chore: Halkyon Learn moves into apps/learn

Its server, client, app and curator, and the tools that write its
assets (maps, Anki fixtures, icons), as they are; paths are fixed in
the commits that follow.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/learn/halkyon_learn_flutter/test/feature/statistics/widget/statistics_view_test.dart

@@ -0,0 +1,169 @@
+import 'package:clock/clock.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_learn_flutter/src/core/content/rich_content.dart';
+import 'package:halkyon_learn_flutter/src/feature/card/data/card_repository.dart';
+import 'package:halkyon_learn_flutter/src/feature/card/model/card_content.dart';
+import 'package:halkyon_learn_flutter/src/feature/statistics/widget/bar_chart.dart';
+import 'package:halkyon_learn_flutter/src/feature/study/data/review_repository.dart';
+import 'package:halkyon_learn_flutter/src/feature/study/model/rating.dart';
+import 'package:halkyon_learn_flutter/src/feature/studyset/data/studyset_payload.dart';
+import 'package:halkyon_learn_flutter/src/feature/studyset/model/studyset_content.dart';
+import 'package:material_ui/material_ui.dart';
+
+import '../../../support/fake_card_gateway.dart';
+import '../../../support/fake_review_gateway.dart';
+import '../../../support/fake_studyset_gateway.dart';
+import '../../../support/pump_app.dart';
+import '../../../support/test_dependencies.dart';
+
+void main() {
+  late FakeStudysetGateway studysets;
+  late FakeCardGateway cardGateway;
+  late FakeReviewGateway reviewGateway;
+
+  setUp(() {
+    studysets = FakeStudysetGateway()
+      ..receiveRemoteChange(
+        'japanese',
+        encodeStudysetPayload(StudysetContent.titled('Japanese')),
+      );
+    cardGateway = FakeCardGateway();
+    reviewGateway = FakeReviewGateway();
+  });
+
+  /// A card of Japanese, rated with each of [ratings]: when, how, and how
+  /// long it took.
+  Future<void> studied(
+    List<({Duration ago, Rating rating, Duration took})> ratings,
+  ) async {
+    final cards = CardRepository(cardGateway);
+    addTearDown(cards.dispose);
+    final reviews = ReviewRepository(reviewGateway);
+    addTearDown(reviews.dispose);
+    final card = await cards.create(
+      'japanese',
+      CardContent(front: RichContent.plain('猫'), back: RichContent.empty()),
+    );
+    for (final (:ago, :rating, :took) in ratings) {
+      await reviews.record(
+        cardId: card,
+        rating: rating,
+        reviewedAt: clock.now().toUtc().subtract(ago),
+        duration: took,
+      );
+    }
+  }
+
+  Future<void> showStatistics(WidgetTester tester, {double width = 400}) async {
+    tester.view
+      ..physicalSize = Size(width, 1600)
+      ..devicePixelRatio = 1;
+    addTearDown(tester.view.reset);
+    await pumpApp(
+      tester,
+      testDependencies(
+        studysetGateway: studysets,
+        cardGateway: cardGateway,
+        reviewGateway: reviewGateway,
+      ),
+    );
+    await openTab(tester, 'Profile');
+    await tester.tap(find.widgetWithText(Tab, 'Statistics'));
+    await tester.pumpAndSettle();
+    // Worked out once the reviews stop changing for a moment.
+    await tester.pump(const Duration(seconds: 1));
+    await tester.pumpAndSettle();
+  }
+
+  testWidgets('the Profile tab has the statistics beside the profile: the '
+      'time in all, per day and the most in a day, each card counted for '
+      'at most a minute, and the ratings', (tester) async {
+    // Today 2 min (one card left on the screen for ten), yesterday 30 s.
+    await studied([
+      (
+        ago: Duration.zero,
+        rating: Rating.easy,
+        took: const Duration(minutes: 10),
+      ),
+      (
+        ago: Duration.zero,
+        rating: Rating.good,
+        took: const Duration(seconds: 60),
+      ),
+      (
+        ago: const Duration(days: 1),
+        rating: Rating.again,
+        took: const Duration(seconds: 30),
+      ),
+    ]);
+    await showStatistics(tester);
+
+    expect(find.text('In total'), findsOneWidget);
+    // 2 min 30 s; 1 min 15 s a day over two days; 2 min today.
+    expect(find.text('3 min'), findsOneWidget);
+    expect(find.text('1 min'), findsOneWidget);
+    expect(find.text('Today · 2 min'), findsOneWidget);
+    expect(find.text('Today · 2 cards rated'), findsOneWidget);
+    expect(find.text('Perfect 1'), findsOneWidget);
+    expect(find.text('Bad 0'), findsOneWidget);
+    expect(find.byType(BarChart), findsNWidgets(2));
+  });
+
+  testWidgets('a tap on a bar says what it holds; Weeks shows weeks', (
+    tester,
+  ) async {
+    await studied([
+      (
+        ago: const Duration(days: 1),
+        rating: Rating.again,
+        took: const Duration(seconds: 30),
+      ),
+    ]);
+    await showStatistics(tester);
+    expect(find.text('Today · No cards rated'), findsOneWidget);
+
+    // Yesterday's bar: the second from the end.
+    final chart = tester.getRect(find.byType(BarChart).last);
+    await tester.tapAt(
+      Offset(chart.right - (chart.width - 24) / 10 * 1.5, chart.center.dy),
+    );
+    await tester.pumpAndSettle();
+    expect(find.textContaining(' · 1 card rated'), findsOneWidget);
+    expect(find.text('Bad 1'), findsOneWidget);
+
+    await tester.tap(find.text('Weeks'));
+    await tester.pumpAndSettle();
+    expect(find.textContaining('Week of '), findsNWidgets(2));
+  });
+
+  testWidgets('from expanded windows on, the two charts stand side by side, '
+      'as tall as each other', (tester) async {
+    await studied([
+      (
+        ago: Duration.zero,
+        rating: Rating.good,
+        took: const Duration(seconds: 20),
+      ),
+    ]);
+    await showStatistics(tester, width: 1200);
+
+    final cards = find.ancestor(
+      of: find.byType(BarChart),
+      matching: find.byType(Card),
+    );
+    final [first, second] = [
+      for (final element in cards.evaluate())
+        tester.getRect(find.byElementPredicate((e) => e == element)),
+    ];
+    expect(first.top, second.top);
+    expect(first.height, second.height);
+    expect(first.right, lessThan(second.left));
+  });
+
+  testWidgets('says so while nothing was studied', (tester) async {
+    await showStatistics(tester);
+
+    expect(find.textContaining('Nothing studied yet'), findsOneWidget);
+    expect(find.byType(BarChart), findsNothing);
+  });
+}