Fix the startup hang and the issues found while debugging

android/app/build.gradle.kts

@@ -34,8 +34,6 @@ android {
         targetSdk = flutter.targetSdkVersion
         versionCode = flutter.versionCode
         versionName = flutter.versionName
-        // OIDC redirect scheme for flutter_appauth's RedirectUriReceiverActivity.
-        // Must match OidcConfig.redirectScheme (lib/config/oidc_config.dart).
     }
 
     flavorDimensions += "environment"

android/app/src/dev/res/xml/network_security_config.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Dev flavor only: a local backend over plain HTTP. -->
+<network-security-config>
+    <domain-config cleartextTrafficPermitted="true">
+        <domain includeSubdomains="true">localhost</domain>
+        <domain includeSubdomains="true">127.0.0.1</domain>
+        <domain includeSubdomains="true">10.0.2.2</domain>
+        <domain includeSubdomains="true">192.168.188.162</domain>
+        <domain includeSubdomains="true">192.168.188.93</domain>
+    </domain-config>
+</network-security-config>

android/app/src/main/res/xml/network_security_config.xml

@@ -1,10 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
+<!-- No cleartext traffic in release flavors. The dev flavor overrides this file in src/dev. -->
 <network-security-config>
-    <domain-config cleartextTrafficPermitted="true">
-        <domain includeSubdomains="true">localhost</domain>
-        <domain includeSubdomains="true">127.0.0.1</domain>
-        <domain includeSubdomains="true">10.0.2.2</domain>
-        <domain includeSubdomains="true">192.168.188.162</domain>
-        <domain includeSubdomains="true">192.168.188.93</domain>
-    </domain-config>
+    <base-config cleartextTrafficPermitted="false" />
 </network-security-config>

lib/services/linked_accounts_controller.dart

@@ -76,9 +76,27 @@ class LinkedAccountsController extends ChangeNotifier with WidgetsBindingObserve
     return out;
   }
 
+  Future<void>? _loadInFlight;
+
   /// Providers and accounts, fresh from the server. A failure is kept in [error] and the last
   /// good lists stay on screen.
-  Future<void> load() async {
+  ///
+  /// Listeners may call this while they are being notified, so a call during a load joins it.
+  /// The load counts as running until its last notification is out; otherwise a listener that
+  /// loads when nothing is [loaded] would start over after every failure.
+  Future<void> load() {
+    final running = _loadInFlight;
+    if (running != null) return running;
+    final done = Completer<void>();
+    _loadInFlight = done.future;
+    _load().whenComplete(() {
+      _loadInFlight = null;
+      done.complete();
+    });
+    return done.future;
+  }
+
+  Future<void> _load() async {
     _loading = true;
     _error = null;
     _notify();

lib/services/private_data_adapter.dart

@@ -16,46 +16,86 @@ class PrivateDataAdapter {
     return d == null ? null : Date(d.year, d.month, d.day);
   }
 
+  static String _classId(String subject) => 'private-class-$subject';
+
+  static String? _classIdOrNull(String? subject) => subject == null || subject.isEmpty ? null : _classId(subject);
+
+  /// The exam a grade belongs to. A grade without an exam id still needs one: the pages list grades through their exam.
+  static String _examIdOf(PrivateGrade g) => g.examId?.isNotEmpty == true ? g.examId! : 'private-grade-${g.id ?? '${g.subject}-${g.date}-${g.score}'}';
+
   static GradeDto grade(PrivateGrade g) => GradeDto((b) => b
     ..id = g.id
     ..score = g.score
-    ..examId = g.examId
+    ..examId = _examIdOf(g)
     ..schoolUserId = privateSchoolUserId);
 
   static ExamDto exam(PrivateExam e) => ExamDto((b) => b
     ..id = e.id
     ..name = (e.name?.isNotEmpty == true ? e.name! : e.subject) ?? 'Exam'
     ..classAverage = 0
+    ..date = _dateOnly(e.startDate)
+    ..classId = _classIdOrNull(e.subject)
     ..description = e.comment);
 
