后端: 添加文件预览API

backend/src/index.js

@@ -4,6 +4,7 @@ const authRoutes = require('./routes/auth');
 const fileRoutes = require('./routes/files');
 const shareRoutes = require('./routes/share');
 const syncRoutes = require('./routes/sync');
+const previewRoutes = require('./routes/preview');
 const errorHandler = require('./middleware/errorHandler');
 
 const app = express();
@@ -17,6 +18,7 @@ app.use('/api/auth', authRoutes);
 app.use('/api/files', fileRoutes);
 app.use('/api/share', shareRoutes);
 app.use('/api/sync', syncRoutes);
+app.use('/api/preview', previewRoutes);
 
 // Error handler
 app.use(errorHandler);

backend/src/routes/preview.js

@@ -0,0 +1,84 @@
+const express = require('express');
+const path = require('path');
+const fs = require('fs');
+const db = require('../db');
+
+const router = express.Router();
+
+// Get preview info
+router.get('/:id', (req, res) => {
+  const token = req.headers.authorization?.replace('Bearer ', '');
+  if (!token) return res.status(401).json({ error: 'No token' });
+  
+  try {
+    const jwt = require('jsonwebtoken');
+    const decoded = jwt.verify(token, process.env.JWT_SECRET || 'clouddisk-secret-key');
+    
+    const file = db.query(
+      'SELECT * FROM files WHERE id = ? AND user_id = ? AND is_folder = 0',
+      [req.params.id, decoded.userId]
+    );
+    
+    if (file.length === 0) {
+      return res.status(404).json({ error: 'File not found' });
+    }
+    
+    const f = file[0];
+    
+    // Determine if file is previewable
+    const previewableTypes = ['jpg', 'jpeg', 'png', 'gif', 'pdf', 'txt', 'md'];
+    const ext = f.name.split('.').pop().toLowerCase();
+    const isPreviewable = previewableTypes.includes(ext);
+    
+    res.json({
+      fileId: f.id,
+      filename: f.name,
+      size: f.size,
+      type: ext,
+      isPreviewable,
+      canDownload: true
+    });
+  } catch (error) {
+    res.status(500).json({ error: error.message });
+  }
+});
+
+// Get preview content (for text files)
+router.get('/:id/content', (req, res) => {
+  const token = req.headers.authorization?.replace('Bearer ', '');
+  if (!token) return res.status(401).json({ error: 'No token' });
+  
+  try {
+    const jwt = require('jsonwebtoken');
+    const decoded = jwt.verify(token, process.env.JWT_SECRET || 'clouddisk-secret-key');
+    
+    const file = db.query(
+      'SELECT * FROM files WHERE id = ? AND user_id = ? AND is_folder = 0',
+      [req.params.id, decoded.userId]
+    );
+    
+    if (file.length === 0) {
+      return res.status(404).json({ error: 'File not found' });
+    }
+    
+    const f = file[0];
+    const ext = f.name.split('.').pop().toLowerCase();
+    
+    // Only allow text files
+    if (!['txt', 'md', 'json', 'js', 'ts', 'html', 'css'].includes(ext)) {
+      return res.status(400).json({ error: 'File type not supported for preview' });
+    }
+    
+    // Limit preview size (100KB)
+    if (f.size > 100 * 1024) {
+      return res.status(400).json({ error: 'File too large for preview' });
+    }
+    
+    const content = fs.readFileSync(f.path, 'utf8');
+    res.json({ content });
+  } catch (error) {
+    res.status(500).json({ error: error.message });
+  }
+});
+
+module.exports = router;