Fix school browser initialization and redirect detection; improve diagnostics

mobile/lib/features/school/undergraduate/session.dart

@@ -11,8 +11,13 @@ import 'navigation_policy.dart';
 import 'page_probe.dart';
 import 'timetable_adapter.dart';
 import 'exam_adapter.dart';
+import '../school_browser.dart';
 
 class UndergraduateSession extends ChangeNotifier {
+  UndergraduateSession({this.configureBrowser = configureSchoolBrowser});
+  final SchoolBrowserConfigurator configureBrowser;
+  Future<SchoolBrowserInfo>? _browserReady;
+  String? browserVersion;
   static final loginUri = Uri.parse('https://eams.uestc.edu.cn/eams/');
   static const manualMessage = '请在学校网页打开课表并选择学期，然后点击导入当前课表。';
   WebViewController? _web;
@@ -99,6 +104,12 @@ class UndergraduateSession extends ChangeNotifier {
                 uri,
                 isMainFrame: request.isMainFrame,
               )) {
+            DiagnosticLog.instance.resourceFailure(
+              'undergraduate',
+              request.url,
+              code: 'blocked_navigation',
+              mainFrame: request.isMainFrame,
+            );
             if (request.isMainFrame) {
               _failure('学校跳转未完成，请重新认证。', code: 'blocked_navigation');
             }
@@ -129,6 +140,13 @@ class UndergraduateSession extends ChangeNotifier {
         },
         onPageFinished: _loaded,
         onWebResourceError: (error) async {
+          DiagnosticLog.instance.resourceFailure(
+            'undergraduate',
+            error.url,
+            code: 'web_resource_error',
+            status: error.errorCode,
+            mainFrame: error.isForMainFrame,
+          );
           if (error.isForMainFrame != true || error.url == null) return;
           final g = _generation,
               d = _document,
@@ -142,6 +160,12 @@ class UndergraduateSession extends ChangeNotifier {
           }
         },
         onHttpError: (error) async {
+          DiagnosticLog.instance.resourceFailure(
+            'undergraduate',
+            error.request?.uri.toString(),
+            code: 'http_error',
+            status: error.response?.statusCode,
+          );
           final g = _generation,
               d = _document,
               current = await web.currentUrl();
@@ -202,8 +226,16 @@ class UndergraduateSession extends ChangeNotifier {
     _loading = true;
     _emit();
     try {
-      await web.loadRequest(uri);
+      final controller = web;
+      final info = await (_browserReady ??= configureBrowser(
+        controller,
+        'undergraduate',
+      ));
+      if (!_valid(g)) return;
+      browserVersion = info.chromiumVersion;
+      await controller.loadRequest(uri);
     } catch (_) {
+      _browserReady = null;
       if (_valid(g)) _failure('学校页面打开未完成，请重试。');
     }
   }
@@ -283,6 +315,11 @@ class UndergraduateSession extends ChangeNotifier {
           !UndergraduateNavigationPolicy.canNavigate(uri, isMainFrame: true)) {
         return;
       }
+      if (!UndergraduateNavigationPolicy.isDataPage(uri)) {
+        _loading = false;
+        _waitForLogin();
+        return;
+      }
       final status = await _evidence(uri, false);
       DiagnosticLog.instance.add(
         'school_evidence',
@@ -346,8 +383,17 @@ class UndergraduateSession extends ChangeNotifier {
         await _requestExam(g);
       }
     } catch (error) {
+      final current = await web.currentUrl();
       if (_valid(g) && d == _document) {
-        _failure('$error', code: error.runtimeType.toString());
+        if (current != url) {
+          DiagnosticLog.instance.add(
+            'school_probe_stale',
+            fields: {'school': 'undergraduate', 'code': 'redirect_in_progress'},
+          );
+          if (current != null) _schedulePoll(g, d, current);
+        } else {
+          _failure('$error', code: error.runtimeType.toString());
+        }
       }
     } finally {
       if (_probeKey == key) _probeKey = null;