fixed image previews

backend/services/s3Service.js

@@ -112,9 +112,10 @@ class S3Service {
    * @param {string} contentType - MIME type of the file
    * @param {string} fileName - Original filename (used for extension)
    * @param {number} fileSize - File size in bytes (required for size enforcement)
+   * @param {string} [baseKey] - Optional base key (UUID) for coordinated variant uploads
    * @returns {Promise<{uploadUrl: string, key: string, publicUrl: string, expiresAt: Date}>}
    */
-  async getPresignedUploadUrl(uploadType, contentType, fileName, fileSize) {
+  async getPresignedUploadUrl(uploadType, contentType, fileName, fileSize, baseKey = null) {
     if (!this.enabled) {
       throw new Error("S3 storage is not enabled");
     }
@@ -135,8 +136,21 @@ class S3Service {
       );
     }
 
+    // Extract known variant suffix from fileName if present (e.g., "photo_th.jpg" -> "_th")
     const ext = path.extname(fileName) || this.getExtFromMime(contentType);
-    const key = `${config.folder}/${uuidv4()}${ext}`;
+    const baseName = path.basename(fileName, ext);
+
+    // Only recognize known variant suffixes
+    let suffix = "";
+    if (baseName.endsWith("_th")) {
+      suffix = "_th";
+    } else if (baseName.endsWith("_md")) {
+      suffix = "_md";
+    }
+
+    // Use provided baseKey or generate new UUID
+    const uuid = baseKey || uuidv4();
+    const key = `${config.folder}/${uuid}${suffix}${ext}`;
 
     const cacheDirective = config.public ? "public" : "private";
     const command = new PutObjectCommand({