import 'package:cached_network_image/cached_network_image.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';

import '../../core/theme/app_colors.dart';
import '../../shared/models/saved_recipe.dart';
import 'recipe_provider.dart';

class SavedRecipesScreen extends ConsumerWidget {
  const SavedRecipesScreen({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final state = ref.watch(savedRecipesProvider);

    return state.when(
      loading: () => const Center(child: CircularProgressIndicator()),
      error: (err, _) => Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            const Icon(Icons.error_outline, size: 48, color: Colors.red),
            const SizedBox(height: 12),
            const Text('Не удалось загрузить сохранённые рецепты'),
            const SizedBox(height: 12),
            ElevatedButton(
              onPressed: () => ref.read(savedRecipesProvider.notifier).load(),
              child: const Text('Повторить'),
            ),
          ],
        ),
      ),
      data: (recipes) => recipes.isEmpty
          ? const _EmptyState()
          : _SavedList(recipes: recipes),
    );
  }
}

// ---------------------------------------------------------------------------
// List
// ---------------------------------------------------------------------------

class _SavedList extends StatelessWidget {
  final List<SavedRecipe> recipes;

  const _SavedList({required this.recipes});

  @override
  Widget build(BuildContext context) {
    return ListView.separated(
      padding: const EdgeInsets.all(16),
      itemCount: recipes.length,
      separatorBuilder: (_, __) => const SizedBox(height: 8),
      itemBuilder: (context, index) =>
          _SavedRecipeItem(recipe: recipes[index]),
    );
  }
}

// ---------------------------------------------------------------------------
// Single item with swipe-to-delete
// ---------------------------------------------------------------------------

class _SavedRecipeItem extends ConsumerWidget {
  final SavedRecipe recipe;

  const _SavedRecipeItem({required this.recipe});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    return Dismissible(
      key: ValueKey(recipe.id),
      direction: DismissDirection.endToStart,
      background: _DeleteBackground(),
      confirmDismiss: (_) => _confirmDelete(context),
      onDismissed: (_) async {
        final ok =
            await ref.read(savedRecipesProvider.notifier).delete(recipe.id);
        if (!ok && context.mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(content: Text('Не удалось удалить рецепт')),
          );
        }
      },
      child: Card(
        clipBehavior: Clip.antiAlias,
        child: InkWell(
          onTap: () => context.push('/recipe-detail', extra: recipe),
          child: Row(
            children: [
              // Thumbnail
              _Thumbnail(imageUrl: recipe.imageUrl),
              // Info
              Expanded(
                child: Padding(
                  padding:
                      const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        recipe.title,
                        style: Theme.of(context)
                            .textTheme
                            .titleSmall
                            ?.copyWith(fontWeight: FontWeight.bold),
                        maxLines: 2,
                        overflow: TextOverflow.ellipsis,
                      ),
                      if (recipe.nutrition != null) ...[
                        const SizedBox(height: 4),
                        Text(
                          '≈ ${recipe.nutrition!.calories.round()} ккал · '
                          '${recipe.nutrition!.proteinG.round()} б · '
                          '${recipe.nutrition!.fatG.round()} ж · '
                          '${recipe.nutrition!.carbsG.round()} у',
                          style: const TextStyle(
                              fontSize: 11, color: AppColors.textSecondary),
                        ),
                      ],
                      if (recipe.prepTimeMin != null ||
                          recipe.cookTimeMin != null) ...[
                        const SizedBox(height: 4),
                        Text(
                          _timeLabel(recipe.prepTimeMin, recipe.cookTimeMin),
                          style: const TextStyle(
                              fontSize: 11, color: AppColors.textSecondary),
                        ),
                      ],
                    ],
                  ),
                ),
              ),
              // Delete button
              IconButton(
                icon: const Icon(Icons.delete_outline,
                    color: AppColors.textSecondary),
                onPressed: () async {
                  final confirmed = await _confirmDelete(context);
                  if (confirmed == true && context.mounted) {
                    final ok = await ref
                        .read(savedRecipesProvider.notifier)
                        .delete(recipe.id);
                    if (!ok && context.mounted) {
                      ScaffoldMessenger.of(context).showSnackBar(
                        const SnackBar(
                            content: Text('Не удалось удалить рецепт')),
                      );
                    }
                  }
                },
              ),
            ],
          ),
        ),
      ),
    );
  }

  String _timeLabel(int? prep, int? cook) {
    final total = (prep ?? 0) + (cook ?? 0);
    return total > 0 ? '$total мин' : '';
  }

  Future<bool?> _confirmDelete(BuildContext context) {
    return showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('Удалить рецепт?'),
        content: Text('«${recipe.title}» будет удалён из сохранённых.'),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(ctx).pop(false),
            child: const Text('Отмена'),
          ),
          TextButton(
            onPressed: () => Navigator.of(ctx).pop(true),
            style: TextButton.styleFrom(foregroundColor: Colors.red),
            child: const Text('Удалить'),
          ),
        ],
      ),
    );
  }
}

class _Thumbnail extends StatelessWidget {
  final String? imageUrl;

  const _Thumbnail({this.imageUrl});

  @override
  Widget build(BuildContext context) {
    if (imageUrl == null || imageUrl!.isEmpty) {
      return Container(
        width: 80,
        height: 80,
        color: AppColors.primaryLight.withValues(alpha: 0.3),
        child: const Icon(Icons.restaurant),
      );
    }
    return CachedNetworkImage(
      imageUrl: imageUrl!,
      width: 80,
      height: 80,
      fit: BoxFit.cover,
      placeholder: (_, __) =>
          Container(width: 80, height: 80, color: Colors.grey[200]),
      errorWidget: (_, __, ___) => Container(
        width: 80,
        height: 80,
        color: AppColors.primaryLight.withValues(alpha: 0.3),
        child: const Icon(Icons.restaurant),
      ),
    );
  }
}

class _DeleteBackground extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      color: AppColors.error,
      alignment: Alignment.centerRight,
      padding: const EdgeInsets.only(right: 20),
      child: const Icon(Icons.delete, color: Colors.white),
    );
  }
}

// ---------------------------------------------------------------------------
// Empty state
// ---------------------------------------------------------------------------

class _EmptyState extends StatelessWidget {
  const _EmptyState();

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Padding(
        padding: const EdgeInsets.all(32),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(
              Icons.favorite_border,
              size: 64,
              color: Colors.grey[400],
            ),
            const SizedBox(height: 16),
            Text(
              'Нет сохранённых рецептов',
              style: Theme.of(context).textTheme.titleMedium?.copyWith(
                    color: AppColors.textSecondary,
                  ),
            ),
            const SizedBox(height: 8),
            Text(
              'Сохраняйте рецепты из рекомендаций,\nнажимая на ♡',
              textAlign: TextAlign.center,
              style: TextStyle(color: Colors.grey[500]),
            ),
          ],
        ),
      ),
    );
  }
}