ens-ipfs - refactor for readability (#5568)

* ens-ipfs - refactor for readability

* ens-ipfs - use official ipfs gateway for better performance

* lint - remove unused code

* ens-ipfs - support path and search

* lint - gotta love that linter

* ens-ipfs - improve loading page formatting

* ens-ipfs - loading - redirect to 404 after 1 min timeout

* ens-ipfs - destructure for cleaner code

4 files changed, 120 insertions, 0 deletions

diff --git a/app/scripts/lib/ens-ipfs/contracts/registrar.js b/app/scripts/lib/ens-ipfs/contracts/registrar.js
new file mode 100644
index 000000000..99ca24458
--- /dev/null
+++ b/app/scripts/lib/ens-ipfs/contracts/registrar.js
@@ -0,0 +1 @@
+module.exports = [{'constant': true, 'inputs': [{'name': 'node', 'type': 'bytes32'}], 'name': 'resolver', 'outputs': [{'name': '', 'type': 'address'}], 'payable': false, 'type': 'function'}, {'constant': true, 'inputs': [{'name': 'node', 'type': 'bytes32'}], 'name': 'owner', 'outputs': [{'name': '', 'type': 'address'}], 'payable': false, 'type': 'function'}, {'constant': false, 'inputs': [{'name': 'node', 'type': 'bytes32'}, {'name': 'label', 'type': 'bytes32'}, {'name': 'owner', 'type': 'address'}], 'name': 'setSubnodeOwner', 'outputs': [], 'payable': false, 'type': 'function'}, {'constant': false, 'inputs': [{'name': 'node', 'type': 'bytes32'}, {'name': 'ttl', 'type': 'uint64'}], 'name': 'setTTL', 'outputs': [], 'payable': false, 'type': 'function'}, {'constant': true, 'inputs': [{'name': 'node', 'type': 'bytes32'}], 'name': 'ttl', 'outputs': [{'name': '', 'type': 'uint64'}], 'payable': false, 'type': 'function'}, {'constant': false, 'inputs': [{'name': 'node', 'type': 'bytes32'}, {'name': 'resolver', 'type': 'address'}], 'name': 'setResolver', 'outputs': [], 'payable': false, 'type': 'function'}, {'constant': false, 'inputs': [{'name': 'node', 'type': 'bytes32'}, {'name': 'owner', 'type': 'address'}], 'name': 'setOwner', 'outputs': [], 'payable': false, 'type': 'function'}, {'anonymous': false, 'inputs': [{'indexed': true, 'name': 'node', 'type': 'bytes32'}, {'indexed': false, 'name': 'owner', 'type': 'address'}], 'name': 'Transfer', 'type': 'event'}, {'anonymous': false, 'inputs': [{'indexed': true, 'name': 'node', 'type': 'bytes32'}, {'indexed': true, 'name': 'label', 'type': 'bytes32'}, {'indexed': false, 'name': 'owner', 'type': 'address'}], 'name': 'NewOwner', 'type': 'event'}, {'anonymous': false, 'inputs': [{'indexed': true, 'name': 'node', 'type': 'bytes32'}, {'indexed': false, 'name': 'resolver', 'type': 'address'}], 'name': 'NewResolver', 'type': 'event'}, {'anonymous': false, 'inputs': [{'indexed': true, 'name': 'node', 'type': 'bytes32'}, {'indexed': false, 'name': 'ttl', 'type': 'uint64'}], 'name': 'NewTTL', 'type': 'event'}]
diff --git a/app/scripts/lib/ens-ipfs/contracts/resolver.js b/app/scripts/lib/ens-ipfs/contracts/resolver.js
new file mode 100644
index 000000000..1bf3f90ce
--- /dev/null
+++ b/app/scripts/lib/ens-ipfs/contracts/resolver.js
@@ -0,0 +1,2 @@
+module.exports =
+[{'constant': true, 'inputs': [{'name': 'interfaceID', 'type': 'bytes4'}], 'name': 'supportsInterface', 'outputs': [{'name': '', 'type': 'bool'}], 'payable': false, 'type': 'function'}, {'constant': true, 'inputs': [{'name': 'node', 'type': 'bytes32'}, {'name': 'contentTypes', 'type': 'uint256'}], 'name': 'ABI', 'outputs': [{'name': 'contentType', 'type': 'uint256'}, {'name': 'data', 'type': 'bytes'}], 'payable': false, 'type': 'function'}, {'constant': false, 'inputs': [{'name': 'node', 'type': 'bytes32'}, {'name': 'x', 'type': 'bytes32'}, {'name': 'y', 'type': 'bytes32'}], 'name': 'setPubkey', 'outputs': [], 