Revamp puzzle tab

lib/src/model/puzzle/puzzle.dart

@@ -54,6 +54,8 @@ class PuzzleData with _$PuzzleData {
     required ISet<String> themes,
   }) = _PuzzleData;
 
+  Side get sideToMove => initialPly.isEven ? Side.black : Side.white;
+
   factory PuzzleData.fromJson(Map<String, dynamic> json) =>
       _$PuzzleDataFromJson(json);
 }

lib/src/utils/connectivity.dart

@@ -151,3 +151,61 @@ Future<bool> isOnline(Client client) {
   }
   return completer.future;
 }
+
+extension AsyncValueConnectivity on AsyncValue<ConnectivityStatus> {
+  /// Switches between device's connectivity status.
+  ///
+  /// Using this method assumes the the device is offline when the status is
+  /// not yet available (i.e. [AsyncValue.isLoading].
+  /// If you want to handle the loading state separately, use
+  /// [whenIsLoading] instead.
+  ///
+  /// This method is similar to [AsyncValueX.maybeWhen], but it takes two
+  /// functions, one for when the device is online and another for when it is
+  /// offline.
+  ///
+  /// Example:
+  /// ```dart
+  /// final status = ref.watch(connectivityChangesProvider);
+  /// final result = status.whenIs(
+  ///   online: () => 'Online',
+  ///   offline: () => 'Offline',
+  /// );
+  /// ```
+  R whenIs<R>({
+    required R Function() online,
+    required R Function() offline,
+  }) {
+    return maybeWhen(
+      data: (status) => status.isOnline ? online() : offline(),
+      orElse: offline,
+    );
+  }
+
+  /// Switches between device's connectivity status, but handling the loading state.
+  ///
+  /// This method is similar to [AsyncValueX.when], but it takes three
+  /// functions, one for when the device is online, another for when it is
+  /// offline, and the last for when the status is still loading.
+  ///
+  /// Example:
+  /// ```dart
+  /// final status = ref.watch(connectivityChangesProvider);
+  /// final result = status.whenIsLoading(
+  ///   online: () => 'Online',
+  ///   offline: () => 'Offline',
+  ///   loading: () => 'Loading',
+  /// );
+  /// ```
+  R whenIsLoading<R>({
+    required R Function() online,
+    required R Function() offline,
+    required R Function() loading,
+  }) {
+    return when(
+      data: (status) => status.isOnline ? online() : offline(),
+      loading: loading,
+      error: (error, stack) => offline(),
+    );
+  }
+}

lib/src/view/puzzle/puzzle_history_screen.dart

@@ -21,6 +21,8 @@ import 'package:timeago/timeago.dart' as timeago;
 final _dateFormatter = DateFormat.yMMMd();
 
 class PuzzleHistoryScreen extends StatelessWidget {
+  const PuzzleHistoryScreen();
+
   @override
   Widget build(BuildContext context) {
     return PlatformScaffold(