// lib/presentation/screens/ai_enhancement/ai_enhancement_screen.dart

import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'dart:typed_data';

import 'package:flutter/material.dart';
import 'package:image/image.dart' as img;

import '../../../domain/app_filter.dart';
import '../../../domain/catalogs/filter_catalog.dart';
import '../../../repositories/ai_repository.dart';
// --- AJOUT NÉCESSAIRE POUR LA NAVIGATION ---
import '../../../routes/app_routes.dart';

// --- CLASSE D'ARGUMENTS (INCHANGÉE) ---
class AiEnhancementScreenArguments {
  AiEnhancementScreenArguments({
    required this.image,
    required this.initialPrompt,
    required this.suggestedFilterIds,
    required this.aiRepository,
  });
  final File image;
  final String initialPrompt;
  final List<String> suggestedFilterIds;
  final AiRepository aiRepository;
}

// --- ÉNUMÉRATIONS (INCHANGÉES) ---
enum GenerationState { idle, generating, done, error }
enum ImageGenerationEngine { stableDiffusion, gemini }

class AiEnhancementScreen extends StatefulWidget {
  const AiEnhancementScreen({required this.arguments, super.key});
  final AiEnhancementScreenArguments arguments;

  @override
  State<AiEnhancementScreen> createState() => _AiEnhancementScreenState();
}

class _AiEnhancementScreenState extends State<AiEnhancementScreen> {
  // --- GESTION D'ÉTAT ---
  GenerationState _generationState = GenerationState.idle;
  ImageGenerationEngine? _selectedEngine;
  final List<Uint8List> _generatedImagesData = [];
  StreamSubscription? _imageStreamSubscription;

  // --- NOUVEL ÉTAT POUR GÉRER LA VISIBILITÉ DU PROMPT ---
  bool _isPromptVisible = false;

  // --- DONNÉES DE L'ÉCRAN ---
  late final TextEditingController _promptController;
  late final List<ImageFilter> _preselectedFilters;

  @override
  void initState() {
    super.initState();
    _promptController = TextEditingController(text: widget.arguments.initialPrompt);
    _preselectedFilters = availableFilters
        .where((filter) => widget.arguments.suggestedFilterIds.contains(filter.id))
        .toList();
  }

  @override
  void dispose() {
    _imageStreamSubscription?.cancel();
    _promptController.dispose();
    super.dispose();
  }

  /// Lance la génération d'images avec le moteur spécifié.
  Future<void> _startGeneration(ImageGenerationEngine engine) async {
    if (_generationState == GenerationState.generating) return;

    setState(() {
      _generatedImagesData.clear();
      _generationState = GenerationState.generating;
      _selectedEngine = engine;
    });

    try {
      final imageBytes = await widget.arguments.image.readAsBytes();
      final imageBase64 = base64Encode(imageBytes);


        // --- DÉBUT DE LA CORRECTION ---

        // 1. Décoder l'image pour obtenir ses dimensions
        final originalImage = img.decodeImage(imageBytes);
        if (originalImage == null) {
          throw Exception("Impossible de lire les dimensions de l'image.");
        }

        // 2. Récupérer la largeur et la hauteur
        final int originalWidth = originalImage.width;
        final int originalHeight = originalImage.height;

        // --- FIN DE LA CORRECTION ---
        await _imageStreamSubscription?.cancel();
      _imageStreamSubscription = widget.arguments.aiRepository.editImage(
        imageBase64,
        _promptController.text,
        originalWidth,
        originalHeight,
        filtersToApply: _preselectedFilters,
      ).listen(
            (receivedBase64Image) {
          if (!mounted) return;
          setState(() => _generatedImagesData.add(base64Decode(receivedBase64Image)));
        },
        onError: (error) {
          if (!mounted) return;
          setState(() => _generationState = GenerationState.error);
          ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Erreur de génération : $error')));
        },
        onDone: () {
          if (!mounted) return;
          setState(() => _generationState = GenerationState.done);
        },
      );

    } catch (e) {
      if (!mounted) return;
      setState(() => _generationState = GenerationState.error);
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Erreur : ${e.toString()}')));
    }
  }

