StudentEnrollmentNew/StudentEnrollment/StudentEnrollmentDatabaseImplement/Models/Student.cs

using StudentEnrollmentContracts.BindingModels;
using StudentEnrollmentContracts.ViewModels;
using StudentEnrollmentDataModels.Models;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

namespace StudentEnrollmentDatabaseImplement.Models
{
	public class Student //: IStudentModel
	{
		[Key]
		public int student_id { get; private set; }
		[Required]
		public string firstname { get; private set; } = string.Empty;
		[Required]
		public string lastname { get; private set; } = string.Empty;
		public string middlename { get; private set; } = string.Empty;
		[Required]
		public string email { get; private set; } = string.Empty;
		[Required]
		public long tin { get; private set; }
		[Required]
		public int exampointsid { get; private set; }
		public virtual ExamPoints ExamPoints { get; private set; }
		private Dictionary<int, ICourseModel>? _studentCourse = null;
		[NotMapped]
		public Dictionary<int, ICourseModel> StudentCourse
		{
			get
			{
				if (_studentCourse == null)
				{
					_studentCourse = Courses
						.ToDictionary(x => x.courseid, x => x.Course as ICourseModel);
				}
				return _studentCourse;
			}
		}
		[ForeignKey("studentid")]
		public virtual List<StudentCourse> Courses { get; set; } = new();
		public static Student? Create(StudentEnrollmentDatabase context,StudentBindingModel model)
		{
			if (model == null)
			{
				return null;
			}
			var test = model.StudentCourse.Select(x => new StudentCourse
			{
				Course = context.course.First(y => y.course_id == x.Key)
			}
				).ToList();
			return new Student()
			{
				student_id = model.Id,
				firstname = model.FirstName,
				lastname = model.LastName,
				middlename = model.MiddleName,
				email = model.Email,
				tin = model.TIN,
				Courses = model.StudentCourse.Select(x => new StudentCourse 
				{
					Course = context.course.First(y => y.course_id == x.Key)
				}
				).ToList(),
				ExamPoints = context.exampoints.First(x => x.exampoints_id == model.ExamPointsId),
			};
		}
		public void Update(StudentBindingModel model)
		{
			if (model == null)
			{
				return;
			}
			firstname = model.FirstName;
			lastname = model.LastName;
			middlename = model.MiddleName;
			tin = model.TIN;
			email = model.Email;
		}

		public StudentViewModel GetViewModel => new()
		{
			Id = student_id,
			FirstName = firstname,
			LastName = lastname,
			MiddleName = middlename,
			TIN = tin,
			Email = email,
			ExamPointsId = exampointsid,
			Summary = ExamPoints.summary,
			StudentCourse = StudentCourse,
		};

		public void UpdateCourses(StudentEnrollmentDatabase context, StudentBindingModel model)
		{
			var StudentCourses = context.student_course.Where(rec => rec.studentid == model.Id).ToList();
			if (StudentCourses != null)
			{
				context.student_course.RemoveRange(StudentCourses.Where(rec
			   => !model.StudentCourse.ContainsKey(rec.courseid)));
				context.SaveChanges();
				foreach (var updateCourse in StudentCourses)
				{
					model.StudentCourse.Remove(updateCourse.courseid);
				}
				context.SaveChanges();
			}
			var Student = context.student.First(x => x.student_id == student_id);
			foreach (var pc in model.StudentCourse)
			{
				context.student_course.Add(new StudentCourse
				{
					Student = Student,
					Course = context.course.First(x => x.course_id == pc.Key),
				});
				context.SaveChanges();
			}
			_studentCourse = null;
		}
	}
}