fix: 修复文件夹右键菜单问题 + 新增文件夹详情功能

修复内容:

1. 【文件夹右键菜单无法显示】
   - 问题: showFileContextMenu() 中仍有 `if (file.isDirectory) return` 阻止代码
   - 原因: 之前的修复脚本替换失败,代码仍在
   - 修复: 手动移除这行限制代码
   - 效果: 文件夹现在可以正常右键操作(重命名、删除、查看详情)

新功能:

2. 【文件夹详情查看】
   后端API (POST /api/files/folder-info):
   - 接收参数: path(当前路径), folderName(文件夹名称)
   - 计算文件夹总大小(递归统计所有文件)
   - 统计文件数量和子文件夹数量
   - 返回数据: name, path, size, fileCount, folderCount
   - 仅支持本地存储

   前端功能:
   - 右键菜单新增"查看详情"选项(仅文件夹显示)
   - 详情弹窗显示:
     * 文件夹名称
     * 文件夹路径
     * 总大小(格式化显示)
     * 文件数量
     * 子文件夹数量
   - 加载中状态提示
   - 错误处理和提示

使用方式:
1. 右键点击任意文件夹
2. 选择"查看详情"
3. 弹窗显示文件夹统计信息

技术改动:
- backend/server.js: +100行 (新增folder-info API)
- frontend/app.html: +40行 (详情弹窗UI + 菜单项)
- frontend/app.js: +30行 (状态 + showFolderInfo方法)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

backend/server.js

@@ -1133,6 +1133,101 @@ app.post('/api/files/mkdir', authMiddleware, async (req, res) => {
   }
 });
 
+// 获取文件夹详情(大小统计)
+app.post('/api/files/folder-info', authMiddleware, async (req, res) => {
+  const { path, folderName } = req.body;
+  let storage;
+
+  if (!folderName) {
+    return res.status(400).json({
+      success: false,
+      message: '缺少文件夹名称参数'
+    });
+  }
+
+  // 只支持本地存储
+  if (req.user.current_storage_type !== 'local') {
+    return res.status(400).json({
+      success: false,
+      message: '只有本地存储支持此功能'
+    });
+  }
+
+  try {
+    const { StorageInterface } = require('./storage');
+    const storageInterface = new StorageInterface(req.user);
+    storage = await storageInterface.connect();
+
+    // 构造文件夹路径
+    const basePath = path || '/';
+    const folderPath = basePath === '/' ? `/${folderName}` : `${basePath}/${folderName}`;
+    const fullPath = storage.getFullPath(folderPath);
+
+    // 检查是否存在且是文件夹
+    if (!fs.existsSync(fullPath)) {
+      return res.status(404).json({
+        success: false,
+        message: '文件夹不存在'
+      });
+    }
+
+    const stats = fs.statSync(fullPath);
+    if (!stats.isDirectory()) {
+      return res.status(400).json({
+        success: false,
+        message: '指定路径不是文件夹'
+      });
+    }
+
+    // 计算文件夹大小
+    const folderSize = storage.calculateFolderSize(fullPath);
+
+    // 计算文件数量
+    function countFiles(dirPath) {
+      let fileCount = 0;
+      let folderCount = 0;
+
+      const items = fs.readdirSync(dirPath, { withFileTypes: true });
+
+      for (const item of items) {
+        const itemPath = path.join(dirPath, item.name);
+
+        if (item.isDirectory()) {
+          folderCount++;
+          const subCounts = countFiles(itemPath);
+          fileCount += subCounts.fileCount;
+          folderCount += subCounts.folderCount;
+        } else {
+          fileCount++;
+        }
+      }
+
+      return { fileCount, folderCount };
+    }
+
+    const counts = countFiles(fullPath);
+
+    res.json({
+      success: true,
+      data: {
+        name: folderName,
+        path: folderPath,
+        size: folderSize,
+        fileCount: counts.fileCount,
+        folderCount: counts.folderCount
+      }
+    });
+  } catch (error) {
+    console.error('[获取文件夹详情失败]', error);
+    res.status(500).json({
+      success: false,
+      message: '获取文件夹详情失败: ' + error.message
+    });
+  } finally {
+    if (storage) await storage.end();
+  }
+});
+
 // 删除文件
 app.post('/api/files/delete', authMiddleware, async (req, res) => {
   const { fileName, path } = req.body;

