add stats page

lib/objects/objects.dart

@@ -168,6 +168,208 @@ class YearlyMileage {
   );
 }
 
+class StatsAbout {
+  final Map<int, StatsYear> years;
+
+  StatsAbout({required this.years});
+
+  factory StatsAbout.fromJson(Map<String, dynamic> json) {
+    final mileageByYear = <int, double>{};
+    final classByYear = <int, List<StatsClassMileage>>{};
+    final networkByYear = <int, List<StatsNetworkMileage>>{};
+    final stationByYear = <int, List<StatsStationVisits>>{};
+    final winnersByYear = <int, int>{};
+
+    void addYearMileage(dynamic entry) {
+      if (entry is Map<String, dynamic>) {
+        final year = entry['year'] is int
+            ? entry['year'] as int
+            : int.tryParse('${entry['year']}');
+        if (year != null) {
+          mileageByYear[year] = _asDouble(entry['mileage']);
+        }
+      }
+    }
+
+    if (json['year_mileages'] is List) {
+      for (final entry in json['year_mileages']) {
+        if (entry is Map<String, dynamic>) {
+          addYearMileage(entry);
+        } else if (entry is Map) {
+          addYearMileage(entry
+              .map((key, value) => MapEntry(key.toString(), value)));
+        }
+      }
+    }
+
+    List<StatsClassMileage> parseClassList(dynamic value) {
+      if (value is List) {
+        return value
+            .whereType<Map>()
+            .map((e) => StatsClassMileage.fromJson(
+                e.map((key, value) => MapEntry(key.toString(), value))))
+            .toList();
+      }
+      return const [];
+    }
+
+    List<StatsNetworkMileage> parseNetworkList(dynamic value) {
+      if (value is List) {
+        return value
+            .whereType<Map>()
+            .map((e) => StatsNetworkMileage.fromJson(
+                e.map((key, value) => MapEntry(key.toString(), value))))
+            .toList();
+      }
+      return const [];
+    }
+
+    List<StatsStationVisits> parseStationList(dynamic value) {
+      if (value is List) {
+        return value
+            .whereType<Map>()
+            .map((e) => StatsStationVisits.fromJson(
+                e.map((key, value) => MapEntry(key.toString(), value))))
+            .toList();
+      }
+      return const [];
+    }
+
+    void parseYearMap<T>(
+      dynamic source,
+      Map<int, T> target,
+      T Function(dynamic value) mapper,
+    ) {
+      if (source is Map) {
+        source.forEach((key, value) {
+          final year = int.tryParse(key.toString());
+          if (year == null) return;
+          target[year] = mapper(value);
+        });
+      }
+    }
+
+    parseYearMap<List<StatsClassMileage>>(
+      json['top_classes'],
+      classByYear,
+      parseClassList,
+    );
+    parseYearMap<List<StatsNetworkMileage>>(
+      json['top_networks'],
+      networkByYear,
+      parseNetworkList,
+    );
+    parseYearMap<List<StatsStationVisits>>(
+      json['top_stations'],
+      stationByYear,
+      parseStationList,
+    );
+    if (json['year_winners'] is Map) {
+      (json['year_winners'] as Map).forEach((key, value) {
+        final year = int.tryParse(key.toString());
+        if (year == null) return;
+        if (value is List) {
+          winnersByYear[year] = value.length;
+        }
+      });
+    }
+
+    final years = <int>{
+      ...mileageByYear.keys,
+      ...classByYear.keys,
+      ...networkByYear.keys,
+      ...stationByYear.keys,
+      ...winnersByYear.keys,
+    }..removeWhere((year) => year == 0);
+
+    final yearMap = <int, StatsYear>{};
+    for (final year in years) {
+      yearMap[year] = StatsYear(
+        year: year,
+        mileage: mileageByYear[year] ?? 0,
+        topClasses: classByYear[year] ?? const [],
+        topNetworks: networkByYear[year] ?? const [],
+        topStations: stationByYear[year] ?? const [],
+        winnerCount: winnersByYear[year] ?? 0,
+      );
+    }
+
+    return StatsAbout(years: yearMap);
+  }
+
+  List<StatsYear> get sortedYears {
+    final list = years.values.toList();
+    list.sort((a, b) => b.year.compareTo(a.year));
+    return list;
+  }
+}
+
+class StatsYear {
+  final int year;
+  final double mileage;
+  final List<StatsClassMileage> topClasses;
+  final List<StatsNetworkMileage> topNetworks;
+  final List<StatsStationVisits> topStations;
+  final int winnerCount;
+
+  StatsYear({
+    required this.year,
+    required this.mileage,
+    required this.topClasses,
+    required this.topNetworks,
+    required this.topStations,
+    required this.winnerCount,
+  });
+}
+
+class StatsClassMileage {
+  final String locoClass;
+  final double mileage;
+
+  StatsClassMileage({
+    required this.locoClass,
+    required this.mileage,
+  });
+
+  factory StatsClassMileage.fromJson(Map<String, dynamic> json) =>
+      StatsClassMileage(
+        locoClass: _asString(json['loco_class'], 'Unknown'),
+        mileage: _asDouble(json['mileage']),
+      );
+}
+
+class StatsNetworkMileage {
+  final String network;
+  final double mileage;
+
+  StatsNetworkMileage({
+    required this.network,
+    required this.mileage,
+  });
+
+  factory StatsNetworkMileage.fromJson(Map<String, dynamic> json) =>
+      StatsNetworkMileage(
+        network: _asString(json['network'], 'Unknown'),
+        mileage: _asDouble(json['mileage']),
+      );
+}
+
+class StatsStationVisits {
+  final String station;
+  final int visits;
+
+  StatsStationVisits({
+    required this.station,
+    required this.visits,
+  });
+
+  factory StatsStationVisits.fromJson(Map<String, dynamic> json) =>
+      StatsStationVisits(
+        station: _asString(json['station'], 'Unknown'),
+        visits: _asInt(json['visits']),
+      );
+}
+
 class Loco {
   final int id;
   final String type, number, locoClass;