using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TaskTrackerContracts.BindingModels;
using TaskTrackerContracts.SearchModels;
using TaskTrackerContracts.StoragesContracts;
using TaskTrackerContracts.ViewModels;
using TaskTrackerDatabase.Models;

namespace TaskTrackerDatabase.Implements
{
    public class ResultStorage : IResultStorage
    {
        public List<ResultViewModel> GetFullList()
		{
			using var context = new TaskTrackerDatabase();
			return context.Results
                    .Include(x => x.Subject)
                    .Select(x => x.GetViewModel)
                    .ToList();
        }

        public List<ResultViewModel> GetFilteredList(ResultSearchModel model)
        {
            using var context = new TaskTrackerDatabase();
            if (model.Id.HasValue)
            {
                return context.Results
                    .Include(x => x.Subject)
                    .Where(x => x.Id == model.Id)
                    .Select(x => x.GetViewModel)
                    .ToList();
            }
            else if (!model.SubjectId.HasValue)
            {
                return context.Results
                    .Include(x => x.Subject)
                    .Include(x => x.Student)
                    .Where(x => x.SubjectId == model.SubjectId)
                    .Select(x => x.GetViewModel)
                    .ToList();
            }
            return new();
        }

        public ResultViewModel? GetElement(ResultSearchModel model)
        {
            if (!model.Id.HasValue)
            {
                return null;
            }
            using var context = new TaskTrackerDatabase();
            return context.Results
                    .Include(x => x.Subject)
					.Include(x => x.Student)
					.FirstOrDefault(x => x.Id == model.Id)
                    ?.GetViewModel;
        }

        public ResultViewModel? Insert(ResultBindingModel model)
        {
            var newResult = Result.Create(model);
            if (newResult == null)
            {
                return null;
            }
            using var context = new TaskTrackerDatabase();
            context.Results.Add(newResult);
            context.SaveChanges();
            return context.Results
                      .Include(x => x.Subject)
					  .Include(x => x.Student)
					  .FirstOrDefault(x => x.Id == newResult.Id)
                      ?.GetViewModel;
        }

        public ResultViewModel? Update(ResultBindingModel model)
        {
            using var context = new TaskTrackerDatabase();
            var order = context.Results.FirstOrDefault(x => x.Id == model.Id);
            if (order == null)
            {
                return null;
            }
            order.Update(model);
            context.SaveChanges();
            return context.Results
                         .Include(x => x.Subject)
						 .Include(x => x.Student)
						 .FirstOrDefault(x => x.Id == model.Id)
                         ?.GetViewModel;
        }

        public ResultViewModel? Delete(ResultBindingModel model)
        {
            using var context = new TaskTrackerDatabase();
            var element = context.Results.FirstOrDefault(rec => rec.Id == model.Id);
            if (element != null)
            {
                var deletedElement = context.Results
                                           .Include(x => x.Subject)
										   .Include(x => x.Student)
										   .FirstOrDefault(x => x.Id == model.Id)
                                           ?.GetViewModel;
                context.Results.Remove(element);
                context.SaveChanges();
                return deletedElement;
            }
            return null;
        }
    }
}