auth: use sessions

lib/core/services/api_client.dart

@@ -10,39 +10,30 @@ import '../models/change.dart';
 import '../models/sheet.dart';
 
 /// HTTP client for communicating with the Sheetless API server.
-///
-/// Handles authentication, sheet listing, and PDF downloads.
-/// Provides caching for PDF files on native platforms.
 class ApiClient {
   final _log = Logger('ApiClient');
+
   final String baseUrl;
-  String? token;
+  String? accessToken; // Short-lived jwt
+  String? refreshToken; // Long lived binary token
 
-  ApiClient({required this.baseUrl, this.token});
-
-  /// Whether the client has an authentication token set.
-  bool get isAuthenticated => token != null;
+  ApiClient({required this.baseUrl, this.refreshToken});
 
   // ---------------------------------------------------------------------------
   // Authentication
   // ---------------------------------------------------------------------------
-
-  /// Authenticates with the server and stores the JWT token.
-  ///
-  /// Throws an [Exception] if login fails.
   Future<void> login(String username, String password) async {
     _log.info('Logging in...');
-    final url = Uri.parse('$baseUrl/auth/login');
 
-    final response = await http.post(
-      url,
-      headers: {'Content-Type': 'application/json'},
-      body: jsonEncode({'username': username, 'password': password}),
-    );
+    final response = await post("/auth/login", {
+      'username': username,
+      'password': password,
+    }, authenticateWithAccessToken: false);
 
     if (response.statusCode == 200) {
       final responseData = jsonDecode(response.body);
-      token = responseData['token'];
+      accessToken = responseData['access_token'];
+      refreshToken = responseData['refresh_token'];
       _log.info('Login successful');
     } else {
       throw ApiException(
@@ -53,9 +44,37 @@ class ApiClient {
     }
   }
 
-  /// Clears the authentication token.
-  void logout() {
-    token = null;
+  Future<void> refreshAccessToken() async {
+    _log.info('Refreshing access token...');
+    _log.info('Refresh token is: $refreshToken');
+    final response = await post("/auth/refresh", {
+      "refresh_token": refreshToken,
+    }, authenticateWithAccessToken: false);
+    if (response.statusCode == 200) {
+      final responseData = jsonDecode(response.body);
+      accessToken = responseData['access_token'];
+      _log.info('Token refresh successful -> $accessToken');
+    } else {
+      throw ApiException(
+        'Token refresh failed',
+        statusCode: response.statusCode,
+        body: response.body,
+      );
+    }
+  }
+
+  Future<void> logout() async {
+    try {
+      await post(
+        "/auth/logout",
+        {},
+        authenticateWithAccessToken: true,
+      ); // Ignoring response, logging out in any case
+    } catch (e) {
+      _log.fine('Logout failed: $e');
+    }
+    accessToken = null;
+    refreshToken = null;
     _log.info('Logged out successfully');
   }
 
@@ -63,21 +82,46 @@ class ApiClient {
   // HTTP Helpers
   // ---------------------------------------------------------------------------
 
-  Map<String, String> _buildHeaders({bool isBinary = false}) {
-    return {
-      'Authorization': 'Bearer $token',
+  Map<String, String> _buildHeaders({
+    bool authenticateWithAccessToken = false,
+    bool isBinary = false,
+  }) {
+    final headers = {
+      if (authenticateWithAccessToken) 'Authorization': 'Bearer $accessToken',
       if (!isBinary) 'Content-Type': 'application/json',
     };
+    _log.fine("Header is: $headers");
+    return headers;
   }
 
   /// Performs a GET request to the given endpoint.
-  Future<http.Response> get(String endpoint, {bool isBinary = false}) async {
+  Future<http.Response> get(
+    String endpoint, {
+    bool isBinary = false,
+    bool authenticateWithAccessToken = true,
+    bool isRetry = false,
+  }) async {
+    _log.fine("Starting get: $endpoint");
     final url = Uri.parse('$baseUrl$endpoint');
     final response = await http.get(
       url,
-      headers: _buildHeaders(isBinary: isBinary),
+      headers: _buildHeaders(
+        isBinary: isBinary,
+        authenticateWithAccessToken: authenticateWithAccessToken,
+      ),
     );
 
+    // Unauthorized, refresh access token
+    if (authenticateWithAccessToken && response.statusCode == 401 && !isRetry) {
+      await refreshAccessToken();
+      return get(
+        endpoint,
+        isBinary: isBinary,
+        authenticateWithAccessToken: authenticateWithAccessToken,
+        isRetry: true,
+      );
+    }
+
     if (response.statusCode != 200) {
       _log.warning(
         "GET '$endpoint' failed: ${response.statusCode}\n${response.body}",
@@ -93,15 +137,33 @@ class ApiClient {
   }
 
   /// Performs a POST request with JSON body.
-  Future<http.Response> post(String endpoint, Map<String, dynamic> body) async {
+  Future<http.Response> post(
+    String endpoint,
+    Map<String, dynamic> body, {
+    bool authenticateWithAccessToken = true,
+    bool isRetry = false,
+  }) async {
     final url = Uri.parse('$baseUrl$endpoint');
 
     final response = await http.post(
       url,
-      headers: _buildHeaders(),
+      headers: _buildHeaders(
+        authenticateWithAccessToken: authenticateWithAccessToken,
+      ),
       body: jsonEncode(body),
     );
 
+    // Unauthorized, refresh access token
+    if (authenticateWithAccessToken && response.statusCode == 401 && !isRetry) {
+      await refreshAccessToken();
+      return post(
+        endpoint,
+        body,
+        authenticateWithAccessToken: authenticateWithAccessToken,
+        isRetry: true,
+      );
+    }
+
     if (response.statusCode != 200 && response.statusCode != 201) {
       _log.warning(
         "POST '$endpoint' failed: ${response.statusCode}\n${response.body}",
@@ -117,18 +179,28 @@ class ApiClient {
   }
 
   /// Performs a POST request with form-encoded body.
-  Future<http.Response> postFormData(String endpoint, String body) async {
+  Future<http.Response> postFormData(
+    String endpoint,
+    String body, {
+    bool isRetry = false,
+  }) async {
     final url = Uri.parse('$baseUrl$endpoint');
 
     final response = await http.post(
       url,
       headers: {
-        'Authorization': 'Bearer $token',
+        'Authorization': 'Bearer $accessToken',
         'Content-Type': 'application/x-www-form-urlencoded',
       },
       body: body,
     );
 
+    // Unauthorized, refresh access token
+    if (response.statusCode == 401 && !isRetry) {
+      await refreshAccessToken();
+      return postFormData(endpoint, body, isRetry: true);
+    }
+
     if (response.statusCode != 200 && response.statusCode != 201) {
       _log.warning(
         "POST Form '$endpoint' failed: ${response.statusCode}\n${response.body}",
@@ -248,10 +320,9 @@ class ApiClient {
   /// Returns true if the server responds, false otherwise.
   Future<bool> checkConnection() async {
     try {
-      final url = Uri.parse('$baseUrl/api/health');
-      final response = await http
-          .get(url, headers: _buildHeaders())
-          .timeout(const Duration(seconds: 5));
+      final response = await get(
+        "/api/health",
+      ).timeout(const Duration(seconds: 5));
       return response.statusCode == 200;
     } catch (e) {
       _log.fine('Connection check failed: $e');