using Microsoft.EntityFrameworkCore;
using StudentEnrollmentContracts.BindingModels;
using StudentEnrollmentContracts.SearchModels;
using StudentEnrollmentContracts.StorageContracts;
using StudentEnrollmentContracts.ViewModels;
using StudentEnrollmentDatabaseImplement.Models;

namespace StudentEnrollmentDatabaseImplement.Implements
{
	public class StudentStorage : IStudentStorage
	{
        public List<StudentViewModel> GetFullList()
        {
            using var context = new StudentEnrollmentDatabase();
            return context.student
                .Include(x => x.ExamPoints)
                .Select(x => x.GetViewModel)
                .ToList();
        }
        public List<StudentViewModel> GetFilteredList(StudentSearchModel model)
        {
            if (model.tin == 0)
            {
                return new();
            }
            using var context = new StudentEnrollmentDatabase();
            return context.student
                .Include(x => x.ExamPoints)
                .Where(x => (model.student_id.HasValue && x.student_id == model.student_id) || (model.tin == 0 && x.tin == model.tin))
                .Select(x => x.GetViewModel)
                .ToList();
        }
        public StudentViewModel? GetElement(StudentSearchModel model)
        {
            if (model.tin == 0 && !model.student_id.HasValue)
            {
                return null;
            }
            using var context = new StudentEnrollmentDatabase();
            return context.student
                .Include(x => x.ExamPoints)
                .FirstOrDefault(x => (model.student_id.HasValue && x.student_id == model.student_id) || (model.tin == 0 && x.tin == model.tin))?
                .GetViewModel;
        }
        public StudentViewModel? Insert(StudentBindingModel model)
        {
            using var context = new StudentEnrollmentDatabase();
            var newStudent = Student.Create(context, model);
            if (newStudent == null)
            {
                return null;
            }
            context.student.Add(newStudent);
            context.SaveChanges();
            return context.student.Include(x => x.ExamPoints).FirstOrDefault(x => x.student_id == newStudent.student_id)?.GetViewModel;
        }
        public StudentViewModel? Update(StudentBindingModel model)
        {
            using var context = new StudentEnrollmentDatabase();
            var student = context.student.FirstOrDefault(x => x.student_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 StudentEnrollmentDatabase();
            var element = context.student.FirstOrDefault(rec => rec.student_id == model.Id);
            if (element != null)
            {
                context.student.Remove(element);
                context.SaveChanges();
                return element.GetViewModel;
            }
            return null;
        }
    }
}