fix: average calculations

firka/lib/data/widget.dart

@@ -1,7 +1,9 @@
+import 'dart:collection';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:firka/api/client/kreta_client.dart';
+import 'package:firka_common/ui/components/grade_helpers.dart';
 import 'package:kreta_api/kreta_api.dart';
 import 'package:firka/core/debug_helper.dart';
 import 'package:firka/data/ios_widget_helper.dart';
@@ -249,31 +251,20 @@ class WidgetCacheHelper {
       );
 
       final Map<String, double> subjectAverages = {};
-      final Set<String> subjectUids = {};
+      final HashSet<Subject> subjects = HashSet(
+        hashCode: (s) => s.uid.hashCode,
+        equals: (s, s2) => s.uid == s2.uid,
+      );
 
-      for (var grade in grades) {
-        subjectUids.add(grade.subject.uid);
-      }
+      subjects.addAll(grades.map((g) => g.subject));
 
-      double overallSum = 0;
-      int validSubjectCount = 0;
-
-      for (var uid in subjectUids) {
-        final subjectGrades = grades
-            .where((g) => g.subject.uid == uid)
-            .toList();
-        final avg = _calculateWeightedAverage(subjectGrades);
-        if (!avg.isNaN && avg > 0) {
-          subjectAverages[uid] = avg;
-          overallSum += avg;
-          validSubjectCount++;
+      for (var subject in subjects) {
+        final average = grades.getAverageBySubject(subject);
+        if (average != null) {
+          subjectAverages[subject.uid] = average;
         }
       }
 
-      final double? overallAverage = validSubjectCount > 0
-          ? overallSum / validSubjectCount
-          : null;
-
       WidgetBreakInfo? currentBreak;
 
       await updateIOSWidgets(
@@ -285,7 +276,7 @@ class WidgetCacheHelper {
         nextSchoolDayDate: nextSchoolDayDate,
         grades: grades,
         subjectAverages: subjectAverages,
-        overallAverage: overallAverage,
+        overallAverage: grades.getSubjectAverage(),
         currentBreak: currentBreak,
       );
 
@@ -315,26 +306,4 @@ class WidgetCacheHelper {
       debugPrint('Error clearing iOS widgets: $e');
     }
   }
-
-  /// Calculate weighted average for a list of grades
-  static double _calculateWeightedAverage(List<Grade> grades) {
-    var weightTotal = 0.0;
-    var sum = 0.0;
-
-    for (var grade in grades) {
-      final name = grade.valueType.name?.toLowerCase() ?? '';
-      final isPercentage =
-          name.contains('szazalek') || name.contains('percent');
-      if (isPercentage) continue;
-
-      if (grade.numericValue != null) {
-        var weight = (grade.weightPercentage ?? 100) / 100.0;
-        weightTotal += weight;
-        sum += grade.numericValue! * weight;
-      }
-    }
-
-    if (weightTotal == 0) return double.nan;
-    return sum / weightTotal;
-  }
 }

firka/lib/ui/phone/widgets/grade_chart.dart

@@ -10,7 +10,13 @@ import 'package:flutter/material.dart';
 
 class GradeChart extends StatefulWidget {
   final List<Grade> grades;
-  const GradeChart({super.key, required this.grades});
+  final bool halfYearFallback;
+  GradeChart({
+    super.key,
+    required List<Grade> grades,
+    this.halfYearFallback = true,
+  }) : grades = grades.where((g) => g.hasClassicValue()).toList()
+         ..sort((a, b) => a.recordDate.compareTo(b.recordDate));
 
   @override
   State<GradeChart> createState() => _GradeChartState();
@@ -20,6 +26,10 @@ class DateSpot extends FlSpot {
   final DateTime date;
 
   const DateSpot(super.x, super.y, this.date);
+
+  DateSpot copyWithX(double x) {
+    return DateSpot(x, y, date);
+  }
 }
 
 class _GradeChartState extends State<GradeChart> {
@@ -36,26 +46,43 @@ class _GradeChartState extends State<GradeChart> {
   }
 
   void _computeSpots() {
-    final sortedGrades =
-        widget.grades.where((grade) => grade.shouldIncludeInAverage()).toList()
-          ..sort((a, b) => a.recordDate.compareTo(b.recordDate));
-
-    if (sortedGrades.isEmpty) {
-      spots = [DateSpot(0, 0, DateTime.now()), DateSpot(1, 0, DateTime.now())];
-      return;
-    }
-
-    if (sortedGrades.length == 1) {
-      sortedGrades.insert(0, sortedGrades[0]);
-    }
-
     spots = [];
-    for (var i = 0; i < sortedGrades.length; i++) {
-      final partialAvg = sortedGrades.take(i + 1).getSubjectAverage();
+    for (var i = 0; i < widget.grades.length; i++) {
+      final grade = widget.grades[i];
+      if (!grade.shouldIncludeInAverage()) {
+        continue;
+      }
+
+      final partialAvg = widget.grades
+          .take(i + 1)
+          .getSubjectAverage(halfYearFallback: widget.halfYearFallback);
+
       spots.add(
-        DateSpot(i.toDouble(), partialAvg!, sortedGrades[i].recordDate),
+        DateSpot(spots.length.toDouble(), partialAvg!, grade.recordDate),
       );
     }
+
+    if (spots.isEmpty) {
+      for (final grade in widget.grades) {
+        if (grade.hasClassicValue()) {
+          spots.add(
+            DateSpot(
+              spots.length.toDouble(),
+              grade.numericValue!.toDouble(),
+              grade.recordDate,
+            ),
+          );
+        }
+      }
+    }
+
+    if (spots.isEmpty) {
+      spots.add(DateSpot(0, 0, DateTime.now()));
+    }
+
+    if (spots.length == 1) {
+      spots = [spots[0], spots[0].copyWithX(1)];
+    }
   }
 