'payable': false, 'type': 'function'}, {'constant': true, 'inputs': [{'name': 'node', 'type': 'bytes32'}], 'name': 'content', 'outputs': [{'name': 'ret', 'type': 'bytes32'}], 'payable': false, 'type': 'function'}, {'constant': true, 'inputs': [{'name': 'node', 'type': 'bytes32'}], 'name': 'addr', 'outputs': [{'name': 'ret', 'type': 'address'}], 'payable': false, 'type': 'function'}, {'constant': false, 'inputs': [{'name': 'node', 'type': 'bytes32'}, {'name': 'contentType', 'type': 'uint256'}, {'name': 'data', 'type': 'bytes'}], 'name': 'setABI', 'outputs': [], 'payable': false, 'type': 'function'}, {'constant': true, 'inputs': [{'name': 'node', 'type': 'bytes32'}], 'name': 'name', 'outputs': [{'name': 'ret', 'type': 'string'}], 'payable': false, 'type': 'function'}, {'constant': false, 'inputs': [{'name': 'node', 'type': 'bytes32'}, {'name': 'name', 'type': 'string'}], 'name': 'setName', 'outputs': [], 'payable': false, 'type': 'function'}, {'constant': false, 'inputs': [{'name': 'node', 'type': 'bytes32'}, {'name': 'hash', 'type': 'bytes32'}], 'name': 'setContent', 'outputs': [], 'payable': false, 'type': 'function'}, {'constant': true, 'inputs': [{'name': 'node', 'type': 'bytes32'}], 'name': 'pubkey', 'outputs': [{'name': 'x', 'type': 'bytes32'}, {'name': 'y', 'type': 'bytes32'}], 'payable': false, 'type': 'function'}, {'constant': false, 'inputs': [{'name': 'node', 'type': 'bytes32'}, {'name': 'addr', 'type': 'address'}], 'name': 'setAddr', 'outputs': [], 'payable': false, 'type': 'function'}, {'inputs': [{'name': 'ensAddr', 'type': 'address'}], 'payable': false, 'type': 'constructor'}, {'anonymous': false, 'inputs': [{'indexed': true, 'name': 'node', 'type': 'bytes32'}, {'indexed': false, 'name': 'a', 'type': 'address'}], 'name': 'AddrChanged', 'type': 'event'}, {'anonymous': false, 'inputs': [{'indexed': true, 'name': 'node', 'type': 'bytes32'}, {'indexed': false, 'name': 'hash', 'type': 'bytes32'}], 'name': 'ContentChanged', 'type': 'event'}, {'anonymous': false, 'inputs': [{'indexed': true, 'name': 'node', 'type': 'bytes32'}, {'indexed': false, 'name': 'name', 'type': 'string'}], 'name': 'NameChanged', 'type': 'event'}, {'anonymous': false, 'inputs': [{'indexed': true, 'name': 'node', 'type': 'bytes32'}, {'indexed': true, 'name': 'contentType', 'type': 'uint256'}], 'name': 'ABIChanged', 'type': 'event'}, {'anonymous': false, 'inputs': [{'indexed': true, 'name': 'node', 'type': 'bytes32'}, {'indexed': false, 'name': 'x', 'type': 'bytes32'}, {'indexed': false, 'name': 'y', 'type': 'bytes32'}], 'name': 'PubkeyChanged', 'type': 'event'}]
diff --git a/app/scripts/lib/ens-ipfs/resolver.js b/app/scripts/lib/ens-ipfs/resolver.js
new file mode 100644
index 000000000..fe2dc1134
--- /dev/null
+++ b/app/scripts/lib/ens-ipfs/resolver.js
@@ -0,0 +1,54 @@
+const namehash = require('eth-ens-namehash')
+const multihash = require('multihashes')
+const Eth = require('ethjs-query')
+const EthContract = require('ethjs-contract')
+const registrarAbi = require('./contracts/registrar')
+const resolverAbi = require('./contracts/resolver')
+
+module.exports = resolveEnsToIpfsContentId
+
+
+async function resolveEnsToIpfsContentId ({ provider, name }) {
+  const eth = new Eth(provider)
+  const hash = namehash.hash(name)
+  const contract = new EthContract(eth)
+  // lookup registrar
+  const chainId = Number.parseInt(await eth.net_version(), 10)
+  const registrarAddress = getRegistrarForChainId(chainId)
+  if (!registrarAddress) {
+    throw new Error(`EnsIpfsResolver - no known ens-ipfs registrar for chainId "${chainId}"`)
+  }
+  const Registrar = contract(registrarAbi).at(registrarAddress)
