From 4455ba598f491ab59e11f4206c39b77fcb064b31 Mon Sep 17 00:00:00 2001
From: david_bai <david_bai@example.com>
Date: Sat, 21 Jun 2025 17:08:11 +0800
Subject: [PATCH] translate comment

---
 backend/ecosystem.config.js             |  4 +--
 backend/scripts/export-tracking-data.js | 26 ++++++++---------
 backend/src/config/env.ts               | 12 ++++----
 backend/src/config/server.ts            | 12 ++++----
 backend/src/routes/api.ts               | 20 ++++++-------
 backend/src/server.ts                   |  8 ++---
 backend/src/services/rateLimit.ts       |  6 ++--
 backend/src/services/redis.ts           | 12 ++++----
 backend/src/services/room.ts            | 39 +++++++++++++------------
 backend/src/socket/handlers.ts          | 38 ++++++++++++------------
 backend/src/types/socket.ts             |  2 +-
 11 files changed, 90 insertions(+), 89 deletions(-)

diff --git a/backend/ecosystem.config.js b/backend/ecosystem.config.js
index c8e832d..1f20e50 100644
--- a/backend/ecosystem.config.js
+++ b/backend/ecosystem.config.js
@@ -1,7 +1,7 @@
 module.exports = {
   apps: [{
     name: "signaling-server",
-    script: "./dist/server.js",  // 指向编译后的文件
+    script: "./dist/server.js",  // Point to the compiled file
     watch: false,
     env: {
       "NODE_ENV": "production",
@@ -13,6 +13,6 @@ module.exports = {
     max_memory_restart: "500M",
     instances: 1,
     exec_mode: "fork",
-    group: "ssl-cert"  // 添加这行，指定进程运行的组
+    group: "ssl-cert"  // Add this line to specify the group the process runs as
   }]
 }
\ No newline at end of file
diff --git a/backend/scripts/export-tracking-data.js b/backend/scripts/export-tracking-data.js
index 1621018..692adf6 100644
--- a/backend/scripts/export-tracking-data.js
+++ b/backend/scripts/export-tracking-data.js
@@ -3,7 +3,7 @@ const Redis = require('ioredis');
 const fs = require('fs/promises');
 const path = require('path');
 
-// Redis 客户端配置
+// Redis client configuration
 const redis = new Redis({
   host: 'localhost',
   port: 6379,
@@ -15,16 +15,16 @@ async function exportTrackingData() {
     const fileName = `tracking-data-${timestamp}.txt`;
     const filePath = path.join(__dirname, '../logs', fileName);
 
-    // 创建输出内容
+    // Create output content
     let output = '=== Tracking Data Export ===\n';
     output += `Generated at: ${new Date().toISOString()}\n\n`;
 
-    // 1. 获取所有来源
+    // 1. Get all sources
     const sources = await redis.smembers('referrers:sources');
     output += '=== Referral Sources ===\n';
     output += sources.join(', ') + '\n\n';
 
-    // 2. 获取总计数
+    // 2. Get total counts
     const totalCounts = await redis.hgetall('referrers:count');
     output += '=== Total Counts by Source ===\n';
     for (const [source, count] of Object.entries(totalCounts)) {
@@ -32,21 +32,21 @@ async function exportTrackingData() {
     }
     output += '\n';
 
-    // 3. 获取每日统计数据并按日期排序
+    // 3. Get daily statistics and sort by date
     output += '=== Daily Statistics ===\n';
     const dailyKeys = await redis.keys('referrers:daily:*');
 
-    // 将 key 转换为包含日期对象的数组,并按日期排序
+    // Convert keys to an array of objects with dates and sort by date
     const dailyData = await Promise.all(dailyKeys.map(async (key) => {
       const date = key.split(':')[2];
       const dailyStats = await redis.hgetall(key);
         return { date: new Date(date), data: dailyStats };
     }));
 
