import 'package:fl_chart/fl_chart.dart';
import 'package:flutter/material.dart';
import 'package:manager_app/Models/managerContext.dart';
import 'package:manager_app/app_context.dart';
import 'package:manager_app/constants.dart';
import 'package:manager_api_new/api.dart';
import 'package:provider/provider.dart';

class StatisticsScreen extends StatefulWidget {
  const StatisticsScreen({Key? key}) : super(key: key);

  @override
  _StatisticsScreenState createState() => _StatisticsScreenState();
}

class _StatisticsScreenState extends State<StatisticsScreen> {
  int _selectedDays = 30;
  AppType? _selectedAppType; // null = "Tous"
  Future<StatsSummaryDTO?>? _future;
  late ManagerAppContext _managerAppContext;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) => _load());
  }

  void _load() {
    final days = _selectedDays;
    final appType = _selectedAppType;
    setState(() {
      _future = _managerAppContext.clientAPI!.statsApi!.statsGetSummary(
        _managerAppContext.instanceId!,
        from: DateTime.now().subtract(Duration(days: days)),
        to: DateTime.now(),
        appType: appType?.name,
      );
    });
  }

  String _formatDuration(int seconds) {
    if (seconds < 60) return '${seconds}s';
    final m = seconds ~/ 60;
    final s = seconds % 60;
    return '${m}m${s > 0 ? ' ${s}s' : ''}';
  }

  @override
  Widget build(BuildContext context) {
    final appContext = Provider.of<AppContext>(context);
    _managerAppContext = appContext.getContext() as ManagerAppContext;

    return Padding(
      padding: const EdgeInsets.all(16),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          _buildHeader(),
          const SizedBox(height: 16),
          Expanded(
            child: FutureBuilder<StatsSummaryDTO?>(
              future: _future,
              builder: (context, snapshot) {
                if (snapshot.connectionState == ConnectionState.waiting) {
                  return const Center(child: CircularProgressIndicator());
                }
                if (snapshot.hasError || snapshot.data == null) {
                  return Center(child: Text('Impossible de charger les statistiques', style: TextStyle(color: kBodyTextColor)));
                }
                final stats = snapshot.data!;
                return _buildDashboard(stats);
              },
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildHeader() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Row(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: [
            Text('Statistiques', style: TextStyle(fontSize: 26, fontWeight: FontWeight.w600, color: kPrimaryColor)),
            SegmentedButton<int>(
              style: SegmentedButton.styleFrom(
                selectedBackgroundColor: kPrimaryColor,
                selectedForegroundColor: kWhite,
              ),
              segments: const [
                ButtonSegment(value: 7, label: Text('7j')),
                ButtonSegment(value: 30, label: Text('30j')),
                ButtonSegment(value: 90, label: Text('90j')),
              ],
              selected: {_selectedDays},
              onSelectionChanged: (s) {
                _selectedDays = s.first;
                _load();
              },
            ),
          ],
        ),
        const SizedBox(height: 10),
        Wrap(
          spacing: 8,
          children: [
            ChoiceChip(
              label: const Text('Tous'),
              selected: _selectedAppType == null,
              selectedColor: kPrimaryColor,
              labelStyle: TextStyle(color: _selectedAppType == null ? kWhite : kBodyTextColor),
              onSelected: (_) { _selectedAppType = null; _load(); },
            ),
            ...AppType.values.map((type) => ChoiceChip(
              label: Text(type.name),
              selected: _selectedAppType == type,
              selectedColor: kPrimaryColor,
              labelStyle: TextStyle(color: _selectedAppType == type ? kWhite : kBodyTextColor),
              onSelected: (_) { _selectedAppType = type; _load(); },
            )),
          ],
        ),
      ],
    );
  }

  Widget _buildDashboard(StatsSummaryDTO stats) {
    if (stats.totalSessions == 0) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(Icons.bar_chart_outlined, size: 56, color: kBodyTextColor.withValues(alpha: 0.4)),
            const SizedBox(height: 16),
            Text(
              'Pas encore de données pour cette période',
              style: TextStyle(fontSize: 15, color: kBodyTextColor),
            ),
            if (_selectedAppType != null) ...[
              const SizedBox(height: 8),
              Text(
                'Aucun event reçu pour le type "${_selectedAppType!.name}"',
                style: TextStyle(fontSize: 13, color: kBodyTextColor.withValues(alpha: 0.6)),
              ),
            ],
          ],
        ),
      );
    }

    return SingleChildScrollView(
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          // KPI cards
          _buildKpiRow(stats),
          const SizedBox(height: 20),
          // Line chart
          _buildLineChart(stats),
          const SizedBox(height: 20),
          // Bar chart + Donut charts
          _buildChartsRow(stats),
          const SizedBox(height: 20),
          // Bottom tables
          _buildTablesRow(stats),
        ],
      ),
    );
  }

