import 'package:drift/native.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:glp1_companion/core/database/app_database.dart';
import 'package:glp1_companion/core/utils/date_time_utils.dart';
import 'package:glp1_companion/core/utils/uuid.dart';
import 'package:glp1_companion/features/meal_planner/data/repositories/drift_meal_plan_repository.dart';
import 'package:glp1_companion/features/meal_planner/data/repositories/drift_recipe_repository.dart';
import 'package:glp1_companion/features/meal_planner/domain/entities/macro_profile.dart';
import 'package:glp1_companion/features/meal_planner/domain/entities/meal_plan_slot.dart';
import 'package:glp1_companion/features/meal_planner/domain/entities/recipe.dart';
import 'package:glp1_companion/features/meal_planner/domain/entities/recipe_ingredient.dart';
import 'package:glp1_companion/features/nutrition/domain/entities/meal_type.dart';
import 'package:glp1_companion/features/pantry/data/repositories/drift_pantry_repository.dart';
import 'package:glp1_companion/features/pantry/domain/entities/pantry_category.dart';
import 'package:glp1_companion/features/pantry/domain/entities/pantry_item.dart';
import 'package:glp1_companion/features/pantry/domain/entities/shopping_list_item.dart';
import 'package:glp1_companion/features/pantry/domain/usecases/calculate_shopping_delta.dart';
import 'package:glp1_companion/features/pantry/presentation/controllers/pantry_inventory_controller.dart';
import 'package:glp1_companion/features/pantry/presentation/controllers/shopping_list_controller.dart';

void main() {
  late AppDatabase database;
  late DriftPantryRepository repository;
  late CalculateShoppingDelta deltaEngine;
  late ProviderContainer container;

  /// A Monday (stable fixture for deterministic slot ordering).
  final weekMonday = DateTime(2026, 10, 12);

  PantryItem makeStock({
    String? id,
    required String name,
    required double quantity,
    String unit = 'g',
    PantryCategory category = PantryCategory.other,
  }) =>
      PantryItem(
        id: id ?? generateUuid(),
        name: name,
        quantityOnHand: quantity,
        unit: unit,
        category: category,
        lastUpdated: DateTime(2026, 10, 12, 9),
      );

  Recipe makeRecipe({
    required String title,
    required List<RecipeIngredient> ingredients,
  }) =>
      Recipe(
        id: generateUuid(),
        title: title,
        sourceUrl: 'https://recipes.test/${generateUuid()}',
        servings: 4,
        ingredients: ingredients,
        instructions: const ['Cook it.'],
        macrosPerServing: const MacroProfile(
          calories: 400,
          proteinGrams: 40,
          carbsGrams: 20,
          fatGrams: 15,
        ),
      );

  MealPlanSlot makeSlot({required DateTime day, required String recipeId}) =>
      MealPlanSlot(
        id: generateUuid(),
        date: day,
        mealType: MealType.dinner,
        recipeId: recipeId,
      );

  RecipeIngredient ingredient(
    String name,
    double quantity,
    String? unit, {
    String? rawText,
  }) =>
      RecipeIngredient(
        rawText: rawText ?? '$quantity ${unit ?? ''} $name'.trim(),
        parsedItemName: name,
        quantity: quantity,
        unit: unit,
      );

  setUp(() {
    database = AppDatabase.forTesting(NativeDatabase.memory());
    repository = DriftPantryRepository(database);
    deltaEngine = CalculateShoppingDelta(repository);
    container = ProviderContainer(
      overrides: [appDatabaseProvider.overrideWithValue(database)],
    );
  });

  tearDown(() {
    container.dispose();
    database.close();
  });

  group('CalculateShoppingDelta', () {
    test('300 g on hand vs an 800 g requirement generates a +500 g entry',
        () async {
      await repository.saveItem(
        makeStock(name: 'chicken breast', quantity: 300, unit: 'g'),
      );
      final recipe = makeRecipe(
        title: 'Lemon Herb Chicken',
        ingredients: [
          ingredient(
            'chicken breast',
            800,
            'g',
            rawText: '800 g chicken breast',
          ),
        ],
      );

      final result = await deltaEngine(
        slots: [makeSlot(day: weekMonday, recipeId: recipe.id)],
        recipes: [recipe],
      );

      final list = await repository.getShoppingList();
      expect(list, hasLength(1));
      final entry = list.single;
      expect(entry.name, 'chicken breast');
      expect(entry.requiredQuantity, 500);
      expect(entry.unit, 'g');
      expect(entry.isAutoGenerated, isTrue);
      expect(entry.isPurchased, isFalse);
      expect(entry.sourceRecipeTitles, ['Lemon Herb Chicken']);
      expect(result.addedCount, 1);
      expect(result.updatedCount, 0);
      expect(result.removedItems, isEmpty);
      expect(result.summary, 'Sync complete: 1 added.');
    });

