import 'dart:typed_data';
import 'package:flutter/material.dart';
import '../../core/service_locator.dart';
import '../../core/logger.dart';
import '../../data/recipes/recipe_service.dart';
import '../../data/recipes/models/recipe_model.dart';
import '../../data/nostr/models/nostr_keypair.dart';
import '../../data/immich/immich_service.dart';
import '../shared/primary_app_bar.dart';
import '../add_recipe/add_recipe_screen.dart';

/// Recipes screen displaying user's recipe collection.
class RecipesScreen extends StatefulWidget {
  const RecipesScreen({super.key});

  @override
  State<RecipesScreen> createState() => _RecipesScreenState();
}

class _RecipesScreenState extends State<RecipesScreen> {
  List<RecipeModel> _recipes = [];
  bool _isLoading = false;
  String? _errorMessage;
  RecipeService? _recipeService;

  @override
  void initState() {
    super.initState();
    _initializeService();
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    // Reload recipes when returning to this screen
    if (_recipeService != null) {
      _loadRecipes();
    }
  }

  Future<void> _initializeService() async {
    try {
      final localStorage = ServiceLocator.instance.localStorageService;
      final nostrService = ServiceLocator.instance.nostrService;
      final sessionService = ServiceLocator.instance.sessionService;
      
      // Get Nostr keypair from session if available
      NostrKeyPair? nostrKeyPair;
      if (sessionService != null && sessionService.currentUser != null) {
        final user = sessionService.currentUser!;
        if (user.nostrPrivateKey != null) {
          try {
            nostrKeyPair = NostrKeyPair.fromNsec(user.nostrPrivateKey!);
          } catch (e) {
            Logger.warning('Failed to parse Nostr keypair from session: $e');
          }
        }
      }

      _recipeService = RecipeService(
        localStorage: localStorage,
        nostrService: nostrService,
        nostrKeyPair: nostrKeyPair,
      );
      
      await _recipeService!.initialize();
      _loadRecipes();
    } catch (e) {
      Logger.error('Failed to initialize RecipeService', e);
      if (mounted) {
        setState(() {
          _errorMessage = 'Failed to initialize recipe service: $e';
          _isLoading = false;
        });
      }
    }
  }

  Future<void> _loadRecipes() async {
    if (_recipeService == null) return;

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

    try {
      final recipes = await _recipeService!.getAllRecipes();
      if (mounted) {
        setState(() {
          _recipes = recipes;
          _isLoading = false;
        });
      }
    } catch (e) {
      Logger.error('Failed to load recipes', e);
      if (mounted) {
        setState(() {
          _errorMessage = 'Failed to load recipes: $e';
          _isLoading = false;
        });
      }
    }
  }

  Future<void> _deleteRecipe(RecipeModel recipe) async {
    if (_recipeService == null) return;

    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Delete Recipe'),
        content: Text('Are you sure you want to delete "${recipe.title}"?'),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(context).pop(false),
            child: const Text('Cancel'),
          ),
          TextButton(
            onPressed: () => Navigator.of(context).pop(true),
            style: TextButton.styleFrom(foregroundColor: Colors.red),
            child: const Text('Delete'),
          ),
        ],
      ),
    );

    if (confirmed != true) return;

    try {
      await _recipeService!.deleteRecipe(recipe.id);
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text('Recipe deleted successfully'),
            backgroundColor: Colors.green,
          ),
        );
        _loadRecipes();
      }
    } catch (e) {
      Logger.error('Failed to delete recipe', e);
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('Failed to delete recipe: $e'),
            backgroundColor: Colors.red,
          ),
        );
      }
    }
  }

  void _editRecipe(RecipeModel recipe) {
    Navigator.of(context).push(
      MaterialPageRoute(
        builder: (context) => AddRecipeScreen(recipe: recipe),
      ),
    ).then((_) {
      // Reload recipes after editing
      _loadRecipes();
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: PrimaryAppBar(title: 'Recipes'),
      body: _buildBody(),
    );
  }

  Widget _buildBody() {
    if (_isLoading) {
      return const Center(
        child: CircularProgressIndicator(),
      );
    }

    if (_errorMessage != null) {
      return Center(
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Icon(Icons.error_outline, size: 64, color: Colors.red.shade300),
              const SizedBox(height: 16),
              Text(
                _errorMessage!,
                style: TextStyle(color: Colors.red.shade700),
                textAlign: TextAlign.center,
              ),
              const SizedBox(height: 16),
              ElevatedButton(
                onPressed: _loadRecipes,
                child: const Text('Retry'),
              ),
            ],
          ),
        ),
      );
    }