  Widget _buildKpiRow(StatsSummaryDTO stats) {
    final topAppType = stats.appTypeDistribution.isNotEmpty
        ? stats.appTypeDistribution.entries.reduce((a, b) => a.value > b.value ? a : b)
        : null;
    final topLang = stats.languageDistribution.isNotEmpty
        ? stats.languageDistribution.entries.reduce((a, b) => a.value > b.value ? a : b)
        : null;

    return Row(
      children: [
        _kpiCard('Sessions', '${stats.totalSessions}', Icons.people_outline),
        const SizedBox(width: 12),
        _kpiCard('Durée moy.', _formatDuration(stats.avgVisitDurationSeconds), Icons.timer_outlined),
        const SizedBox(width: 12),
        _kpiCard('App top', topAppType?.key ?? '—', Icons.phone_iphone),
        const SizedBox(width: 12),
        _kpiCard('Langue top', topLang?.key.toUpperCase() ?? '—', Icons.language),
      ],
    );
  }

  Widget _kpiCard(String label, String value, IconData icon) {
    return Expanded(
      child: Card(
        elevation: 0,
        color: kWhite,
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
        child: Padding(
          padding: const EdgeInsets.symmetric(vertical: 20, horizontal: 16),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Icon(icon, color: kPrimaryColor, size: 22),
              const SizedBox(height: 8),
              Text(value, style: TextStyle(fontSize: 26, fontWeight: FontWeight.w700, color: kPrimaryColor)),
              const SizedBox(height: 4),
              Text(label, style: TextStyle(fontSize: 13, color: kBodyTextColor)),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildLineChart(StatsSummaryDTO stats) {
    if (stats.visitsByDay.isEmpty) return const SizedBox();

    final spots = <FlSpot>[];
    final mobileSpots = <FlSpot>[];
    final tabletSpots = <FlSpot>[];

    for (var i = 0; i < stats.visitsByDay.length; i++) {
      final d = stats.visitsByDay[i];
      spots.add(FlSpot(i.toDouble(), d.total.toDouble()));
      mobileSpots.add(FlSpot(i.toDouble(), d.mobile.toDouble()));
      tabletSpots.add(FlSpot(i.toDouble(), d.tablet.toDouble()));
    }

    final isFiltered = _selectedAppType != null;

    return Card(
      elevation: 0,
      color: kWhite,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text('Visites par jour', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: kPrimaryColor)),
            const SizedBox(height: 4),
            if (!isFiltered) Row(children: [
              _legendDot(kPrimaryColor), const SizedBox(width: 4), Text('Mobile', style: TextStyle(fontSize: 12, color: kBodyTextColor)),
              const SizedBox(width: 12),
              _legendDot(kSecond), const SizedBox(width: 4), Text('Tablet', style: TextStyle(fontSize: 12, color: kBodyTextColor)),
            ]),
            const SizedBox(height: 16),
            SizedBox(
              height: 200,
              child: LineChart(LineChartData(
                gridData: FlGridData(show: true, drawVerticalLine: false),
                titlesData: FlTitlesData(
                  leftTitles: AxisTitles(sideTitles: SideTitles(showTitles: true, reservedSize: 32)),
                  rightTitles: AxisTitles(sideTitles: SideTitles(showTitles: false)),
                  topTitles: AxisTitles(sideTitles: SideTitles(showTitles: false)),
                  bottomTitles: AxisTitles(sideTitles: SideTitles(
                    showTitles: true,
                    interval: (stats.visitsByDay.length / 5).ceilToDouble().clamp(1, double.infinity),
                    getTitlesWidget: (value, meta) {
                      final idx = value.toInt();
                      if (idx < 0 || idx >= stats.visitsByDay.length) return const SizedBox();
                      final date = stats.visitsByDay[idx].date ?? '';
                      return Text(date.length >= 5 ? date.substring(5) : date, style: const TextStyle(fontSize: 10));
                    },
                  )),
                ),
                borderData: FlBorderData(show: false),
                lineBarsData: isFiltered
                    ? [_lineBar(spots, kPrimaryColor)]
                    : [_lineBar(mobileSpots, kPrimaryColor), _lineBar(tabletSpots, kSecond)],
              )),
            ),
          ],
        ),
      ),
    );
  }

