Add friends leaderboard, reverse button in add page

lib/components/dashboard/leaderboard_panel.dart

@@ -1,19 +1,31 @@
 import 'package:flutter/material.dart';
 import 'package:mileograph_flutter/services/data_service.dart';
 import 'package:mileograph_flutter/services/distance_unit_service.dart';
-
 import 'package:provider/provider.dart';
+enum _LeaderboardScope { global, friends }
 
-class LeaderboardPanel extends StatelessWidget {
+class LeaderboardPanel extends StatefulWidget {
   const LeaderboardPanel({super.key});
 
+  @override
+  State<LeaderboardPanel> createState() => _LeaderboardPanelState();
+}
+
+class _LeaderboardPanelState extends State<LeaderboardPanel> {
+  _LeaderboardScope _scope = _LeaderboardScope.global;
+
   @override
   Widget build(BuildContext context) {
     final data = context.watch<DataService>();
     final distanceUnits = context.watch<DistanceUnitService>();
-    final leaderboard = data.homepageStats?.leaderboard ?? [];
+    final leaderboard = _scope == _LeaderboardScope.global
+        ? (data.homepageStats?.leaderboard ?? [])
+        : data.friendsLeaderboard;
+    final loading = _scope == _LeaderboardScope.global
+        ? data.isHomepageLoading
+        : data.isFriendsLeaderboardLoading;
     final textTheme = Theme.of(context).textTheme;
-    if (data.isHomepageLoading && leaderboard.isEmpty) {
+    if (loading && leaderboard.isEmpty) {
       return const Padding(
         padding: EdgeInsets.all(16.0),
         child: Center(child: CircularProgressIndicator()),
@@ -51,6 +63,38 @@ class LeaderboardPanel extends StatelessWidget {
                       style: textTheme.labelSmall,
                     ),
                   ),
+                const SizedBox(width: 8),
+                SegmentedButton<_LeaderboardScope>(
+                  segments: const [
+                    ButtonSegment(
+                      value: _LeaderboardScope.global,
+                      label: Text('Global'),
+                    ),
+                    ButtonSegment(
+                      value: _LeaderboardScope.friends,
+                      label: Text('Friends'),
+                    ),
+                  ],
+                  selected: {_scope},
+                  onSelectionChanged: (vals) async {
+                    if (vals.isEmpty) return;
+                    final selected = vals.first;
+                    setState(() => _scope = selected);
+                    if (selected == _LeaderboardScope.friends &&
+                        data.friendsLeaderboard.isEmpty &&
+                        !data.isFriendsLeaderboardLoading) {
+                      await data.fetchFriendsLeaderboard();
+                    } else if (selected == _LeaderboardScope.global &&
+                        (data.homepageStats?.leaderboard.isEmpty ?? true) &&
+                        !data.isHomepageLoading) {
+                      await data.fetchHomepageStats();
+                    }
+                  },
+                  style: SegmentedButton.styleFrom(
+                    visualDensity: VisualDensity.compact,
+                    padding: const EdgeInsets.symmetric(horizontal: 8),
+                  ),
+                ),
               ],
             ),
             const SizedBox(height: 8),