fix: Prevent concurrent upload conflicts with unique file names

- Add generateUniqueFileName function using crypto.randomBytes
- Replace Date.now() with timestamp + random hex for all file names
- Ensures unique file names even when multiple users upload simultaneously
- Fixes: temp PSD files, temp preview files, S3 preview files, and material files
- Resolves reported issue of upload errors with concurrent users

app/api/materials/upload/route.ts

@@ -7,6 +7,14 @@ import { processImage, getProcessedFileName } from '@/lib/image-processor'
 import { generatePsdPreview, hasPsdExtension } from '@/lib/psd-processor'
 import { writeFile, mkdir, unlink } from 'fs/promises'
 import path from 'path'
+import { randomBytes } from 'crypto'
+
+// 生成唯一文件名（避免并发冲突）
+function generateUniqueFileName(prefix: string, ext: string): string {
+  const timestamp = Date.now()
+  const randomId = randomBytes(8).toString('hex') // 16个字符的随机字符串
+  return `${prefix}-${timestamp}-${randomId}${ext}`
+}
 
 // Configure route to handle large files
 export const runtime = 'nodejs'
@@ -105,14 +113,14 @@ export async function POST(req: NextRequest) {
         const uploadDir = process.env.UPLOAD_DIR || './uploads'
         await mkdir(uploadDir, { recursive: true })
         
-        const tempPsdFileName = `temp-psd-${Date.now()}-${zipFile.name}`
+        const tempPsdFileName = generateUniqueFileName('temp-psd', `.${zipFile.name.split('.').pop()}`)
         const tempPsdPath = path.join(uploadDir, tempPsdFileName)
         const psdBuffer = Buffer.from(await zipFile.arrayBuffer())
         await writeFile(tempPsdPath, psdBuffer)
         console.log('[Upload] Temporary PSD saved:', tempPsdPath)
 
         // Generate preview image
-        const tempPreviewPath = path.join(uploadDir, `temp-preview-${Date.now()}.jpg`)
+        const tempPreviewPath = path.join(uploadDir, generateUniqueFileName('temp-preview', '.jpg'))
         const result = await generatePsdPreview(tempPsdPath, tempPreviewPath, 800)
 
         if (!result.success || !result.previewPath) {
@@ -147,7 +155,7 @@ export async function POST(req: NextRequest) {
         console.log('[Upload] Temporary files cleaned up')
 
         // Upload to S3
-        previewFileName = `preview-${Date.now()}-generated.webp`
+        previewFileName = generateUniqueFileName('preview', '-generated.webp')
         previewUrl = await uploadToS3(processedBuffer, previewFileName, 'image/webp')
         console.log('[Upload] Auto-generated preview uploaded to S3:', previewUrl)
 
@@ -209,7 +217,8 @@ export async function POST(req: NextRequest) {
       // Upload processed preview image to S3
       console.log('[Upload] Uploading image to S3...')
       const processedFileName = getProcessedFileName(previewImage.name)
-      previewFileName = `preview-${Date.now()}-${processedFileName}`
+      const fileExt = path.extname(processedFileName)
+      previewFileName = generateUniqueFileName('preview', fileExt)
       previewUrl = await uploadToS3(processedBuffer, previewFileName, 'image/webp')
       console.log('[Upload] Image uploaded to S3:', previewUrl)
     }
@@ -219,7 +228,8 @@ export async function POST(req: NextRequest) {
     const uploadDir = process.env.UPLOAD_DIR || './uploads'
     await mkdir(uploadDir, { recursive: true })
 
-    const zipFileName = `zip-${Date.now()}-${zipFile.name}`
+    const zipFileExt = path.extname(zipFile.name)
+    const zipFileName = generateUniqueFileName('material', zipFileExt)
     const zipFilePath = path.join(uploadDir, zipFileName)
     
     // If it's a PSD file, we already have the buffer from above