  Widget _legendDot(Color color) {
    return Container(width: 10, height: 10, decoration: BoxDecoration(color: color, shape: BoxShape.circle));
  }

  LineChartBarData _lineBar(List<FlSpot> spots, Color color) {
    return LineChartBarData(
      spots: spots,
      isCurved: true,
      color: color,
      barWidth: 2,
      dotData: FlDotData(show: false),
      belowBarData: BarAreaData(show: true, color: color.withOpacity(0.1)),
    );
  }

  Widget _buildChartsRow(StatsSummaryDTO stats) {
    final showAppTypeDonut = _selectedAppType == null;
    return Row(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Expanded(flex: 2, child: _buildTopSectionsChart(stats)),
        const SizedBox(width: 12),
        if (showAppTypeDonut) ...[
          Expanded(child: _buildDonut(stats.appTypeDistribution, 'Apps')),
          const SizedBox(width: 12),
        ],
        Expanded(child: _buildDonut(stats.languageDistribution, 'Langues')),
      ],
    );
  }

  Widget _buildTopSectionsChart(StatsSummaryDTO stats) {
    if (stats.topSections.isEmpty) return const SizedBox();
    final sections = stats.topSections.take(8).toList();
    final maxViews = sections.map((s) => s.views).reduce((a, b) => a > b ? a : b);

    return Card(
      elevation: 0,
      color: kWhite,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text('Top sections', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: kPrimaryColor)),
            const SizedBox(height: 16),
            SizedBox(
              height: 240,
              child: BarChart(BarChartData(
                alignment: BarChartAlignment.spaceAround,
                maxY: maxViews.toDouble() * 1.2,
                barTouchData: BarTouchData(enabled: true),
                titlesData: FlTitlesData(
                  leftTitles: AxisTitles(sideTitles: SideTitles(showTitles: true, reservedSize: 32)),
                  rightTitles: AxisTitles(sideTitles: SideTitles(showTitles: false)),
                  topTitles: AxisTitles(sideTitles: SideTitles(showTitles: false)),
                  bottomTitles: AxisTitles(sideTitles: SideTitles(
                    showTitles: true,
                    getTitlesWidget: (value, meta) {
                      final idx = value.toInt();
                      if (idx < 0 || idx >= sections.length) return const SizedBox();
                      final title = sections[idx].sectionTitle ?? sections[idx].sectionId ?? '';
                      return Padding(
                        padding: const EdgeInsets.only(top: 4),
                        child: Text(
                          title.length > 8 ? '${title.substring(0, 8)}…' : title,
                          style: const TextStyle(fontSize: 10),
                        ),
                      );
                    },
                  )),
                ),
                borderData: FlBorderData(show: false),
                gridData: FlGridData(drawVerticalLine: false),
                barGroups: List.generate(sections.length, (i) => BarChartGroupData(
                  x: i,
                  barRods: [BarChartRodData(
                    toY: sections[i].views.toDouble(),
                    color: kPrimaryColor,
                    width: 16,
                    borderRadius: const BorderRadius.vertical(top: Radius.circular(4)),
                  )],
                )),
              )),
            ),
          ],
        ),
      ),
    );
  }

  static const _chartColors = [
    Color(0xFF264863),
    Color(0xFF4A8FAD),
    Color(0xFF87C4D8),
    Color(0xFFC2C9D6),
    Color(0xFF8BA7B8),
    Color(0xFF1A3347),
  ];

  Widget _buildDonut(Map<String, int> data, String title) {
    if (data.isEmpty) return const SizedBox();
    final total = data.values.fold(0, (a, b) => a + b);
    final entries = data.entries.toList();

