/// Écran des statistiques détaillées.
///
/// Affiche les métriques de performance avec filtrage par période
/// (session, semaine, mois, tout). Inclut heat map, précision,
/// écart-type et distribution régionale des tirs.
library;

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../../core/constants/app_constants.dart';
import '../../core/theme/app_theme.dart';
import '../../data/models/session.dart';
import '../../data/repositories/session_repository.dart';
import '../../services/statistics_service.dart';
import 'widgets/heat_map_widget.dart';

class StatisticsScreen extends StatefulWidget {
  final Session? singleSession; // If provided, show stats for this session only

  const StatisticsScreen({super.key, this.singleSession});

  @override
  State<StatisticsScreen> createState() => _StatisticsScreenState();
}

class _StatisticsScreenState extends State<StatisticsScreen> {
  final StatisticsService _statisticsService = StatisticsService();
  StatsPeriod _selectedPeriod = StatsPeriod.all;
  SessionStatistics? _statistics;
  bool _isLoading = true;
  List<Session> _allSessions = [];

  @override
  void initState() {
    super.initState();
    // Use addPostFrameCallback to ensure context is available
    WidgetsBinding.instance.addPostFrameCallback((_) {
      _loadStatistics();
    });
  }

  Future<void> _loadStatistics() async {
    if (!mounted) return;
    setState(() => _isLoading = true);

    try {
      if (widget.singleSession != null) {
        // Single session mode
        _statistics = _statisticsService.calculateStatistics(
          [widget.singleSession!],
          period: StatsPeriod.session,
          targetCenterX: widget.singleSession!.targetCenterX ?? 0.5,
          targetCenterY: widget.singleSession!.targetCenterY ?? 0.5,
        );
      } else {
        // Load all sessions
        final repository = context.read<SessionRepository>();
        _allSessions = await repository.getAllSessions();
        _calculateStats();
      }
    } catch (e) {
      debugPrint('Error loading statistics: $e');
    }

    if (mounted) {
      setState(() => _isLoading = false);
    }
  }

  void _calculateStats() {
    debugPrint('Calculating stats for ${_allSessions.length} sessions, period: $_selectedPeriod');
    for (final session in _allSessions) {
      debugPrint('  Session: ${session.id}, shots: ${session.shots.length}, date: ${session.createdAt}');
    }
    _statistics = _statisticsService.calculateStatistics(
      _allSessions,
      period: _selectedPeriod,
    );
    debugPrint('Statistics result: totalShots=${_statistics?.totalShots}, totalScore=${_statistics?.totalScore}');
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.singleSession != null ? 'Statistiques Session' : 'Statistiques'),
      ),
      body: _isLoading
          ? const Center(child: CircularProgressIndicator())
          : _statistics == null || _statistics!.totalShots == 0
              ? _buildEmptyState()
              : _buildStatistics(),
    );
  }

  Widget _buildEmptyState() {
    return Center(
      child: Padding(
        padding: const EdgeInsets.all(AppConstants.defaultPadding),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(Icons.analytics_outlined, size: 64, color: Colors.grey.shade400),
            const SizedBox(height: 16),
            Text(
              'Aucune donnee disponible',
              style: Theme.of(context).textTheme.titleLarge,
            ),
            const SizedBox(height: 8),
            Text(
              'Effectuez des sessions de tir pour voir vos statistiques',
              textAlign: TextAlign.center,
              style: TextStyle(color: Colors.grey.shade600),
            ),
            const SizedBox(height: 16),
            Text(
              'Sessions trouvees: ${_allSessions.length}',
              style: TextStyle(color: Colors.grey.shade400, fontSize: 12),
            ),
            if (_allSessions.isNotEmpty)
              Text(
                'Tirs totaux: ${_allSessions.fold<int>(0, (sum, s) => sum + s.shots.length)}',
                style: TextStyle(color: Colors.grey.shade400, fontSize: 12),
              ),
          ],
        ),
      ),
    );
  }

  Widget _buildStatistics() {
    return RefreshIndicator(
      onRefresh: _loadStatistics,
      child: SingleChildScrollView(
        physics: const AlwaysScrollableScrollPhysics(),
        padding: const EdgeInsets.all(AppConstants.defaultPadding),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            // Period filter (only for multi-session view)
            if (widget.singleSession == null) _buildPeriodFilter(),
            const SizedBox(height: 16),

            // Summary cards
            _buildSummaryCards(),
            const SizedBox(height: 24),

            // Heat Map
            _buildHeatMapSection(),
            const SizedBox(height: 24),

            // Precision stats
            _buildPrecisionSection(),
            const SizedBox(height: 24),

            // Standard deviation
            _buildStdDevSection(),
            const SizedBox(height: 24),