    if (_recipes.isEmpty) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(Icons.menu_book, size: 64, color: Colors.grey.shade400),
            const SizedBox(height: 16),
            Text(
              'No recipes yet',
              style: TextStyle(
                fontSize: 18,
                color: Colors.grey.shade600,
              ),
            ),
            const SizedBox(height: 8),
            Text(
              'Tap the + button to add your first recipe',
              style: TextStyle(
                fontSize: 14,
                color: Colors.grey.shade500,
              ),
            ),
          ],
        ),
      );
    }

    return RefreshIndicator(
      onRefresh: _loadRecipes,
      child: ListView.builder(
        padding: const EdgeInsets.all(16),
        itemCount: _recipes.length,
        itemBuilder: (context, index) {
          final recipe = _recipes[index];
          return _RecipeCard(
            recipe: recipe,
            onEdit: () => _editRecipe(recipe),
            onDelete: () => _deleteRecipe(recipe),
          );
        },
      ),
    );
  }
}

/// Card widget for displaying a recipe.
class _RecipeCard extends StatelessWidget {
  final RecipeModel recipe;
  final VoidCallback onEdit;
  final VoidCallback onDelete;

  const _RecipeCard({
    required this.recipe,
    required this.onEdit,
    required this.onDelete,
  });

  /// Builds an image widget using ImmichService for authenticated access.
  Widget _buildRecipeImage(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: CircularProgressIndicator(),
                ),
              );
            }

            if (snapshot.hasError || !snapshot.hasData || snapshot.data == null) {
              return Container(
                color: Colors.grey.shade200,
                child: const Icon(Icons.broken_image, size: 48),
              );
            }

            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 Container(
          color: Colors.grey.shade200,
          child: const Icon(Icons.broken_image, size: 48),
        );
      },
      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,
            ),
          ),
        );
      },
    );
  }

  @override
  Widget build(BuildContext context) {
    return Card(
      margin: const EdgeInsets.only(bottom: 16),
      elevation: 2,
      child: InkWell(
        onTap: onEdit,
        borderRadius: BorderRadius.circular(12),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            // Image section
            if (recipe.imageUrls.isNotEmpty)
              ClipRRect(
                borderRadius: const BorderRadius.vertical(top: Radius.circular(12)),
                child: AspectRatio(
                  aspectRatio: 16 / 9,
                  child: Stack(
                    fit: StackFit.expand,
                    children: [
                      _buildRecipeImage(recipe.imageUrls.first),
                      if (recipe.isFavourite)
                        Positioned(
                          top: 8,
                          right: 8,
                          child: Container(
                            padding: const EdgeInsets.all(6),
                            decoration: BoxDecoration(
                              color: Colors.red.withOpacity(0.8),
                              shape: BoxShape.circle,
                            ),
                            child: const Icon(
                              Icons.favorite,
                              color: Colors.white,
                              size: 20,
                            ),
                          ),
                        ),
                    ],
                  ),
                ),
              ),
            // Content section
            Padding(
              padding: const EdgeInsets.all(16),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Row(
                    children: [
                      Expanded(
                        child: Text(
                          recipe.title,
                          style: const TextStyle(
                            fontSize: 20,
                            fontWeight: FontWeight.bold,
                          ),
                        ),
                      ),
                      if (recipe.rating > 0)
                        Row(
                          children: List.generate(5, (index) {
                            return Icon(
                              index < recipe.rating
                                  ? Icons.star
                                  : Icons.star_border,
                              size: 16,
                              color: index < recipe.rating
                                  ? Colors.amber
                                  : Colors.grey,
                            );
                          }),
                        ),
                    ],
                  ),
                  if (recipe.description != null && recipe.description!.isNotEmpty) ...[
                    const SizedBox(height: 8),
                    Text(
                      recipe.description!,
                      style: TextStyle(
                        fontSize: 14,
                        color: Colors.grey.shade700,
                      ),
                      maxLines: 2,
                      overflow: TextOverflow.ellipsis,
                    ),
                  ],
                  if (recipe.tags.isNotEmpty) ...[
                    const SizedBox(height: 8),
                    Wrap(
                      spacing: 4,
                      runSpacing: 4,
                      children: recipe.tags.map((tag) {
                        return Chip(
                          label: Text(
                            tag,
                            style: const TextStyle(fontSize: 12),
                          ),
                          padding: EdgeInsets.zero,
                          materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
                          visualDensity: VisualDensity.compact,
                        );
                      }).toList(),
                    ),
                  ],
                  const SizedBox(height: 12),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.end,
                    children: [
                      IconButton(
                        icon: const Icon(Icons.edit),
                        onPressed: onEdit,
                        tooltip: 'Edit',
                      ),
                      IconButton(
                        icon: const Icon(Icons.delete),
                        onPressed: onDelete,
                        tooltip: 'Delete',
                        color: Colors.red,
                      ),
                    ],
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}