import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import '../../../../shared/widgets/common/unified_page_layout.dart';
import '../../../../shared/widgets/common/unified_card.dart';
import '../../../../shared/theme/design_system.dart';
import '../../../../core/utils/constants.dart';
import '../bloc/analytics_bloc.dart';
import '../widgets/kpi_card_widget.dart';
import '../widgets/trend_chart_widget.dart';
import '../widgets/period_selector_widget.dart';
import '../widgets/metrics_grid_widget.dart';
import '../widgets/performance_gauge_widget.dart';
import '../widgets/alerts_panel_widget.dart';
import '../../domain/entities/analytics_data.dart';

/// Page principale du tableau de bord analytics
class AnalyticsDashboardPage extends StatefulWidget {
  const AnalyticsDashboardPage({super.key});

  @override
  State<AnalyticsDashboardPage> createState() => _AnalyticsDashboardPageState();
}

class _AnalyticsDashboardPageState extends State<AnalyticsDashboardPage>
    with TickerProviderStateMixin {
  late TabController _tabController;
  PeriodeAnalyse _periodeSelectionnee = PeriodeAnalyse.ceMois;
  String? _organisationId;

  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 4, vsync: this);
    _chargerDonneesInitiales();
  }

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

  void _chargerDonneesInitiales() {
    context.read<AnalyticsBloc>().add(
          ChargerTableauBordEvent(
            periodeAnalyse: _periodeSelectionnee,
            organisationId: _organisationId,
          ),
        );
  }

  void _onPeriodeChanged(PeriodeAnalyse nouvellePeriode) {
    setState(() {
      _periodeSelectionnee = nouvellePeriode;
    });
    _chargerDonneesInitiales();
  }

  @override
  Widget build(BuildContext context) {
    return UnifiedPageLayout(
      title: 'Analytics',
      subtitle: 'Tableau de bord et métriques',
      showBackButton: false,
      actions: [
        IconButton(
          icon: const Icon(Icons.refresh),
          onPressed: _chargerDonneesInitiales,
          tooltip: 'Actualiser',
        ),
        IconButton(
          icon: const Icon(Icons.settings),
          onPressed: () => _ouvrirParametres(context),
          tooltip: 'Paramètres',
        ),
      ],
      body: Column(
        children: [
          // Sélecteur de période
          Padding(
            padding: const EdgeInsets.all(DesignSystem.spacing16),
            child: PeriodSelectorWidget(
              periodeSelectionnee: _periodeSelectionnee,
              onPeriodeChanged: _onPeriodeChanged,
            ),
          ),

          // Onglets
          TabBar(
            controller: _tabController,
            labelColor: DesignSystem.primaryColor,
            unselectedLabelColor: DesignSystem.textSecondaryColor,
            indicatorColor: DesignSystem.primaryColor,
            tabs: const [
              Tab(
                icon: Icon(Icons.dashboard),
                text: 'Vue d\'ensemble',
              ),
              Tab(
                icon: Icon(Icons.trending_up),
                text: 'Tendances',
              ),
              Tab(
                icon: Icon(Icons.analytics),
                text: 'Détails',
              ),
              Tab(
                icon: Icon(Icons.warning),
                text: 'Alertes',
              ),
            ],
          ),

          // Contenu des onglets
          Expanded(
            child: TabBarView(
              controller: _tabController,
              children: [
                _buildVueEnsemble(),
                _buildTendances(),
                _buildDetails(),
                _buildAlertes(),
              ],
            ),
          ),
        ],
      ),
    );
  }

  /// Vue d'ensemble avec KPI principaux
  Widget _buildVueEnsemble() {
    return BlocBuilder<AnalyticsBloc, AnalyticsState>(
      builder: (context, state) {
        if (state is AnalyticsLoading) {
          return const Center(
            child: CircularProgressIndicator(),
          );
        }

        if (state is AnalyticsError) {
          return Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Icon(
                  Icons.error_outline,
                  size: 64,
                  color: DesignSystem.errorColor,
                ),
                const SizedBox(height: DesignSystem.spacing16),
                Text(
                  'Erreur lors du chargement',
                  style: DesignSystem.textTheme.headlineSmall,
                ),
                const SizedBox(height: DesignSystem.spacing8),
                Text(
                  state.message,
                  style: DesignSystem.textTheme.bodyMedium,
                  textAlign: TextAlign.center,
                ),
                const SizedBox(height: DesignSystem.spacing16),
                ElevatedButton(
                  onPressed: _chargerDonneesInitiales,
                  child: const Text('Réessayer'),
                ),
              ],
            ),
          );
        }

        if (state is AnalyticsLoaded) {
          return SingleChildScrollView(
            padding: const EdgeInsets.all(DesignSystem.spacing16),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                // Performance globale
                if (state.performanceGlobale != null)
                  UnifiedCard(
                    variant: UnifiedCardVariant.elevated,
                    child: PerformanceGaugeWidget(
                      score: state.performanceGlobale!,
                      periode: _periodeSelectionnee,
                    ),
                  ),

                const SizedBox(height: DesignSystem.spacing16),

                // KPI principaux
                Text(
                  'Indicateurs clés',
                  style: DesignSystem.textTheme.headlineSmall,
                ),
                const SizedBox(height: DesignSystem.spacing12),

