import 'dart:io';
import 'dart:typed_data';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import '../../core/service_locator.dart';
import '../../core/logger.dart';
import '../../data/recipes/recipe_service.dart';
import '../../data/recipes/models/recipe_model.dart';

/// Add Recipe screen for creating new recipes.
class AddRecipeScreen extends StatefulWidget {
  final RecipeModel? recipe; // For editing existing recipes
  final bool viewMode; // If true, display in view-only mode

  const AddRecipeScreen({
    super.key,
    this.recipe,
    this.viewMode = false,
  });

  @override
  State<AddRecipeScreen> createState() => _AddRecipeScreenState();
}

class _AddRecipeScreenState extends State<AddRecipeScreen> {
  final _formKey = GlobalKey<FormState>();
  final _titleController = TextEditingController();
  final _descriptionController = TextEditingController();
  final _tagsController = TextEditingController();
  
  int _rating = 0;
  bool _isFavourite = false;
  List<File> _selectedImages = [];
  List<String> _uploadedImageUrls = [];
  bool _isUploading = false;
  bool _isSaving = false;
  String? _errorMessage;

  final ImagePicker _imagePicker = ImagePicker();
  RecipeService? _recipeService;

  @override
  void initState() {
    super.initState();
    _initializeService();
    if (widget.recipe != null) {
      _loadRecipeData();
    }
  }

  Future<void> _initializeService() async {
    try {
      // Use the shared RecipeService from ServiceLocator instead of creating a new instance
      // This ensures we're using the same instance that SessionService manages
      _recipeService = ServiceLocator.instance.recipeService;
      
      if (_recipeService == null) {
        throw Exception('RecipeService not available in ServiceLocator');
      }

      // The database should already be initialized by SessionService on login
      // If not initialized, we'll get an error when trying to use it
    } catch (e) {
      Logger.error('Failed to initialize RecipeService', e);
      if (mounted) {
        setState(() {
          _errorMessage = 'Failed to initialize recipe service: $e';
        });
      }
    }
  }

  void _loadRecipeData() {
    if (widget.recipe == null) return;
    
    final recipe = widget.recipe!;
    _titleController.text = recipe.title;
    _descriptionController.text = recipe.description ?? '';
    _tagsController.text = recipe.tags.join(', ');
    _rating = recipe.rating;
    _isFavourite = recipe.isFavourite;
    _uploadedImageUrls = List.from(recipe.imageUrls);
  }

  @override
  void dispose() {
    _titleController.dispose();
    _descriptionController.dispose();
    _tagsController.dispose();
    super.dispose();
  }

  Future<void> _pickImages() async {
    try {
      final List<XFile> pickedFiles = await _imagePicker.pickMultiImage();
      
      if (pickedFiles.isEmpty) return;

      final newImages = pickedFiles.map((file) => File(file.path)).toList();
      
      setState(() {
        _selectedImages.addAll(newImages);
        _isUploading = true;
      });

      // Auto-upload images immediately
      await _uploadImages();
    } catch (e) {
      Logger.error('Failed to pick images', e);
      if (mounted) {
        setState(() {
          _isUploading = false;
        });
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('Failed to pick images: $e'),
            backgroundColor: Colors.red,
          ),
        );
      }
    }
  }

  Future<void> _uploadImages() async {
    if (_selectedImages.isEmpty) return;

    final immichService = ServiceLocator.instance.immichService;
    if (immichService == null) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text('Immich service not available'),
            backgroundColor: Colors.orange,
          ),
        );
      }
      return;
    }

    setState(() {
      _isUploading = true;
      _errorMessage = null;
    });

    try {
      final List<String> uploadedUrls = [];
      
      for (final imageFile in _selectedImages) {
        try {
          final uploadResponse = await immichService.uploadImage(imageFile);
          final imageUrl = immichService.getImageUrl(uploadResponse.id);
          uploadedUrls.add(imageUrl);
          Logger.info('Image uploaded: $imageUrl');
        } catch (e) {
          Logger.warning('Failed to upload image ${imageFile.path}: $e');
          // Continue with other images
        }
      }

      setState(() {
        _uploadedImageUrls.addAll(uploadedUrls);
        _selectedImages.clear();
        _isUploading = false;
      });

      if (mounted && uploadedUrls.isNotEmpty) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('${uploadedUrls.length} image(s) uploaded successfully'),
            backgroundColor: Colors.green,
          ),
        );
      }
    } catch (e) {
      Logger.error('Failed to upload images', e);
      if (mounted) {
        setState(() {
          _isUploading = false;
          _errorMessage = 'Failed to upload images: $e';
        });
      }
    }
  }

  Future<void> _saveRecipe() async {
    if (!_formKey.currentState!.validate()) {
      return;
    }

    if (_recipeService == null) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text('Recipe service not initialized'),
            backgroundColor: Colors.red,
          ),
        );
      }
      return;
    }

    // Upload any pending images first and wait for completion
    if (_selectedImages.isNotEmpty) {
      setState(() {
        _isSaving = true;
        _errorMessage = null;
      });
      
      await _uploadImages();
      
