Move difficulty adjustment code to separate module

frontend/src/app/components/difficulty/difficulty.component.ts

@@ -0,0 +1,111 @@
+import { ChangeDetectionStrategy, Component, Input, OnInit } from '@angular/core';
+import { combineLatest, Observable, timer } from 'rxjs';
+import { map, switchMap } from 'rxjs/operators';
+import { StateService } from '../..//services/state.service';
+
+interface EpochProgress {
+  base: string;
+  change: number;
+  progress: string;
+  remainingBlocks: number;
+  newDifficultyHeight: number;
+  colorAdjustments: string;
+  colorPreviousAdjustments: string;
+  timeAvg: string;
+  remainingTime: number;
+  previousRetarget: number;
+}
+
+@Component({
+  selector: 'app-difficulty',
+  templateUrl: './difficulty.component.html',
+  styleUrls: ['./difficulty.component.scss'],
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class DifficultyComponent implements OnInit {
+  isLoadingWebSocket$: Observable<boolean>;
+  difficultyEpoch$: Observable<EpochProgress>;
+
+  constructor(
+    public stateService: StateService,
+  ) { }
+
+  ngOnInit(): void {
+    this.isLoadingWebSocket$ = this.stateService.isLoadingWebSocket$;
+    this.difficultyEpoch$ = timer(0, 1000)
+      .pipe(
+        switchMap(() => combineLatest([
+          this.stateService.blocks$.pipe(map(([block]) => block)),
+          this.stateService.lastDifficultyAdjustment$,
+          this.stateService.previousRetarget$
+        ])),
+        map(([block, DATime, previousRetarget]) => {
+          const now = new Date().getTime() / 1000;
+          const diff = now - DATime;
+          const blocksInEpoch = block.height % 2016;
+          const progress = (blocksInEpoch >= 0) ? (blocksInEpoch / 2016 * 100).toFixed(2) : `100`;
+          const remainingBlocks = 2016 - blocksInEpoch;
+          const newDifficultyHeight = block.height + remainingBlocks;
+
+          let change = 0;
+          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;
+
+          let timeAvgMins = 10;
+          if (timeAvgDiff > 0) {
+            timeAvgMins -= Math.abs(timeAvgDiff);
+          } else {
+            timeAvgMins += Math.abs(timeAvgDiff);
+          }
+
+          const timeAvg = timeAvgMins.toFixed(0);
+          const remainingTime = (remainingBlocks * timeAvgMins * 60 * 1000) + (now * 1000);
+
+          let colorAdjustments = '#ffffff66';
+          if (change > 0) {
+            colorAdjustments = '#3bcc49';
+          }
+          if (change < 0) {
+            colorAdjustments = '#dc3545';
+          }
+
+          let colorPreviousAdjustments = '#dc3545';
+          if (previousRetarget) {
+            if (previousRetarget >= 0) {
+              colorPreviousAdjustments = '#3bcc49';
+            }
+            if (previousRetarget === 0) {
+              colorPreviousAdjustments = '#ffffff66';
+            }
+          } else {
+            colorPreviousAdjustments = '#ffffff66';
+          }
+
+          return {
+            base: `${progress}%`,
+            change,
+            progress,
+            remainingBlocks,
+            timeAvg,
+            colorAdjustments,
+            colorPreviousAdjustments,
+            blocksInEpoch,
+            newDifficultyHeight,
+            remainingTime,
+            previousRetarget,
+          };
+        })
+      );
+  }
+}