feat(points): Init user points statistics page

* User points statistics page need further optimization.
* User points changelog page is unimplemented.

lib/extensions/universal_html.dart

@@ -177,7 +177,7 @@ extension GrepExtension on Element {
     if (children.length > 1) {
       // The value here is not a plain text, it's a normal node.
       // TODO: If we have a normal node value, parse it's link, img even styles.
-      value = childAtOrNull(1)?.firstEndDeepText();
+      value = nodes.elementAtOrNull(1)?.text;
     } else {
       value = nodes.lastOrNull?.text?.trim();
     }

lib/features/points/bloc/points_bloc.dart

@@ -0,0 +1,87 @@
+import 'package:bloc/bloc.dart';
+import 'package:equatable/equatable.dart';
+import 'package:tsdm_client/exceptions/exceptions.dart';
+import 'package:tsdm_client/extensions/universal_html.dart';
+import 'package:tsdm_client/features/points/models/points_change.dart';
+import 'package:tsdm_client/features/points/repository/points_repository.dart';
+import 'package:tsdm_client/utils/debug.dart';
+import 'package:universal_html/html.dart' as uh;
+
+part 'points_event.dart';
+part 'points_state.dart';
+
+/// Statistics emitter.
+typedef PointsStatisticsEmitter = Emitter<PointsStatisticsState>;
+
+/// Bloc of user points statistics page.
+final class PointsStatisticsBloc
+    extends Bloc<PointsStatisticsEvent, PointsStatisticsState> {
+  /// Constructor.
+  PointsStatisticsBloc({required PointsRepository pointsRepository})
+      : _pointsRepository = pointsRepository,
+        super(const PointsStatisticsState()) {
+    on<PointsStatisticsRefreshRequired>(_onPointsStatisticsRefreshRequired);
+  }
+
+  final PointsRepository _pointsRepository;
+
+  Future<void> _onPointsStatisticsRefreshRequired(
+    PointsStatisticsRefreshRequired event,
+    PointsStatisticsEmitter emit,
+  ) async {
+    emit(state.copyWith(status: PointsStatus.loading));
+    try {
+      final document = await _pointsRepository.fetchStatisticsPage();
+      final result = _parseDocument(document);
+      if (result == null) {
+        emit(state.copyWith(status: PointsStatus.failed));
+        return;
+      }
+      emit(
+        state.copyWith(
+          status: PointsStatus.success,
+          pointsMap: result.$1,
+          pointsRecentChangelog: result.$2,
+        ),
+      );
+    } on HttpRequestFailedException catch (e) {
+      debug('failed to fetch points statistics page: $e');
+      emit(state.copyWith(status: PointsStatus.failed));
+    }
+  }
+
+  (Map<String, String>, List<PointsChange>)? _parseDocument(
+    uh.Document document,
+  ) {
+    final rootNode = document.querySelector('div#ct_shell div.bm.bw0');
+    if (rootNode == null) {
+      debug('points change root node not found');
+      return null;
+    }
+    final pointsMapEntries = rootNode
+        .querySelectorAll('ul.creditl > li')
+        .map((e) => e.parseLiEmNode())
+        .whereType<(String, String)>()
+        .map((e) => MapEntry(e.$1, e.$2));
+    final pointsMap = Map<String, String>.fromEntries(pointsMapEntries);
+
+    final tableNode = rootNode.querySelector('table.dt');
+    if (tableNode == null) {
+      debug('points change table not found');
+      return null;
+    }
+    final pointsChangeList = _buildChangeListFromTable(tableNode);
+    return (pointsMap, pointsChangeList);
+  }
+
+  /// Build a list of [PointsChange] from <table class="dt">
+  List<PointsChange> _buildChangeListFromTable(uh.Element element) {
+    final ret = element
+        .querySelectorAll('table > tbody > tr')
+        .skip(1)
+        .map(PointsChange.fromTrNode)
+        .whereType<PointsChange>()
+        .toList();
+    return ret;
+  }
+}