-    dailyData.sort((a, b) => b.date.getTime() - a.date.getTime()); // 按日期降序排序(最近到最远)
+    dailyData.sort((a, b) => b.date.getTime() - a.date.getTime()); // Sort by date in descending order (most recent to oldest)
 
     for (const item of dailyData) {
-        const dateString = item.date.toISOString().split('T')[0]; //日期格式化字符串
+        const dateString = item.date.toISOString().split('T')[0]; // Format date string
         output += `\nDate: ${dateString}\n`;
         for (const [source, count] of Object.entries(item.data)) {
         output += `  ${source}: ${count}\n`;
@@ -55,14 +55,14 @@ async function exportTrackingData() {
 
     output += '\n';
 
-    // 5. 添加基本统计信息
+    // 5. Add basic statistics
     output += '\n=== Summary ===\n';
     output += `Total Sources: ${sources.length}\n`;
     
-    // 确保日志目录存在
+    // Ensure the log directory exists
     await fs.mkdir(path.join(__dirname, '../logs'), { recursive: true });
     
-    // 写入文件
+    // Write to file
     await fs.writeFile(filePath, output, 'utf8');
     
     console.log(`Data exported successfully to: ${filePath}`);
@@ -71,7 +71,7 @@ async function exportTrackingData() {
     console.log(output.slice(0, 500) + '...');
     console.log('='.repeat(50));
 
-    // 关闭 Redis 连接
+    // Close Redis connection
     await redis.quit();
 
   } catch (error) {
@@ -80,5 +80,5 @@ async function exportTrackingData() {
   }
 }
 
-// 执行导出
+// Execute export
 exportTrackingData();
diff --git a/backend/src/config/env.ts b/backend/src/config/env.ts
index 95c1cf3..5de934d 100644
--- a/backend/src/config/env.ts
+++ b/backend/src/config/env.ts
@@ -1,7 +1,7 @@
 import dotenv from "dotenv";
 import path from "path";
 
-// 定义配置对象的类型
+// Define the type for the configuration object
 interface AppConfig {
   PORT: number;
   CORS_ORIGIN: string;
@@ -12,23 +12,23 @@ interface AppConfig {
   };
 }
 
-// 根据环境加载对应的.env文件
+// Load the corresponding .env file based on the environment
 dotenv.config({
   path:
     process.env.NODE_ENV === "production"
       ? path.resolve(process.cwd(), ".env.production.local")
       : path.resolve(process.cwd(), ".env.development.local"),
 });
-// 检查必要的 Redis 环境变量
+// Check for necessary Redis environment variables
 if (!process.env.REDIS_HOST) {
   console.error("FATAL ERROR: REDIS_HOST environment variable is not set.");
-  process.exit(1); // 或者抛出错误 new Error("REDIS_HOST environment variable is not set.");
+  process.exit(1); // Or throw an error: new Error("REDIS_HOST environment variable is not set.");
 }
 if (!process.env.REDIS_PORT) {
   console.error("FATAL ERROR: REDIS_PORT environment variable is not set.");
-  process.exit(1); // 或者抛出错误 new Error("REDIS_PORT environment variable is not set.");
+  process.exit(1); // Or throw an error: new Error("REDIS_PORT environment variable is not set.");
 }
-// 导出类型安全的配置对象
+// Export the type-safe configuration object
 export const CONFIG: AppConfig = {
   PORT: parseInt(process.env.BACKEND_PORT || "3001", 10),
   CORS_ORIGIN: process.env.CORS_ORIGIN!,
diff --git a/backend/src/config/server.ts b/backend/src/config/server.ts
index 1e01d9b..0afaaa9 100644
--- a/backend/src/config/server.ts
+++ b/backend/src/config/server.ts
@@ -1,6 +1,6 @@
 import { CorsOptions } from 'cors';
 import { CONFIG } from './env';
-// 配置 CORS
+// Configure CORS
 export const corsOptions: CorsOptions = CONFIG.NODE_ENV === 'production' 
   ? {
       origin: CONFIG.CORS_ORIGIN,
@@ -9,23 +9,23 @@ export const corsOptions: CorsOptions = CONFIG.NODE_ENV === 'production'
       allowedHeaders: ['Content-Type', 'Authorization']
     }
   : {
-    origin: true, // 开发环境允许所有源
+    origin: true, // Allow all origins in development environment
     credentials: true,
     methods: ['GET', 'POST', 'OPTIONS'],
     allowedHeaders: ['Content-Type', 'Authorization']
   };
-// 配置 Socket.IO 的 CORS
+// Configure CORS for Socket.IO
 export const corsWSOptions = CONFIG.NODE_ENV === 'production'
   ? {
-      origin: CONFIG.CORS_ORIGIN,// 允许的源，替换为你的Next.js应用的URL
+      origin: CONFIG.CORS_ORIGIN, // Allowed origin, replace with your Next.js application's URL
       methods: ['GET', 'POST'],
       credentials: true
     }
   : {
-      // 开发环境下允许多个源
+      // Allow multiple origins in development environment
       origin: [
         CONFIG.CORS_ORIGIN,
-        /^http:\/\/192\.168\.\d+\.\d+:3000$/,// 匹配所有 192.168.x.x:3000 格式的局域网地址
+        /^http:\/\/192\.168\.\d+\.\d+:3000$/, // Match all LAN addresses in the format 192.168.x.x:3000
       ],
       methods: ['GET', 'POST'],
       credentials: true
diff --git a/backend/src/routes/api.ts b/backend/src/routes/api.ts
index bdfc375..126ded5 100644
--- a/backend/src/routes/api.ts
+++ b/backend/src/routes/api.ts
@@ -20,7 +20,7 @@ import { ReferrerTrack, LogMessage } from "../types/room";
 
