CourseWork_SchoolStudyAgain/SchoolAgainStudy/SchoolAgainStudyDataBaseImplements/Implements/InterestStorage.cs

using SchoolAgainStudyContracts.BindingModel;
using SchoolAgainStudyContracts.SearchModel;
using SchoolAgainStudyContracts.StorageContracts;
using SchoolAgainStudyContracts.ViewModel;
using SchoolAgainStudyDataBaseImplements.Models;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SchoolAgainStudyDataBaseImplements.Implements
{
    public class InterestStorage : IInterestStorage
    {
        public List<InterestViewModel> GetFullList()
        {
            using var context = new SchoolDataBase();
            return context.Interests
                    .Select(x => x.GetViewModel)
                    .ToList();
        }

        public List<InterestViewModel> GetFilteredList(InterestSearchModel model)
        {
            if (!model.StudentId.HasValue)
            {
                return new();
            }
            using var context = new SchoolDataBase();
            return context.Interests
                    .Where(x => x.StudentId == model.StudentId)
                    .Select(x => x.GetViewModel)
                    .ToList();
        }

        public InterestViewModel? GetElement(InterestSearchModel model)
        {
            if ((string.IsNullOrEmpty(model.Title) && !model.Id.HasValue) || !model.StudentId.HasValue)
            {
                return null;
            }
            using var context = new SchoolDataBase();
            return context.Interests
                    .FirstOrDefault(x => ((!string.IsNullOrEmpty(model.Title) && x.Title == model.Title) ||
                                        (model.Id.HasValue && x.Id == model.Id)) && x.StudentId==model.StudentId)
                    ?.GetViewModel;
        }

        public InterestViewModel? Insert(InterestBindingModel model)
        {
            var newInterest = Interest.Create(model);
            if (newInterest == null)
            {
                return null;
            }
            using var context = new SchoolDataBase();
            context.Interests.Add(newInterest);
            context.SaveChanges();
            return newInterest.GetViewModel;
        }

        public InterestViewModel? Update(InterestBindingModel model)
        {
            using var context = new SchoolDataBase();
            var interest = context.Interests.FirstOrDefault(x => x.Id == model.Id);
            if (interest == null)
            {
                return null;
            }
            interest.Update(model);
            context.SaveChanges();
            return interest.GetViewModel;
        }

        public InterestViewModel? Delete(InterestBindingModel model)
        {
            using var context = new SchoolDataBase();
            var element = context.Interests.FirstOrDefault(rec => rec.Id == model.Id);
            if (element != null )
            {
                context.Interests.Remove(element);
                context.SaveChanges();
                return element.GetViewModel;
            }
            return null;
        }
    }
}