lib/features/points/bloc/points_event.dart

@@ -0,0 +1,34 @@
+part of 'points_bloc.dart';
+
+/// Event of points statistics page.
+sealed class PointsStatisticsEvent extends Equatable {
+  /// Constructor.
+  const PointsStatisticsEvent();
+
+  @override
+  List<Object?> get props => [];
+}
+
+/// User required to refresh the points statistics page.
+final class PointsStatisticsRefreshRequired extends PointsStatisticsEvent {}
+
+/// Event of points changelog page.
+sealed class PointsChangelogEvent extends Equatable {
+  /// Constructor.
+  const PointsChangelogEvent();
+
+  @override
+  List<Object?> get props => [];
+}
+
+/// User required to refresh the points changelog page.
+final class PointsChangelogRefreshRequired extends PointsChangelogEvent {}
+
+/// User required to load more page in points changelog page.
+final class PointsChangelogLoadMoreRequired extends PointsChangelogEvent {
+  /// Constructor.
+  const PointsChangelogLoadMoreRequired(this.pageNumber);
+
+  /// Page number to fetch data from.
+  final String pageNumber;
+}

lib/features/points/bloc/points_state.dart

@@ -0,0 +1,119 @@
+part of 'points_bloc.dart';
+
+/// State of current user points.
+enum PointsStatus {
+  /// Initial.
+  initial,
+
+  /// Loading data.
+  loading,
+
+  /// Load succeed.
+  success,
+
+  /// Load failed.
+  failed,
+}
+
+/// State of user points statistics page.
+///
+/// This page has no pagination and the length of points changelog is expected
+/// to no more than 10.
+final class PointsStatisticsState extends Equatable {
+  /// Constructor.
+  const PointsStatisticsState({
+    this.status = PointsStatus.initial,
+    this.pointsMap = const {},
+    this.pointsRecentChangelog = const [],
+  });
+
+  /// Status.
+  final PointsStatus status;
+
+  /// Map of user's different attributes points.
+  ///
+  /// With `name` and `value`.
+  final Map<String, String> pointsMap;
+
+  /// A list of changes event on user's points.
+  ///
+  /// But this field only contains recent changes that shows in user's points
+  /// page.
+  ///
+  /// The length is expected to be no more than 10.
+  ///
+  /// For full changelog, see [PointsChangelogState.pointsFullChangelog].
+  final List<PointsChange> pointsRecentChangelog;
+
+  /// Copy with
+  PointsStatisticsState copyWith({
+    PointsStatus? status,
+    Map<String, String>? pointsMap,
+    List<PointsChange>? pointsRecentChangelog,
+  }) {
+    return PointsStatisticsState(
+      status: status ?? this.status,
+      pointsMap: pointsMap ?? this.pointsMap,
+      pointsRecentChangelog:
+          pointsRecentChangelog ?? this.pointsRecentChangelog,
+    );
+  }
+
+  @override
+  List<Object?> get props => [
+        status,
+        pointsMap,
+        pointsRecentChangelog,
+      ];
+}
+
+/// State of points changelog page.
+final class PointsChangelogState extends Equatable {
+  /// Constructor.
+  const PointsChangelogState({
+    this.status = PointsStatus.initial,
+    this.pointsFullChangelog = const [],
+    this.pointsLogPageCurrentNumber = 1,
+    this.pointsLogPageTotalNumber = 1,
+  });
+
+  /// Status.
+  final PointsStatus status;
+
+  /// A list of changes event on user's points.
+  ///
+  /// This field contains all queried changes on user's points, may contains
+  /// a long period.
+  ///
+  /// For recent changes, see [PointsStatisticsState.pointsRecentChangelog].
+  final List<PointsChange> pointsFullChangelog;
+
+  /// Current page number of user's points changelog page.
+  final int pointsLogPageCurrentNumber;
+
+  /// Total pages count of user's points changelog page.
+  final int pointsLogPageTotalNumber;
+
+  /// Copy with.
+  PointsChangelogState copyWith({
+    List<PointsChange>? pointsFullChangelog,
+    int? pointsLogPageCurrentNumber,
+    int? pointsLogPageTotalNumber,
+  }) {
+    return PointsChangelogState(
+      pointsFullChangelog: pointsFullChangelog ?? this.pointsFullChangelog,
+      pointsLogPageCurrentNumber:
+          pointsLogPageCurrentNumber ?? this.pointsLogPageCurrentNumber,
+      pointsLogPageTotalNumber:
+          pointsLogPageTotalNumber ?? this.pointsLogPageTotalNumber,
+    );
+  }
+
+  @override
+  List<Object?> get props => [
+        status,
+        pointsFullChangelog,
+        pointsLogPageCurrentNumber,
+        pointsLogPageTotalNumber,
+      ];
+}