      // Check if upload failed
      if (_selectedImages.isNotEmpty) {
        setState(() {
          _isSaving = false;
          _errorMessage = 'Some images failed to upload. Please try again.';
        });
        return;
      }
    } else {
      setState(() {
        _isSaving = true;
        _errorMessage = null;
      });
    }

    // Wait for any ongoing uploads to complete
    while (_isUploading) {
      await Future.delayed(const Duration(milliseconds: 100));
    }

    try {
      // Parse tags
      final tags = _tagsController.text
          .split(',')
          .map((tag) => tag.trim())
          .where((tag) => tag.isNotEmpty)
          .toList();

      final recipe = RecipeModel(
        id: widget.recipe?.id ?? 'recipe-${DateTime.now().millisecondsSinceEpoch}',
        title: _titleController.text.trim(),
        description: _descriptionController.text.trim().isEmpty
            ? null
            : _descriptionController.text.trim(),
        tags: tags,
        rating: _rating,
        isFavourite: _isFavourite,
        imageUrls: _uploadedImageUrls,
      );

      if (widget.recipe != null) {
        // Update existing recipe
        await _recipeService!.updateRecipe(recipe);
      } else {
        // Create new recipe
        await _recipeService!.createRecipe(recipe);
      }

      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text(widget.recipe != null
                ? 'Recipe updated successfully'
                : 'Recipe added successfully'),
            backgroundColor: Colors.green,
          ),
        );

        // Navigate back to Recipes screen with result to indicate success
        Navigator.of(context).pop(true);
      }
    } catch (e) {
      Logger.error('Failed to save recipe', e);
      if (mounted) {
        setState(() {
          _isSaving = false;
          _errorMessage = 'Failed to save recipe: $e';
        });
      }
    }
  }

  void _removeImage(int index) {
    setState(() {
      _uploadedImageUrls.removeAt(index);
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(
          widget.viewMode
              ? 'View Recipe'
              : (widget.recipe != null ? 'Edit Recipe' : 'Add Recipe'),
        ),
        actions: [
          // Edit button in view mode
          if (widget.viewMode)
            IconButton(
              icon: const Icon(Icons.edit),
              onPressed: () {
                // Navigate to edit mode
                Navigator.of(context).pushReplacement(
                  MaterialPageRoute(
                    builder: (context) => AddRecipeScreen(recipe: widget.recipe),
                  ),
                );
              },
              tooltip: 'Edit',
            ),
        ],
      ),
      body: Form(
        key: _formKey,
        child: ListView(
          padding: const EdgeInsets.all(16),
          children: [
            // Title field
            TextFormField(
              controller: _titleController,
              enabled: !widget.viewMode,
              readOnly: widget.viewMode,
              decoration: const InputDecoration(
                labelText: 'Title *',
                hintText: 'Enter recipe title',
                border: OutlineInputBorder(),
              ),
              validator: widget.viewMode
                  ? null
                  : (value) {
                      if (value == null || value.trim().isEmpty) {
                        return 'Title is required';
                      }
                      return null;
                    },
            ),
            const SizedBox(height: 16),

            // Description field
            TextFormField(
              controller: _descriptionController,
              enabled: !widget.viewMode,
              readOnly: widget.viewMode,
              decoration: const InputDecoration(
                labelText: 'Description',
                hintText: 'Enter recipe description',
                border: OutlineInputBorder(),
              ),
              maxLines: 4,
            ),
            const SizedBox(height: 16),

            // Tags field
            TextFormField(
              controller: _tagsController,
              enabled: !widget.viewMode,
              readOnly: widget.viewMode,
              decoration: const InputDecoration(
                labelText: 'Tags',
                hintText: 'Enter tags separated by commas',
                border: OutlineInputBorder(),
                helperText: 'Separate tags with commas',
              ),
            ),
            const SizedBox(height: 16),

            // Rating
            Card(
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    const Text(
                      'Rating',
                      style: TextStyle(
                        fontSize: 16,
                        fontWeight: FontWeight.bold,
                      ),
                    ),
                    const SizedBox(height: 8),
                    Row(
                      children: List.generate(5, (index) {
                        return IconButton(
                          icon: Icon(
                            index < _rating ? Icons.star : Icons.star_border,
                            color: index < _rating ? Colors.amber : Colors.grey,
                            size: 32,
                          ),
                          onPressed: widget.viewMode
                              ? null
                              : () {
                                  setState(() {
                                    _rating = index + 1;
                                  });
                                },
                        );
                      }),
                    ),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 16),

            // Favourite toggle
            Card(
              child: SwitchListTile(
                title: const Text('Favourite'),
                value: _isFavourite,
                onChanged: widget.viewMode
                    ? null
                    : (value) {
                        setState(() {
                          _isFavourite = value;
                        });
                      },
              ),
            ),
            const SizedBox(height: 16),

