdn.shopify.com/s/javascripts/tricorder/xtld-read-only-frame.html',
      'adyen.com',
      'gravityforms.com',
      'harbourair.com',
      'ani.gamer.com.tw',
      'blueskybooking.com',
    ]
    const currentUrl = window.location.href
    let currentRegex
    for (let i = 0; i < blacklistedDomains.length; i++) {
      const blacklistedDomain = blacklistedDomains[i].replace('.', '\\.')
      currentRegex = new RegExp(`(?:https?:\\/\\/)(?:(?!${blacklistedDomain}).)*$`)
      if (!currentRegex.test(currentUrl)) {
        return true
      }
    }
    return false
  }
  
  /**
   * Redirects the current page to a phishing information page
   */
  function redirectToPhishingWarning () {
    console.log('Nifty Wallet - routing to Phishing Warning component')
    const extensionURL = extension.runtime.getURL('phishing.html')
    window.location.href = `${extensionURL}#${querystring.stringify({
      hostname: window.location.hostname,
      href: window.location.href,
    })}`
  }
  