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

namespace StudentEnrollmentDatabaseImplement.Implements
{
	public class CourseStorage : ICourseStorage
	{
        public List<CourseViewModel> GetFullList()
        {
            using var context = new StudentEnrollmentDatabase();
            return context.course
                .Include(x => x.Faculty)
                .Select(x => x.GetViewModel)
                .ToList();
        }
        public List<CourseViewModel> GetFilteredList(CourseSearchModel model)
        {
            if (string.IsNullOrEmpty(model.name))
            {
                return new();
            }
            using var context = new StudentEnrollmentDatabase();
            return context.course
                .Include(x => x.Faculty)
                .Where(x => (model.course_id.HasValue && x.course_id == model.course_id) || (string.IsNullOrEmpty(model.name) && x.name == model.name))
                .Select(x => x.GetViewModel)
                .ToList();
        }
        public CourseViewModel? GetElement(CourseSearchModel model)
        {
            if (string.IsNullOrEmpty(model.name) && !model.course_id.HasValue)
            {
                return null;
            }
            using var context = new StudentEnrollmentDatabase();
            return context.course
                .Include(x => x.Faculty)
                .FirstOrDefault(x => (model.course_id.HasValue && x.course_id == model.course_id) || (string.IsNullOrEmpty(model.name) && x.name == model.name))?
                .GetViewModel;
        }
        public CourseViewModel? Insert(CourseBindingModel model)
        {
            using var context = new StudentEnrollmentDatabase();
            var newCourse = Course.Create(model);
            if (newCourse == null)
            {
                return null;
            }
            context.course.Add(newCourse);
            context.SaveChanges();
            return context.course
                .Include(x => x.Faculty)
                .FirstOrDefault(x => x.course_id == newCourse.course_id)?
                .GetViewModel;
        }
        public CourseViewModel? Update(CourseBindingModel model)
        {
            using var context = new StudentEnrollmentDatabase();
            var course = context.course.Include(x => x.Faculty).FirstOrDefault(x => x.course_id == model.course_id);
            if (course == null)
            {
                return null;
            }
            course.Update(model);
            context.SaveChanges();
            return course.GetViewModel;
        }
        public CourseViewModel? Delete(CourseBindingModel model)
        {
            using var context = new StudentEnrollmentDatabase();
            var element = context.course.Include(x => x.Faculty).FirstOrDefault(rec => rec.course_id == model.course_id);
            if (element != null)
            {
                context.course.Remove(element);
                context.SaveChanges();
                return element.GetViewModel;
            }
            return null;
        }
    }
}