EM2_ERP/em2rp/lib/views/widgets/common/qr_code_dialog.dart

import 'package:flutter/material.dart';
import 'package:flutter/foundation.dart';
import 'package:qr_flutter/qr_flutter.dart';
import 'package:em2rp/utils/colors.dart';
import 'package:em2rp/services/qr_code_service.dart';
import 'package:printing/printing.dart';

/// Widget réutilisable pour afficher un QR code avec option de téléchargement
/// Utilisable pour équipements, containers, et autres entités
class QRCodeDialog<T> extends StatelessWidget {
  final T item;
  final String Function(T) getId;
  final String Function(T) getTitle;
  final List<Widget> Function(T)? buildSubtitle;

  const QRCodeDialog({
    super.key,
    required this.item,
    required this.getId,
    required this.getTitle,
    this.buildSubtitle,
  });

  @override
  Widget build(BuildContext context) {
    final id = getId(item);
    final title = getTitle(item);

    return Dialog(
      child: Container(
        padding: const EdgeInsets.all(24),
        constraints: const BoxConstraints(maxWidth: 400),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            // En-tête
            Row(
              children: [
                const Icon(Icons.qr_code, color: AppColors.rouge, size: 32),
                const SizedBox(width: 12),
                Expanded(
                  child: Text(
                    'QR Code - $id',
                    style: const TextStyle(
                      fontSize: 20,
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                ),
                IconButton(
                  icon: const Icon(Icons.close),
                  onPressed: () => Navigator.pop(context),
                ),
              ],
            ),
            const SizedBox(height: 24),

            // QR Code
            Container(
              padding: const EdgeInsets.all(16),
              decoration: BoxDecoration(
                color: Colors.white,
                borderRadius: BorderRadius.circular(8),
                border: Border.all(color: Colors.grey[300]!),
              ),
              child: QrImageView(
                data: id,
                version: QrVersions.auto,
                size: 250,
                backgroundColor: Colors.white,
              ),
            ),
            const SizedBox(height: 16),

            // Informations
            Container(
              padding: const EdgeInsets.all(12),
              decoration: BoxDecoration(
                color: Colors.grey[100],
                borderRadius: BorderRadius.circular(8),
              ),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    id,
                    style: const TextStyle(
                      fontWeight: FontWeight.bold,
                      fontSize: 16,
                    ),
                  ),
                  const SizedBox(height: 4),
                  Text(
                    title,
                    style: TextStyle(color: Colors.grey[700]),
                  ),
                  if (buildSubtitle != null) ...[
                    const SizedBox(height: 4),
                    ...buildSubtitle!(item),
                  ],
                ],
              ),
            ),
            const SizedBox(height: 24),

            // Bouton télécharger
            ElevatedButton.icon(
              onPressed: () => _downloadQRCode(context, id),
              style: ElevatedButton.styleFrom(
                backgroundColor: AppColors.rouge,
                minimumSize: const Size(double.infinity, 48),
              ),
              icon: const Icon(Icons.download, color: Colors.white),
              label: const Text(
                'Télécharger l\'image',
                style: TextStyle(color: Colors.white),
              ),
            ),
          ],
        ),
      ),
    );
  }

  Future<void> _downloadQRCode(BuildContext context, String id) async {
    // Afficher le dialog de chargement
    showDialog(
      context: context,
      barrierDismissible: false,
      builder: (context) => Dialog(
        child: Container(
          padding: const EdgeInsets.all(24),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              const CircularProgressIndicator(
                valueColor: AlwaysStoppedAnimation<Color>(AppColors.rouge),
              ),
              const SizedBox(height: 16),
              const Text(
                'Génération du QR Code...',
                style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
              ),
            ],
          ),
        ),
      ),
    );

    try {
      // Exécuter la génération dans un isolate séparé
      final qrImage = await compute(
        _generateQRCodeIsolate,
        id,
      );

      // Fermer le dialog de chargement
      if (context.mounted) {
        Navigator.pop(context);
      }

      // Utiliser la bibliothèque printing pour sauvegarder l'image
      await Printing.sharePdf(
        bytes: qrImage,
        filename: 'QRCode_$id.png',
      );

      if (context.mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text('Image QR Code téléchargée avec succès'),
            backgroundColor: Colors.green,
          ),
        );
      }
    } catch (e) {
      // Fermer le dialog de chargement en cas d'erreur
      if (context.mounted) {
        Navigator.pop(context);
      }

      if (context.mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('Erreur lors du téléchargement: $e'),
            backgroundColor: Colors.red,
          ),
        );
      }
    }
  }

  /// Fonction statique pour exécuter la génération QR code dans un isolate
  static Future<Uint8List> _generateQRCodeIsolate(String id) async {
    return await QRCodeService.generateQRCode(
      id,
      size: 1024,
      useCache: false,
    );
  }

  /// Factory pour équipement
  static QRCodeDialog forEquipment(dynamic equipment) {
    return QRCodeDialog(
      item: equipment,
      getId: (eq) => eq.id,
      getTitle: (eq) => '${eq.brand ?? ''} ${eq.model ?? ''}'.trim(),
    );
  }

  /// Factory pour container
  static QRCodeDialog forContainer(dynamic container) {
    return QRCodeDialog(
      item: container,
      getId: (c) => c.id,
      getTitle: (c) => c.name,
      buildSubtitle: (c) {
        return [
          Text(
            _getContainerTypeLabel(c.type),
            style: TextStyle(
              color: Colors.grey[600],
              fontSize: 12,
            ),
          ),
        ];
      },
    );
  }

  static String _getContainerTypeLabel(dynamic type) {
    // Simple fallback - à améliorer avec import du model
    return type.toString().split('.').last;
  }
}