add attendance

2026-06-20 19:33:04 -07:00
parent 2af169fa60
commit 87425b3276
24 changed files with 1357 additions and 5 deletions
@@ -0,0 +1,68 @@
+import { Injectable } from '@angular/core';
+import { BehaviorSubject, Observable } from 'rxjs';
+import {
+  HubConnection, HubConnectionBuilder, HubConnectionState, LogLevel,
+} from '@microsoft/signalr';
+import { environment } from '../../../../environments/environment';
+import { AttendanceCounts, AttendanceCategory } from '../models/attendance.model';
+
+/**
+ * Thin wrapper around the AttendanceHub SignalR connection. Exposes the latest
+ * authoritative counts as an observable and a fire-and-forget increment() that
+ * sends a batched delta to the server. The server broadcasts the new totals
+ * back to every connected client.
+ */
+@Injectable({ providedIn: 'root' })
+export class AttendanceSignalrService {
+  // Hub lives at the host root; environment.apiUrl is e.g. http://localhost:42019/api
+  private readonly hubUrl = environment.apiUrl.replace(/\/api\/?$/, '') + '/hubs/attendance';
+
+  private connection?: HubConnection;
+  private readonly counts$$ = new BehaviorSubject<AttendanceCounts | null>(null);
+
+  /** Latest authoritative counts pushed by the server (null until first message). */
+  get counts$(): Observable<AttendanceCounts | null> {
+    return this.counts$$.asObservable();
+  }
+
+  async start(): Promise<void> {
+    if (this.connection) {
+      return;
+    }
+
+    this.connection = new HubConnectionBuilder()
+      .withUrl(this.hubUrl)
+      .withAutomaticReconnect()
+      .configureLogging(LogLevel.Warning)
+      .build();
+
+    this.connection.on('ReceiveCounts', (counts: AttendanceCounts) => {
+      this.counts$$.next(counts);
+    });
+
+    await this.connection.start();
+  }
+
+  async stop(): Promise<void> {
+    if (this.connection) {
+      await this.connection.stop();
+      this.connection = undefined;
+    }
+  }
+
+  /** Send a batched delta (may be negative) for one age group. */
+  async increment(category: AttendanceCategory, delta: number): Promise<void> {
+    if (delta === 0 || this.connection?.state !== HubConnectionState.Connected) {
+      return;
+    }
+    await this.connection.invoke('Increment', category, delta);
+  }
+
+  /** Overwrite one age group with an absolute value (clamped at zero server-side). */
+  async setCount(category: AttendanceCategory, value: number): Promise<void> {
+    if (this.connection?.state !== HubConnectionState.Connected) {
+      throw new Error('Not connected to the attendance hub.');
+    }
+    await this.connection.invoke('SetCount', category, value);
+  }
+}