import 'package:flutter_test/flutter_test.dart';
import 'package:kooltab2/models/product.dart';
import 'package:kooltab2/models/tab_item.dart';
import 'package:kooltab2/services/bar_tab_service.dart';
import 'package:kooltab2/services/product_service.dart';
import 'package:kooltab2/viewmodels/bar_screen_view_model.dart';
import 'package:kooltab2/viewmodels/inventory_view_model.dart';
import 'package:mocktail/mocktail.dart';

class MockBarTabService extends Mock implements BarTabService {}

class MockProductService extends Mock implements ProductService {}

void main() {
  late MockBarTabService barTabService;
  late MockProductService productService;
  late InventoryViewModel inventory;
  late BarScreenViewModel viewModel;

  setUp(() {
    barTabService = MockBarTabService();
    productService = MockProductService();
    inventory = InventoryViewModel(productService: productService);
    viewModel = BarScreenViewModel(
      barTabService: barTabService,
      inventory: inventory,
    );
  });

  test(
    'does not increase a tab item when its product is out of stock',
    () async {
      const product = Product(
        id: 'prod-1',
        name: 'Chips',
        category: 'Snacks',
        stockQuantity: 0,
        lowStockThreshold: 5,
        priceInCents: 150,
      );
      const item = TabItem(
        id: 'item-1',
        tabId: 'tab-1',
        productId: 'prod-1',
        productName: 'Chips',
        quantity: 20,
        unitPriceInCents: 150,
      );

      when(
        () => productService.getProducts(),
      ).thenAnswer((_) async => [product]);
      await inventory.load();

      await expectLater(
        viewModel.changeItemQuantity(item, 21),
        throwsA(isA<InsufficientStockException>()),
      );

      expect(viewModel.errorMessage, isNull);
      verifyNoMoreInteractions(barTabService);
    },
  );
}