frontend/app.html

@@ -856,6 +856,50 @@
       </div>
     </div>
 
+    <!-- 文件夹详情模态框 -->
+    <div v-if="showFolderInfoModal" class="modal-overlay" @mousedown.self="handleModalMouseDown" @mouseup.self="handleModalMouseUp('showFolderInfoModal')">
+      <div class="modal-content" @click.stop>
+        <h3 style="margin-bottom: 20px;">
+          <i class="fas fa-folder"></i> 文件夹详情
+        </h3>
+        <div v-if="folderInfo" style="background: #f9f9f9; padding: 20px; border-radius: 8px;">
+          <div style="margin-bottom: 15px;">
+            <strong style="color: #666;">名称:</strong>
+            <div style="margin-top: 5px; font-size: 16px;">{{ folderInfo.name }}</div>
+          </div>
+          <div style="margin-bottom: 15px;">
+            <strong style="color: #666;">路径:</strong>
+            <div style="margin-top: 5px; color: #667eea;">{{ folderInfo.path }}</div>
+          </div>
+          <div style="margin-bottom: 15px;">
+            <strong style="color: #666;">总大小:</strong>
+            <div style="margin-top: 5px; font-size: 18px; font-weight: 600; color: #667eea;">
+              {{ formatFileSize(folderInfo.size) }}
+            </div>
+          </div>
+          <div style="display: flex; gap: 20px;">
+            <div style="flex: 1;">
+              <strong style="color: #666;">文件数:</strong>
+              <div style="margin-top: 5px; font-size: 16px;">{{ folderInfo.fileCount }} 个</div>
+            </div>
+            <div style="flex: 1;">
+              <strong style="color: #666;">子文件夹:</strong>
+              <div style="margin-top: 5px; font-size: 16px;">{{ folderInfo.folderCount }} 个</div>
+            </div>
+          </div>
+        </div>
+        <div v-else style="text-align: center; padding: 40px; color: #999;">
+          <i class="fas fa-spinner fa-spin" style="font-size: 32px;"></i>
+          <div style="margin-top: 10px;">加载中...</div>
+        </div>
+        <div style="margin-top: 20px;">
+          <button class="btn btn-secondary" @click="showFolderInfoModal = false; folderInfo = null" style="width: 100%;">
+            <i class="fas fa-times"></i> 关闭
+          </button>
+        </div>
+      </div>
+    </div>
+
     <!-- 分享所有文件模态框 -->
     <div v-if="showShareAllModal" class="modal-overlay" @mousedown.self="handleModalMouseDown" @mouseup.self="handleModalMouseUp('showShareAllModal')">
       <div class="modal-content" @click.stop>
@@ -1726,6 +1770,9 @@
       <div class="context-menu-item" @click="contextMenuAction('rename')">
         <i class="fas fa-edit"></i> 重命名
       </div>
+      <div v-if="contextMenuFile.isDirectory" class="context-menu-item" @click="contextMenuAction('info')">
+        <i class="fas fa-info-circle"></i> 查看详情
+      </div>
       <div v-if="!contextMenuFile.isDirectory" class="context-menu-item" @click="contextMenuAction('share')">
         <i class="fas fa-share"></i> 分享
       </div>

frontend/app.js

@@ -85,6 +85,10 @@ createApp({
         folderName: ""
       },
 
+      // 文件夹详情
+      showFolderInfoModal: false,
+      folderInfo: null,
+
       // 上传
       showUploadModal: false,
       uploadProgress: 0,
@@ -903,6 +907,34 @@ handleDragLeave(e) {
       }
     },
 
+    // 显示文件夹详情
+    async showFolderInfo(file) {
+      if (!file.isDirectory) {
+        this.showToast('error', '错误', '只能查看文件夹详情');
+        return;
+      }
+
+      this.showFolderInfoModal = true;
+      this.folderInfo = null; // 先清空,显示加载中
+
+      try {
+        const response = await axios.post(`${this.apiBase}/api/files/folder-info`, {
+          path: this.currentPath,
+          folderName: file.name
+        }, {
+          headers: { 'Authorization': `Bearer ${this.token}` }
+        });
+
+        if (response.data.success) {
+          this.folderInfo = response.data.data;
+        }
+      } catch (error) {
+        console.error('[获取文件夹详情失败]', error);
+        this.showToast('error', '错误', error.response?.data?.message || '获取文件夹详情失败');
+        this.showFolderInfoModal = false;
+      }
+    },
+
     confirmDeleteFile(file) {
       const fileType = file.isDirectory ? '文件夹' : '文件';
       const warning = file.isDirectory ? "\n⚠️ 警告：文件夹内所有文件将被永久删除！" : "";
@@ -915,8 +947,7 @@ handleDragLeave(e) {
 
     // 显示右键菜单（PC端）
     showFileContextMenu(file, event) {
-      if (file.isDirectory) return; // 文件夹不显示菜单
-      
+      // 文件和文件夹都可以显示右键菜单
       event.preventDefault();
       this.contextMenuFile = file;
       this.contextMenuX = event.clientX;