PIbd-23-Radaev-A.V.-GiftShop/GiftShop/GiftShopFileImplement/Implements/OrderStorage.cs

using GiftShopContracts.BindingModels;
using GiftShopContracts.SearchModels;
using GiftShopContracts.StoragesContracts;
using GiftShopContracts.ViewModels;
using GiftShopFileImplement.Models;

namespace GiftShopFileImplement.Implements
{
    public class OrderStorage : IOrderStorage
    {
        private readonly DataFileSingleton source;

        public OrderStorage()
        {
            source = DataFileSingleton.GetInstance();
        }

        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 element.GetViewModel;
            }

            return null;
        }

        public OrderViewModel? GetElement(OrderSearchModel model)
        {
            if (!model.Id.HasValue)
            {
                return null;
            }

            return source.Orders.FirstOrDefault(x => (model.Id.HasValue && x.Id == model.Id))?.GetViewModel;
        }

        public List<OrderViewModel> GetFilteredList(OrderSearchModel model)
        {
            if (!model.Id.HasValue)
            {
                return new();
            }

            return source.Orders.Where(x => x.Id == model.Id).Select(x => x.GetViewModel).ToList();
        }

        public List<OrderViewModel> GetFullList()
        {
            return source.Orders.Select(x => x.GetViewModel).ToList();
        }

        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 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 order.GetViewModel;
        }
    }
}