[PM-10613] End User Notification Service (#13721)

* new end user notification service to retrieve and update notifications from API

libs/vault/src/notifications/services/default-end-user-notification.service.ts

@@ -0,0 +1,104 @@
+import { Injectable } from "@angular/core";
+import { map, Observable, switchMap } from "rxjs";
+
+import { ApiService } from "@bitwarden/common/abstractions/api.service";
+import { ListResponse } from "@bitwarden/common/models/response/list.response";
+import { StateProvider } from "@bitwarden/common/platform/state";
+import { UserId } from "@bitwarden/common/types/guid";
+
+import { filterOutNullish, perUserCache$ } from "../../utils/observable-utilities";
+import { EndUserNotificationService } from "../abstractions/end-user-notification.service";
+import { NotificationView, NotificationViewData, NotificationViewResponse } from "../models";
+import { NOTIFICATIONS } from "../state/end-user-notification.state";
+
+/**
+ * A service for retrieving and managing notifications for end users.
+ */
+@Injectable()
+export class DefaultEndUserNotificationService implements EndUserNotificationService {
+  constructor(
+    private stateProvider: StateProvider,
+    private apiService: ApiService,
+  ) {}
+
+  notifications$ = perUserCache$((userId: UserId): Observable<NotificationView[]> => {
+    return this.notificationState(userId).state$.pipe(
+      switchMap(async (notifications) => {
+        if (notifications == null) {
+          await this.fetchNotificationsFromApi(userId);
+        }
+        return notifications;
+      }),
+      filterOutNullish(),
+      map((notifications) =>
+        notifications.map((notification) => new NotificationView(notification)),
+      ),
+    );
+  });
+
+  unreadNotifications$ = perUserCache$((userId: UserId): Observable<NotificationView[]> => {
+    return this.notifications$(userId).pipe(
+      map((notifications) => notifications.filter((notification) => notification.readDate == null)),
+    );
+  });
+
+  async markAsRead(notificationId: any, userId: UserId): Promise<void> {
+    await this.apiService.send("PATCH", `/notifications/${notificationId}/read`, null, true, false);
+    await this.getNotifications(userId);
+  }
+
+  async markAsDeleted(notificationId: any, userId: UserId): Promise<void> {
+    await this.apiService.send(
+      "DELETE",
+      `/notifications/${notificationId}/delete`,
+      null,
+      true,
+      false,
+    );
+    await this.getNotifications(userId);
+  }
+
+  upsert(notification: Notification): any {}
+
+  async clearState(userId: UserId): Promise<void> {
+    await this.updateNotificationState(userId, []);
+  }
+
+  async getNotifications(userId: UserId) {
+    await this.fetchNotificationsFromApi(userId);
+  }
+
+  /**
+   * Fetches the notifications from the API and updates the local state
+   * @param userId
+   * @private
+   */
+  private async fetchNotificationsFromApi(userId: UserId): Promise<void> {
+    const res = await this.apiService.send("GET", "/notifications", null, true, true);
+    const response = new ListResponse(res, NotificationViewResponse);
+    const notificationData = response.data.map((n) => new NotificationView(n));
+    await this.updateNotificationState(userId, notificationData);
+  }
+
+  /**
+   * Updates the local state with notifications and returns the updated state
+   * @param userId
+   * @param notifications
+   * @private
+   */
+  private updateNotificationState(
+    userId: UserId,
+    notifications: NotificationViewData[],
+  ): Promise<NotificationViewData[] | null> {
+    return this.notificationState(userId).update(() => notifications);
+  }
+
+  /**
+   * Returns the local state for notifications
+   * @param userId
+   * @private
+   */
+  private notificationState(userId: UserId) {
+    return this.stateProvider.getUser(userId, NOTIFICATIONS);
+  }
+}