+  /// The stateless exam list holds upcoming exams, while grades mostly belong to past ones. An exam
+  /// is made up from the grade for those, as the account-mode sync does on the server.
+  static ExamDto _examFromGrade(PrivateGrade g) {
+    final date = _dateOnly(g.date);
+    return ExamDto((b) => b
+      ..id = _examIdOf(g)
+      ..name = g.comment?.isNotEmpty == true ? g.comment! : (date == null ? (g.subject ?? 'Grade') : 'Grade ${date.day}.${date.month}.${date.year}')
+      ..classAverage = 0
+      ..date = date
+      ..classId = _classIdOrNull(g.subject));
+  }
+
   static AbsenceDto absence(PrivateAbsence a) {
     final from = _dateOr(a.from, DateTime.now());
     return AbsenceDto((b) => b
       ..id = a.id
-      ..reason = (a.reason?.isNotEmpty == true ? a.reason! : 'Absence')
+      ..reason = a.reason?.isNotEmpty == true ? a.reason! : (a.subject?.isNotEmpty == true ? a.subject! : 'Absence')
       ..type = AbsenceType.absence
+      ..isExcused = a.excused
       ..from = from
       ..until = _dateOr(a.to, from)
       ..schoolUserId = privateSchoolUserId);
   }
 
+  /// Mirrors the words the server's holiday sync treats as a day off.
+  static const _dayOffWords = ['ferien', 'feiertag', 'schulfrei', 'unterrichtsfrei', 'brückentag', 'brueckentag', 'vacances', 'vacanze', 'congé', 'conge', 'neujahr', 'berchtold', 'karfreitag', 'ostern', 'ostermontag', 'tag der arbeit', 'auffahrt', 'pfingst', 'fronleichnam', 'bundesfeier', 'nationalfeiertag', 'maria himmelfahrt', 'allerheiligen', 'maria empfängnis', 'weihnacht', 'stephan'];
+
+  /// The stateless routes pass the school's own event type on: "Timetable", "Event", "Exam" and the like.
+  static AgendaEntryType _entryType(PrivateAgendaEvent e) {
+    final title = (e.title ?? '').toLowerCase();
+    return switch (e.type?.toLowerCase()) {
+      'holiday' => AgendaEntryType.holiday,
+      'exam' || 'test' => AgendaEntryType.test,
+      'event' => _dayOffWords.any(title.contains) ? AgendaEntryType.holiday : AgendaEntryType.event,
+      _ => AgendaEntryType.lesson,
+    };
+  }
+
   static AgendaEntryDto agendaEntry(PrivateAgendaEvent e) => AgendaEntryDto((b) => b
     ..id = e.id
-    ..entryType = e.type?.toLowerCase() == 'holiday'
-        ? AgendaEntryType.holiday
-        : AgendaEntryType.lesson
+    ..entryType = _entryType(e)
     ..title = (e.title?.isNotEmpty == true ? e.title! : 'Entry')
     ..place = e.room
     ..description = e.comment
     ..date = _dateOr(e.startDate, DateTime.now())
     ..endDate = _date(e.endDate)
     ..schoolUserId = privateSchoolUserId);
 
-  static SchoolUserDto schoolUser(
-    PrivateUserInfo? info,
-    List<PrivateGrade> grades,
-    List<PrivateAbsence> absences,
-  ) =>
+  static List<String> _subjects(List<PrivateGrade> grades, List<PrivateExam> exams) {
+    final subjects = <String>{
+      for (final g in grades)
+        if (g.subject?.isNotEmpty == true) g.subject!,
+      for (final e in exams)
+        if (e.subject?.isNotEmpty == true) e.subject!,
+    };
+    return subjects.toList()..sort();
+  }
+
+  static SchoolUserDto schoolUser(PrivateUserInfo? info, List<PrivateGrade> grades, List<PrivateAbsence> absences, [List<PrivateExam> exams = const []]) =>
       SchoolUserDto((b) => b
         ..id = privateSchoolUserId
         ..firstName = info?.firstName ?? ''
@@ -64,35 +104,55 @@ class PrivateDataAdapter {
         ..entryDate = _dateOnly(info?.entryDate)
         ..role = Roles.student
         ..grades = ListBuilder<GradeDto>(grades.map(grade))
-        ..absences = ListBuilder<AbsenceDto>(absences.map(absence)));
+        ..absences = ListBuilder<AbsenceDto>(absences.map(absence))
+        ..classes = ListBuilder<UserClassDto>(_subjects(grades, exams).map((s) => UserClassDto((c) => c
+          ..classId = _classId(s)
+          ..className = s))));
 
-  static List<ExamDto> exams(List<PrivateExam> e) =>
-      e.map(exam).toList(growable: false);
+  /// The school's exams, plus one for every grade that has none in that list.
+  static List<ExamDto> exams(List<PrivateExam> e, [List<PrivateGrade> grades = const []]) {
+    final known = {for (final x in e) x.id};
+    return [
+      ...e.map(exam),
+      for (final g in grades)
+        if (known.add(_examIdOf(g))) _examFromGrade(g),
+    ];
+  }
 
   static List<AbsenceDto> absencesList(List<PrivateAbsence> a) =>
       a.map(absence).toList(growable: false);
 
