import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:fl_chart/fl_chart.dart';
import 'package:intl/intl.dart';
import '../../../providers/auth_provider.dart';
import '../../../providers/database_provider.dart';
import '../../../business/statistics_service.dart';

class StatisticsPage extends ConsumerStatefulWidget {
  const StatisticsPage({super.key});

  @override
  ConsumerState<StatisticsPage> createState() => _StatisticsPageState();
}

class _StatisticsPageState extends ConsumerState<StatisticsPage>
    with SingleTickerProviderStateMixin {
  late TabController _tabCtrl;

  @override
  void initState() {
    super.initState();
    _tabCtrl = TabController(length: 2, vsync: this);
  }

  @override
  void dispose() {
    _tabCtrl.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Statistiche'),
        bottom: TabBar(
          controller: _tabCtrl,
          tabs: const [
            Tab(text: 'Andamento Mensile'),
            Tab(text: 'Top Clienti'),
          ],
        ),
      ),
      body: TabBarView(
        controller: _tabCtrl,
        children: [
          _MonthlyChart(),
          _TopClientsChart(),
        ],
      ),
    );
  }
}

class _MonthlyChart extends ConsumerWidget {
  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final agente = ref.watch(authProvider).agente;
    if (agente == null) return const Center(child: Text('Login richiesto'));

    final statsService = StatisticsService(
      ref.read(statisticheDaoProvider),
      ref.read(articoliDaoProvider),
      ref.read(clientiDaoProvider),
      ref.read(agentiDaoProvider),
    );

    return FutureBuilder(
      future: statsService.getMonthlyTotals(agente.idAgente),
      builder: (_, snap) {
        if (!snap.hasData) return const Center(child: CircularProgressIndicator());
        final data = snap.data!;
        if (data.isEmpty) return const Center(child: Text('Nessun dato statistico'));

        final sortedKeys = data.keys.toList()..sort();
        final maxVal = data.values.reduce((a, b) => a > b ? a : b);

        return Padding(
          padding: const EdgeInsets.all(16),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text('Andamento Vendite', style: Theme.of(context).textTheme.titleMedium),
              const SizedBox(height: 16),
              Expanded(
                child: BarChart(
                  BarChartData(
                    alignment: BarChartAlignment.spaceAround,
                    maxY: maxVal * 1.2,
                    barGroups: sortedKeys.asMap().entries.map((e) => BarChartGroupData(
                      x: e.key,
                      barRods: [BarChartRodData(
                        toY: data[e.value]!,
                        color: Theme.of(context).colorScheme.primary,
                        width: 20,
                        borderRadius: const BorderRadius.vertical(top: Radius.circular(4)),
                      )],
                    )).toList(),
                    titlesData: FlTitlesData(
                      bottomTitles: AxisTitles(
                        sideTitles: SideTitles(
                          showTitles: true,
                          getTitlesWidget: (value, _) {
                            final idx = value.toInt();
                            if (idx < 0 || idx >= sortedKeys.length) return const SizedBox();
                            final label = sortedKeys[idx];
                            return Text(label.length >= 7 ? label.substring(5, 7) : label, style: const TextStyle(fontSize: 10));
                          },
                        ),
                      ),
                      leftTitles: AxisTitles(
                        sideTitles: SideTitles(
                          showTitles: true,
                          reservedSize: 60,
                          getTitlesWidget: (value, _) => Text(
                            NumberFormat.compact(locale: 'it').format(value),
                            style: const TextStyle(fontSize: 10),
                          ),
                        ),
                      ),
                      topTitles: const AxisTitles(sideTitles: SideTitles(showTitles: false)),
                      rightTitles: const AxisTitles(sideTitles: SideTitles(showTitles: false)),
                    ),
                    gridData: FlGridData(show: true, drawVerticalLine: false),
                    borderData: FlBorderData(show: false),
                  ),
                ),
              ),
            ],
          ),
        );
      },
    );
  }
}

class _TopClientsChart extends ConsumerWidget {
  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final agente = ref.watch(authProvider).agente;
    if (agente == null) return const Center(child: Text('Login richiesto'));

    final statsService = StatisticsService(
      ref.read(statisticheDaoProvider),
      ref.read(articoliDaoProvider),
      ref.read(clientiDaoProvider),
      ref.read(agentiDaoProvider),
    );

    return FutureBuilder(
      future: statsService.getTotalsByClient(agente.idAgente),
      builder: (_, snap) {
        if (!snap.hasData) return const Center(child: CircularProgressIndicator());
        final data = snap.data!;
        if (data.isEmpty) return const Center(child: Text('Nessun dato'));

        final sorted = data.entries.toList()..sort((a, b) => b.value.compareTo(a.value));
        final top5 = sorted.take(5).toList();
        // final total = top5.fold(0.0, (s, e) => s + e.value);

        return Padding(
          padding: const EdgeInsets.all(16),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text('Top 5 Clienti per Fatturato', style: Theme.of(context).textTheme.titleMedium),
              const SizedBox(height: 16),
              Expanded(
                child: PieChart(
                  PieChartData(
                    sections: top5.asMap().entries.map((e) => PieChartSectionData(
                      value: e.value.value,
                      title: '${e.key + 1}',
                      color: _colors[e.key % _colors.length],
                      radius: 60,
                      titleStyle: const TextStyle(color: Colors.white, fontWeight: FontWeight.bold),
                    )).toList(),
                    sectionsSpace: 2,
                    centerSpaceRadius: 40,
                  ),
                ),
              ),
              const SizedBox(height: 16),
              ...top5.asMap().entries.map((e) => Padding(
                padding: const EdgeInsets.symmetric(vertical: 2),
                child: Row(
                  children: [
                    Container(width: 12, height: 12, decoration: BoxDecoration(color: _colors[e.key % _colors.length], shape: BoxShape.circle)),
                    const SizedBox(width: 8),
                    Text('Cliente #${e.value.key}', style: Theme.of(context).textTheme.bodySmall),
                    const Spacer(),
                    Text(NumberFormat.currency(locale: 'it', symbol: '€').format(e.value.value),
                      style: Theme.of(context).textTheme.bodySmall?.copyWith(fontWeight: FontWeight.bold)),
                  ],
                ),
              )),
            ],
          ),
        );
      },
    );
  }
}

const _colors = [
  Colors.blue,
  Colors.red,
  Colors.green,
  Colors.orange,
  Colors.purple,
  Colors.teal,
  Colors.pink,
  Colors.indigo,
];