    test('sufficient stock generates no shopping entry', () async {
      await repository.saveItem(
        makeStock(name: 'chicken breast', quantity: 900, unit: 'g'),
      );
      final recipe = makeRecipe(
        title: 'Lemon Herb Chicken',
        ingredients: [ingredient('chicken breast', 800, 'g')],
      );

      final result = await deltaEngine(
        slots: [makeSlot(day: weekMonday, recipeId: recipe.id)],
        recipes: [recipe],
      );

      expect(await repository.getShoppingList(), isEmpty);
      expect(result.addedCount, 0);
      expect(result.satisfiedNames, ['chicken breast']);
      expect(
        result.summary,
        "Your pantry already covers this week's meal plan.",
      );
    });

    test('manual shopping items are preserved when the sync runs', () async {
      final manual = ShoppingListItem(
        id: generateUuid(),
        name: 'Olive Oil',
        requiredQuantity: 1,
        unit: 'bottle',
      );
      await repository.saveShoppingListItem(manual);
      await repository.saveItem(
        makeStock(name: 'chicken breast', quantity: 300, unit: 'g'),
      );
      final recipe = makeRecipe(
        title: 'Lemon Herb Chicken',
        ingredients: [ingredient('chicken breast', 800, 'g')],
      );
      final slots = [makeSlot(day: weekMonday, recipeId: recipe.id)];

      await deltaEngine(slots: slots, recipes: [recipe]);
      // Re-running the sync must neither drop nor duplicate the manual row.
      await deltaEngine(slots: slots, recipes: [recipe]);

      final list = await repository.getShoppingList();
      expect(list, hasLength(2));
      final restoredManual = list.firstWhere((item) => item.id == manual.id);
      expect(restoredManual.name, 'Olive Oil');
      expect(restoredManual.requiredQuantity, 1);
      expect(restoredManual.unit, 'bottle');
      expect(restoredManual.isAutoGenerated, isFalse);
      expect(restoredManual.isPurchased, isFalse);
      expect(list.where((item) => item.isAutoGenerated), hasLength(1));
      expect(list.where((item) => item.id == manual.id), hasLength(1));
    });

    test('stale auto entries are cleared once stock covers the plan', () async {
      final stock = makeStock(name: 'chicken breast', quantity: 300, unit: 'g');
      await repository.saveItem(stock);
      final recipe = makeRecipe(
        title: 'Lemon Herb Chicken',
        ingredients: [ingredient('chicken breast', 800, 'g')],
      );
      final slots = [makeSlot(day: weekMonday, recipeId: recipe.id)];

      await deltaEngine(slots: slots, recipes: [recipe]);
      expect(await repository.getShoppingList(), hasLength(1));

      await repository.saveItem(stock.copyWith(quantityOnHand: 900));
      final result = await deltaEngine(slots: slots, recipes: [recipe]);

      expect(await repository.getShoppingList(), isEmpty);
      expect(result.removedItems, hasLength(1));
      expect(result.clearedCount, 1);
    });

    test('aggregates across recipes and normalizes plurals and units',
        () async {
      // Plural/missing-unit lines fold onto one canonical "egg" key:
      // 4 eggs + 2 egg − 2 in stock = a +4 "egg" deficit.
      await repository.saveItem(
        makeStock(name: 'egg', quantity: 2, unit: 'count'),
      );
      final breakfast = makeRecipe(
        title: 'Baked Eggs',
        ingredients: [ingredient('eggs', 4, null, rawText: '4 eggs')],
      );
      final brunch = makeRecipe(
        title: 'Sunday Omelette',
        ingredients: [ingredient('egg', 2, null, rawText: '2 egg')],
      );

      final result = await deltaEngine(
        slots: [
          makeSlot(day: weekMonday, recipeId: breakfast.id),
          makeSlot(
            day: weekMonday.add(const Duration(days: 1)),
            recipeId: brunch.id,
          ),
        ],
        recipes: [breakfast, brunch],
      );

      final eggEntry = (await repository.getShoppingList())
          .singleWhere((item) => item.name == 'egg');
      expect(eggEntry.requiredQuantity, 4);
      expect(eggEntry.unit, 'count');
      expect(eggEntry.sourceRecipeTitles, ['Baked Eggs', 'Sunday Omelette']);
      expect(result.addedCount, 1);
    });

