feat: 实现统一日志系统和维护模式功能

backend/middleware/requestLogger.js

@@ -0,0 +1,40 @@
+/**
+ * HTTP 请求日志中间件
+ * 为每个请求生成唯一 ID，记录请求/响应信息
+ */
+
+const logger = require('../utils/logger');
+const crypto = require('crypto');
+
+/**
+ * 请求日志中间件
+ * 记录每个 HTTP 请求的方法、URL、状态码、耗时、用户ID 等信息
+ */
+const requestLogger = (req, res, next) => {
+  const requestId = crypto.randomBytes(4).toString('hex');
+  const startTime = Date.now();
+
+  req.requestId = requestId;
+
+  res.on('finish', () => {
+    const duration = Date.now() - startTime;
+    const level = res.statusCode >= 500 ? 'error'
+      : res.statusCode >= 400 ? 'warn' : 'debug';
+
+    logger[level](`${req.method} ${req.originalUrl}`, {
+      module: 'HTTP',
+      requestId,
+      method: req.method,
+      url: req.originalUrl,
+      statusCode: res.statusCode,
+      duration: `${duration}ms`,
+      ip: req.ip || req.connection.remoteAddress,
+      userAgent: req.get('User-Agent'),
+      userId: req.user?.userId || null,
+    });
+  });
+
+  next();
+};
+
+module.exports = requestLogger;