From 80f0eabcc9ccbdc0dfb7feb955d6390aa8e07884 Mon Sep 17 00:00:00 2001
From: maciejhirsz <maciej.hirsz@gmail.com>
Date: Wed, 18 Jul 2018 20:29:47 +0200
Subject: [PATCH] Handle system.interval at block height 0

---
 packages/backend/src/Node.ts              | 52 ++++++++++++++++-------
 packages/frontend/src/components/Node.css |  2 +
 2 files changed, 39 insertions(+), 15 deletions(-)

diff --git a/packages/backend/src/Node.ts b/packages/backend/src/Node.ts
index 2cfb4cd..13858d8 100644
--- a/packages/backend/src/Node.ts
+++ b/packages/backend/src/Node.ts
@@ -49,6 +49,7 @@ export default class Node {
     config: string,
     implentation: Types.NodeImplementation,
     version: Types.NodeVersion,
+    messages: Array<Message>,
   ) {
     this.ip = ip;
     this.id = nextId();
@@ -67,18 +68,7 @@ export default class Node {
         return;
       }
 
-      this.lastMessage = timestamp();
-      this.updateLatency(message.ts);
-
-      const update = getBestBlock(message);
-
-      if (update) {
-        this.updateBestBlock(update);
-      }
-
-      if (message.msg === 'system.interval') {
-        this.onSystemInterval(message);
-      }
+      this.onMessage(message);
     });
 
     socket.on('close', () => {
@@ -93,6 +83,11 @@ export default class Node {
       this.disconnect();
     });
 
+    // Handle cached messages
+    for (const message of messages) {
+      this.onMessage(message);
+    }
+
     locate(ip).then((location) => {
       if (!location) {
         return;
@@ -111,15 +106,27 @@ export default class Node {
         socket.removeAllListeners('message');
       }
 
+      const messages: Array<Message> = [];
+
       function handler(data: WebSocket.Data) {
         const message = parseMessage(data);
 
-        if (message && message.msg === "system.connected") {
+        if (!message || !message.msg) {
+          return;
+        }
+
+        if (message.msg === "system.connected") {
           cleanup();
 
           const { name, chain, config, implementation, version } = message;
 
-          resolve(new Node(ip, socket, name, chain, config, implementation, version));
+          resolve(new Node(ip, socket, name, chain, config, implementation, version, messages));
+        } else {
+          if (messages.length === 10) {
+            messages.shift();
+          }
+
+          messages.push(message);
         }
       }
 
@@ -192,6 +199,21 @@ export default class Node {
     this.events.emit('disconnect');
   }
 
+  private onMessage(message: Message) {
+    this.lastMessage = timestamp();
+    this.updateLatency(message.ts);
+
+    const update = getBestBlock(message);
+
+    if (update) {
+      this.updateBestBlock(update);
+    }
+
+    if (message.msg === 'system.interval') {
+      this.onSystemInterval(message);
+    }
+  }
+
   private onSystemInterval(message: SystemInterval) {
     const { peers, txcount } = message;
 
@@ -210,7 +232,7 @@ export default class Node {
   private updateBestBlock(update: BestBlock) {
     const { height, ts: time, best } = update;
 
-    if (this.height < height) {
+    if (this.best !== best && this.height <= height) {
       const blockTime = this.getBlockTime(time);
 
       this.best = best;
diff --git a/packages/frontend/src/components/Node.css b/packages/frontend/src/components/Node.css
index cd6b1d4..927063e 100644
--- a/packages/frontend/src/components/Node.css
+++ b/packages/frontend/src/components/Node.css
@@ -36,6 +36,8 @@
 }
 
 .Node-details td:nth-child(odd) {
+  width: 16px;
+  text-align: center;
   padding-right: 0.2em;
 }