CodeWithErrors.cs

CodeWithErrors.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace InterviewTest
{
    public class OrderService
    {
        private static List<Order> _orders = new List<Order>();

        private ILogger _logger;

        public void AddOrder(Order order)
        {
            if (order == null)
                throw new NullReferenceException(nameof(order));

            lock (_orders)
            {
                _orders.Add(order);
            }
        }

        public double CalculateTotal(string orderId)
        {
            var order = _orders.FirstOrDefault(o => o.Id == orderId);

            if (order is null) return 0;

            double total = 0;
            foreach (var item in order.Items)
            {
                total += item.Price * item.Quantity;
            }
            return total;
        }

        public async Task<List<Order>> GetOrdersAsync()
        {
            return await Task.Run(() => _orders);
        }

        public void SaveReport(string path)
        {
            var writer = new System.IO.StreamWriter(path);
            writer.WriteLine($"Orders: {_orders.Count}");
            writer.Flush();
        }
    }

    [Serializable]
    public class Order
    {
        public string Id { get; set; }
        public List<OrderItem> Items { get; set; } = new();
    }

    public record OrderItem(string Name, double Price, int Quantity);
}