feat: add favorite/unfavorite of articles

src/articles/articles.plugin.ts

@@ -211,5 +211,45 @@ export const articlesPlugin = new Elysia().use(setupArticles).group(
             summary: 'Delete Comment',
           },
         },
+      )
+      .post(
+        '/:slug/favorite',
+        async ({ params, store, request }) =>
+          store.articlesService.favoriteArticle(
+            params.slug,
+            await store.authService.getUserIdFromHeader(request.headers),
+          ),
+        {
+          beforeHandle: app.store.authService.requireLogin,
+          response: ReturnedArticleResponseSchema,
+          detail: {
+            summary: 'Favorite Article',
+            security: [
+              {
+                tokenAuth: [],
+              },
+            ],
+          },
+        },
+      )
+      .delete(
+        '/:slug/favorite',
+        async ({ params, store, request }) =>
+          store.articlesService.unfavoriteArticle(
+            params.slug,
+            await store.authService.getUserIdFromHeader(request.headers),
+          ),
+        {
+          beforeHandle: app.store.authService.requireLogin,
+          response: ReturnedArticleResponseSchema,
+          detail: {
+            summary: 'Unfavorite Article',
+            security: [
+              {
+                tokenAuth: [],
+              },
+            ],
+          },
+        },
       ),
 );

src/articles/articles.repository.ts

@@ -193,4 +193,42 @@ export class ArticlesRepository {
         and(eq(articles.slug, slug), eq(articles.authorId, currentUserId)),
       );
   }
+
+  async favoriteArticle(slug: string, currentUserId: number) {
+    // TODO: Use a transaction to optimize from 1-3 ops to 1 op
+    const article = await this.findBySlug(slug);
+    if (!article) {
+      return null;
+    }
+
+    // Insert the favorite and get the updated article state
+    await this.db
+      .insert(favoriteArticles)
+      .values({ articleId: article.id, userId: currentUserId })
+      .onConflictDoNothing();
+
+    // Return the updated article state
+    return this.findBySlug(slug);
+  }
+
+  async unfavoriteArticle(slug: string, currentUserId: number) {
+    // TODO: Use a transaction to optimize from 1-3 ops to 1 op
+    const article = await this.findBySlug(slug);
+    if (!article) {
+      return null;
+    }
+
+    // Delete the favorite and get the updated article state
+    await this.db
+      .delete(favoriteArticles)
+      .where(
+        and(
+          eq(favoriteArticles.articleId, article.id),
+          eq(favoriteArticles.userId, currentUserId),
+        ),
+      );
+
+    // Return the updated article state
+    return this.findBySlug(slug);
+  }
 }

src/articles/articles.service.ts

@@ -118,4 +118,20 @@ export class ArticlesService {
       },
     };
   }
+
+  async favoriteArticle(slug: string, currentUserId: number) {
+    const article = await this.repository.favoriteArticle(slug, currentUserId);
+    if (!article) {
+      throw new NotFoundError('Article not found');
+    }
+    return await this.generateArticleResponse(article, currentUserId);
+  }
+
+  async unfavoriteArticle(slug: string, currentUserId: number) {
+    const article = await this.repository.unfavoriteArticle(slug, currentUserId);
+    if (!article) {
+      throw new NotFoundError('Article not found');
+    }
+    return await this.generateArticleResponse(article, currentUserId);
+  }
 }