KOP/KOP/EnterpriseDataBaseImplement/Implements/EmployeeStorage.cs

using EnterpriseContracts.BindingModels;
using EnterpriseContracts.StorageContracts;
using EnterpriseContracts.ViewModels;
using EnterpriseDataBaseImplement.Models;

namespace EnterpriseDataBaseImplement.Implements
{
    public class EmployeeStorage : IEmployeeStorage
    {
        public List<EmployeeViewModel> GetFullList()
        {
            var context = new EnterpriseDataBase();
            return context.Employees
                .ToList()
                .Select(x => x.GetViewModel)
                .ToList();
        }

        public List<EmployeeViewModel> GetFilteredList(EmployeeBindingModel model)
        {
            var context = new EnterpriseDataBase();
            if (!model.ExperienceStep.HasValue)
            {
                return new();
            }
            return context.Employees
                .Where(x => model.ExperienceStep.Value.Item1 <= x.Experience &&
                            model.ExperienceStep.Value.Item2 >= x.Experience)
                .ToList()
                .Select(x => x.GetViewModel)
                .ToList();
        }

        public EmployeeViewModel? GetElement(EmployeeBindingModel model)
        {
            if (model == null || !model.Id.HasValue)
            { 
                return null; 
            }
            using var context = new EnterpriseDataBase();
            var x = context.Employees
                .ToList()
                .FirstOrDefault(rec => rec.Id == model.Id);
            return x?.GetViewModel;
        }

        public void Insert(EmployeeBindingModel model)
        {
            var context = new EnterpriseDataBase();
            var transaction = context.Database.BeginTransaction();
            try
            {
                var x = Employee.Create(model);
                context.Employees.Add(x);
                context.SaveChanges();
                transaction.Commit();
            }
            catch
            {
                transaction.Rollback();
                throw;
            }
        }

        public void Update(EmployeeBindingModel model)
        {
            var context = new EnterpriseDataBase();
            var transaction = context.Database.BeginTransaction();
            try
            {
                var x = context.Employees.FirstOrDefault(rec => rec.Id == model.Id);
                if (x == null)
                {
                    throw new Exception("Not found");
                }
                x.Update(model);
                context.SaveChanges();
                transaction.Commit();
            }
            catch
            {
                transaction.Rollback();
                throw;
            }
        }

        public void Delete(EmployeeBindingModel model)
        {
            var context = new EnterpriseDataBase();
            var x = context.Employees.FirstOrDefault(rec => rec.Id == model.Id);
            if (x != null)
            {
                context.Employees.Remove(x);
                context.SaveChanges();
            }
            else
            {
                throw new Exception("Id isn't exists");
            }
        }
    }
}