    test('converts lbs and oz onto one scale before computing the delta',
        () async {
      await repository.saveItem(
        makeStock(name: 'butter', quantity: 4, unit: 'oz'),
      );
      final lbRecipe = makeRecipe(
        title: 'Cake Batter',
        ingredients: [ingredient('butter', 0.5, 'lb', rawText: '0.5 lb butter')],
      );
      final ozRecipe = makeRecipe(
        title: 'Sauté Night',
        ingredients: [ingredient('butter', 8, 'oz', rawText: '8 oz butter')],
      );

      await deltaEngine(
        slots: [
          // Earlier date wins the dominant-unit tie (lb is aggregated first).
          makeSlot(day: weekMonday, recipeId: lbRecipe.id),
          makeSlot(
            day: weekMonday.add(const Duration(days: 1)),
            recipeId: ozRecipe.id,
          ),
        ],
        recipes: [lbRecipe, ozRecipe],
      );

      final butter = (await repository.getShoppingList())
          .singleWhere((item) => item.name == 'butter');
      expect(butter.unit, 'lb');
      // (0.5 lb + 8 oz − 4 oz) = 0.75 lb.
      expect(butter.requiredQuantity, closeTo(0.75, 0.001));
    });
  });

  group('ShoppingListController', () {
    test('checking off with pantry transfer increments stock', () async {
      await repository.saveItem(
        makeStock(name: 'chicken breast', quantity: 300, unit: 'g'),
      );
      final item = ShoppingListItem(
        id: generateUuid(),
        name: 'Chicken Breast',
        requiredQuantity: 500,
        unit: 'g',
        isAutoGenerated: true,
        sourceRecipeTitles: const ['Lemon Herb Chicken'],
      );
      await repository.saveShoppingListItem(item);

      final controller =
          container.read(shoppingListControllerProvider.notifier);
      final ok = await controller.completeItem(item, addToPantry: true);
      expect(ok, isTrue);

      final stock = await repository.getItems();
      expect(stock, hasLength(1));
      expect(stock.single.quantityOnHand, 800);
      expect((await repository.getShoppingList()).single.isPurchased, isTrue);
    });

    test('checking off a new item creates aisle-inferred pantry stock',
        () async {
      final item = ShoppingListItem(
        id: generateUuid(),
        name: 'Greek Yogurt',
        requiredQuantity: 2,
        unit: 'count',
      );
      await repository.saveShoppingListItem(item);

      final controller =
          container.read(shoppingListControllerProvider.notifier);
      await controller.completeItem(item, addToPantry: true);

      final stock = await repository.getItems();
      expect(stock.single.name, 'greek yogurt');
      expect(stock.single.quantityOnHand, 2);
      expect(stock.single.unit, 'count');
      expect(stock.single.category, PantryCategory.dairy);
    });

    test('syncWithMealPlan wires the planner window into the delta engine',
        () async {
      final recipeRepository = DriftRecipeRepository(database);
      final mealPlanRepository = DriftMealPlanRepository(database);
      final recipe = makeRecipe(
        title: 'Lemon Herb Chicken',
        ingredients: [ingredient('chicken breast', 800, 'g')],
      );
      await recipeRepository.saveRecipe(recipe);
      await mealPlanRepository.saveSlot(
        makeSlot(day: startOfWeek(DateTime.now()), recipeId: recipe.id),
      );

      final controller =
          container.read(shoppingListControllerProvider.notifier);
      final summary = await controller.syncWithMealPlan();

      expect(summary, isNotNull);
      expect(
        container.read(shoppingListControllerProvider).statusMessage,
        summary,
      );
      final list = await repository.getShoppingList();
      expect(list, hasLength(1));
      expect(list.single.isAutoGenerated, isTrue);
      expect(list.single.requiredQuantity, 800);
    });
  });

  group('PantryInventoryController', () {
    test('addItem canonicalizes the name and quick adjust clamps at zero',
        () async {
      final controller =
          container.read(pantryInventoryControllerProvider.notifier);
      final saved = await controller.addItem(
        name: 'Chicken Breasts',
        quantityOnHand: 300,
        unit: 'g',
        category: PantryCategory.meatSeafood,
      );
      expect(saved, isTrue);

      final stock = await repository.getItems();
      expect(stock.single.name, 'chicken breast');
      expect(stock.single.category, PantryCategory.meatSeafood);

      await controller.adjustQuantity(stock.single, -500);
      expect((await repository.getItems()).single.quantityOnHand, 0);

      await controller.adjustQuantity(
        (await repository.getItems()).single,
        50,
      );
      expect((await repository.getItems()).single.quantityOnHand, 50);
    });
  });
}