            // Regional distribution
            _buildRegionalSection(),
          ],
        ),
      ),
    );
  }

  Widget _buildPeriodFilter() {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(12),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const Text(
              'Periode',
              style: TextStyle(fontWeight: FontWeight.bold),
            ),
            const SizedBox(height: 8),
            SegmentedButton<StatsPeriod>(
              segments: const [
                ButtonSegment(
                  value: StatsPeriod.week,
                  label: Text('7 jours'),
                  icon: Icon(Icons.date_range),
                ),
                ButtonSegment(
                  value: StatsPeriod.month,
                  label: Text('30 jours'),
                  icon: Icon(Icons.calendar_month),
                ),
                ButtonSegment(
                  value: StatsPeriod.all,
                  label: Text('Tout'),
                  icon: Icon(Icons.all_inclusive),
                ),
              ],
              selected: {_selectedPeriod},
              onSelectionChanged: (selection) {
                setState(() {
                  _selectedPeriod = selection.first;
                  _calculateStats();
                });
              },
            ),
            const SizedBox(height: 8),
            Text(
              '${_statistics!.sessions.length} session(s) - ${_statistics!.totalShots} tir(s)',
              style: TextStyle(color: Colors.grey.shade600, fontSize: 12),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildSummaryCards() {
    return Row(
      children: [
        Expanded(
          child: _StatCard(
            icon: Icons.gps_fixed,
            title: 'Tirs',
            value: '${_statistics!.totalShots}',
            color: AppTheme.primaryColor,
          ),
        ),
        const SizedBox(width: 12),
        Expanded(
          child: _StatCard(
            icon: Icons.score,
            title: 'Score Total',
            value: '${_statistics!.totalScore}',
            color: AppTheme.secondaryColor,
          ),
        ),
      ],
    );
  }

  Widget _buildHeatMapSection() {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                const Icon(Icons.grid_on, color: AppTheme.primaryColor),
                const SizedBox(width: 8),
                const Text(
                  'Zones Chaudes',
                  style: TextStyle(fontWeight: FontWeight.bold, fontSize: 16),
                ),
              ],
            ),
            const SizedBox(height: 8),
            Text(
              'Repartition de vos tirs sur la cible',
              style: TextStyle(color: Colors.grey.shade600, fontSize: 12),
            ),
            const SizedBox(height: 16),
            Center(
              child: HeatMapWidget(
                heatMap: _statistics!.heatMap,
                size: MediaQuery.of(context).size.width - 80,
              ),
            ),
            const SizedBox(height: 12),
            // Legend - gradient bar
            Container(
              height: 24,
              margin: const EdgeInsets.symmetric(horizontal: 16),
              decoration: BoxDecoration(
                borderRadius: BorderRadius.circular(4),
                gradient: const LinearGradient(
                  colors: [
                    Color(0xFF2196F3), // Blue (cold)
                    Color(0xFF00BCD4), // Cyan
                    Color(0xFFFFEB3B), // Yellow
                    Color(0xFFFF9800), // Orange
                    Color(0xFFFF1744), // Red (hot)
                  ],
                ),
              ),
            ),
            const SizedBox(height: 4),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Padding(
                  padding: const EdgeInsets.only(left: 16),
                  child: Text('Peu', style: TextStyle(fontSize: 12, color: Colors.grey.shade600)),
                ),
                Padding(
                  padding: const EdgeInsets.only(right: 16),
                  child: Text('Beaucoup', style: TextStyle(fontSize: 12, color: Colors.grey.shade600)),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildLegendItem(Color color, String label) {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 4),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          Container(
            width: 16,
            height: 16,
            decoration: BoxDecoration(
              color: color,
              borderRadius: BorderRadius.circular(2),
              border: Border.all(color: Colors.grey.shade400),
            ),
          ),
          const SizedBox(width: 4),
          Text(label, style: const TextStyle(fontSize: 10)),
        ],
      ),
    );
  }

  Widget _buildPrecisionSection() {
    final precision = _statistics!.precision;

    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                const Icon(Icons.center_focus_strong, color: AppTheme.successColor),
                const SizedBox(width: 8),
                const Text(
                  'Precision',
                  style: TextStyle(fontWeight: FontWeight.bold, fontSize: 16),
                ),
              ],
            ),
            const SizedBox(height: 16),
            Row(
              children: [
                Expanded(
                  child: _buildPrecisionGauge(
                    'Precision',
                    precision.precisionScore,
                    'Distance moyenne du centre',
                  ),
                ),
                const SizedBox(width: 16),
                Expanded(
                  child: _buildPrecisionGauge(
                    'Regularite',
                    precision.consistencyScore,
                    'Groupement des tirs',
                  ),
                ),
              ],
            ),
            const Divider(height: 32),
            _buildStatRow('Distance moyenne du centre',
              '${(precision.avgDistanceFromCenter * 100).toStringAsFixed(1)}%'),
            _buildStatRow('Diametre de groupement',
              '${(precision.groupingDiameter * 100).toStringAsFixed(1)}%'),
            _buildStatRow('Score moyen',
              _statistics!.avgScore.toStringAsFixed(2)),
            _buildStatRow('Meilleur score', '${_statistics!.maxScore}'),
            _buildStatRow('Plus bas score', '${_statistics!.minScore}'),
          ],
        ),
      ),
    );
  }