 const router = Router();
 
-// 定义接口提高代码可读性和类型安全性
+// Define interfaces to improve code readability and type safety
 interface CreateRoomRequest {
   roomId: string;
 }
@@ -29,7 +29,7 @@ interface CheckRoomRequest {
   roomId: string;
 }
 
-// 创建房间的路由处理函数
+// Route handler for creating a room
 const createRoomHandler: RequestHandler<{}, any, CreateRoomRequest> = async (
   req,
   res
@@ -58,7 +58,7 @@ const createRoomHandler: RequestHandler<{}, any, CreateRoomRequest> = async (
   }
 };
 
-// 获取房间的路由处理函数
+// Route handler for getting a room
 const getRoomHandler: RequestHandler = async (req, res) => {
   try {
     const roomId = await roomService.getAvailableRoomId();
@@ -70,7 +70,7 @@ const getRoomHandler: RequestHandler = async (req, res) => {
   }
 };
 
-// 检查房间的路由处理函数
+// Route handler for checking a room
 const checkRoomHandler: RequestHandler<{}, any, CheckRoomRequest> = async (
   req,
   res
@@ -90,7 +90,7 @@ const checkRoomHandler: RequestHandler<{}, any, CheckRoomRequest> = async (
   }
 };
 
-// 设置跟踪的路由处理函数
+// Route handler for setting tracking
 const setTrackHandler: RequestHandler<{}, any, ReferrerTrack> = async (
   req,
   res
@@ -102,16 +102,16 @@ const setTrackHandler: RequestHandler<{}, any, ReferrerTrack> = async (
 
   try {
     const { ref, timestamp, path } = req.body;
-    // 按日期统计
+    // Statistics by date
     const date = new Date(timestamp).toISOString().split("T")[0];
     const dailyKey = `referrers:daily:${date}`;
     const thirtyDaysInSeconds = 30 * 24 * 60 * 60;
 
-    // 使用MULTI确保hincrby和expire的原子性
+    // Use MULTI to ensure atomicity of hincrby and expire
     await redis
       .multi()
       .hincrby(dailyKey, ref, 1) // \"referrers:daily:2024-01-20\" : { \"producthunt\": \"5\", \"twitter\": \"3\" }
-      .expire(dailyKey, thirtyDaysInSeconds) // 设置30天过期
+      .expire(dailyKey, thirtyDaysInSeconds) // Set a 30-day expiration
       .exec();
 
     res.status(200).json({ success: true });
@@ -121,7 +121,7 @@ const setTrackHandler: RequestHandler<{}, any, ReferrerTrack> = async (
   }
 };
 
