Simple Managment webapp [LLM]

webapp/src/app/core/services/api.service.ts

@@ -5,6 +5,7 @@ import { environment } from '../../../environments/environment';
 import {
   User,
   UserWithExtra,
+  UserPreview,
   Message,
   MessageListParams,
   MessageListResponse,
@@ -41,6 +42,10 @@ export class ApiService {
     return this.http.get<UserWithExtra>(`${this.baseUrl}/users/${userId}`);
   }
 
+  getUserPreview(userId: string): Observable<UserPreview> {
+    return this.http.get<UserPreview>(`${this.baseUrl}/preview/users/${userId}`);
+  }
+
   updateUser(userId: string, data: { username?: string; pro_token?: string }): Observable<User> {
     return this.http.patch<User>(`${this.baseUrl}/users/${userId}`, data);
   }

webapp/src/app/core/services/index.ts

@@ -1,3 +1,4 @@
 export * from './auth.service';
 export * from './api.service';
 export * from './notification.service';
+export * from './user-cache.service';

webapp/src/app/core/services/user-cache.service.ts

@@ -0,0 +1,55 @@
+import { Injectable, inject, signal } from '@angular/core';
+import { Observable, of, tap, catchError, map, shareReplay } from 'rxjs';
+import { ApiService } from './api.service';
+import { AuthService } from './auth.service';
+import { UserPreview } from '../models';
+
+export interface ResolvedUser {
+  userId: string;
+  displayName: string;
+  isCurrentUser: boolean;
+}
+
+@Injectable({
+  providedIn: 'root'
+})
+export class UserCacheService {
+  private apiService = inject(ApiService);
+  private authService = inject(AuthService);
+
+  private cache = new Map<string, Observable<UserPreview | null>>();
+
+  resolveUser(userId: string): Observable<ResolvedUser> {
+    const currentUserId = this.authService.getUserId();
+    const isCurrentUser = userId === currentUserId;
+
+    return this.getUserPreview(userId).pipe(
+      map(preview => {
+        let displayName = preview?.username || userId;
+        if (isCurrentUser) {
+          displayName += ' (you)';
+        }
+        return {
+          userId,
+          displayName,
+          isCurrentUser
+        };
+      })
+    );
+  }
+
+  private getUserPreview(userId: string): Observable<UserPreview | null> {
+    if (!this.cache.has(userId)) {
+      const request$ = this.apiService.getUserPreview(userId).pipe(
+        catchError(() => of(null)),
+        shareReplay(1)
+      );
+      this.cache.set(userId, request$);
+    }
+    return this.cache.get(userId)!;
+  }
+
+  clearCache(): void {
+    this.cache.clear();
+  }
+}