                MetricsGridWidget(
                  metriques: state.metriques,
                  onMetriquePressed: (metrique) => _ouvrirDetailMetrique(
                    context,
                    metrique,
                  ),
                ),

                const SizedBox(height: DesignSystem.spacing24),

                // Graphiques de tendance rapide
                Text(
                  'Évolutions récentes',
                  style: DesignSystem.textTheme.headlineSmall,
                ),
                const SizedBox(height: DesignSystem.spacing12),

                if (state.tendances.isNotEmpty)
                  SizedBox(
                    height: 200,
                    child: ListView.builder(
                      scrollDirection: Axis.horizontal,
                      itemCount: state.tendances.length,
                      itemBuilder: (context, index) {
                        final tendance = state.tendances[index];
                        return Container(
                          width: 300,
                          margin: const EdgeInsets.only(
                            right: DesignSystem.spacing12,
                          ),
                          child: UnifiedCard(
                            variant: UnifiedCardVariant.outlined,
                            child: TrendChartWidget(
                              trend: tendance,
                              compact: true,
                            ),
                          ),
                        );
                      },
                    ),
                  ),
              ],
            ),
          );
        }

        return const SizedBox.shrink();
      },
    );
  }

  /// Onglet des tendances détaillées
  Widget _buildTendances() {
    return BlocBuilder<AnalyticsBloc, AnalyticsState>(
      builder: (context, state) {
        if (state is AnalyticsLoaded && state.tendances.isNotEmpty) {
          return ListView.builder(
            padding: const EdgeInsets.all(DesignSystem.spacing16),
            itemCount: state.tendances.length,
            itemBuilder: (context, index) {
              final tendance = state.tendances[index];
              return Padding(
                padding: const EdgeInsets.only(
                  bottom: DesignSystem.spacing16,
                ),
                child: UnifiedCard(
                  variant: UnifiedCardVariant.elevated,
                  child: TrendChartWidget(
                    trend: tendance,
                    compact: false,
                    showPredictions: true,
                    showAnomalies: true,
                  ),
                ),
              );
            },
          );
        }

        return const Center(
          child: Text('Aucune tendance disponible'),
        );
      },
    );
  }

  /// Onglet des détails par métrique
  Widget _buildDetails() {
    return BlocBuilder<AnalyticsBloc, AnalyticsState>(
      builder: (context, state) {
        if (state is AnalyticsLoaded) {
          return ListView.builder(
            padding: const EdgeInsets.all(DesignSystem.spacing16),
            itemCount: TypeMetrique.values.length,
            itemBuilder: (context, index) {
              final typeMetrique = TypeMetrique.values[index];
              final metrique = state.metriques.firstWhere(
                (m) => m.typeMetrique == typeMetrique,
                orElse: () => AnalyticsData(
                  id: 'placeholder_$index',
                  typeMetrique: typeMetrique,
                  periodeAnalyse: _periodeSelectionnee,
                  valeur: 0,
                  dateDebut: DateTime.now().subtract(const Duration(days: 30)),
                  dateFin: DateTime.now(),
                  dateCalcul: DateTime.now(),
                ),
              );

              return Padding(
                padding: const EdgeInsets.only(
                  bottom: DesignSystem.spacing12,
                ),
                child: KPICardWidget(
                  analyticsData: metrique,
                  onTap: () => _ouvrirDetailMetrique(context, metrique),
                  showTrend: true,
                  showDetails: true,
                ),
              );
            },
          );
        }

        return const Center(
          child: Text('Aucun détail disponible'),
        );
      },
    );
  }

  /// Onglet des alertes
  Widget _buildAlertes() {
    return BlocBuilder<AnalyticsBloc, AnalyticsState>(
      builder: (context, state) {
        if (state is AnalyticsLoaded) {
          final alertes = state.metriques
              .where((m) => m.isCritique || !m.isDonneesFiables)
              .toList();

          if (alertes.isEmpty) {
            return Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Icon(
                    Icons.check_circle_outline,
                    size: 64,
                    color: DesignSystem.successColor,
                  ),
                  const SizedBox(height: DesignSystem.spacing16),
                  Text(
                    'Aucune alerte active',
                    style: DesignSystem.textTheme.headlineSmall,
                  ),
                  const SizedBox(height: DesignSystem.spacing8),
                  Text(
                    'Toutes les métriques sont dans les normes',
                    style: DesignSystem.textTheme.bodyMedium,
                    textAlign: TextAlign.center,
                  ),
                ],
              ),
            );
          }

          return AlertsPanelWidget(
            alertes: alertes,
            onAlertePressed: (alerte) => _ouvrirDetailMetrique(
              context,
              alerte,
            ),
          );
        }

        return const Center(
          child: Text('Aucune alerte disponible'),
        );
      },
    );
  }

  void _ouvrirDetailMetrique(BuildContext context, AnalyticsData metrique) {
    Navigator.of(context).pushNamed(
      AppRoutes.analyticsDetail,
      arguments: {
        'metrique': metrique,
        'periode': _periodeSelectionnee,
        'organisationId': _organisationId,
      },
    );
  }

  void _ouvrirParametres(BuildContext context) {
    Navigator.of(context).pushNamed(AppRoutes.analyticsSettings);
  }
}