-// 日志调试的路由处理函数
+// Route handler for log debugging
 const logsDebugHandler: RequestHandler<{}, any, LogMessage> = async (
   req,
   res
@@ -136,7 +136,7 @@ const logsDebugHandler: RequestHandler<{}, any, LogMessage> = async (
   }
 };
 
-// 注册路由
+// Register routes
 router.post("/api/create_room", createRoomHandler);
 router.get("/api/get_room", getRoomHandler);
 router.post("/api/check_room", checkRoomHandler);
diff --git a/backend/src/server.ts b/backend/src/server.ts
index 8d1d4a2..25970b1 100644
--- a/backend/src/server.ts
+++ b/backend/src/server.ts
@@ -1,14 +1,14 @@
-import express from "express"; //express: 用于创建一个简洁且灵活的Node.js web应用框架
+import express from "express"; // express: A minimalist and flexible Node.js web application framework
 import cors from "cors";
 import http from "http";
-import { Server } from "socket.io"; //实时通信库，基于WebSocket协议，实现双向通信
+import { Server } from "socket.io"; // socket.io: A library for real-time web applications, enables real-time, bi-directional communication between web clients and servers.
 import { CONFIG } from "./config/env";
 import { corsOptions, corsWSOptions } from "./config/server";
 import apiRouter from "./routes/api";
 import { setupSocketHandlers } from "./socket/handlers";
 
-const app = express(); //创建一个Express应用
-app.use(cors(corsOptions)); // 添加 CORS 中间件
+const app = express(); // Create an Express application
+app.use(cors(corsOptions)); // Add CORS middleware
 app.use(express.json());
 app.use(apiRouter);
 
diff --git a/backend/src/services/rateLimit.ts b/backend/src/services/rateLimit.ts
index a341cc4..48c1469 100644
--- a/backend/src/services/rateLimit.ts
+++ b/backend/src/services/rateLimit.ts
@@ -20,8 +20,8 @@
 import { redis } from './redis';
 
 const RATE_LIMIT_PREFIX = 'ratelimit:join:';
-const RATE_WINDOW = 5; // 5秒时间窗口
-const RATE_LIMIT = 2;  // 允许的最大请求次数
+const RATE_WINDOW = 5; // 5-second time window
+const RATE_LIMIT = 2;  // Maximum number of requests allowed
 
 export async function checkRateLimit(ip: string): Promise<{
   allowed: boolean;
@@ -32,7 +32,7 @@ export async function checkRateLimit(ip: string): Promise<{
   const now = Date.now();
   const windowStart = now - (RATE_WINDOW * 1000);
 
-  // 使用 Redis 的 MULTI 命令开启事务
+  // Use Redis's MULTI command to start a transaction
   const pipeline = redis.pipeline();
   
   // 1. Add current request's timestamp
diff --git a/backend/src/services/redis.ts b/backend/src/services/redis.ts
index cdcea8f..7afc370 100644
--- a/backend/src/services/redis.ts
+++ b/backend/src/services/redis.ts
@@ -1,21 +1,21 @@
 import { Redis } from 'ioredis';
 import { CONFIG } from '../config/env';
-// 房间前缀和过期时间（秒）
+// Room prefix and expiration time (seconds)
 export const ROOM_PREFIX = 'room:';
 export const SOCKET_PREFIX = 'socket:';
 export const ROOM_EXPIRY = 3600 * 24; // 24 hours
-// Redis 配置选项
+// Redis configuration options
 const redisConfig = {
   host: CONFIG.REDIS.HOST,
   port: CONFIG.REDIS.PORT,
-  // Redis 持久化配置需要在 redis.conf 中设置，而不是在客户端
-  // appendonly: 'yes',// 启用 AOF 持久化
-  // save: '900 1 300 10',// 启用 RDB 快照
+  // Redis persistence configuration needs to be set in redis.conf, not in the client
+  // appendonly: 'yes',// Enable AOF persistence
+  // save: '900 1 300 10',// Enable RDB snapshot
 };
 
 export const redis = new Redis(redisConfig);
 
