SushiBarBase/SushiBar/SushiBarFileImplement/Implements/OrderStorage.cs

using SushiBarContracts.BindingModels;
using SushiBarContracts.SearchModels;
using SushiBarContracts.StoragesContracts;
using SushiBarContracts.ViewModels;
using SushiBarFileImplement.Models;

namespace SushiBarFileImplement.Implements
{
    public class OrderStorage : IOrderStorage
    {
        private readonly DataFileSingleton source;
        public OrderStorage()
        {
            source = DataFileSingleton.GetInstance();
        }
        public List<OrderViewModel> GetFullList()
        {
            return source.Orders.Select(x => AttachSushiName(x.GetViewModel)).ToList();
        }
        public List<OrderViewModel> GetFilteredList(OrderSearchModel model)
        {
            if (!model.Id.HasValue)
            {
                return new();
            }
            return source.Orders.Where(x =>
            x.Id == model.Id).Select(x =>
            AttachSushiName(x.GetViewModel)).ToList();
        }
        public OrderViewModel? GetElement(OrderSearchModel model)
        {
            if (!model.Id.HasValue)
            {
                return null;
            }
            return AttachSushiName(source.Orders.FirstOrDefault(x =>
            (x.Id == model.Id))?.GetViewModel);
        }
        public OrderViewModel? Insert(OrderBindingModel model)
        {
            model.Id = source.Orders.Count > 0 ? source.Orders.Max(x => x.Id) + 1 : 1;
            var newOrder = Order.Create(model);
            if (newOrder == null)
            {
                return null;
            }
            source.Orders.Add(newOrder);
            source.SaveOrders();
            return AttachSushiName(newOrder.GetViewModel);
        }
        public OrderViewModel? Update(OrderBindingModel model)
        {
            var order = source.Orders.FirstOrDefault(x => x.Id == model.Id);
            if (order == null)
            {
                return null;
            }
            order.Update(model);
            source.SaveOrders();
            return AttachSushiName(order.GetViewModel);
        }
        public OrderViewModel? Delete(OrderBindingModel model)
        {
            var element = source.Orders.FirstOrDefault(x => x.Id == model.Id);
            if (element != null)
            {
                source.Orders.Remove(element);
                source.SaveOrders();
                return AttachSushiName(element.GetViewModel);
            }
            return null;
        }
        private OrderViewModel AttachSushiName(OrderViewModel ?model)
        {
            if (model == null) { return null; }
            model.SushiName = source.Sushis.First(x => x.Id == model.SushiId).SushiName;
            return model;
        }
    }
}