import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../core/auth/auth_provider.dart';
import '../../shared/models/recipe.dart';
import '../../shared/models/saved_recipe.dart';
import 'recipe_service.dart';

// ---------------------------------------------------------------------------
// Service provider
// ---------------------------------------------------------------------------

final recipeServiceProvider = Provider<RecipeService>((ref) {
  return RecipeService(ref.read(apiClientProvider));
});

// ---------------------------------------------------------------------------
// Recommendations
// ---------------------------------------------------------------------------

class RecommendationsNotifier
    extends StateNotifier<AsyncValue<List<Recipe>>> {
  final RecipeService _service;

  RecommendationsNotifier(this._service) : super(const AsyncValue.loading()) {
    load();
  }

  Future<void> load({int count = 5}) async {
    state = const AsyncValue.loading();
    state = await AsyncValue.guard(
      () => _service.getRecommendations(count: count),
    );
  }
}

final recommendationsProvider = StateNotifierProvider<RecommendationsNotifier,
    AsyncValue<List<Recipe>>>((ref) {
  return RecommendationsNotifier(ref.read(recipeServiceProvider));
});

// ---------------------------------------------------------------------------
// Saved recipes
// ---------------------------------------------------------------------------

class SavedRecipesNotifier
    extends StateNotifier<AsyncValue<List<SavedRecipe>>> {
  final RecipeService _service;

  SavedRecipesNotifier(this._service) : super(const AsyncValue.loading()) {
    load();
  }

  Future<void> load() async {
    state = const AsyncValue.loading();
    state = await AsyncValue.guard(() => _service.getSavedRecipes());
  }

  /// Saves [recipe] and reloads the list. Returns the saved record or null on error.
  Future<SavedRecipe?> save(Recipe recipe) async {
    try {
      final saved = await _service.saveRecipe(recipe);
      await load();
      return saved;
    } catch (_) {
      return null;
    }
  }

  /// Removes the recipe with [id] optimistically and reverts on error.
  Future<bool> delete(String id) async {
    final previous = state;
    state = state.whenData(
      (list) => list.where((r) => r.id != id).toList(),
    );
    try {
      await _service.deleteSavedRecipe(id);
      return true;
    } catch (_) {
      state = previous;
      return false;
    }
  }

  /// Returns true if any saved recipe has the same title.
  bool isSaved(String title) {
    return state.whenOrNull(
          data: (list) => list.any((r) => r.title == title),
        ) ??
        false;
  }

  /// Returns the saved recipe ID for the given title, or null.
  String? savedId(String title) {
    return state.whenOrNull(
      data: (list) {
        try {
          return list.firstWhere((r) => r.title == title).id;
        } catch (_) {
          return null;
        }
      },
    );
  }
}

final savedRecipesProvider = StateNotifierProvider<SavedRecipesNotifier,
    AsyncValue<List<SavedRecipe>>>((ref) {
  return SavedRecipesNotifier(ref.read(recipeServiceProvider));
});