-// 可以在这里添加连接事件监听
+// Connection event listeners can be added here
 redis.on('connect', () => {
   console.log('Redis connected successfully');
 });
diff --git a/backend/src/services/room.ts b/backend/src/services/room.ts
index f52a133..6e12f66 100644
--- a/backend/src/services/room.ts
+++ b/backend/src/services/room.ts
@@ -29,7 +29,7 @@ import { redis, ROOM_PREFIX, SOCKET_PREFIX, ROOM_EXPIRY } from './redis';
 const MAX_NUMERIC_ID_ATTEMPTS = 10;
 const MAX_ALPHANUMERIC_ID_ATTEMPTS = 50;
 
-// 生成随机房间号--4位数字
+// Generate a random 4-digit numeric room ID
 function generateNumericRoomId(length: number = 4): string {
   let id = '';
   for (let i = 0; i < length; i++) {
@@ -37,6 +37,7 @@ function generateNumericRoomId(length: number = 4): string {
   }
   return id;
 }
+// Generate a random 4-character alphanumeric room ID
 function generateAlphanumericRoomId(length: number = 4): string {
   const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
   let result = '';
@@ -46,11 +47,11 @@ function generateAlphanumericRoomId(length: number = 4): string {
   }
   return result;
 }
-// 检查房间是否存在
+// Check if a room exists
 export async function isRoomExist(roomId: string): Promise<boolean> {
-  return await redis.hexists(ROOM_PREFIX + roomId, 'created_at') === 1;//hset和hexists方法操作哈希,created_at是字段名
+  return await redis.hexists(ROOM_PREFIX + roomId, 'created_at') === 1; // hset and hexists operate on hashes, 'created_at' is the field name
 }
-// 创建新房间
+// Create a new room
 // (Hash)
 // "room:1234" : {
 //   "created_at": "1705123456789"
@@ -59,16 +60,16 @@ export async function createRoom(roomId: string): Promise<void> {
   const roomKey = ROOM_PREFIX + roomId;
   const socketsKey = `${roomKey}:sockets`;
   await redis.multi()
-    .hset(roomKey, 'created_at', Date.now())//设置hash，存储房间的创建时间；
-    .expire(roomKey, ROOM_EXPIRY)//设置过期时间
+    .hset(roomKey, 'created_at', Date.now()) // Set hash to store the room's creation time
+    .expire(roomKey, ROOM_EXPIRY) // Set expiration time
     .expire(socketsKey, ROOM_EXPIRY)
     .exec();
 }
-// 删除房间
+// Delete a room
 export async function deleteRoom(roomId: string): Promise<void> {
   await redis.del(ROOM_PREFIX + roomId);
 }
-// 刷新房间过期时间
+// Refresh a room's expiration time
 export async function refreshRoom(roomId: string, expiry: number = 0): Promise<void> {
   const actualExpiry = expiry > 0 ? expiry : ROOM_EXPIRY;
   const roomKey = ROOM_PREFIX + roomId;
@@ -79,7 +80,7 @@ export async function refreshRoom(roomId: string, expiry: number = 0): Promise<v
     .expire(socketsKey, actualExpiry)
     .exec();
 }
-// 获取可用房间号
+// Get an available room ID
 export async function getAvailableRoomId(): Promise<string> {
   let roomId: string;
   let attempts = 0;
@@ -106,32 +107,32 @@ export async function getAvailableRoomId(): Promise<string> {
   }
   return roomId;
 }
-// 将socket.id与房间号绑定
+// Bind a socket.id to a room ID
 export async function bindSocketToRoom(socketId: string, roomId: string): Promise<void> {
   await redis.multi()
-    //字符串，存储与该socket ID相关联的房间号,"socket:abcd1234" : "1234"
+    // String, stores the room ID associated with this socket ID, e.g., "socket:abcd1234" : "1234"
     .set(SOCKET_PREFIX + socketId, roomId, 'EX', ROOM_EXPIRY+3600) // Set with expiry
