From d534c42c4708b2160bf2e9a735b54ea67a5e8b71 Mon Sep 17 00:00:00 2001
From: softsimon <softsimon@protonmail.com>
Date: Wed, 17 Nov 2021 13:05:14 +0400
Subject: [PATCH] Handle recent difficulty adjustment estimate gracefully

fixes #927
---
 backend/src/routes.ts                          | 18 ++++++++++--------
 .../src/app/dashboard/dashboard.component.html |  5 ++++-
 .../src/app/dashboard/dashboard.component.ts   | 18 ++++++++++--------
 3 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/backend/src/routes.ts b/backend/src/routes.ts
index fd53f4765..11502c839 100644
--- a/backend/src/routes.ts
+++ b/backend/src/routes.ts
@@ -724,14 +724,16 @@ class Routes {
       const nextRetargetHeight = blockHeight + remainingBlocks;
 
       let difficultyChange = 0;
-      if (blocksInEpoch > 0) {
-        difficultyChange = (600 / (diff / blocksInEpoch ) - 1) * 100;
-      }
-      if (difficultyChange > 300) {
-        difficultyChange = 300;
-      }
-      if (difficultyChange < -75) {
-        difficultyChange = -75;
+      if (remainingBlocks < 1870) {
+        if (blocksInEpoch > 0) {
+          difficultyChange = (600 / (diff / blocksInEpoch ) - 1) * 100;
+        }
+        if (difficultyChange > 300) {
+          difficultyChange = 300;
+        }
+        if (difficultyChange < -75) {
+          difficultyChange = -75;
+        }
       }
 
       const timeAvgDiff = difficultyChange * 0.1;
diff --git a/frontend/src/app/dashboard/dashboard.component.html b/frontend/src/app/dashboard/dashboard.component.html
index 72d71b8ad..002f3c702 100644
--- a/frontend/src/app/dashboard/dashboard.component.html
+++ b/frontend/src/app/dashboard/dashboard.component.html
@@ -242,7 +242,7 @@
           </div>
           <div class="item">
             <h5 class="card-title" i18n="difficulty-box.estimate">Estimate</h5>
-            <div class="card-text" [ngStyle]="{'color': epochData.colorAdjustments}">
+            <div *ngIf="epochData.remainingBlocks < 1870; else recentlyAdjusted" class="card-text" [ngStyle]="{'color': epochData.colorAdjustments}">
               <span *ngIf="epochData.change > 0; else arrowDownDifficulty" >
                 <fa-icon class="retarget-sign" [icon]="['fas', 'caret-up']" [fixedWidth]="true"></fa-icon>
               </span>
@@ -252,6 +252,9 @@
               {{ epochData.change | absolute | number: '1.2-2' }}
               <span class="symbol">%</span>
             </div>
+            <ng-template #recentlyAdjusted>
+              <div class="card-text">&#8212;</div>
+            </ng-template>
             <div class="symbol">
               <span i18n="difficulty-box.previous">Previous</span>:
               <span [ngStyle]="{'color': epochData.colorPreviousAdjustments}">
diff --git a/frontend/src/app/dashboard/dashboard.component.ts b/frontend/src/app/dashboard/dashboard.component.ts
index f76438942..dad5b4a9f 100644
--- a/frontend/src/app/dashboard/dashboard.component.ts
+++ b/frontend/src/app/dashboard/dashboard.component.ts
@@ -144,14 +144,16 @@ export class DashboardComponent implements OnInit {
           const newDifficultyHeight = block.height + remainingBlocks;
 
           let change = 0;
-          if (blocksInEpoch > 0) {
-            change = (600 / (diff / blocksInEpoch ) - 1) * 100;
-          }
-          if (change > 300) {
-            change = 300;
-          }
-          if (change < -75) {
-            change = -75;
+          if (remainingBlocks < 1870) {
+            if (blocksInEpoch > 0) {
+              change = (600 / (diff / blocksInEpoch ) - 1) * 100;
+            }
+            if (change > 300) {
+              change = 300;
+            }
+            if (change < -75) {
+              change = -75;
+            }
           }
 
           const timeAvgDiff = change * 0.1;