+  // lookup resolver
+  const resolverLookupResult = await Registrar.resolver(hash)
+  const resolverAddress = resolverLookupResult[0]
+  if (hexValueIsEmpty(resolverAddress)) {
+    throw new Error(`EnsIpfsResolver - no resolver found for name "${name}"`)
+  }
+  const Resolver = contract(resolverAbi).at(resolverAddress)
+  // lookup content id
+  const contentLookupResult = await Resolver.content(hash)
+  const contentHash = contentLookupResult[0]
+  if (hexValueIsEmpty(contentHash)) {
+    throw new Error(`EnsIpfsResolver - no content ID found for name "${name}"`)
+  }
+  const nonPrefixedHex = contentHash.slice(2)
+  const buffer = multihash.fromHexString(nonPrefixedHex)
+  const contentId = multihash.toB58String(multihash.encode(buffer, 'sha2-256'))
+  return contentId
+}
+
+function hexValueIsEmpty(value) {
+  return [undefined, null, '0x', '0x0', '0x0000000000000000000000000000000000000000000000000000000000000000'].includes(value)
+}
+
+function getRegistrarForChainId (chainId) {
+  switch (chainId) {
+    // mainnet
+    case 1:
+      return '0x314159265dd8dbb310642f98f50c066173c1259b'
+    // ropsten
+    case 3:
+      return '0x112234455c3a32fd11230c42e7bccd4a84e02010'
+  }
+}
diff --git a/app/scripts/lib/ens-ipfs/setup.js b/app/scripts/lib/ens-ipfs/setup.js
new file mode 100644
index 000000000..45eb1ce14
--- /dev/null
+++ b/app/scripts/lib/ens-ipfs/setup.js
@@ -0,0 +1,63 @@
+const urlUtil = require('url')
+const extension = require('extensionizer')
+const resolveEnsToIpfsContentId = require('./resolver.js')
+
+const supportedTopLevelDomains = ['eth']
+
+module.exports = setupEnsIpfsResolver
+
+function setupEnsIpfsResolver({ provider }) {
+
+  // install listener
+  const urlPatterns = supportedTopLevelDomains.map(tld => `*://*.${tld}/*`)
+  extension.webRequest.onErrorOccurred.addListener(webRequestDidFail, { urls: urlPatterns })
+
+  // return api object
+  return {
+    // uninstall listener
+    remove () {
+      extension.webRequest.onErrorOccurred.removeListener(webRequestDidFail)
+    },
+  }
+
+  async function webRequestDidFail (details) {
+    const { tabId, url } = details
+    // ignore requests that are not associated with tabs
+    if (tabId === -1) return
+    // parse ens name
+    const urlData = urlUtil.parse(url)
+    const { hostname: name, path, search } = urlData
+    const domainParts = name.split('.')
+    const topLevelDomain = domainParts[domainParts.length - 1]
+    // if unsupported TLD, abort
+    if (!supportedTopLevelDomains.includes(topLevelDomain)) return
+    // otherwise attempt resolve
+    attemptResolve({ tabId, name, path, search })
+  }
+
+  async function attemptResolve({ tabId, name, path, search }) {
+    extension.tabs.update(tabId, { url: `loading.html` })
+    try {
+      const ipfsContentId = await resolveEnsToIpfsContentId({ provider, name })
+      let url = `https://gateway.ipfs.io/ipfs/${ipfsContentId}${path}${search || ''}`
+      try {
+        // check if ipfs gateway has result
+        const response = await fetch(url, { method: 'HEAD' })
+        // if failure, redirect to 404 page
+        if (response.status !== 200) {
+          extension.tabs.update(tabId, { url: '404.html' })
+          return
+        }
+        // otherwise redirect to the correct page
+        extension.tabs.update(tabId, { url })
+      } catch (err) {
+        console.warn(err)
+        // if HEAD fetch failed, redirect so user can see relevant error page
+        extension.tabs.update(tabId, { url })
+      }
+    } catch (err) {
+      console.warn(err)
+      extension.tabs.update(tabId, { url: `error.html?name=${name}` })
+    }
+  }
+}