-    //添加集合，房间内的 Socket 列表 (Set),"room:1234:sockets" : ["socket1", "socket2", ...]
+    // Set, list of sockets in the room, e.g., "room:1234:sockets" : ["socket1", "socket2", ...]
     .sadd(ROOM_PREFIX + roomId + ':sockets', socketId)
     .exec();
 }
-// 获取socket.id对应的房间号
+// Get the room ID for a given socket.id
 export async function getRoomBySocketId(socketId: string): Promise<string | null> {
   return await redis.get(SOCKET_PREFIX + socketId);
 }
-// 解绑socket.id与房间号
+// Unbind a socket.id from a room ID
 export async function unbindSocketFromRoom(socketId: string, roomId: string): Promise<void> {
   await redis.multi()
-    .del(SOCKET_PREFIX + socketId)//解绑socket ID与房间号
-    .srem(ROOM_PREFIX + roomId + ':sockets', socketId)//从房间的集合中移除socket ID
+    .del(SOCKET_PREFIX + socketId) // Unbind socket ID from room ID
+    .srem(ROOM_PREFIX + roomId + ':sockets', socketId) // Remove socket ID from the room's set
     .exec();
 }
-// 检查房间是否为空
+// Check if a room is empty
 export async function isRoomEmpty(roomId: string): Promise<boolean> {
-  const count = await redis.scard(ROOM_PREFIX + roomId + ':sockets');//返回集合中元素的数量
+  const count = await redis.scard(ROOM_PREFIX + roomId + ':sockets'); // Returns the number of elements in the set
   return count === 0;
 }
-// 检查房间连接数
+// Get the number of connections in a room
 export async function roomNumOfConnection(roomId: string): Promise<number> {
   return await redis.scard(ROOM_PREFIX + roomId + ':sockets');
 }
\ No newline at end of file
diff --git a/backend/src/socket/handlers.ts b/backend/src/socket/handlers.ts
index 5ba9181..b4fbf8a 100644
--- a/backend/src/socket/handlers.ts
+++ b/backend/src/socket/handlers.ts
@@ -2,12 +2,12 @@ import { Server, Socket } from 'socket.io';
 import * as roomService from '../services/room';
 import { JoinData, SignalingData, InitiatorData, RecipientData } from '../types/socket';
 import { checkRateLimit } from '../services/rateLimit';
-// 房间管理：
-// 使用 roomId 进行广播消息（socket.to(roomId).emit()）
-// 场景：新用户加入通知、房间状态更新等
-// WebRTC 信令：
-// 使用 peerId 进行点对点通信（socket.to(peerId).emit()）
-// 场景：offer、answer、ice-candidate 等 WebRTC 连接建立过程中的所有信令
+// Room Management:
+// Use roomId to broadcast messages (socket.to(roomId).emit())
+// Scenarios: Notifying new user joined, room status updates, etc.
+// WebRTC Signaling:
+// Use peerId for peer-to-peer communication (socket.to(peerId).emit())
+// Scenarios: All signaling during WebRTC connection setup, like offer, answer, ice-candidate.
 export function setupSocketHandlers(io: Server): void {
   io.on('connection', (socket: Socket) => {
     console.log('New client connected:', socket.id);
@@ -15,10 +15,10 @@ export function setupSocketHandlers(io: Server): void {
     socket.on('join', async (data: JoinData) => {
       const { roomId: targetRoomId } = data; // Renamed for clarity
       try {
-        // 获取客户端IP
+        // Get client IP
         const clientIp = socket.handshake.headers['x-forwarded-for'] || 
                         socket.handshake.address;
-        // 检查频率限制
+        // Check rate limit
         const rateLimitCheck = await checkRateLimit(clientIp as string);
         if (!rateLimitCheck.allowed) {
           socket.emit('joinResponse', {
@@ -35,16 +35,16 @@ export function setupSocketHandlers(io: Server): void {
         }
         
