import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../app/load_state.dart';
import '../models/stats_summary.dart';
import '../providers/providers.dart';
import '../widgets/load_error_view.dart';

/// Экран просмотра статистики.
/// Показывает сводку по группам за выбранный период.
class StatsScreen extends ConsumerStatefulWidget {
  const StatsScreen({super.key});

  @override
  ConsumerState<StatsScreen> createState() => _StatsScreenState();
}

class _StatsScreenState extends ConsumerState<StatsScreen> {
  int _days = 7;

  @override
  void initState() {
    super.initState();
    _load();
  }

  Future<void> _load() async {
    await ref.read(statsProvider.notifier).load(days: _days);
  }

  @override
  Widget build(BuildContext context) {
    final statsState = ref.watch(statsProvider);
    final stats = statsState.data;

    return Scaffold(
      appBar: AppBar(title: const Text('СТАТИСТИКА')),
      body: Column(
        children: [
          // ─── Переключатель периода ───
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
            child: Row(
              children: [
                const Text('Период:', style: TextStyle(color: Colors.white54)),
                const SizedBox(width: 12),
                ...[1, 7, 14, 30].map(
                  (d) => Padding(
                    padding: const EdgeInsets.only(right: 8),
                    child: ChoiceChip(
                      label: Text('$d д.'),
                      selected: _days == d,
                      selectedColor: Colors.deepOrange,
                      onSelected: (_) {
                        setState(() => _days = d);
                        _load();
                      },
                    ),
                  ),
                ),
              ],
            ),
          ),

          // ─── Содержимое ───
          Expanded(child: _buildContent(statsState, stats.groups)),
        ],
      ),
    );
  }

  Widget _buildContent(
    LoadState<StatsSummary> statsState,
    List<GroupStats> groups,
  ) {
    if ((statsState.isIdle || statsState.isLoading) && groups.isEmpty) {
      return const Center(
        child: CircularProgressIndicator(color: Colors.deepOrange),
      );
    }

    if (statsState.hasError && groups.isEmpty) {
      return LoadErrorView(
        title: 'Не удалось загрузить статистику',
        message: statsState.errorMessage,
        icon: Icons.bar_chart,
        onRetry: _load,
      );
    }

    if (groups.isEmpty) {
      return const Center(
        child: Text('Нет данных', style: TextStyle(color: Colors.white54)),
      );
    }

    final hasStatusHeader = statsState.isLoading || statsState.hasError;
    final statusHeaderCount = hasStatusHeader ? 1 : 0;

    return RefreshIndicator(
      color: Colors.deepOrange,
      onRefresh: _load,
      child: ListView.builder(
        physics: const AlwaysScrollableScrollPhysics(),
        padding: const EdgeInsets.all(12),
        itemCount: groups.length + statusHeaderCount,
        itemBuilder: (context, index) {
          if (hasStatusHeader && index == 0) {
            if (statsState.isLoading) {
              return const Padding(
                padding: EdgeInsets.only(bottom: 12),
                child: LinearProgressIndicator(color: Colors.deepOrange),
              );
            }

            return LoadErrorBanner(
              title: 'Не удалось обновить статистику',
              message: statsState.errorMessage,
              onRetry: _load,
            );
          }

          final groupIndex = index - statusHeaderCount;
          return _StatsCard(data: groups[groupIndex]);
        },
      ),
    );
  }
}

/// Карточка статистики одной группы
class _StatsCard extends StatelessWidget {
  final GroupStats data;

  const _StatsCard({required this.data});

  @override
  Widget build(BuildContext context) {
    return Card(
      margin: const EdgeInsets.only(bottom: 8),
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              data.name,
              style: const TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
            ),
            const SizedBox(height: 12),
            _StatRow(
              icon: Icons.touch_app,
              label: 'Всего команд',
              value: data.totalCommands.toString(),
            ),
            const SizedBox(height: 4),
            _StatRow(
              icon: Icons.power_settings_new,
              label: 'Включений',
              value: data.togglesOn.toString(),
              color: Colors.green,
            ),
            const SizedBox(height: 4),
            _StatRow(
              icon: Icons.power_off,
              label: 'Выключений',
              value: data.togglesOff.toString(),
              color: Colors.redAccent,
            ),
            if (data.estimatedHours != null) ...[
              const SizedBox(height: 4),
              _StatRow(
                icon: Icons.access_time,
                label: 'Примерное время работы',
                value: data.formattedEstimatedHours,
                color: Colors.amber,
              ),
            ],
          ],
        ),
      ),
    );
  }
}

/// Строка с иконкой, меткой и значением
class _StatRow extends StatelessWidget {
  final IconData icon;
  final String label;
  final String value;
  final Color? color;

  const _StatRow({
    required this.icon,
    required this.label,
    required this.value,
    this.color,
  });

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        Icon(icon, size: 16, color: color ?? Colors.white38),
        const SizedBox(width: 8),
        Expanded(
          child: Text(
            label,
            style: const TextStyle(fontSize: 13, color: Colors.white54),
          ),
        ),
        Text(
          value,
          style: TextStyle(
            fontSize: 14,
            fontWeight: FontWeight.bold,
            color: color ?? Colors.white70,
          ),
        ),
      ],
    );
  }
}