feat: add ability to like books

2026-02-04 21:14:13 -08:00
parent a9764a4a82
commit 729f410443
19 changed files with 1256 additions and 8 deletions
@@ -0,0 +1,172 @@
+/**
+ * @copyright 2026 NHCarrigan
+ * @license Naomi's Public License
+ * @author Naomi Carrigan
+ */
+
+import { Injectable, inject, signal, computed } from '@angular/core';
+import { Observable, map, tap, catchError, of } from 'rxjs';
+import { ApiService } from './api.service';
+import { CreateLikeDto, LikeResponse, LikedItemDto, Like } from '@library/shared-types';
+
+interface LikeState {
+  entityType: Like['entityType'];
+  entityId: string;
+  liked: boolean;
+  count: number;
+}
+
+@Injectable({
+  providedIn: 'root'
+})
+export class LikesService {
+  private api = inject(ApiService);
+
+  // Store like states for caching
+  private likeStates = signal<Map<string, LikeState>>(new Map());
+
+  /**
+   * Toggle like on an item.
+   */
+  toggleLike(entityType: Like['entityType'], entityId: string): Observable<LikeResponse> {
+    const dto: CreateLikeDto = { entityType, entityId };
+
+    return this.api.post<LikeResponse>('/likes/toggle', dto).pipe(
+      tap(response => {
+        const key = this.getCacheKey(entityType, entityId);
+        this.likeStates.update(states => {
+          const newStates = new Map(states);
+          newStates.set(key, {
+            entityType,
+            entityId,
+            liked: response.liked,
+            count: response.count
+          });
+          return newStates;
+        });
+      }),
+      catchError(() => {
+        // On error, return current state or default
+        const key = this.getCacheKey(entityType, entityId);
+        const currentState = this.likeStates().get(key);
+        return of({
+          liked: currentState?.liked || false,
+          count: currentState?.count || 0
+        });
+      })
+    );
+  }
+
+  /**
+   * Get like count for an item.
+   */
+  getLikeCount(entityType: Like['entityType'], entityId: string): Observable<number> {
+    return this.api.get<{ count: number }>(`/likes/count?entityType=${entityType}&entityId=${entityId}`).pipe(
+      map(response => response.count),
+      tap(count => {
+        const key = this.getCacheKey(entityType, entityId);
+        this.likeStates.update(states => {
+          const newStates = new Map(states);
+          const currentState = newStates.get(key);
+          newStates.set(key, {
+            entityType,
+            entityId,
+            liked: currentState?.liked || false,
+            count
+          });
+          return newStates;
+        });
+      })
+    );
+  }
+
+  /**
+   * Check if current user has liked an item.
+   */
+  getUserLikeStatus(entityType: Like['entityType'], entityId: string): Observable<boolean> {
+    return this.api.get<{ liked: boolean }>(`/likes/status?entityType=${entityType}&entityId=${entityId}`).pipe(
+      map(response => response.liked),
+      tap(liked => {
+        const key = this.getCacheKey(entityType, entityId);
+        this.likeStates.update(states => {
+          const newStates = new Map(states);
+          const currentState = newStates.get(key);
+          newStates.set(key, {
+            entityType,
+            entityId,
+            liked,
+            count: currentState?.count || 0
+          });
+          return newStates;
+        });
+      })
+    );
+  }
+
+  /**
+   * Get all items liked by the current user.
+   */
+  getUserLikedItems(entityType?: Like['entityType']): Observable<LikedItemDto[]> {
+    const query = entityType ? `?entityType=${entityType}` : '';
+    return this.api.get<LikedItemDto[]>(`/likes/user${query}`);
+  }
+
+  /**
+   * Get bulk like statuses for multiple items.
+   */
+  getBulkLikeStatuses(items: Array<{ entityType: string; entityId: string }>): Observable<Array<{
+    entityType: string;
+    entityId: string;
+    liked: boolean;
+    count: number;
+  }>> {
+    return this.api.post<Array<{
+      entityType: string;
+      entityId: string;
+      liked: boolean;
+      count: number;
+    }>>('/likes/bulk-status', { items }).pipe(
+      tap(results => {
+        this.likeStates.update(states => {
+          const newStates = new Map(states);
+          results.forEach(result => {
+            const key = this.getCacheKey(result.entityType as Like['entityType'], result.entityId);
+            newStates.set(key, {
+              entityType: result.entityType as Like['entityType'],
+              entityId: result.entityId,
+              liked: result.liked,
+              count: result.count
+            });
+          });
+          return newStates;
+        });
+      })
+    );
+  }
+
+  /**
+   * Get like state from cache.
+   */
+  getCachedLikeState(entityType: Like['entityType'], entityId: string): LikeState | undefined {
+    const key = this.getCacheKey(entityType, entityId);
+    return this.likeStates().get(key);
+  }
+
+  /**
+   * Create computed signal for specific item's like state.
+   */
+  createLikeStateSignal(entityType: Like['entityType'], entityId: string) {
+    const key = this.getCacheKey(entityType, entityId);
+    return computed(() => {
+      const state = this.likeStates().get(key);
+      return {
+        liked: state?.liked || false,
+        count: state?.count || 0
+      };
+    });
+  }
+
+  private getCacheKey(entityType: Like['entityType'], entityId: string): string {
+    return `${entityType}:${entityId}`;
+  }
+}