backend: 拆分API路由至router目录并重构存储模块，优化数据库交互与历史消息查询功能

router/api.js

@@ -0,0 +1,41 @@
+import express from 'express';
+import { loadHistory, getDatabaseState } from "../utils/storage.js";
+import { onlineList } from '../data.js';
+
+const router = express.Router();
+
+router.get("/online", (req, res) => {
+    res.status(200).send({
+        online: onlineList.length,
+        user: onlineList
+    })
+})
+
+router.get("/history", (req, res) => {
+    if (!getDatabaseState()) {
+        res.status(500).send({
+            status: 500,
+            msg: "database is not ready",
+            data: null
+        })
+    }
+    if (!req.query.limit || isNaN(req.query.limit) || req.query.limit <= 0 || req.query.limit > 100) {
+        req.query.limit = 10;
+    }
+    loadHistory(req.query.limit).then((data) => {
+        res.status(200).send({
+            status: 200,
+            msg: "success",
+            data: data
+        })
+    }).catch((err) => {
+        logger.error(`database error: ${err}`)
+        res.status(500).send({
+            status: 500,
+            msg: "database error",
+            data: null
+        })
+    })
+})
+
+export default router;