DB/TransportGuideDatabaseImplements/Implements/RouteStorage.cs

using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TransportGuideContracts.BindingModels;
using TransportGuideContracts.SearchModels;
using TransportGuideContracts.StoragesContracts;
using TransportGuideContracts.ViewModels;
using TransportGuideDatabaseImplements.Models;

namespace TransportGuideDatabaseImplements.Implements
{
	public class RouteStorage : IRouteStorage
	{
		public RouteViewModel? Delete(RouteBindingModel model)
		{
			using var context = new TransportGuideDB();

			var element = context.Routes.Include(x => x.Stops).Include(x => x.TransportType).FirstOrDefault(rec => rec.Id == model.Id);

			if (element != null)
			{
				context.Routes.Remove(element);
				context.SaveChanges();
				return element.GetViewModel;
			}

			return null;
		}

		public RouteViewModel? GetElement(RouteSearchModel model)
		{
			if (string.IsNullOrEmpty(model.Name) && !model.Id.HasValue)
			{
				return null;
			}

			using var context = new TransportGuideDB();

			return context.Routes.Include(x => x.Stops).ThenInclude(x => x.Stop).FirstOrDefault(x => (!string.IsNullOrEmpty(model.Name) && x.Name == model.Name) || (model.Id.HasValue && x.Id == model.Id))?.GetViewModel;
		}

		public List<RouteViewModel> GetFilteredList(RouteSearchModel model)
		{
			if (string.IsNullOrEmpty(model.Name))
			{
				return new();
			}

			using var context = new TransportGuideDB();

			return context.Routes.Include(x => x.Stops).ThenInclude(x => x.Stop).Where(x => x.Name.Contains(model.Name)).ToList().Select(x => x.GetViewModel).ToList();
		}

		public List<RouteViewModel> GetFullList()
		{
			using var context = new TransportGuideDB();

			return context.Routes.Include(x => x.TransportType).Include(x => x.Stops).ThenInclude(x => x.Stop).ToList().Select(x => x.GetViewModel).ToList();
		}

		public RouteViewModel? Insert(RouteBindingModel model)
		{
			using var context = new TransportGuideDB();

			var newRoute = Route.Create(context, model);

			if (newRoute == null)
			{
				return null;
			}

			context.Routes.Add(newRoute);
			context.SaveChanges();

			return newRoute.GetViewModel;
		}

		public RouteViewModel? Update(RouteBindingModel model)
		{
			using var context = new TransportGuideDB();

			using var transaction = context.Database.BeginTransaction();

			try
			{
				var route = context.Routes.Include(x => x.TransportType).FirstOrDefault(rec => rec.Id == model.Id);

				if (route == null)
				{
					return null;
				}

				route.Update(model);
				context.SaveChanges();
				route.UpdateStops(context, model);
				transaction.Commit();

				return route.GetViewModel;
			}
			catch
			{
				transaction.Rollback();

				throw;
			}
		}
	}
}