feat(api): implement token auto-refresh mechanism and enhance token management

- Add support for proactive token refresh when nearing expiration to improve user experience.
- Introduce a refresh lock to prevent concurrent token refresh requests.
- Update token handling in API client to ensure valid tokens are used for requests.
- Modify authService to handle refresh token requests with improved error handling and response management.

src/services/api.ts

@@ -2,6 +2,7 @@
  * API 客户端
  * 使用 fetch API 进行 HTTP 请求
  * 支持请求/响应拦截器
+ * 支持主动刷新 token（快过期时自动刷新）
  */
 
 import AsyncStorage from '@react-native-async-storage/async-storage';
@@ -24,6 +25,9 @@ const SSE_URL = `${BASE_URL.replace(/\/+$/, '')}/realtime/sse`;
 const TOKEN_KEY = 'auth_token';
 const REFRESH_TOKEN_KEY = 'refresh_token';
 
+// Token 提前刷新阈值（秒）：提前 5 分钟刷新
+const TOKEN_REFRESH_THRESHOLD_SECONDS = 5 * 60;
+
 // API 响应格式
 export interface ApiResponse<T> {
   code: number;
@@ -53,10 +57,21 @@ export class ApiError extends Error {
   }
 }
 
+// JWT Payload 结构
+interface JwtPayload {
+  user_id: string;
+  username: string;
+  exp?: number;
+  iat?: number;
+  iss?: string;
+}
+
 // API 客户端类
 class ApiClient {
   private baseUrl: string;
   private navigation: any = null;
+  // 刷新锁：防止并发刷新
+  private refreshLock: Promise<boolean> | null = null;
 
   constructor(baseUrl: string) {
     this.baseUrl = baseUrl;
@@ -67,6 +82,33 @@ class ApiClient {
     this.navigation = navigation;
   }
 
+  // 解析 JWT token 获取 payload
+  private parseJwt(token: string): JwtPayload | null {
+    try {
+      const parts = token.split('.');
+      if (parts.length !== 3) {
+        return null;
+      }
+      // React Native/Expo 环境使用 atob
+      const payload = JSON.parse(atob(parts[1]));
+      return payload as JwtPayload;
+    } catch {
+      return null;
+    }
+  }
+
+  // 检查 token 是否快过期（返回 true 表示需要刷新）
+  private isTokenExpiringSoon(token: string): boolean {
+    const payload = this.parseJwt(token);
+    if (!payload || !payload.exp) {
+      return false;
+    }
+    const now = Math.floor(Date.now() / 1000);
+    const remaining = payload.exp - now;
+    // 剩余时间小于阈值时需要刷新
+    return remaining < TOKEN_REFRESH_THRESHOLD_SECONDS && remaining > 0;
+  }
+
   // 获取 token
   async getToken(): Promise<string | null> {
     try {
@@ -137,11 +179,34 @@ class ApiClient {
       'Content-Type': 'application/json',
     };
 
-    // 添加认证 token
+    // 添加认证 token（主动刷新快过期的 token）
     const token = await this.getToken();
     if (token) {
+      // 检查 token 是否快过期，如果是则主动刷新
+      if (this.isTokenExpiringSoon(token)) {
+        const refreshed = await this.refreshToken();
+        if (!refreshed) {
+          // 刷新失败，清除 token 并跳转登录
+          await this.clearToken();
+          if (this.navigation) {
+            this.navigation.dispatch(
+              CommonActions.reset({
+                index: 0,
+                routes: [{ name: 'Login' }],
+              })
+            );
+          }
+          throw new ApiError(401, '登录已过期，请重新登录');
+        }
+        // 刷新成功，使用新 token
+        const newToken = await this.getToken();
+        if (newToken) {
+          headers['Authorization'] = `Bearer ${newToken}`;
+        }
+      } else {
         headers['Authorization'] = `Bearer ${token}`;
       }
+    }
 
     // 构建请求配置
     const config: RequestInit = {
@@ -230,8 +295,27 @@ class ApiClient {
     }
   }
 
-  // 刷新 token
+  // 刷新 token（带锁，防止并发刷新）
   private async refreshToken(): Promise<boolean> {
+    // 如果已有刷新操作正在进行，等待其完成
+    if (this.refreshLock) {
+      return this.refreshLock;
+    }
+
+    // 创建刷新锁
+    this.refreshLock = this.doRefreshToken();
+
+    try {
+      const result = await this.refreshLock;
+      return result;
+    } finally {
+      // 释放刷新锁
+      this.refreshLock = null;
+    }
+  }
+
+  // 实际执行刷新 token
+  private async doRefreshToken(): Promise<boolean> {
     try {
       const refreshToken = await this.getRefreshToken();
       if (!refreshToken) {
@@ -242,8 +326,10 @@ class ApiClient {
         method: 'POST',
         headers: {
           'Content-Type': 'application/json',
-          'Authorization': `Bearer ${refreshToken}`,
         },
+        body: JSON.stringify({
+          refresh_token: refreshToken,
+        }),
       });
 
       if (!response.ok) {
@@ -309,11 +395,23 @@ class ApiClient {
       });
     }
 
+    // 获取 token 并检查是否需要刷新
     const token = await this.getToken();
     const headers: HeadersInit = {};
     if (token) {
+      // 检查 token 是否快过期
+      if (this.isTokenExpiringSoon(token)) {
+        const refreshed = await this.refreshToken();
+        if (refreshed) {
+          const newToken = await this.getToken();
+          if (newToken) {
+            headers['Authorization'] = `Bearer ${newToken}`;
+          }
+        }
+      } else {
         headers['Authorization'] = `Bearer ${token}`;
       }
+    }
 
     const response = await fetch(`${this.baseUrl}${path}`, {
       method: 'POST',

src/services/authService.ts

@@ -237,7 +237,14 @@ class AuthService {
   // 刷新Token
   async refreshToken(): Promise<RefreshTokenResponse | null> {
     try {
-      const response = await api.post<RefreshTokenResponse>('/auth/refresh');
+      const refreshToken = await api.getRefreshToken();
+      if (!refreshToken) {
+        return null;
+      }
+      
+      const response = await api.post<RefreshTokenResponse>('/auth/refresh', {
+        refresh_token: refreshToken,
+      });
       
       if (!response.data) {
         return null;
@@ -245,8 +252,9 @@ class AuthService {
       if (response.data.token) {
         await api.setToken(response.data.token);
       }
-      if (response.data.refreshToken) {
+      const newRefreshToken = response.data.refresh_token || response.data.refreshToken;
-        await api.setRefreshToken(response.data.refreshToken);
+      if (newRefreshToken) {
+        await api.setRefreshToken(newRefreshToken);
       }
       
       return response.data;