import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:glp1_companion/features/nutrition/domain/entities/food_log_entry.dart';
import 'package:glp1_companion/features/nutrition/domain/entities/hydration_log_entry.dart';
import 'package:glp1_companion/features/nutrition/domain/entities/meal_type.dart';
import 'package:glp1_companion/features/nutrition/domain/repositories/nutrition_repository.dart';
import 'package:glp1_companion/features/nutrition/presentation/controllers/nutrition_controller.dart';

/// In-memory [INutritionRepository] honoring the `[from, to)` range filter.
class _FakeNutritionRepository implements INutritionRepository {
  final List<FoodLogEntry> foods = [];
  final List<HydrationLogEntry> hydration = [];
  int _nextId = 1;
  bool failNextSave = false;

  static bool _inRange(DateTime timestamp, DateTime? from, DateTime? to) {
    if (from != null && timestamp.isBefore(from)) return false;
    if (to != null && !timestamp.isBefore(to)) return false;
    return true;
  }

  List<FoodLogEntry> _sortedFood(Iterable<FoodLogEntry> entries) {
    final list = entries.toList()
      ..sort((a, b) => b.timestamp.compareTo(a.timestamp));
    return List.unmodifiable(list);
  }

  List<HydrationLogEntry> _sortedWater(Iterable<HydrationLogEntry> entries) {
    final list = entries.toList()
      ..sort((a, b) => b.timestamp.compareTo(a.timestamp));
    return List.unmodifiable(list);
  }

  void _maybeFail() {
    if (failNextSave) {
      failNextSave = false;
      throw StateError('write failed');
    }
  }

  @override
  Stream<List<FoodLogEntry>> watchFoodLogs({int limit = 500}) =>
      Stream.value(_sortedFood(foods));

  @override
  Future<List<FoodLogEntry>> getFoodLogs({
    int limit = 500,
    DateTime? from,
    DateTime? to,
  }) async =>
      _sortedFood(foods.where((e) => _inRange(e.timestamp, from, to)));

  @override
  Future<FoodLogEntry> saveFoodLog(FoodLogEntry entry) async {
    _maybeFail();
    final stored = FoodLogEntry(
      id: entry.id ?? _nextId++,
      timestamp: entry.timestamp,
      mealType: entry.mealType,
      description: entry.description,
      proteinGrams: entry.proteinGrams,
      calories: entry.calories,
      carbsGrams: entry.carbsGrams,
      fatGrams: entry.fatGrams,
    );
    final index = foods.indexWhere((e) => e.id == stored.id);
    if (index == -1) {
      foods.add(stored);
    } else {
      foods[index] = stored;
    }
    return stored;
  }

  @override
  Future<void> deleteFoodLog(int id) async {
    foods.removeWhere((entry) => entry.id == id);
  }

  @override
  Stream<List<HydrationLogEntry>> watchHydrationLogs({int limit = 500}) =>
      Stream.value(_sortedWater(hydration));

  @override
  Future<List<HydrationLogEntry>> getHydrationLogs({
    int limit = 500,
    DateTime? from,
    DateTime? to,
  }) async =>
      _sortedWater(hydration.where((e) => _inRange(e.timestamp, from, to)));

  @override
  Future<HydrationLogEntry> saveHydrationLog(HydrationLogEntry entry) async {
    _maybeFail();
    final stored = HydrationLogEntry(
      id: entry.id ?? _nextId++,
      timestamp: entry.timestamp,
      volumeOz: entry.volumeOz,
    );
    hydration.add(stored);
    return stored;
  }

  @override
  Future<void> deleteHydrationLog(int id) async {
    hydration.removeWhere((entry) => entry.id == id);
  }
}

void main() {
  late _FakeNutritionRepository repository;
  late ProviderContainer container;

  final today = DateTime.now();

  setUp(() {
    repository = _FakeNutritionRepository();
    container = ProviderContainer(
      overrides: [
        nutritionRepositoryProvider.overrideWithValue(repository),
      ],
    );
    addTearDown(container.dispose);
  });