  // --- NOUVELLE MÉTHODE POUR NAVIGUER VERS L'APERÇU ---
  void _navigateToPreview(int index) {
    if (index >= _generatedImagesData.length) return;
    final selectedImageData = _generatedImagesData[index];
    final imageBase64 = base64Encode(selectedImageData);
    Navigator.pushNamed(context, AppRoutes.imagePreview, arguments: imageBase64);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('2. Amélioration IA')),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            _buildEngineChoiceSection(),
            const SizedBox(height: 24),
            // --- SECTION DU PROMPT MISE À JOUR ---
            _buildCollapsiblePromptSection(),
            const SizedBox(height: 24),
            Text('Résultats de la génération', style: Theme.of(context).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.bold)),
            const SizedBox(height: 16),
            // --- GRILLE DES RÉSULTATS MISE À JOUR ---
            _buildGeneratedVariationsGrid(),
          ],
        ),
      ),
    );
  }

  Widget _buildEngineChoiceSection() {
    return Card(
      elevation: 2,
      child: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Row(
          children: [
            ClipRRect(
              borderRadius: BorderRadius.circular(8.0),
              child: Image.file(
                widget.arguments.image,
                width: 100,
                height: 100,
                fit: BoxFit.cover,
              ),
            ),
            const SizedBox(width: 16),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: [
                  Text('Choisir le moteur IA', style: Theme.of(context).textTheme.titleMedium),
                  const SizedBox(height: 12),
                  FilledButton.icon(
                    onPressed: _generationState == GenerationState.generating ? null : () => _startGeneration(ImageGenerationEngine.stableDiffusion),
                    icon: const Icon(Icons.auto_awesome_outlined),
                    label: const Text('Stable Diffusion'),
                  ),
                  const SizedBox(height: 8),
                  OutlinedButton.icon(
                    onPressed: _generationState == GenerationState.generating ? null : () => _startGeneration(ImageGenerationEngine.gemini),
                    icon: const Icon(Icons.bubble_chart_outlined),
                    label: const Text('Gemini'),
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }

  /// --- NOUVELLE VERSION DE LA SECTION PROMPT ---
  /// Utilise un ExpansionTile pour être masquable/affichable.
  Widget _buildCollapsiblePromptSection() {
    return ExpansionTile(
      title: Text(
        'Prompt de Guidage',
        style: Theme.of(context).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.bold),
      ),
      subtitle: Text(
        _isPromptVisible ? 'Modifiez le prompt pour affiner le résultat' : 'Afficher pour modifier',
        style: Theme.of(context).textTheme.bodySmall?.copyWith(color: Colors.grey.shade600),
      ),
      onExpansionChanged: (isExpanded) {
        setState(() => _isPromptVisible = isExpanded);
      },
      children: [
        Padding(
          padding: const EdgeInsets.only(top: 8.0, bottom: 16.0),
          child: TextField(
            controller: _promptController,
            decoration: const InputDecoration(
              hintText: 'Décrivez l\'image que vous souhaitez obtenir...',
              border: OutlineInputBorder(),
            ),
            maxLines: 4,
            minLines: 2,
          ),
        ),
      ],
    );
  }

  /// --- NOUVELLE VERSION DE LA GRILLE DES RÉSULTATS ---
  /// Utilise un GestureDetector pour rendre chaque image cliquable.
  Widget _buildGeneratedVariationsGrid() {
    if (_generationState == GenerationState.idle) {
      return Container(
        height: 100,
        decoration: BoxDecoration(color: Colors.grey.shade200, borderRadius: BorderRadius.circular(8)),
        child: const Center(child: Text("Choisissez un moteur pour commencer.")),
      );
    }
    if (_generationState == GenerationState.generating) {
      return const Padding(
        padding: EdgeInsets.all(32.0),
        child: Center(child: CircularProgressIndicator()),
      );
    }
    if (_generationState == GenerationState.done && _generatedImagesData.isEmpty) {
      return Container(
        height: 100,
        decoration: BoxDecoration(color: Colors.red.shade50, borderRadius: BorderRadius.circular(8), border: Border.all(color: Colors.red.shade200)),
        child: const Center(child: Text("La génération n'a produit aucune image.", textAlign: TextAlign.center)),
      );
    }
    return GridView.builder(
      shrinkWrap: true,
      physics: const NeverScrollableScrollPhysics(),
      gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
        crossAxisCount: 2,
        crossAxisSpacing: 8,
        mainAxisSpacing: 8,
      ),
      itemCount: _generatedImagesData.length,
      itemBuilder: (context, index) {
        // ON ENTOURE L'IMAGE D'UN GESTUREDETECTOR
        return GestureDetector(
          onTap: () => _navigateToPreview(index),
          child: ClipRRect(
            borderRadius: BorderRadius.circular(8),
            child: Image.memory(_generatedImagesData[index], fit: BoxFit.cover),
          ),
        );
      },
    );
  }
}