content.js

'use strict'

import rawCode from './../../../dist/bundles/ipfsProxyContentScriptPayload.bundle.js'

const browser = require('webextension-polyfill')
const injectScript = require('./inject-script')

function init () {
  const port = browser.runtime.connect({ name: 'ipfs-proxy' })
  // Forward on messages from background to the page and vice versa
  port.onMessage.addListener((data) => {
    if (data && data.sender && data.sender.startsWith('postmsg-rpc/')) {
      window.postMessage(data, '*')
    }
  })
  window.addEventListener('message', (msg) => {
    if (msg.data && msg.data.sender && msg.data.sender.startsWith('postmsg-rpc/')) {
      port.postMessage(msg.data)
    }
  })

  injectScript(rawCode)
}

function injectIpfsProxy () {
  // Skip if proxy is already present
  if (window.ipfs) {
    return false
  }
  // Restricting window.ipfs to Secure Context
  // See: https://github.com/ipfs-shipyard/ipfs-companion/issues/476
  if (!window.isSecureContext) {
    return false
  }
  // Skip if not in HTML context
  // Check 1/2
  const doctype = window.document.doctype
  if (doctype && doctype.name !== 'html') {
    return false
  }
  // Check 2/2
  if (document.documentElement.nodeName !== 'HTML') {
    return false
  }
  // Should be ok by now
  return true
}

if (injectIpfsProxy()) {
  init()
}