  Future<NutritionState> load() =>
      container.read(nutritionControllerProvider.future);

  group('NutritionController daily targets', () {
    test('build loads today-only entries and applies 100g/96oz targets',
        () async {
      repository.foods.add(
        FoodLogEntry(
          id: 1,
          timestamp: DateTime(today.year, today.month, today.day, 8),
          mealType: MealType.breakfast,
          description: 'Eggs',
          proteinGrams: 30,
          calories: 320,
        ),
      );
      repository.hydration.add(
        HydrationLogEntry(
          id: 2,
          timestamp: DateTime(today.year, today.month, today.day, 9),
          volumeOz: 16,
        ),
      );
      // Outside today's window: must be excluded.
      repository.foods.add(
        FoodLogEntry(
          id: 3,
          timestamp: DateTime(today.year, today.month, today.day - 1, 8),
          mealType: MealType.dinner,
          description: 'Yesterday stew',
          proteinGrams: 50,
          calories: 600,
        ),
      );

      final state = await load();

      expect(state.foodLogs, hasLength(1));
      expect(state.totalProteinGrams, 30);
      expect(state.proteinTargetGrams, 100);
      expect(state.proteinProgress, 0.3);
      expect(state.totalWaterOz, 16);
      expect(state.hydrationTargetOz, 96);
      expect(state.hydrationProgress, closeTo(16 / 96, 1e-9));
    });

    test('logFood updates totals and groups meals by type', () async {
      final initial = await load();
      expect(initial.foodLogs, isEmpty);
      expect(initial.mealsByType, isEmpty);

      final notifier = container.read(nutritionControllerProvider.notifier);
      final okBreakfast = await notifier.logFood(
        mealType: MealType.breakfast,
        description: 'Protein shake',
        proteinGrams: 40,
        calories: 220,
      );
      await notifier.logFood(
        mealType: MealType.lunch,
        description: 'Chicken salad',
        proteinGrams: 45.5,
        calories: 480,
        carbsGrams: 20,
        fatGrams: 15,
      );

      expect(okBreakfast, isTrue);

      final state = container.read(nutritionControllerProvider).valueOrNull!;
      expect(state.foodLogs, hasLength(2));
      expect(state.totalProteinGrams, closeTo(85.5, 1e-9));
      expect(state.totalCalories, 700);
      expect(state.totalCarbsGrams, 20);
      expect(state.totalFatGrams, 15);
      expect(state.mealsByType.keys, [MealType.breakfast, MealType.lunch]);
      expect(state.proteinProgress, closeTo(0.855, 1e-9));
    });

    test('logFood rejects empty descriptions and negative macros', () async {
      await load();
      final notifier = container.read(nutritionControllerProvider.notifier);

      expect(
        await notifier.logFood(
          mealType: MealType.snack,
          description: '   ',
          proteinGrams: 10,
          calories: 100,
        ),
        isFalse,
      );
      expect(
        await notifier.logFood(
          mealType: MealType.snack,
          description: 'Bad',
          proteinGrams: -1,
          calories: 100,
        ),
        isFalse,
      );
      expect(
        container.read(nutritionControllerProvider).valueOrNull!.foodLogs,
        isEmpty,
      );
    });

    test('quick-add water accumulates toward the 96 oz target', () async {
      await load();
      final notifier = container.read(nutritionControllerProvider.notifier);

      await notifier.logWater(8);
      await notifier.logWater(16);
      await notifier.logWater(24);

      final state = container.read(nutritionControllerProvider).valueOrNull!;
      expect(state.totalWaterOz, 48);
      expect(state.hydrationLogs, hasLength(3));
      expect(state.hydrationProgress, 0.5);

      expect(await notifier.logWater(0), isFalse);
    });

    test('deleteFood and deleteWater remove entries and refresh totals',
        () async {
      await load();
      final notifier = container.read(nutritionControllerProvider.notifier);

      await notifier.logFood(
        mealType: MealType.dinner,
        description: 'Tofu stir fry',
        proteinGrams: 25,
        calories: 300,
      );
      await notifier.logWater(16);

      var state = container.read(nutritionControllerProvider).valueOrNull!;
      final foodId = state.foodLogs.single.id!;
      final waterId = state.hydrationLogs.single.id!;

      await notifier.deleteFood(foodId);
      await notifier.deleteWater(waterId);

      state = container.read(nutritionControllerProvider).valueOrNull!;
      expect(state.foodLogs, isEmpty);
      expect(state.hydrationLogs, isEmpty);
      expect(state.totalProteinGrams, 0);
      expect(state.totalWaterOz, 0);
    });

    test('failed writes keep the previous state and report false', () async {
      await load();
      final notifier = container.read(nutritionControllerProvider.notifier);
      await notifier.logWater(8);

      repository.failNextSave = true;
      final ok = await notifier.logWater(16);

      expect(ok, isFalse);
      final state = container.read(nutritionControllerProvider).valueOrNull!;
      // First entry survives; the rejected write was not applied.
      expect(state.hydrationLogs, hasLength(1));
      expect(state.totalWaterOz, 8);
    });
  });
}