  Widget _buildPrecisionGauge(String title, double value, String subtitle) {
    final color = value > 70
        ? AppTheme.successColor
        : value > 40
            ? AppTheme.warningColor
            : AppTheme.errorColor;

    return Column(
      children: [
        Stack(
          alignment: Alignment.center,
          children: [
            SizedBox(
              width: 80,
              height: 80,
              child: CircularProgressIndicator(
                value: value / 100,
                strokeWidth: 8,
                backgroundColor: Colors.grey.shade200,
                valueColor: AlwaysStoppedAnimation(color),
              ),
            ),
            Text(
              '${value.toStringAsFixed(0)}',
              style: TextStyle(
                fontSize: 20,
                fontWeight: FontWeight.bold,
                color: color,
              ),
            ),
          ],
        ),
        const SizedBox(height: 8),
        Text(
          title,
          style: const TextStyle(fontWeight: FontWeight.bold),
        ),
        Text(
          subtitle,
          style: TextStyle(fontSize: 10, color: Colors.grey.shade600),
          textAlign: TextAlign.center,
        ),
      ],
    );
  }

  Widget _buildStdDevSection() {
    final stdDev = _statistics!.stdDev;

    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                const Icon(Icons.stacked_line_chart, color: AppTheme.warningColor),
                const SizedBox(width: 8),
                const Text(
                  'Ecart Type',
                  style: TextStyle(fontWeight: FontWeight.bold, fontSize: 16),
                ),
              ],
            ),
            const SizedBox(height: 8),
            Text(
              'Mesure de la dispersion de vos tirs',
              style: TextStyle(color: Colors.grey.shade600, fontSize: 12),
            ),
            const SizedBox(height: 16),
            _buildStatRow('Ecart type X (horizontal)',
              '${(stdDev.stdDevX * 100).toStringAsFixed(2)}%'),
            _buildStatRow('Ecart type Y (vertical)',
              '${(stdDev.stdDevY * 100).toStringAsFixed(2)}%'),
            _buildStatRow('Ecart type radial',
              '${(stdDev.stdDevRadial * 100).toStringAsFixed(2)}%'),
            _buildStatRow('Ecart type score',
              stdDev.stdDevScore.toStringAsFixed(2)),
            const Divider(height: 24),
            _buildStatRow('Position moyenne X',
              '${(stdDev.meanX * 100).toStringAsFixed(1)}%'),
            _buildStatRow('Position moyenne Y',
              '${(stdDev.meanY * 100).toStringAsFixed(1)}%'),
            _buildStatRow('Score moyen',
              stdDev.meanScore.toStringAsFixed(2)),
          ],
        ),
      ),
    );
  }

  Widget _buildRegionalSection() {
    final regional = _statistics!.regional;

    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                const Icon(Icons.explore, color: AppTheme.secondaryColor),
                const SizedBox(width: 8),
                const Text(
                  'Distribution Regionale',
                  style: TextStyle(fontWeight: FontWeight.bold, fontSize: 16),
                ),
              ],
            ),
            const SizedBox(height: 16),

            // Dominant direction
            Container(
              padding: const EdgeInsets.all(12),
              decoration: BoxDecoration(
                color: AppTheme.primaryColor.withValues(alpha: 0.1),
                borderRadius: BorderRadius.circular(8),
              ),
              child: Row(
                children: [
                  const Icon(Icons.compass_calibration, color: AppTheme.primaryColor),
                  const SizedBox(width: 12),
                  Expanded(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        const Text('Direction dominante'),
                        Text(
                          regional.dominantDirection,
                          style: const TextStyle(
                            fontWeight: FontWeight.bold,
                            fontSize: 18,
                          ),
                        ),
                      ],
                    ),
                  ),
                ],
              ),
            ),
            const SizedBox(height: 16),

            // Bias
            if (regional.biasX.abs() > 0.02 || regional.biasY.abs() > 0.02)
              Container(
                padding: const EdgeInsets.all(12),
                decoration: BoxDecoration(
                  color: AppTheme.warningColor.withValues(alpha: 0.1),
                  borderRadius: BorderRadius.circular(8),
                ),
                child: Row(
                  children: [
                    const Icon(Icons.warning_amber, color: AppTheme.warningColor),
                    const SizedBox(width: 12),
                    Expanded(
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          const Text('Biais detecte'),
                          Text(
                            _getBiasDescription(regional.biasX, regional.biasY),
                            style: const TextStyle(fontWeight: FontWeight.bold),
                          ),
                        ],
                      ),
                    ),
                  ],
                ),
              ),
            const SizedBox(height: 16),

