Update ischool login method with retry mechanism

.gitignore

@@ -54,3 +54,6 @@ app.*.map.json
 /android/app/debug
 /android/app/profile
 /android/app/release
+
+# Test files
+**/test/ischool_plus_connector_test/credential.json

lib/src/connector/ischool_plus_connector.dart

@@ -1,6 +1,7 @@
 // TODO: remove sdk version selector after migrating to null-safety.
 // @dart=2.10
 import 'dart:convert';
+import 'dart:developer';
 import 'dart:io';
 
 import 'package:dio/dio.dart';
@@ -17,7 +18,7 @@ import '../model/course/course_student.dart';
 import 'core/connector_parameter.dart';
 import 'ntut_connector.dart';
 
-enum ISchoolPlusConnectorStatus { loginSuccess, loginFail, unknownError }
+enum ISchoolPlusConnectorStatus { loginSuccess, loginGetSSOIndexError, loginRedirectionError, unknownError }
 
 enum IPlusReturnStatus { success, fail, noPermission }
 
@@ -38,80 +39,73 @@ class ISchoolPlusConnector {
 
   /// The Authorization Step of ISchool (2023-10-21)
   /// 1. GET https://app.ntut.edu.tw/ssoIndex.do
-  /// 2. POST https://app.ntut.edu.tw/oauth2Server.do (It should be. See the comment on step 2)
-  /// 3. GET https://istudy.ntut.edu.tw/login2.php (It should be. See the comment on step 3)
-  /// 4. do something...
-  static Future<ISchoolPlusConnectorStatus> login(String account) async {
-    String result;
+  /// 2-1. POST https://app.ntut.edu.tw/oauth2Server.do (It should be. See the comment on step 2-1)
+  /// 2-2. follow the redirection to https://istudy.ntut.edu.tw/login2.php (It should be. See the comment on step 2-2)
+  static Future<ISchoolPlusConnectorStatus> login(String account, {bool logEventToFirebase = true}) async {
     try {
-      ConnectorParameter parameter;
-      html.Document tagNode;
-      List<html.Element> nodes;
-      final data = {
-        "apUrl": "https://istudy.ntut.edu.tw/login.php",
-        "apOu": "ischool_plus_oauth",
-        "sso": "true",
-        "datetime1": DateTime.now().millisecondsSinceEpoch.toString()
-      };
+      final ssoIndexResponse = await getSSOIndexResponse();
+      if (ssoIndexResponse.isEmpty) return ISchoolPlusConnectorStatus.loginGetSSOIndexError;
 
-      // Step 1
-      parameter = ConnectorParameter(_ssoLoginUrl);
-      parameter.data = data;
-      result = (await Connector.getDataByGet(parameter));
+      final ssoIndexTagNode = html.parse(ssoIndexResponse);
+      final ssoIndexNodes = ssoIndexTagNode.getElementsByTagName("input");
+      final ssoIndexJumpUrl = ssoIndexTagNode.getElementsByTagName("form")[0].attributes["action"];
 
-      tagNode = html.parse(result.toString().trim());
-      nodes = tagNode.getElementsByTagName("input");
-      data.clear();
-      for (final node in nodes) {
+      final Map<String, String> oauthData = {};
+      for (final node in ssoIndexNodes) {
         final name = node.attributes['name'];
         final value = node.attributes['value'];
-        data[name] = value;
+        oauthData[name] = value;
       }
 
-      // Step 2
-      // The `jumpUrl` should be "oauth2Server.do".
-      // If not, it means that the school server has changed.
-      // TODO: Add a validation measurement to check whether Step 1 is died or not. (It should not die if auth is correct)
-      final jumpUrl = tagNode.getElementsByTagName("form")[0].attributes["action"];
-      parameter = ConnectorParameter("${NTUTConnector.host}$jumpUrl");
-      parameter.data = data;
-
-      Response<dynamic> jumpResult = (await Connector.getDataByPostResponse(parameter));
-      tagNode = html.parse(jumpResult.data.toString().trim());
-      nodes = tagNode.getElementsByTagName("a");
-
-      // Step 3
-      // The redirectUrl is provided by <a> HTML DOM on Step 2.
-      // It should be https://istudy.ntut.edu.tw/login2.php with lot of the parameters.
-      final redirectUrl = nodes.first.attributes["href"];
-      parameter = ConnectorParameter(redirectUrl);
-      await Connector.getDataByGet(parameter);
-
-      // Perform retry for cryptic API errors (?).
-      // If the string `connect lost` be found in the response, we will do the retry.
-
-      // [2023-10-21] We may not need this since the step was changed.
-      // TODO: Remove I-School retry loop since it's outdated.
-
-      int retryTimes = 3;
-      do {
-        if (jumpResult.data.toString().contains('connect lost')) {
-          // Take a short delay to avoid being blocked.
+      for (int retry = 0; retry < 3; retry++) {
+        // Step 2-1
+        // The ssoIndexJumpUrl should be "oauth2Server.do", and the response should contain redirection location.
+        // If not, a retry of getting redirection location will perform.
+        final jumpParameter = ConnectorParameter("${NTUTConnector.host}$ssoIndexJumpUrl");
+        jumpParameter.data = oauthData;
+        final jumpResult = (await Connector.getDataByPostResponse(jumpParameter));
+        if (jumpResult.statusCode != 302) {
+          log("[TAT] ischool_plus_connector.dart: failed to get redirection location from oauth2Server, retrying...");
           await Future.delayed(const Duration(milliseconds: 100));
-          jumpResult = (await Connector.getDataByPostResponse(parameter));
-        } else {
-          break;
+          continue;
         }
-      } while ((retryTimes--) > 0);
+        // Step 2-2
+        // The redirect location should be "https://istudy.ntut.edu.tw/login2.php", and the response should not contain
+        // "connection `lost`", if it does, a retry of getting redirection location will perform.
+        final login2Parameter = ConnectorParameter(jumpResult.headers['location'][0]);
+        final login2Result = await Connector.getDataByGet(login2Parameter);
+        if (login2Result.contains("lost")) {
+          log("[TAT] ischool_plus_connector.dart: connection lost during redirection, retrying...");
+          await Future.delayed(const Duration(milliseconds: 100));
+          continue;
+        }
+        return ISchoolPlusConnectorStatus.loginSuccess;
+      }
 
