First naive pass at implementing etherscan provider (not working)

Committing and pushing to get feedback.

app/manifest.json

@@ -1,5 +1,6 @@
 {
   "name": "__MSG_appName__",
+  "short_name": "Metamask",
   "version": "1.2.1",
   "manifest_version": 2,
   "description": "__MSG_appDescription__",

app/scripts/background.js

@@ -7,6 +7,7 @@ const extend = require('xtend')
 const EthStore = require('eth-store')
 const PortStream = require('./lib/port-stream.js')
 const MetaMaskProvider = require('web3-provider-engine/zero.js')
+const EtherscanProvider = require('web3-provider-engine/subproviders/etherscan')
 const IdentityStore = require('./lib/idStore')
 const createTxNotification = require('./lib/tx-notification.js')
 const configManager = require('./lib/config-manager-singleton')
@@ -36,8 +37,9 @@ function handleEthRpcRequestStream(stream){
 // state and network
 //
 
+var providerConfig = configManager.getProvider()
 var idStore = new IdentityStore()
-var zeroClient = MetaMaskProvider({
+var providerOpts = {
   rpcUrl: configManager.getCurrentRpcAddress(),
   getAccounts: function(cb){
     var selectedAddress = idStore.getSelectedAddress()
@@ -46,14 +48,23 @@ var zeroClient = MetaMaskProvider({
   },
   approveTransaction: addUnconfirmedTx,
   signTransaction: idStore.signTransaction.bind(idStore),
-})
+}
+var provider
+switch (providerConfig.type) {
+  case 'rpc':
+    provider = MetaMaskProvider(providerOpts)
+    break
+  case 'etherscan':
+    provider = EtherscanProvider(providerOpts)
+    break
+}
 
 // log new blocks
-zeroClient.on('block', function(block){
+provider.on('block', function(block){
   console.log('BLOCK CHANGED:', '#'+block.number.toString('hex'), '0x'+block.hash.toString('hex'))
 })
 
-var ethStore = new EthStore(zeroClient)
+var ethStore = new EthStore(provider)
 idStore.setStore(ethStore)
 
 function getState(){
@@ -68,7 +79,7 @@ function getState(){
 // handle rpc requests
 function onRpcRequest(remoteStream, payload){
   // console.log('MetaMaskPlugin - incoming payload:', payload)
-  zeroClient.sendAsync(payload, function onPayloadHandled(err, response){
+  provider.sendAsync(payload, function onPayloadHandled(err, response){
     // provider engine errors are included in response objects
     if (!payload.isMetamaskInternal) console.log('MetaMaskPlugin - RPC complete:', payload, '->', response)
     try {
@@ -111,6 +122,7 @@ function linkDnode(stream){
   var connection = Dnode({
     getState:           function(cb){ cb(null, getState()) },
     setRpcTarget:       setRpcTarget,
+    useEtherscanProvider: useEtherscanProvider,
     // forward directly to idStore
     createNewVault:     idStore.createNewVault.bind(idStore),
     recoverFromSeed:    idStore.recoverFromSeed.bind(idStore),
@@ -179,6 +191,11 @@ function setRpcTarget(rpcTarget){
   chrome.runtime.reload()
 }
 
+function useEtherscanProvider() {
+  configManager.useEtherscanProvider()
+  chrome.runtime.reload()
+}
+
 // util
 
 function jsonParseStream(){

app/scripts/lib/config-manager.js

@@ -47,15 +47,6 @@ ConfigManager.prototype.setConfig = function(config) {
   this.setData(data)
 }
 
-ConfigManager.prototype.setRpcTarget = function(rpcUrl) {
-  var config = this.getConfig()
-  config.provider = {
-    type: 'rpc',
-    rpcTarget: rpcUrl,
-  }
-  this.setConfig(config)
-}
-
 ConfigManager.prototype.getConfig = function() {
   var data = this.migrator.getData()
   if ('config' in data) {
@@ -70,6 +61,28 @@ ConfigManager.prototype.getConfig = function() {
   }
 }
 
+ConfigManager.prototype.setRpcTarget = function(rpcUrl) {
+  var config = this.getConfig()
+  config.provider = {
+    type: 'rpc',
+    rpcTarget: rpcUrl,
+  }
+  this.setConfig(config)
+}
+
+ConfigManager.prototype.useEtherscanProvider = function() {
+  var config = this.getConfig()
+  config.provider = {
+    type: 'etherscan',
+  }
+  this.setConfig(config)
+}
+
+ConfigManager.prototype.getProvider = function() {
+  var config = this.getConfig()
+  return config.provider
+}
+
 ConfigManager.prototype.setData = function(data) {
   this.migrator.saveData(data)
 }