New dashboard widgets

- Custom time range can now be picked
- Map now shows accuracy of latest beat
- Presets removed

frontend/src/app/dashboard/dashboard.component.ts

@@ -10,6 +10,9 @@ import { APIService, IBeat } from '../api.service';
 })
 export class DashboardComponent implements AfterViewInit {
 
+  totalDistance = '0';
+  devices = 0;
+
   // Array of different segments in chart
   lineChartData: ChartDataSets[] = [
     { data: [], label: 'Battery' }
@@ -38,7 +41,11 @@ export class DashboardComponent implements AfterViewInit {
     }
   };
 
-  constructor(private api: APIService) {
+  constructor(public api: APIService) {
+    this.api.phoneEvent.subscribe(phones => {
+      this.devices = phones.length;
+    });
+
     this.api.beatsEvent.subscribe(beats => {
       this.lineChartData[0].data = [];
       this.lineChartLabels = [];
@@ -58,11 +65,22 @@ export class DashboardComponent implements AfterViewInit {
         this.lineChartData[0].data.push(beat.battery);
         this.lineChartLabels.push(this.formatDateTime(new Date(beat.createdAt)));
       });
-    });
-  }
 
-  async fetchData(): Promise<void> {
-    await this.api.getBeats();
+      let tDistance = 0;
+
+      // Calculate distance
+      for (let i = 0; i < beats.length; i++) {
+        if (i >= beats.length || (i + 1) >= beats.length) { break; }
+
+        const dist1 = beats[i].coordinate;
+        const dist2 = beats[i + 1].coordinate;
+        tDistance += this.api.distanceInKmBetweenEarthCoordinates(dist1[0], dist1[1], dist2[0], dist2[1]);
+
+        i++;
+      }
+
+      this.totalDistance = tDistance.toFixed(2);
+    });
   }
 
   private formatDateTime(date: Date): string {
@@ -70,7 +88,6 @@ export class DashboardComponent implements AfterViewInit {
   }
 
   ngAfterViewInit(): void {
-    this.fetchData();
   }
 
 }