-  static List<AgendaEntryDto> agenda(List<PrivateAgendaEvent> e) =>
-      e.map(agendaEntry).toList(growable: false);
+  /// The school's agenda, plus the exams still to come, which account mode also shows in the timetable.
+  static List<AgendaEntryDto> agenda(List<PrivateAgendaEvent> e, {List<PrivateExam> exams = const [], List<PrivateGrade> grades = const []}) {
+    final known = {for (final x in e) x.id};
+    final graded = {for (final g in grades) _examIdOf(g)};
+    return [
+      ...e.map(agendaEntry),
+      for (final x in exams)
+        if (_date(x.startDate) != null && !graded.contains(x.id) && known.add(x.id))
+          AgendaEntryDto((b) => b
+            ..id = x.id
+            ..entryType = AgendaEntryType.test
+            ..title = [if (x.subject?.isNotEmpty == true) x.subject!, if (x.name?.isNotEmpty == true && x.name != x.subject) x.name!].join(': ')
+            ..place = x.room
+            ..description = x.comment
+            ..date = _date(x.startDate)!
+            ..endDate = _date(x.endDate)
+            ..classId = _classIdOrNull(x.subject)
+            ..schoolUserId = privateSchoolUserId),
+    ];
+  }
 
   static List<ClassDto> classes(
     List<PrivateGrade> grades,
     List<PrivateExam> exams,
   ) {
-    final subjects = <String>{};
-    for (final g in grades) {
-      if (g.subject != null && g.subject!.isNotEmpty) subjects.add(g.subject!);
-    }
-    for (final e in exams) {
-      if (e.subject != null && e.subject!.isNotEmpty) subjects.add(e.subject!);
-    }
-    final sorted = subjects.toList()..sort();
-    return sorted
+    final all = PrivateDataAdapter.exams(exams, grades);
+    return _subjects(grades, exams)
         .map((subject) => ClassDto((b) => b
-          ..id = 'private-class-$subject'
+          ..id = _classId(subject)
           ..name = subject
-          ..exams = ListBuilder<ExamDto>(
-              exams.where((e) => e.subject == subject).map(exam))))
+          ..exams = ListBuilder<ExamDto>(all.where((e) => e.classId == _classId(subject)))))
         .toList(growable: false);
   }
 }

lib/services/school_data_service.dart

@@ -46,6 +46,18 @@ class SchoolDataService extends ChangeNotifier {
   Object? get error => _error;
   bool get hasLoaded => _hasLoaded;
 
+  /// Test-only: sets the data directly and notifies, as a finished refresh does.
+  @visibleForTesting
+  void setForTest({SchoolUserDto? me, List<ExamDto> exams = const [], List<AgendaEntryDto> agenda = const [], List<AbsenceDto> absences = const [], List<ClassDto> classes = const []}) {
+    _me = me;
+    _exams = exams;
+    _agenda = agenda;
+    _absences = absences;
+    _classes = classes;
+    _hasLoaded = true;
+    notifyListeners();
+  }
+
   Map<String, String> get classNameById {
     final out = <String, String>{};
     for (final c in _classes) {
@@ -229,19 +241,21 @@ class SchoolDataService extends ChangeNotifier {
       List<AbsenceDto> absences;
       List<AgendaEntryDto> agenda;
       List<ClassDto> classes;
+      var complete = true;
       if (account.accessToken != null) {
         final d = await TokenProxyClient.instance.fetchAll(account);
-        mine = PrivateDataAdapter.schoolUser(d.userInfo, d.grades, d.absences);
-        exams = PrivateDataAdapter.exams(d.exams);
+        complete = d.failedSections == 0;
+        mine = PrivateDataAdapter.schoolUser(d.userInfo, d.grades, d.absences, d.exams);
+        exams = PrivateDataAdapter.exams(d.exams, d.grades);
         absences = PrivateDataAdapter.absencesList(d.absences);
-        agenda = PrivateDataAdapter.agenda(d.agenda);
+        agenda = PrivateDataAdapter.agenda(d.agenda, exams: d.exams, grades: d.grades);
         classes = PrivateDataAdapter.classes(d.grades, d.exams);
       } else {
         final d = await ScrapeProxyClient.instance.data(account);
-        mine = PrivateDataAdapter.schoolUser(d.userInfo, d.grades, const []);
-        exams = PrivateDataAdapter.exams(d.exams);
+        mine = PrivateDataAdapter.schoolUser(d.userInfo, d.grades, const [], d.exams);
+        exams = PrivateDataAdapter.exams(d.exams, d.grades);
         absences = const [];
-        agenda = PrivateDataAdapter.agenda(d.agenda);
+        agenda = PrivateDataAdapter.agenda(d.agenda, exams: d.exams, grades: d.grades);
         classes = PrivateDataAdapter.classes(d.grades, d.exams);
       }
 