   List<FlSpot> _smoothSpots(List<FlSpot> input) {
@@ -356,8 +383,13 @@ class _GradeChartState extends State<GradeChart> {
 /// so the navigator does not intercept touch/drag (e.g. for swipe back).
 class GradeChartWithInteraction extends StatelessWidget {
   final List<Grade> grades;
+  final bool halfYearFallback;
 
-  const GradeChartWithInteraction({super.key, required this.grades});
+  const GradeChartWithInteraction({
+    super.key,
+    required this.grades,
+    this.halfYearFallback = true,
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -366,7 +398,7 @@ class GradeChartWithInteraction extends StatelessWidget {
       onPointerDown: (_) => ChartInteractionScope.of(context).value = true,
       onPointerUp: (_) => ChartInteractionScope.of(context).value = false,
       onPointerCancel: (_) => ChartInteractionScope.of(context).value = false,
-      child: GradeChart(grades: grades),
+      child: GradeChart(grades: grades, halfYearFallback: halfYearFallback),
     );
   }
 }

firka_common/lib/ui/components/grade.dart

@@ -43,7 +43,7 @@ class GradeWidget extends StatelessWidget {
       );
     }
 
-    if (g.valueType.name == 'Szazalekos') {
+    if (g.isInPercentage()) {
       final gradeColor = appStyle.colors.accent;
       return FilledCircle(
         diameter: size,

firka_common/lib/ui/components/grade_helpers.dart

@@ -58,20 +58,31 @@ extension GradeListExtension on Iterable<Grade> {
     return (filtered.length, counts);
   }
 
-  double? getAverageBySubject(Subject subject) {
+  double? _getAverageBySubject(String uid, {bool halfYearFallback = true}) {
     return where(
-      (g) => g.subject.uid == subject.uid && g.shouldIncludeInAverage(),
-    ).getAverage();
+      (g) => g.subject.uid == uid,
+    ).getAverage(halfYearFallback: halfYearFallback);
+  }
+
+  double? getAverageBySubject(Subject subject, {bool halfYearFallback = true}) {
+    return _getAverageBySubject(
+      subject.uid,
+      halfYearFallback: halfYearFallback,
+    );
   }
 
   double? getRoundedSubjectAverage({
+    bool halfYearFallback = true,
     double t1 = 1,
     double t2 = 0.5,
     double t3 = 0.5,
     double t4 = 0.5,
   }) {
     final averages = map((g) => g.subject).toSet().map((subject) {
-      final average = getAverageBySubject(subject);
+      final average = getAverageBySubject(
+        subject,
+        halfYearFallback: halfYearFallback,
+      );
       if (average == null) {
         return null;
       }
@@ -85,10 +96,15 @@ extension GradeListExtension on Iterable<Grade> {
     return averages.reduce((sum, avg) => sum + avg) / averages.length;
   }
 
-  double? getSubjectAverage() {
-    final averages = map(
-      (g) => g.subject,
-    ).toSet().map((subject) => getAverageBySubject(subject)).nonNulls;
+  double? getSubjectAverage({bool halfYearFallback = true}) {
+    final averages = where((g) => g.hasClassicValue())
+        .map((g) => g.subject.uid)
+        .toSet()
+        .map(
+          (uid) =>
+              _getAverageBySubject(uid, halfYearFallback: halfYearFallback),
+        )
+        .nonNulls;
 
     if (averages.isEmpty) {
       return null;
@@ -97,25 +113,31 @@ extension GradeListExtension on Iterable<Grade> {
     return averages.reduce((sum, avg) => sum + avg) / averages.length;
   }
 
-  double? getAverage() {
+  double? getAverage({bool halfYearFallback = true}) {
     if (isEmpty) {
       return null;
     }
 
     double weightTotal = 0;
     double sum = 0;
+    int? fallback;
     for (Grade grade in this) {
+      if (grade.hasClassicValue() && halfYearFallback) {
+        fallback = grade.numericValue!;
+      }
+
       if (!grade.shouldIncludeInAverage()) {
         continue;
       }
 
-      double weight = (grade.weightPercentage ?? 100) / 100.0;
+      double weight = grade.weightPercentage! / 100.0;
       weightTotal += weight;
       sum += grade.numericValue! * weight;
     }
 
     if (sum == 0) {
-      return null;
+      // use classification exam results or half-year evaluations
+      return fallback?.toDouble();
     }
 
     return sum / weightTotal;
@@ -124,25 +146,15 @@ extension GradeListExtension on Iterable<Grade> {
 
 extension GradeExtension on Grade {
   bool isInPercentage() {
-    final name = valueType.name.toLowerCase();
-    return name.contains('szazalek') || name.contains('percent');
+    return valueType.name == 'Szazalekos';
   }
 
+  bool hasClassicValue() {
+    return valueType.name == "Osztalyzat";
+  }
+
+  // https://tudasbazis.ekreta.hu/pages/viewpage.action?pageId=2426172
   bool shouldIncludeInAverage() {
-    if (isInPercentage()) {
-      return false;
-    }
-
-    final typeName = type.name.toLowerCase();
-    if (typeName == 'felevi_jegy_ertekeles' ||
-        typeName == 'evvegi_jegy_ertekeles') {
-      return false;
-    }
-
-    if (numericValue == null) {
-      return false;
-    }
-
-    return true;
+    return weightPercentage != null && hasClassicValue();
   }
 }