Add blog thumbnail and banner upload endpoints with storage keys.

Store image filenames in DB, resolve paths for cleanup on replace/delete, and reuse product-thumb multer limits.

backend/src/modules/blog/services/BlogPostsService.ts

@@ -1,7 +1,9 @@
 import { Injectable, NotFoundException } from '@nestjs/common';
 import { InjectRepository } from '@nestjs/typeorm';
 import { Repository } from 'typeorm';
+import { resolveBlogImagePath } from '../../../config/uploadPaths';
 import type { PaginatedResponse } from '../../../types/PaginatedResponse';
+import { removeFileFromDisk } from '../../../utils/removeFileFromDisk';
 import type { ListBlogPostsQueryDto } from '../dto/ListBlogPostsQueryDto';
 import { UpdateBlogPostDto } from '../dto/UpdateBlogPostDto';
 import { BlogPost } from '../entities/BlogPost';
@@ -61,13 +63,46 @@ export class BlogPostsService {
         return this.findOne(id);
     }
 
-    async remove(id: string): Promise<void> {
-        const exists = await this.blogPostRepo.exists({ where: { id } });
+    async uploadThumbnail(id: string, filename: string): Promise<BlogPost> {
+        const post = await this.findOne(id);
 
-        if (!exists) {
-            throw new NotFoundException();
-        }
+        const previousStorageKey = post.thumbnailStorageKey;
+
+        await this.blogPostRepo.update(id, { thumbnailStorageKey: filename });
+        await this.removeBlogImageFile(previousStorageKey);
+
+        return this.findOne(id);
+    }
+
+    async uploadBanner(id: string, filename: string): Promise<BlogPost> {
+        const post = await this.findOne(id);
+
+        const previousStorageKey = post.bannerStorageKey;
+
+        await this.blogPostRepo.update(id, { bannerStorageKey: filename });
+        await this.removeBlogImageFile(previousStorageKey);
+
+        return this.findOne(id);
+    }
+
+    async remove(id: string): Promise<void> {
+        const post = await this.findOne(id);
 
         await this.blogPostRepo.delete(id);
+
+        await Promise.all([
+            this.removeBlogImageFile(post.thumbnailStorageKey),
+            this.removeBlogImageFile(post.bannerStorageKey)
+        ]);
+    }
+
+    private async removeBlogImageFile(storageKey: string | null): Promise<void> {
+        if (!storageKey) {
+            return;
+        }
+
+        const path = resolveBlogImagePath(storageKey);
+
+        await removeFileFromDisk(path, BlogPostsService.name);
     }
 }