using Microsoft.EntityFrameworkCore;
using UniversityContracts.BindingModels;
using UniversityContracts.SearchModels;
using UniversityContracts.StoragesContracts;
using UniversityContracts.ViewModels;
using UniversityDatabaseImplement.Models;

namespace UniversityDatabaseImplement.Implements
{
    public class StudentStorage : IStudentStorage
    {
        public List<StudentViewModel> GetFullList()
        {
            using var context = new UniversityDatabase();
            return context.Students
            .Select(x => x.GetViewModel)
            .ToList();
        }
        public List<StudentViewModel> GetFilteredList(StudentSearchModel model)
        {
            if (string.IsNullOrEmpty(model.FIO))
            {
                return new();
            }
            using var context = new UniversityDatabase();
            return context.Students
               .Select(x => x.GetViewModel)
               .ToList();
        }
        public StudentViewModel? GetElement(StudentSearchModel model)
        {
            if (!model.Id.HasValue)
            {
                return null;
            }
            using var context = new UniversityDatabase();
            return context.Students
             .FirstOrDefault(x => (!string.IsNullOrEmpty(model.FIO) &&
            x.FIO == model.FIO) ||
            (model.Id.HasValue && x.Id == model.Id))
            ?.GetViewModel;
        }
        public StudentViewModel? Insert(StudentBindingModel model)
        {
            using var context = new UniversityDatabase();
            var newStudent = Student.Create(model);
            if (newStudent == null)
            {
                return null;
            }
            context.Students.Add(newStudent);
            context.SaveChanges();
            return newStudent.GetViewModel;
        }
        public StudentViewModel? Update(StudentBindingModel model)
        {
            using var context = new UniversityDatabase();
            var student = context.Students.FirstOrDefault(rec => rec.Id == model.Id);
            if (student == null)
            {
                return null;
            }
            student.Update(model);
            context.SaveChanges();
            return student.GetViewModel;
        }
        public StudentViewModel? Delete(StudentBindingModel model)
        {
            using var context = new UniversityDatabase();
            var element = context.Students
            .FirstOrDefault(rec => rec.Id == model.Id);
            if (element != null)
            {
                context.Students.Remove(element);
                context.SaveChanges();
                return element.GetViewModel;
            }
            return null;
        }
    }
}