@@ -254,9 +268,14 @@ class SchoolDataService extends ChangeNotifier {
       _reports = const [];
       _teachers = const [];
       _documents = const [];
-      await SchoolDataSnapshotStore.instance.save(
-          'private',
-          SchoolDataSnapshot(me: _me, exams: _exams, agenda: _agenda, absences: _absences, classes: _classes, reports: _reports, teachers: _teachers, documents: _documents));
+      // A partial answer is shown, but the last complete snapshot stays on disk for the next launch.
+      if (complete) {
+        await SchoolDataSnapshotStore.instance.save(
+            'private',
+            SchoolDataSnapshot(me: _me, exams: _exams, agenda: _agenda, absences: _absences, classes: _classes, reports: _reports, teachers: _teachers, documents: _documents));
+      } else {
+        ToastService.error('Some data could not be refreshed', 'Your school did not answer every request. Pull down to try again.');
+      }
       _hasLoaded = true;
     } catch (e) {
       if (gen != _generation) return;

lib/services/token_proxy_client.dart

@@ -2,6 +2,7 @@ import 'dart:convert';
 import '../ui/widgets/browser_sign_in.dart';
 
 import 'package:dio/dio.dart';
+import 'package:flutter/foundation.dart';
 
 import '../domain/private_data.dart';
 import 'backend_dio.dart';
@@ -15,13 +16,17 @@ import 'totp_service.dart';
 /// supplies its own credentials (token + context_state) per request; nothing is
 /// stored server-side. The system's stateless route comes from the catalog.
 class TokenProxyClient {
-  TokenProxyClient._();
+  TokenProxyClient._()
+      : _dio = backendDio(
+          connectTimeout: const Duration(seconds: 10),
+          receiveTimeout: const Duration(seconds: 60),
+        );
   static final TokenProxyClient instance = TokenProxyClient._();
 
-  final Dio _dio = backendDio(
-    connectTimeout: const Duration(seconds: 10),
-    receiveTimeout: const Duration(seconds: 60),
-  );
+  @visibleForTesting
+  TokenProxyClient.withDio(this._dio);
+
+  final Dio _dio;
 
   /// Headless credential login (private mode): POST email + password (+ TOTP) to
   /// the stateless `/login` and get back tokens + the rotated context_state.
@@ -117,18 +122,36 @@ class TokenProxyClient {
     }
   }
 
+  /// Fetches every section at once. One section the school fails to answer does not cost the
+  /// others; only a refused token (the caller refreshes it) or a total failure throws.
   Future<TokenPrivateData> _fetchAll(PrivateAccount a) async {
-    final info = await userInfo(a);
-    final g = await grades(a);
-    final e = await exams(a);
-    final ab = await absences(a);
-    final ag = await agenda(a);
+    var failed = 0;
+    DioException? failure;
+    Future<T> section<T>(Future<T> fetch, T fallback) async {
+      try {
+        return await fetch;
+      } on DioException catch (e) {
+        if (e.response?.statusCode == 401) rethrow;
+        failed++;
+        failure ??= e;
+        return fallback;
+      }
+    }
+
+    final info = section<PrivateUserInfo?>(userInfo(a), null);
+    final g = section(grades(a), const <PrivateGrade>[]);
+    final e = section(exams(a), const <PrivateExam>[]);
+    final ab = section(absences(a), const <PrivateAbsence>[]);
+    final ag = section(agenda(a), const <PrivateAgendaEvent>[]);
+    await Future.wait<Object?>([info, g, e, ab, ag]);
+    if (failed == 5) throw failure!;
     return TokenPrivateData(
-      userInfo: info,
-      grades: g,
-      exams: e,
-      absences: ab,
-      agenda: ag,
+      userInfo: await info,
+      grades: await g,
+      exams: await e,
+      absences: await ab,
+      agenda: await ag,
+      failedSections: failed,
     );
   }
 
@@ -239,11 +262,15 @@ class TokenPrivateData {
   final List<PrivateExam> exams;
   final List<PrivateAbsence> absences;
   final List<PrivateAgendaEvent> agenda;
+
+  /// How many sections could not be fetched and are empty here.
+  final int failedSections;
   const TokenPrivateData({
     required this.userInfo,
     required this.grades,
     required this.exams,
     required this.absences,
     required this.agenda,
+    this.failedSections = 0,
   });
 }