    return Card(
      elevation: 0,
      color: kWhite,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.center,
          children: [
            Text(title, style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: kPrimaryColor)),
            const SizedBox(height: 16),
            SizedBox(
              height: 160,
              child: PieChart(PieChartData(
                centerSpaceRadius: 45,
                sectionsSpace: 2,
                sections: List.generate(entries.length, (i) {
                  final pct = total > 0 ? (entries[i].value / total * 100).round() : 0;
                  return PieChartSectionData(
                    value: entries[i].value.toDouble(),
                    color: _chartColors[i % _chartColors.length],
                    title: '$pct%',
                    titleStyle: const TextStyle(fontSize: 11, color: Colors.white, fontWeight: FontWeight.w600),
                    radius: 40,
                  );
                }),
              )),
            ),
            const SizedBox(height: 12),
            ...List.generate(entries.length, (i) => Padding(
              padding: const EdgeInsets.symmetric(vertical: 2),
              child: Row(children: [
                Container(width: 10, height: 10, decoration: BoxDecoration(
                  color: _chartColors[i % _chartColors.length], shape: BoxShape.circle)),
                const SizedBox(width: 6),
                Expanded(child: Text(entries[i].key, style: TextStyle(fontSize: 12, color: kBodyTextColor), overflow: TextOverflow.ellipsis)),
                Text('${entries[i].value}', style: TextStyle(fontSize: 12, color: kBodyTextColor)),
              ]),
            )),
          ],
        ),
      ),
    );
  }

  Widget _buildTablesRow(StatsSummaryDTO stats) {
    return Row(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        if (stats.topPois.isNotEmpty) Expanded(child: _buildPoiTable(stats)),
        if (stats.topPois.isNotEmpty && stats.topAgendaEvents.isNotEmpty) const SizedBox(width: 12),
        if (stats.topAgendaEvents.isNotEmpty) Expanded(child: _buildAgendaTable(stats)),
        if ((stats.topPois.isNotEmpty || stats.topAgendaEvents.isNotEmpty) && stats.quizStats.isNotEmpty) const SizedBox(width: 12),
        if (stats.quizStats.isNotEmpty) Expanded(child: _buildQuizTable(stats)),
        if ((stats.topPois.isNotEmpty || stats.topAgendaEvents.isNotEmpty || stats.quizStats.isNotEmpty) && stats.gameStats.isNotEmpty) const SizedBox(width: 12),
        if (stats.gameStats.isNotEmpty) Expanded(child: _buildGameTable(stats)),
      ],
    );
  }

  Widget _buildPoiTable(StatsSummaryDTO stats) {
    return _tableCard('Top POI', ['POI', 'Taps'], stats.topPois.map((p) => [
      p.title ?? p.geoPointId?.toString() ?? '—',
      '${p.taps}',
    ]).toList());
  }

  Widget _buildAgendaTable(StatsSummaryDTO stats) {
    return _tableCard('Top événements agenda', ['Événement', 'Taps'], stats.topAgendaEvents.map((e) => [
      e.eventTitle ?? e.eventId ?? '—',
      '${e.taps}',
    ]).toList());
  }

  Widget _buildQuizTable(StatsSummaryDTO stats) {
    return _tableCard('Quiz', ['Section', 'Score moy', 'Complétions'], stats.quizStats.map((q) => [
      q.sectionTitle ?? q.sectionId ?? '—',
      '${q.avgScore.toStringAsFixed(1)} / ${q.totalQuestions}',
      '${q.completions}',
    ]).toList());
  }

  Widget _buildGameTable(StatsSummaryDTO stats) {
    return _tableCard('Jeux', ['Type', 'Complétions', 'Durée moy.'], stats.gameStats.map((g) => [
      g.gameType ?? '—',
      '${g.completions}',
      _formatDuration(g.avgDurationSeconds),
    ]).toList());
  }

  Widget _tableCard(String title, List<String> headers, List<List<String>> rows) {
    return Card(
      elevation: 0,
      color: kWhite,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(title, style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: kPrimaryColor)),
            const SizedBox(height: 12),
            Table(
              columnWidths: const {0: FlexColumnWidth(2), 1: FlexColumnWidth(1)},
              children: [
                TableRow(
                  decoration: BoxDecoration(border: Border(bottom: BorderSide(color: kSecond))),
                  children: headers.map((h) => Padding(
                    padding: const EdgeInsets.only(bottom: 8),
                    child: Text(h, style: TextStyle(fontSize: 12, fontWeight: FontWeight.w600, color: kBodyTextColor)),
                  )).toList(),
                ),
                ...rows.map((row) => TableRow(
                  children: row.map((cell) => Padding(
                    padding: const EdgeInsets.symmetric(vertical: 6),
                    child: Text(cell, style: TextStyle(fontSize: 13, color: kBodyTextColor), overflow: TextOverflow.ellipsis),
                  )).toList(),
                )).toList(),
              ],
            ),
          ],
        ),
      ),
    );
  }
}