            // Images section
            Card(
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: [
                        const Text(
                          'Images',
                          style: TextStyle(
                            fontSize: 16,
                            fontWeight: FontWeight.bold,
                          ),
                        ),
                        if (!widget.viewMode)
                          ElevatedButton.icon(
                            onPressed: _isUploading ? null : _pickImages,
                            icon: const Icon(Icons.add_photo_alternate),
                            label: const Text('Add Images'),
                          ),
                      ],
                    ),
                    const SizedBox(height: 8),
                    if (_isUploading)
                      const Padding(
                        padding: EdgeInsets.all(8),
                        child: Row(
                          children: [
                            SizedBox(
                              width: 20,
                              height: 20,
                              child: CircularProgressIndicator(strokeWidth: 2),
                            ),
                            SizedBox(width: 8),
                            Text('Uploading images...'),
                          ],
                        ),
                      ),
                    if (_uploadedImageUrls.isNotEmpty)
                      Wrap(
                        spacing: 8,
                        runSpacing: 8,
                        children: _uploadedImageUrls.asMap().entries.map((entry) {
                          final index = entry.key;
                          final url = entry.value;
                          return Stack(
                            children: [
                              Container(
                                width: 100,
                                height: 100,
                                decoration: BoxDecoration(
                                  border: Border.all(color: Colors.grey),
                                  borderRadius: BorderRadius.circular(8),
                                ),
                                child: ClipRRect(
                                  borderRadius: BorderRadius.circular(8),
                                  child: _buildImagePreview(url),
                                ),
                              ),
                              if (!widget.viewMode)
                                Positioned(
                                  top: 4,
                                  right: 4,
                                  child: IconButton(
                                    icon: const Icon(Icons.close, size: 20),
                                    color: Colors.red,
                                    onPressed: () => _removeImage(index),
                                  ),
                                ),
                            ],
                          );
                        }).toList(),
                      ),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 16),

            // Error message
            if (_errorMessage != null)
              Container(
                padding: const EdgeInsets.all(12),
                decoration: BoxDecoration(
                  color: Colors.red.shade50,
                  borderRadius: BorderRadius.circular(8),
                  border: Border.all(color: Colors.red.shade200),
                ),
                child: Row(
                  children: [
                    Icon(Icons.error_outline, color: Colors.red.shade700),
                    const SizedBox(width: 8),
                    Expanded(
                      child: Text(
                        _errorMessage!,
                        style: TextStyle(color: Colors.red.shade700),
                      ),
                    ),
                  ],
                ),
              ),
            const SizedBox(height: 16),

            // Save and Cancel buttons (only show in edit/add mode)
            if (!widget.viewMode)
              Row(
                children: [
                  Expanded(
                    child: OutlinedButton(
                      onPressed: _isSaving ? null : () => Navigator.of(context).pop(),
                      child: const Text('Cancel'),
                    ),
                  ),
                  const SizedBox(width: 16),
                  Expanded(
                    child: ElevatedButton(
                      onPressed: _isSaving ? null : _saveRecipe,
                      child: _isSaving
                          ? const SizedBox(
                              width: 20,
                              height: 20,
                              child: CircularProgressIndicator(
                                strokeWidth: 2,
                                valueColor: AlwaysStoppedAnimation<Color>(Colors.white),
                              ),
                            )
                          : Text(widget.recipe != null ? 'Update' : 'Save'),
                    ),
                  ),
                ],
              ),
          ],
        ),
      ),
    );
  }

  /// Builds an image preview widget using ImmichService for authenticated access.
  Widget _buildImagePreview(String imageUrl) {
    final immichService = ServiceLocator.instance.immichService;
    
    // Try to extract asset ID from URL (format: .../api/assets/{id}/original)
    final assetIdMatch = RegExp(r'/api/assets/([^/]+)/').firstMatch(imageUrl);
    
    if (assetIdMatch != null && immichService != null) {
      final assetId = assetIdMatch.group(1);
      if (assetId != null) {
        // Use ImmichService to fetch image with proper authentication
        return FutureBuilder<Uint8List?>(
          future: immichService.fetchImageBytes(assetId, isThumbnail: true),
          builder: (context, snapshot) {
            if (snapshot.connectionState == ConnectionState.waiting) {
              return Container(
                color: Colors.grey.shade200,
                child: const Center(
                  child: SizedBox(
                    width: 20,
                    height: 20,
                    child: CircularProgressIndicator(strokeWidth: 2),
                  ),
                ),
              );
            }

            if (snapshot.hasError || !snapshot.hasData || snapshot.data == null) {
              return const Icon(Icons.broken_image);
            }

            return Image.memory(
              snapshot.data!,
              fit: BoxFit.cover,
            );
          },
        );
      }
    }
    
    // Fallback to direct network image if not an Immich URL or service unavailable
    return Image.network(
      imageUrl,
      fit: BoxFit.cover,
      errorBuilder: (context, error, stackTrace) {
        return const Icon(Icons.broken_image);
      },
      loadingBuilder: (context, child, loadingProgress) {
        if (loadingProgress == null) return child;
        return Container(
          color: Colors.grey.shade200,
          child: Center(
            child: CircularProgressIndicator(
              value: loadingProgress.expectedTotalBytes != null
                  ? loadingProgress.cumulativeBytesLoaded /
                      loadingProgress.expectedTotalBytes!
                  : null,
            ),
          ),
        );
      },
    );
  }
}