import 'package:flutter/material.dart';
import '../../theme/app_theme.dart';
import '../cards/unified_card_widget.dart';

/// Section KPI unifiée pour afficher des indicateurs clés
/// 
/// Fournit :
/// - Cartes KPI avec animations
/// - Layouts adaptatifs (grille ou liste)
/// - Indicateurs de tendance
/// - Couleurs thématiques
class UnifiedKPISection extends StatelessWidget {
  /// Liste des KPI à afficher
  final List<UnifiedKPIData> kpis;
  
  /// Titre de la section
  final String? title;
  
  /// Nombre de colonnes dans la grille (par défaut : 2)
  final int crossAxisCount;
  
  /// Espacement entre les cartes
  final double spacing;
  
  /// Callback lors du tap sur un KPI
  final void Function(UnifiedKPIData kpi)? onKPITap;

  const UnifiedKPISection({
    super.key,
    required this.kpis,
    this.title,
    this.crossAxisCount = 2,
    this.spacing = 16.0,
    this.onKPITap,
  });

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        if (title != null) ...[
          Text(
            title!,
            style: const TextStyle(
              fontSize: 18,
              fontWeight: FontWeight.w600,
              color: AppTheme.textPrimary,
            ),
          ),
          const SizedBox(height: 16),
        ],
        _buildKPIGrid(),
      ],
    );
  }

  Widget _buildKPIGrid() {
    return GridView.builder(
      shrinkWrap: true,
      physics: const NeverScrollableScrollPhysics(),
      gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
        crossAxisCount: crossAxisCount,
        crossAxisSpacing: spacing,
        mainAxisSpacing: spacing,
        childAspectRatio: 1.4,
      ),
      itemCount: kpis.length,
      itemBuilder: (context, index) {
        final kpi = kpis[index];
        return UnifiedCard.kpi(
          onTap: onKPITap != null ? () => onKPITap!(kpi) : null,
          child: _buildKPIContent(kpi),
        );
      },
    );
  }

  Widget _buildKPIContent(UnifiedKPIData kpi) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        // En-tête avec icône et titre
        Row(
          children: [
            Container(
              padding: const EdgeInsets.all(8),
              decoration: BoxDecoration(
                color: kpi.color.withOpacity(0.1),
                borderRadius: BorderRadius.circular(8),
              ),
              child: Icon(
                kpi.icon,
                color: kpi.color,
                size: 20,
              ),
            ),
            const SizedBox(width: 12),
            Expanded(
              child: Text(
                kpi.title,
                style: const TextStyle(
                  fontSize: 14,
                  fontWeight: FontWeight.w500,
                  color: AppTheme.textSecondary,
                ),
                maxLines: 2,
                overflow: TextOverflow.ellipsis,
              ),
            ),
          ],
        ),
        
        const SizedBox(height: 12),
        
        // Valeur principale
        Row(
          crossAxisAlignment: CrossAxisAlignment.end,
          children: [
            Expanded(
              child: Text(
                kpi.value,
                style: const TextStyle(
                  fontSize: 24,
                  fontWeight: FontWeight.w700,
                  color: AppTheme.textPrimary,
                ),
                maxLines: 1,
                overflow: TextOverflow.ellipsis,
              ),
            ),
            if (kpi.trend != null) ...[
              const SizedBox(width: 8),
              _buildTrendIndicator(kpi.trend!),
            ],
          ],
        ),
        
        // Sous-titre ou description
        if (kpi.subtitle != null) ...[
          const SizedBox(height: 4),
          Text(
            kpi.subtitle!,
            style: const TextStyle(
              fontSize: 12,
              color: AppTheme.textSecondary,
            ),
            maxLines: 1,
            overflow: TextOverflow.ellipsis,
          ),
        ],
      ],
    );
  }

  Widget _buildTrendIndicator(UnifiedKPITrend trend) {
    IconData icon;
    Color color;
    
    switch (trend.direction) {
      case UnifiedKPITrendDirection.up:
        icon = Icons.trending_up;
        color = AppTheme.successColor;
        break;
      case UnifiedKPITrendDirection.down:
        icon = Icons.trending_down;
        color = AppTheme.errorColor;
        break;
      case UnifiedKPITrendDirection.stable:
        icon = Icons.trending_flat;
        color = AppTheme.textSecondary;
        break;
    }
    
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
      decoration: BoxDecoration(
        color: color.withOpacity(0.1),
        borderRadius: BorderRadius.circular(4),
      ),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          Icon(
            icon,
            size: 12,
            color: color,
          ),
          const SizedBox(width: 2),
          Text(
            trend.value,
            style: TextStyle(
              fontSize: 10,
              fontWeight: FontWeight.w600,
              color: color,
            ),
          ),
        ],
      ),
    );
  }
}

/// Données pour un KPI unifié
class UnifiedKPIData {
  /// Titre du KPI
  final String title;
  
  /// Valeur principale à afficher
  final String value;
  
  /// Sous-titre ou description optionnelle
  final String? subtitle;
  
  /// Icône représentative
  final IconData icon;
  
  /// Couleur thématique
  final Color color;
  
  /// Indicateur de tendance optionnel
  final UnifiedKPITrend? trend;
  
  /// Données supplémentaires pour les callbacks
  final Map<String, dynamic>? metadata;

  const UnifiedKPIData({
    required this.title,
    required this.value,
    required this.icon,
    required this.color,
    this.subtitle,
    this.trend,
    this.metadata,
  });
}

/// Indicateur de tendance pour les KPI
class UnifiedKPITrend {
  /// Direction de la tendance
  final UnifiedKPITrendDirection direction;

  /// Valeur de la tendance (ex: "+12%", "-5", "stable")
  final String value;

  /// Label descriptif de la tendance (ex: "ce mois", "vs mois dernier")
  final String? label;

  const UnifiedKPITrend({
    required this.direction,
    required this.value,
    this.label,
  });
}

/// Direction de tendance disponibles
enum UnifiedKPITrendDirection {
  up,
  down,
  stable,
}