-      await FirebaseAnalytics.instance.logLogin(
-        loginMethod: 'ntut_iplus',
-      );
-      return ISchoolPlusConnectorStatus.loginSuccess;
+      if (logEventToFirebase) {
+        await FirebaseAnalytics.instance.logLogin(
+          loginMethod: 'ntut_iplus',
+        );
+      }
+      return ISchoolPlusConnectorStatus.loginRedirectionError;
     } catch (e, stack) {
       Log.eWithStack(e.toString(), stack);
-      return ISchoolPlusConnectorStatus.loginFail;
+      rethrow;
+    }
+  }
+
+  static Future<String> getSSOIndexResponse() async {
+    final data = {"apOu": "ischool_plus_oauth", "datetime1": DateTime.now().millisecondsSinceEpoch.toString()};
+    for (int retry = 0; retry < 5; retry++) {
+      final parameter = ConnectorParameter(_ssoLoginUrl);
+      parameter.data = data;
+
+      final response = (await Connector.getDataByGet(parameter)).toString().trim();
+      if (response.contains("ssoForm")) return response;
+      log("[TAT] ischool_plus_connector.dart: failed to get ssoForm, retrying...");
+      await Future.delayed(const Duration(milliseconds: 100));
     }
+    return "";
   }
 
   static Future<ReturnWithStatus<List<CourseStudent>>> getCourseStudent(String courseId) async {

lib/src/task/iplus/iplus_system_task.dart

@@ -24,8 +24,14 @@ class IPlusSystemTask<T> extends NTUTTask<T> {
       final value = await ISchoolPlusConnector.login(studentId);
       super.onEnd();
 
-      if (value != ISchoolPlusConnectorStatus.loginSuccess) {
-        return onError(R.current.loginISchoolPlusError);
+      //TODO: generate string for this
+      switch (value) {
+        case ISchoolPlusConnectorStatus.loginGetSSOIndexError:
+          return onError("ischool login get SSO index error");
+        case ISchoolPlusConnectorStatus.loginRedirectionError:
+          return onError("ischool login redirection error");
+        default:
+          break;
       }
     }
     return status;

test/ischool_plus_connector_test/ischool_plus_connector_test.dart

@@ -0,0 +1,62 @@
+// TODO: remove sdk version selector after migrating to null-safety.
+// @dart=2.10
+import 'dart:io';
+import 'package:cookie_jar/cookie_jar.dart';
+import 'package:dio_cookie_manager/dio_cookie_manager.dart';
+import 'package:flutter_app/src/connector/blocked_cookies.dart';
+import 'package:flutter_app/src/connector/core/dio_connector.dart';
+import 'package:flutter_app/src/connector/interceptors/request_interceptor.dart';
+import 'package:flutter_app/src/connector/ischool_plus_connector.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:get/get.dart';
+import 'package:path/path.dart';
+import 'package:tat_core/tat_core.dart';
+import 'dart:developer' as dev;
+import 'dart:convert';
+
+Future<void> main() async {
+  final tempDir = await Directory.systemTemp.createTemp();
+
+  final appDocDir = join(tempDir.path, '.cookies');
+  final CookieJar cookieJar = PersistCookieJar(storage: FileStorage('$appDocDir/.cookies'));
+  Get.put(cookieJar);
+  final apiInterceptors = [
+    ResponseCookieFilter(blockedCookieNamePatterns: blockedCookieNamePatterns),
+    CookieManager(cookieJar),
+    RequestInterceptors(),
+  ];
+  await DioConnector.instance.init(interceptors: apiInterceptors);
+  final schoolApiService = SchoolApiService(interceptors: apiInterceptors);
+
+  final simpleLoginRepository = SimpleLoginRepository(apiService: schoolApiService);
+  // final checkSessionRepository = CheckSessionRepository(apiService: schoolApiService);
+
+  final simpleLoginUseCase = SimpleLoginUseCase(simpleLoginRepository);
+  // final checkSessionIsAliveUseCase = CheckSessionUseCase(checkSessionRepository);
+
+  const credentialFilePath = 'test/ischool_plus_connector_test/credential.json';
+  final file = File(credentialFilePath);
+  final json = jsonDecode(await file.readAsString());
+  final userId = json['userId'];
+  final password = json['password'];
+
+  dev.log('userId: $userId');
+  dev.log('password: $password');
+
+  final Stopwatch stopwatch = Stopwatch()..start();
+  test('ntut_login', () async {
+    final loginCredential = LoginCredential(userId: userId, password: password);
+    final loginResult = await simpleLoginUseCase(credential: loginCredential);
+    expect(loginResult.isSuccess, isTrue);
+    dev.log('ntut login Done Test execution time: ${stopwatch.elapsed}');
+
+    // final isCurrentSessionAlive = await checkSessionIsAliveUseCase();
+    // expect(isCurrentSessionAlive, isTrue);
+  });
+  test('ischool_login', () async {
+    final result = await ISchoolPlusConnector.login(userId, logEventToFirebase: false);
+    expect(result, ISchoolPlusConnectorStatus.loginSuccess);
+    dev.log('ischool login Done Test execution time: ${stopwatch.elapsed}');
+    stopwatch.stop();
+  });
+}