feat: determine block sync progress early

Determine the current block height directly from the lnd log output and
pass the data into the app as soon as we have it. Do not call out to
block explorers if we don't need to.

app/components/Onboarding/Syncing.js

@@ -9,9 +9,13 @@ import styles from './Syncing.scss'
 
 class Syncing extends Component {
   componentWillMount() {
-    const { fetchBlockHeight, newAddress } = this.props
+    const { fetchBlockHeight, blockHeight, newAddress } = this.props
+
+    // If we don't already know the target block height, fetch it now.
+    if (!blockHeight) {
+      fetchBlockHeight()
+    }
 
-    fetchBlockHeight()
     newAddress('np2wkh')
   }
 

app/lnd/lib/neutrino.js

@@ -10,6 +10,14 @@ class Neutrino extends EventEmitter {
     this.alias = alias
     this.autopilot = autopilot
     this.process = null
+    this.state = {
+      grpcProxyStarted: false,
+      walletOpened: false,
+      chainSyncStarted: false,
+      chainSyncFinished: false,
+      currentBlockHeight: null,
+      targetBlockHeight: null
+    }
   }
 
   start() {
@@ -52,37 +60,58 @@ class Neutrino extends EventEmitter {
       }
 
       // gRPC started.
-      if (line.includes('gRPC proxy started') && line.includes('password')) {
-        this.emit('grpc-proxy-started')
+      if (!this.state.grpcProxyStarted) {
+        if (line.includes('gRPC proxy started') && line.includes('password')) {
+          this.state.grpcProxyStarted = true
+          this.emit('grpc-proxy-started')
+        }
       }
 
       // Wallet opened.
-      if (line.includes('gRPC proxy started') && !line.includes('password')) {
-        this.emit('wallet-opened')
+      if (!this.state.walletOpened) {
+        if (line.includes('gRPC proxy started') && !line.includes('password')) {
+          this.state.walletOpened = true
+          this.emit('wallet-opened')
+        }
       }
 
       // LND syncing has started.
-      if (line.includes('Waiting for chain backend to finish sync')) {
-        this.emit('chain-sync-started')
+      if (!this.state.chainSyncStarted) {
+        if (line.includes('Syncing to block height')) {
+          const height = line.match(/Syncing to block height (\d+)/)[1]
+          this.state.chainSyncStarted = true
+          this.state.targetBlockHeight = height
+          this.emit('chain-sync-started')
+          this.emit('got-final-block-height', height)
+        }
       }
 
       // LND syncing has completed.
-      if (line.includes('Chain backend is fully synced')) {
-        this.emit('chain-sync-finished')
+      if (!this.state.chainSyncFinished) {
+        if (line.includes('Chain backend is fully synced')) {
+          this.state.chainSyncFinished = true
+          this.emit('chain-sync-finished')
+        }
       }
 
       // Pass current block height progress to front end for loading state UX
-      if (line.includes('Rescanned through block')) {
-        const height = line.match(/Rescanned through block.+\(height (\d*)/)[1]
-        this.emit('got-block-height', height)
-      } else if (line.includes('Caught up to height')) {
-        const height = line.match(/Caught up to height (\d*)/)[1]
-        this.emit('got-block-height', height)
-      } else if (line.includes('in the last')) {
-        const height = line.match(/Processed \d* blocks? in the last.+\(height (\d*)/)[1]
-        this.emit('got-block-height', height)
+      if (this.state.chainSyncStarted) {
+        if (line.includes('Downloading headers for blocks')) {
+          const height = line.match(/Downloading headers for blocks (\d+) to \d+/)[1]
+          this.emit('got-current-block-height', height)
+        } else if (line.includes('Rescanned through block')) {
+          const height = line.match(/Rescanned through block.+\(height (\d+)/)[1]
+          this.emit('got-current-block-height', height)
+        } else if (line.includes('Caught up to height')) {
+          const height = line.match(/Caught up to height (\d+)/)[1]
+          this.emit('got-current-block-height', height)
+        } else if (line.includes('in the last')) {
+          const height = line.match(/Processed \d* blocks? in the last.+\(height (\d+)/)[1]
+          this.emit('got-current-block-height', height)
+        }
       }
     })
+
     return this.process
   }
 

app/reducers/ipc.js

@@ -1,5 +1,12 @@
 import createIpc from 'redux-electron-ipc'
-import { lndSyncing, lndSynced, lndBlockHeight, grpcDisconnected, grpcConnected } from './lnd'
+import {
+  lndSyncing,
+  lndSynced,
+  lndBlockHeightTarget,
+  lndBlockHeight,
+  grpcDisconnected,
+  grpcConnected
+} from './lnd'
 import { receiveInfo } from './info'
 import { receiveAddress } from './address'
 import { receiveCryptocurrency } from './ticker'
@@ -53,6 +60,7 @@ import {
 const ipc = createIpc({
   lndSyncing,
   lndSynced,
+  lndBlockHeightTarget,
   lndBlockHeight,
   grpcDisconnected,
   grpcConnected,

app/reducers/lnd.js

@@ -52,6 +52,10 @@ export const lndBlockHeight = (event, height) => dispatch => {
   dispatch({ type: RECEIVE_BLOCK, lndBlockHeight: height })
 }
 
+export const lndBlockHeightTarget = (event, height) => dispatch => {
+  dispatch({ type: RECEIVE_BLOCK_HEIGHT, blockHeight: height })
+}
+
 export function getBlockHeight() {
   return {
     type: GET_BLOCK_HEIGHT

app/zap.js

@@ -170,7 +170,11 @@ class ZapController {
       this.sendMessage('lndSynced')
     })
 
-    this.neutrino.on('got-block-height', height => {
+    this.neutrino.on('got-final-block-height', height => {
+      this.sendMessage('lndBlockHeightTarget', Number(height))
+    })
+
+    this.neutrino.on('got-current-block-height', height => {
       this.sendMessage('lndBlockHeight', Number(height))
     })