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 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 = _scope == _LeaderboardScope.global
        ? (data.homepageStats?.leaderboard ?? [])
        : data.friendsLeaderboard;
    final loading = _scope == _LeaderboardScope.global
        ? data.isHomepageLoading
        : data.isFriendsLeaderboardLoading;
    final textTheme = Theme.of(context).textTheme;
    if (loading && leaderboard.isEmpty) {
      return const Padding(
        padding: EdgeInsets.all(16.0),
        child: Center(child: CircularProgressIndicator()),
      );
    }
    return Card(
      clipBehavior: Clip.antiAlias,
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Row(
              children: [
                const Icon(Icons.emoji_events, size: 20),
                const SizedBox(width: 8),
                Expanded(
                  child: Text(
                    "Leaderboard",
                    style: textTheme.titleMedium?.copyWith(
                      fontWeight: FontWeight.w800,
                    ),
                  ),
                ),
                if (leaderboard.isNotEmpty &&
                    MediaQuery.of(context).size.width > 600)
                  Container(
                    padding:
                        const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                    decoration: BoxDecoration(
                      color: Theme.of(context).colorScheme.surfaceContainerHighest,
                      borderRadius: BorderRadius.circular(10),
                    ),
                    child: Text(
                      'Top ${leaderboard.length}',
                      style: textTheme.labelSmall,
                    ),
                  ),
              ],
            ),
            const SizedBox(height: 8),
            Center(
              child: 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),
            if (leaderboard.isEmpty)
              const Padding(
                padding: EdgeInsets.all(8.0),
                child: Text('No leaderboard data yet'),
              )
            else
              Column(
                children: [
                  for (int index = 0; index < leaderboard.length; index++) ...[
                    ListTile(
                      contentPadding: EdgeInsets.zero,
                      dense: true,
                      leading: CircleAvatar(
                        radius: 18,
                        backgroundColor:
                            Theme.of(context).colorScheme.secondaryContainer,
                        child: Text(
                          '${index + 1}',
                          style: textTheme.labelLarge?.copyWith(
                            fontWeight: FontWeight.w800,
                          ),
                        ),
                      ),
                      title: Text(
                        leaderboard[index].userFullName,
                        style: textTheme.titleSmall?.copyWith(
                          fontWeight: FontWeight.w700,
                        ),
                      ),
                      trailing: Text(
                        distanceUnits.format(
                          leaderboard[index].mileage,
                          decimals: 1,
                        ),
                        style: textTheme.labelLarge?.copyWith(
                          fontWeight: FontWeight.w700,
                        ),
                      ),
                    ),
                    if (index != leaderboard.length - 1) const Divider(height: 12),
                  ],
                ],
              ),
          ],
        ),
      ),
    );
  }
}