         const existingRoomId = await roomService.getRoomBySocketId(socket.id);
-        if (!existingRoomId) {//socket.id不在房间里面 才允许新连接进入房间
+        if (!existingRoomId) { // Only allow new connection to join if the socket.id is not already in a room
           socket.join(targetRoomId);
           console.log(`Client ${socket.id} joined room ${targetRoomId}`);
           await roomService.bindSocketToRoom(socket.id, targetRoomId);
         }
         
         await roomService.refreshRoom(targetRoomId);
-        // 通知用户加入成功
+        // Notify the user that the join was successful
         socket.emit('joinResponse', { success: true, message: 'Successfully joined room', roomId: targetRoomId });
-        // 通知房间内所有其他用户有新成员加入
+        // Notify all other users in the room that a new member has joined
         socket.to(targetRoomId).emit('ready', { peerId: socket.id });
       } catch (error) {
         console.error('Error joining room:', error);
@@ -55,16 +55,16 @@ export function setupSocketHandlers(io: Server): void {
         });
       }
     });
-    // 处理WebRTC信令--直接转发
-    // offer, answer, ice-candidate: 这些事件处理WebRTC连接的信令。它们负责转发客户端之间的连接请求和网络协商消息。
-    // offer: 当一个客户端发起连接请求时，会发送一个offer给服务器，服务器将其转发给相同房间中的其他客户端。
-    // answer: 被邀请的客户端接收到offer后，生成一个answer，通过服务器返回给发起连接的客户端。
-    // ice-candidate: 当WebRTC需要穿透NAT防火墙时，会生成ICE候选者，客户端通过服务器相互交换这些信息，帮助建立P2P连接。
+    // Handle WebRTC signaling - direct forwarding
+    // offer, answer, ice-candidate: These events handle WebRTC connection signaling. They are responsible for forwarding connection requests and network negotiation messages between clients.
+    // offer: When a client initiates a connection request, it sends an offer to the server, which forwards it to other clients in the same room.
+    // answer: The invited client receives the offer, generates an answer, and sends it back to the initiating client via the server.
+    // ice-candidate: When WebRTC needs to traverse NAT firewalls, it generates ICE candidates. Clients exchange this information through the server to help establish a P2P connection.
     socket.on('offer', (data: SignalingData) => {
       socket.to(data.peerId).emit('offer', {
         offer: data.offer,
         from: data.from,
-        peerId: socket.id // 发送方的ID
+        peerId: socket.id // Sender's ID
       });
     });
 
@@ -83,13 +83,13 @@ export function setupSocketHandlers(io: Server): void {
         peerId: socket.id
       });
     });
-    // 处理发起方重新上线的通知--广播给房间内的其他用户
+    // Handle notification for initiator coming back online -- broadcast to other users in the room
     socket.on('initiator-online', (data: InitiatorData) => {
       socket.to(data.roomId).emit('initiator-online', {
         roomId: data.roomId
       });
     });
-    // 处理接收方的响应
+    // Handle recipient's response
     socket.on('recipient-ready', (data: RecipientData) => {
       socket.to(data.roomId).emit('recipient-ready', {
         peerId: data.peerId
diff --git a/backend/src/types/socket.ts b/backend/src/types/socket.ts
index 1528244..3d49629 100644
--- a/backend/src/types/socket.ts
+++ b/backend/src/types/socket.ts
@@ -2,7 +2,7 @@ export interface JoinData {
   roomId: string;
 }
 
-// 添加 WebRTC 相关类型定义
+// Add WebRTC related type definitions
 declare global {
   interface RTCSessionDescriptionInit {
     type: RTCSdpType;