PIbd31.Lyovushkina_COP32_2/WinFormUchetLab/UchetLabDatabaseImplement/Implements/CheckerStorage.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using UchetLabContracts.BindingModels;
using UchetLabContracts.SearchModels;
using UchetLabContracts.StorageContracts;
using UchetLabContracts.ViewModels;
using UchetLabDatabaseImplement.Models;

namespace UchetLabDatabaseImplement.Implements
{
    public class CheckerStorage : ICheckerStorage
    {
        public CheckerViewModel? Delete(CheckerBindingModel model)
        {
            using var context = new UchetLabDataBase();
            var element = context.Checkers.FirstOrDefault(rec => rec.Id == model.Id);
            if (element != null)
            {
                context.Checkers.Remove(element);
                context.SaveChanges();
                return element.GetViewModel;
            }
            return null;
        }

        public CheckerViewModel? GetElement(CheckerSearchModel model)
        {
            if (!model.Id.HasValue)
            {
                return null;
            }
            using var context = new UchetLabDataBase();
            return context.Checkers.FirstOrDefault(x => x.Id == model.Id)?.GetViewModel;
        }

        public List<CheckerViewModel> GetFilteredList(CheckerSearchModel model)
        {
            using var context = new UchetLabDataBase();
            return context.Checkers
            .Select(x => x.GetViewModel)
            .ToList();
        }

        public List<CheckerViewModel> GetFullList()
        {
            using var context = new UchetLabDataBase();
            return context.Checkers
            .Select(x => x.GetViewModel)
            .ToList();
        }

        public CheckerViewModel? Insert(CheckerBindingModel model)
        {
            using var context = new UchetLabDataBase();
            using var transaction = context.Database.BeginTransaction();
            {
                try
                {
                    var newEl = Checker.Create(model);
                    if (newEl == null)
                    {
                        transaction.Rollback();
                        return null;
                    }
                    context.Checkers.Add(newEl);

                    context.SaveChanges();
                    context.Database.CommitTransaction();

                    return newEl.GetViewModel;
                }
                catch (Exception)
                {
                    transaction.Rollback();
                    return null;
                }
            }
        }

        public CheckerViewModel? Update(CheckerBindingModel model)
        {
            using var context = new UchetLabDataBase();
            using var transaction = context.Database.BeginTransaction();
            {
                try
                {
                    var el = context.Checkers.FirstOrDefault(x => x.Id == model.Id);
                    if (el == null)
                    {
                        transaction.Rollback();
                        return null;
                    }
                    el.Update(model);

                    context.SaveChanges();
                    context.Database.CommitTransaction();

                    return el.GetViewModel;
                }
                catch (Exception)
                {
                    transaction.Rollback();
                    return null;
                }
            }
        }
    }
}