Upload public.js

backend/src/routes/public.js

@@ -467,20 +467,26 @@ router.post('/generate-share-link', async (req, res, next) => {
 // 截图功能 - 返回JPEG图片
 router.get('/screenshot/:userId/:pptId/:slideIndex?', async (req, res, next) => {
   try {
+    console.log('Screenshot request received:', req.params);
+    
     const { userId, pptId, slideIndex = 0 } = req.params;
     const slideIdx = parseInt(slideIndex);
     const fileName = `${pptId}.json`;
     const storageService = getStorageService();
 
+    console.log(`Generating screenshot for: ${userId}/${pptId}/${slideIdx}`);
+
     let pptData = null;
     
     // 获取PPT数据（复用现有逻辑）
     if (storageService === githubService && storageService.repositories) {
+      console.log('Checking GitHub repositories...');
       for (let i = 0; i < storageService.repositories.length; i++) {
         try {
           const result = await storageService.getFile(userId, fileName, i);
           if (result) {
             pptData = result.content;
+            console.log(`PPT data found in repository ${i}`);
             break;
           }
         } catch (error) {
@@ -488,46 +494,70 @@ router.get('/screenshot/:userId/:pptId/:slideIndex?', async (req, res, next) =>
         }
       }
     } else {
+      console.log('Checking memory storage...');
       const result = await storageService.getFile(userId, fileName);
       if (result) {
         pptData = result.content;
+        console.log('PPT data found in memory storage');
       }
     }
 
     // 如果GitHub失败，尝试内存存储fallback
     if (!pptData && storageService === githubService) {
+      console.log('Trying memory storage fallback...');
       try {
         const memoryResult = await memoryStorageService.getFile(userId, fileName);
         if (memoryResult) {
           pptData = memoryResult.content;
+          console.log('PPT data found in memory storage fallback');
         }
       } catch (memoryError) {
-        // 忽略内存存储错误
+        console.log('Memory storage fallback failed:', memoryError.message);
       }
     }
 
     if (!pptData) {
+      console.log('PPT not found');
       return res.status(404).json({ error: 'PPT not found' });
     }
 
     if (slideIdx >= pptData.slides.length || slideIdx < 0) {
+      console.log('Slide index out of bounds');
       return res.status(404).json({ error: 'Slide not found' });
     }
 
+    console.log('Generating HTML content...');
     // 生成HTML内容（复用现有函数）
     const htmlContent = generateSlideHTML(pptData, slideIdx, pptData.title);
     
+    console.log('Calling screenshot service...');
     // 生成截图
     const screenshot = await screenshotService.generateScreenshot(htmlContent);
     
+    console.log('Screenshot generated, sending response...');
+    
     // 返回图片
     res.setHeader('Content-Type', 'image/jpeg');
-    res.setHeader('Cache-Control', 'public, max-age=300'); // 5分钟缓存
+    res.setHeader('Cache-Control', 'public, max-age=60'); // 1分钟缓存，减少服务器压力
     res.setHeader('Content-Disposition', `inline; filename="${pptData.title}-${slideIdx + 1}.jpg"`);
     res.send(screenshot);
   } catch (error) {
-    console.error('Screenshot generation error:', error);
-    next(error);
+    console.error('Screenshot route error:', error);
+    console.error('Stack trace:', error.stack);
+    
+    // 返回一个简单的错误响应而不是抛出异常
+    try {
+      res.status(500).setHeader('Content-Type', 'application/json');
+      res.json({ 
+        error: 'Screenshot generation failed', 
+        message: error.message,
+        details: process.env.NODE_ENV === 'development' ? error.stack : undefined
+      });
+    } catch (responseError) {
+      console.error('Error sending error response:', responseError);
+      // 如果连错误响应都发送失败，调用next
+      next(error);
+    }
   }
 });