lib/features/points/models/points_change.dart

@@ -0,0 +1,130 @@
+import 'package:equatable/equatable.dart';
+import 'package:tsdm_client/extensions/string.dart';
+import 'package:tsdm_client/utils/debug.dart';
+import 'package:universal_html/html.dart' as uh;
+
+/// A single change on the user's points.
+///
+/// Contains of change operation, attr points change list, change detail and
+/// happened datetime.
+class PointsChange extends Equatable {
+  /// Constructor
+  const PointsChange({
+    required this.operation,
+    required this.changeMap,
+    required this.detail,
+    required this.time,
+    this.redirectUrl,
+  });
+
+  /// Operation type of this change.
+  final String operation;
+
+  /// Map of the changes in different attr types with their names and values.
+  final Map<String, String> changeMap;
+
+  /// Html node to parse the detail change.
+  final String detail;
+
+  /// An url to redirect.
+  ///
+  /// Point changes usually have this, but not guaranteed.
+  final String? redirectUrl;
+
+  /// Datetime of this change.
+  final DateTime time;
+
+  /// [PointsChange] is expected to exists inside a <table class="dt">.
+  ///
+  /// In that table, each <tr> (except the table header) can be converted to an
+  /// instance of [PointsChange] :
+  ///
+  /// <tr>
+  ///   <td>
+  ///     <a>operation</a>
+  ///   </td>
+  ///   <td>
+  ///     attr1
+  ///     <span class="xi1">signed_value1</span>
+  ///     attr2
+  ///     <span class="xi1">signed_value2</span>
+  ///     attr3
+  ///     <span class="xi1">signed_value3</span>
+  ///     ...
+  ///   </td>
+  ///   <td>
+  ///     <a href=link_to_the_thread>detail</a>
+  ///   </td>
+  ///   <td>datetime</td>
+  ///
+  /// This function tries to build [PointsChange] from <tr> [element].
+  static PointsChange? fromTrNode(uh.Element element) {
+    final tdList = element.querySelectorAll('td');
+    if (tdList.length != 4) {
+      debug('failed to build PointsChange instance: '
+          'invalid td count: ${tdList.length}');
+      return null;
+    }
+
+    final operation = tdList[0].querySelector('a')?.innerText;
+    if (operation == null) {
+      debug('failed to build PointsChange: operation not found');
+      return null;
+    }
+    final attrNameList = <String>[];
+    final attrValueList = <String>[];
+    for (final node in tdList[1].childNodes) {
+      if (node.nodeType == uh.Node.ELEMENT_NODE) {
+        final e = node as uh.Element;
+        if (e.localName == 'span') {
+          attrValueList.add(e.innerText.trim());
+        }
+      } else if (node.nodeType == uh.Node.TEXT_NODE) {
+        final attrNameText = node.text?.trim();
+        if (attrNameText?.isNotEmpty ?? false) {
+          attrNameList.add(attrNameText!);
+        }
+      }
+    }
+    if (attrNameList.length != attrValueList.length) {
+      debug('failed to build PointsChange: invalid attar name '
+          'value length: $attrNameList and $attrValueList');
+      return null;
+    }
+    final changeMap = <String, String>{};
+    for (var i = 0; i < attrNameList.length; i++) {
+      changeMap[attrNameList[i]] = attrValueList[i];
+    }
+
+    final detail = tdList[2].innerText;
+    final redirectUrl =
+        tdList[2].querySelector('a')?.attributes['href']?.prependHost();
+    final changedTime = tdList[3].innerText.trim().parseToDateTimeUtc8();
+    if (changedTime == null) {
+      debug('failed to build PointsChange: invalid change time:'
+          '${tdList[3].innerText.trim()}');
+      return null;
+    }
+
+    return PointsChange(
+      operation: operation,
+      detail: detail,
+      redirectUrl: redirectUrl,
+      changeMap: changeMap,
+      time: changedTime,
+    );
+  }
+
+  /// Get tht formatted change.
+  String get changeMapString =>
+      changeMap.entries.map((e) => '${e.key} ${e.value}').join(',');
+
+  @override
+  List<Object?> get props => [
+        operation,
+        changeMap,
+        detail,
+        redirectUrl,
+        time,
+      ];
+}