            // Sector distribution
            const Text('Repartition par secteur:', style: TextStyle(fontWeight: FontWeight.bold)),
            const SizedBox(height: 8),
            Wrap(
              spacing: 8,
              runSpacing: 8,
              children: regional.sectorDistribution.entries.map((entry) {
                final percentage = _statistics!.totalShots > 0
                    ? (entry.value / _statistics!.totalShots * 100)
                    : 0.0;
                return _buildSectorChip(entry.key, entry.value, percentage);
              }).toList(),
            ),

            const SizedBox(height: 16),

            // Quadrant distribution
            const Text('Repartition par quadrant:', style: TextStyle(fontWeight: FontWeight.bold)),
            const SizedBox(height: 8),
            _buildQuadrantGrid(regional.quadrantDistribution),
          ],
        ),
      ),
    );
  }

  Widget _buildStatRow(String label, String value) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: [
          Text(label),
          Text(value, style: const TextStyle(fontWeight: FontWeight.bold)),
        ],
      ),
    );
  }

  Widget _buildSectorChip(String sector, int count, double percentage) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
      decoration: BoxDecoration(
        color: count > 0 ? AppTheme.primaryColor.withValues(alpha: 0.1) : Colors.grey.shade100,
        borderRadius: BorderRadius.circular(16),
        border: Border.all(
          color: count > 0 ? AppTheme.primaryColor : Colors.grey.shade300,
        ),
      ),
      child: Text(
        '$sector: $count (${percentage.toStringAsFixed(0)}%)',
        style: TextStyle(
          fontSize: 12,
          color: count > 0 ? AppTheme.primaryColor : Colors.grey.shade600,
        ),
      ),
    );
  }

  Widget _buildQuadrantGrid(Map<String, int> quadrants) {
    return Table(
      border: TableBorder.all(color: Colors.grey.shade300),
      children: [
        TableRow(
          children: [
            _buildQuadrantCell('Haut-Gauche', quadrants['Haut-Gauche'] ?? 0),
            _buildQuadrantCell('Haut-Droite', quadrants['Haut-Droite'] ?? 0),
          ],
        ),
        TableRow(
          children: [
            _buildQuadrantCell('Bas-Gauche', quadrants['Bas-Gauche'] ?? 0),
            _buildQuadrantCell('Bas-Droite', quadrants['Bas-Droite'] ?? 0),
          ],
        ),
      ],
    );
  }

  Widget _buildQuadrantCell(String label, int count) {
    final percentage = _statistics!.totalShots > 0
        ? (count / _statistics!.totalShots * 100)
        : 0.0;
    final intensity = _statistics!.totalShots > 0
        ? count / _statistics!.totalShots
        : 0.0;

    return Container(
      padding: const EdgeInsets.all(16),
      color: Color.lerp(Colors.white, AppTheme.primaryColor, intensity * 0.5),
      child: Column(
        children: [
          Text(
            '$count',
            style: const TextStyle(
              fontWeight: FontWeight.bold,
              fontSize: 24,
            ),
          ),
          Text(
            '${percentage.toStringAsFixed(0)}%',
            style: TextStyle(color: Colors.grey.shade600),
          ),
          Text(
            label,
            style: const TextStyle(fontSize: 10),
            textAlign: TextAlign.center,
          ),
        ],
      ),
    );
  }

  String _getBiasDescription(double biasX, double biasY) {
    final descriptions = <String>[];

    if (biasX.abs() > 0.02) {
      descriptions.add(biasX > 0 ? 'vers la droite' : 'vers la gauche');
    }
    if (biasY.abs() > 0.02) {
      descriptions.add(biasY > 0 ? 'vers le bas' : 'vers le haut');
    }

    return 'Tendance ${descriptions.join(' et ')}';
  }
}

class _StatCard extends StatelessWidget {
  final IconData icon;
  final String title;
  final String value;
  final Color color;

  const _StatCard({
    required this.icon,
    required this.title,
    required this.value,
    required this.color,
  });

  @override
  Widget build(BuildContext context) {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          children: [
            Icon(icon, color: color, size: 32),
            const SizedBox(height: 8),
            Text(
              value,
              style: TextStyle(
                fontSize: 24,
                fontWeight: FontWeight.bold,
                color: color,
              ),
            ),
            Text(
              title,
              style: TextStyle(color: Colors.grey.shade600),
            ),
          ],
        ),
      ),
    );
  }
}