Upload public.js

backend/src/routes/public.js

@@ -778,94 +778,123 @@ 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);
+    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}`);
+    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...');
+      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}`);
+            console.log(`✅ PPT data found in repository ${i}`);
             break;
           }
         } catch (error) {
+          console.log(`❌ Repository ${i} check failed:`, error.message);
           continue;
         }
       }
     } 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');
+      console.log('📂 Checking memory storage...');
+      try {
+        const result = await storageService.getFile(userId, fileName);
+        if (result) {
+          pptData = result.content;
+          console.log('✅ PPT data found in memory storage');
+        }
+      } catch (error) {
+        console.log('❌ Memory storage check failed:', error.message);
       }
     }
 
     // 如果GitHub失败，尝试内存存储fallback
     if (!pptData && storageService === githubService) {
-      console.log('Trying memory storage fallback...');
+      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');
+          console.log('✅ PPT data found in memory storage fallback');
         }
       } catch (memoryError) {
-        console.log('Memory storage fallback failed:', memoryError.message);
+        console.log('❌ Memory storage fallback failed:', memoryError.message);
       }
     }
 
     if (!pptData) {
-      console.log('PPT not found');
-      return res.status(404).json({ error: 'PPT not found' });
+      console.log('❌ PPT not found anywhere');
+      
+      // 生成"PPT未找到"的错误图片
+      const errorImage = screenshotService.generateFallbackImage(960, 720, 'PPT未找到');
+      res.setHeader('Content-Type', 'image/svg+xml');
+      res.setHeader('Cache-Control', 'no-cache');
+      return res.send(errorImage);
     }
 
     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(`❌ Slide index out of bounds: ${slideIdx}/${pptData.slides.length}`);
+      
+      // 生成"幻灯片不存在"的错误图片
+      const errorImage = screenshotService.generateFallbackImage(960, 720, '幻灯片不存在');
+      res.setHeader('Content-Type', 'image/svg+xml');
+      res.setHeader('Cache-Control', 'no-cache');
+      return res.send(errorImage);
     }
 
-    console.log('Generating HTML content...');
+    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...');
+    console.log('🎯 Calling screenshot service...');
     // 生成截图
-    const screenshot = await screenshotService.generateScreenshot(htmlContent);
+    const screenshot = await screenshotService.generateScreenshot(htmlContent, {
+      format: 'jpeg',
+      quality: 90
+    });
+    
+    console.log(`✅ Screenshot generated successfully, size: ${screenshot.length} bytes`);
     
-    console.log('Screenshot generated, sending response...');
+    // 检查是否是SVG fallback（通过内容检测）
+    const isSvgFallback = screenshot.toString().includes('<svg');
+    
+    if (isSvgFallback) {
+      console.log('📋 Returning SVG fallback image');
+      res.setHeader('Content-Type', 'image/svg+xml');
+      res.setHeader('Cache-Control', 'no-cache');
+      res.setHeader('Content-Disposition', `inline; filename="${pptData.title}-${slideIdx + 1}-fallback.svg"`);
+    } else {
+      console.log('📸 Returning JPEG screenshot');
+      res.setHeader('Content-Type', 'image/jpeg');
+      res.setHeader('Cache-Control', 'public, max-age=300'); // 5分钟缓存
+      res.setHeader('Content-Disposition', `inline; filename="${pptData.title}-${slideIdx + 1}.jpg"`);
+    }
     
-    // 返回图片
-    res.setHeader('Content-Type', 'image/jpeg');
-    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 route error:', 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
-      });
+      // 生成错误截图
+      const errorImage = screenshotService.generateFallbackImage(960, 720, '截图生成失败');
+      res.setHeader('Content-Type', 'image/svg+xml');
+      res.setHeader('Cache-Control', 'no-cache');
+      res.setHeader('Content-Disposition', 'inline; filename="error.svg"');
+      res.send(errorImage);
     } catch (responseError) {
-      console.error('Error sending error response:', 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);
     }