Lightning indexing indicators

refs  #2647

frontend/src/app/lightning/nodes-per-isp-chart/nodes-per-isp-chart.component.html

@@ -38,7 +38,7 @@
     </small>
   </div>
 
-  <div [class]="!widget ? 'bottom-padding' : 'pb-0'" class="container pb-lg-0">
+  <div *ngIf="!indexingInProgress else indexing" [class]="!widget ? 'bottom-padding' : 'pb-0'" class="container pb-lg-0">
     <div [class]="widget ? 'chart-widget' : 'chart'" echarts [initOpts]="chartInitOptions" [options]="chartOptions"
       (chartInit)="onChartInit($event)">
     </div>
@@ -99,3 +99,7 @@
     </div>
   </div>
 </ng-template>
+
+<ng-template #indexing>
+  <div class="indexing-message" i18n="lightning.indexing-in-progress">Indexing in progress</div>
+</ng-template>

frontend/src/app/lightning/nodes-per-isp-chart/nodes-per-isp-chart.component.scss

@@ -167,4 +167,14 @@
     padding-left: 105px;
     padding-right: 105px;
   }
-}
+}
+
+.indexing-message {
+  font-size: 15px;
+  color: grey;
+  font-weight: bold;
+  width: 100%;
+  padding-top: 100px;
+  text-align: center;
+  height: 240px;
+}

frontend/src/app/lightning/nodes-per-isp-chart/nodes-per-isp-chart.component.ts

@@ -29,6 +29,7 @@ export class NodesPerISPChartComponent implements OnInit {
   sortBy = 'capacity';
   showUnknown = false;
   chartInstance = undefined;
+  indexingInProgress = false;
 
   @HostBinding('attr.dir') dir = 'ltr';
 
@@ -88,6 +89,8 @@ export class NodesPerISPChartComponent implements OnInit {
 
                 this.prepareChartOptions(data.ispRanking);
 
+                this.indexingInProgress = !data.ispRanking.length;
+
                 return {
                   taggedISP: data.ispRanking.length,
                   clearnetCapacity: data.clearnetCapacity,