using PersonnelDepartmentContracts.BindingModels;
using PersonnelDepartmentContracts.SearchModels;
using PersonnelDepartmentContracts.StoragesContracts;
using PersonnelDepartmentContracts.ViewModels;
using PersonnelDepartmentDatabaseImplement.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace PersonnelDepartmentDatabaseImplement.Implements
{
	public class EmployeeStorage : IEmployeeStorage
	{
		public EmployeeViewModel? Delete(EmployeeBindingModel model)
		{
			using var context = new PersonnelDepartmentDatabase();
			var element = context.Employees
				.FirstOrDefault(x => x.Id == model.Id);
			if (element == null)
			{
				return null;
			}
			context.Employees.Remove(element);
			return element.GetViewModel;
		}

		public EmployeeViewModel? GetElement(EmployeeSearchModel model)
		{
			if (!model.Id.HasValue)
			{
				return null;
			}
			using var context = new PersonnelDepartmentDatabase();
			return context.Employees
				.FirstOrDefault(x => (model.Id.HasValue && x.Id == model.Id) ||
				(!string.IsNullOrEmpty(model.FirstName) && x.FirstName == model.FirstName) ||
				(!string.IsNullOrEmpty(model.LastName) && x.LastName == model.LastName) ||
				(!string.IsNullOrEmpty(model.Patronymic) && x.Patronymic == model.Patronymic))?.GetViewModel;
		}

		public List<EmployeeViewModel> GetFilteredList(EmployeeSearchModel model)
		{
			using var context = new PersonnelDepartmentDatabase();
			return context.Employees
				.Where(x => (model.Id.HasValue && x.Id == model.Id) ||
				(!string.IsNullOrEmpty(model.FirstName) && x.FirstName == model.FirstName) ||
				(!string.IsNullOrEmpty(model.LastName) && x.LastName == model.LastName) ||
				(!string.IsNullOrEmpty(model.Patronymic) && x.Patronymic == model.Patronymic))
				.Select(x => x.GetViewModel).ToList();
		}

		public List<EmployeeViewModel> GetFullList()
		{
			using var context = new PersonnelDepartmentDatabase();
			return context.Employees
				.Select(x => x.GetViewModel)
				.ToList();
		}

		public EmployeeViewModel? Insert(EmployeeBindingModel model)
		{
			var newElement = Employee.Create(model);
			if (newElement == null)
			{
				return null;
			}
			using var context = new PersonnelDepartmentDatabase();
			context.Employees.Add(newElement);
			context.SaveChanges();
			return newElement.GetViewModel;
		}

		public EmployeeViewModel? Update(EmployeeBindingModel model)
		{
			using var context = new PersonnelDepartmentDatabase();
			var element = context.Employees
				.FirstOrDefault(x => x.Id == model.Id);
			if (element == null)
			{
				return null;
			}
			element.Update(model);
			context.SaveChanges();
			return element.GetViewModel;
		}
	}
}