import 'dart:io';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:google_mlkit_document_scanner/google_mlkit_document_scanner.dart';
import 'package:device_info_plus/device_info_plus.dart';

import '../../core/constants/app_constants.dart';
import '../../core/theme/app_theme.dart';
import '../../data/models/target_type.dart';
import '../crop/crop_screen.dart';
import 'widgets/image_source_button.dart';

class CaptureScreen extends StatefulWidget {
  const CaptureScreen({super.key});

  @override
  State<CaptureScreen> createState() => _CaptureScreenState();
}

class _CaptureScreenState extends State<CaptureScreen> {
  final ImagePicker _picker = ImagePicker();
  TargetType _selectedType = TargetType.concentric;
  String? _selectedImagePath;
  bool _isLoading = false;

  /// Gère la demande de permission et la sélection d'image
  Future<void> _handleGallerySelection() async {
    PermissionStatus status;

    if (Platform.isAndroid) {
      final deviceInfo = DeviceInfoPlugin();
      final androidInfo = await deviceInfo.androidInfo;

      // Android 13+ (SDK 33) utilise .photos, les versions précédentes utilisent .storage
      if (androidInfo.version.sdkInt >= 33) {
        status = await Permission.photos.request();
      } else {
        status = await Permission.storage.request();
      }
    } else {
      status = await Permission.photos.request();
    }

    if (status.isGranted) {
      _captureImage(ImageSource.gallery);
    } else if (status.isPermanentlyDenied) {
      _showSettingsDialog();
    } else {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text('Accès à la galerie requis pour continuer'),
          ),
        );
      }
    }
  }

  void _showSettingsDialog() {
    showDialog(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Permission requise'),
        content: const Text(
          'L\'accès aux photos est nécessaire. Veuillez l\'activer dans les paramètres.',
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context),
            child: const Text('Annuler'),
          ),
          TextButton(
            onPressed: () => openAppSettings(),
            child: const Text('Paramètres'),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Source')),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(AppConstants.defaultPadding),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            const SizedBox(height: AppConstants.largePadding),

            _buildSectionTitle('Source de l\'Image'),
            const SizedBox(height: 12),
            Row(
              children: [
                Expanded(
                  child: ImageSourceButton(
                    icon: Icons.camera_alt,
                    label: 'Scanner',
                    onPressed: _isLoading ? null : _scanDocument,
                  ),
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: ImageSourceButton(
                    icon: Icons.photo_library,
                    label: 'Galerie',
                    onPressed: _isLoading
                        ? null
                        : _handleGallerySelection, // Appelle la nouvelle fonction
                  ),
                ),
              ],
            ),
            const SizedBox(height: AppConstants.largePadding),

            if (_isLoading)
              const Center(
                child: Padding(
                  padding: EdgeInsets.all(32),
                  child: CircularProgressIndicator(),
                ),
              )
            else if (_selectedImagePath != null)
              _buildImagePreview()
            else
              _buildGuide(),
          ],
        ),
      ),
      floatingActionButton: _selectedImagePath != null
          ? FloatingActionButton.extended(
              onPressed: _analyzeImage,
              icon: const Icon(Icons.arrow_forward),
              label: const Text('Suivant'),
            )
          : null,
    );
  }

  // Tes widgets _buildSectionTitle, _buildImagePreview, _buildFramingHints restent identiques

  Widget _buildSectionTitle(String title) {
    return Text(
      title,
      style: Theme.of(
        context,
      ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.bold),
    );
  }

  Widget _buildImagePreview() {
    return Column(
      children: [
        _buildSectionTitle('Aperçu'),
        const SizedBox(height: 12),
        ClipRRect(
          borderRadius: BorderRadius.circular(AppConstants.borderRadius),
          child: Stack(
            children: [
              Image.file(
                File(_selectedImagePath!),
                fit: BoxFit.contain,
                width: double.infinity,
              ),
              Positioned(
                top: 8,
                right: 8,
                child: IconButton(
                  icon: const Icon(Icons.close),
                  onPressed: () => setState(() => _selectedImagePath = null),
                  style: IconButton.styleFrom(
                    backgroundColor: Colors.black54,
                    foregroundColor: Colors.white,
                  ),
                ),
              ),
            ],
          ),
        ),
        const SizedBox(height: 12),
        _buildFramingHints(),
      ],
    );
  }

  Widget _buildFramingHints() {
    return Card(
      color: AppTheme.warningColor.withOpacity(0.1),
      child: Padding(
        padding: const EdgeInsets.all(12),
        child: Row(
          children: [
            Icon(Icons.info_outline, color: AppTheme.warningColor),
            const SizedBox(width: 12),
            Expanded(
              child: Text(
                'Assurez-vous que la cible est bien centrée et visible.',
                style: TextStyle(color: AppTheme.warningColor.withOpacity(0.8)),
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildGuide() {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(AppConstants.defaultPadding),
        child: Column(
          children: [
            Icon(Icons.help_outline, size: 48, color: Colors.grey[400]),
            const SizedBox(height: 12),
            Text(
              'Conseils pour une bonne analyse',
              style: Theme.of(
                context,
              ).textTheme.titleSmall?.copyWith(fontWeight: FontWeight.bold),
            ),
            const SizedBox(height: 12),
            _buildGuideItem(
              Icons.crop_free,
              'Cadrez la cible entière dans l\'image',
            ),
            _buildGuideItem(Icons.wb_sunny, 'Utilisez un bon éclairage'),
            _buildGuideItem(Icons.straighten, 'Prenez la photo de face'),
            _buildGuideItem(Icons.blur_off, 'Évitez les images floues'),
            _buildGuideItem(
              Icons.cleaning_services,
              'Nettoyer votre objectif avec une chiffonnette pour lunette si nécessaire',
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildGuideItem(IconData icon, String text) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4),
      child: Row(
        children: [
          Icon(icon, size: 20, color: AppTheme.primaryColor),
          const SizedBox(width: 12),
          Expanded(child: Text(text)),
        ],
      ),
    );
  }

  // --- LOGIQUE DE CAPTURE ---

  Future<void> _scanDocument() async {
    setState(() => _isLoading = true);
    try {
      final options = DocumentScannerOptions(
        documentFormat: DocumentFormat.jpeg,
        mode: ScannerMode.base,
        pageLimit: 1,
        isGalleryImport: false,
      );
      final scanner = DocumentScanner(options: options);
      final documents = await scanner.scanDocument();
      if (documents.images.isNotEmpty) {
        setState(() => _selectedImagePath = documents.images.first);
      }
    } catch (e) {
      debugPrint('Erreur scan: $e');
    } finally {
      if (mounted) setState(() => _isLoading = false);
    }
  }

  Future<void> _captureImage(ImageSource source) async {
    setState(() => _isLoading = true);
    try {
      final XFile? image = await _picker.pickImage(
        source: source,
        maxWidth: 2048,
        maxHeight: 2048,
        imageQuality: 90,
      );
      if (image != null) {
        setState(() => _selectedImagePath = image.path);
      }
    } catch (e) {
      debugPrint('Erreur capture: $e');
    } finally {
      if (mounted) setState(() => _isLoading = false);
    }
  }

  void _analyzeImage() {
    if (_selectedImagePath == null) return;
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (_) => CropScreen(
          imagePath: _selectedImagePath!,
          targetType: _selectedType,
        ),
      ),
    );
  }
}