using UniversityContracts.BindingModels;
using UniversityContracts.StoragesContracts;
using UniversityContracts.ViewModels;
using UniversityDatabaseImplement;
using UniversityDatabaseImplement.Models;

namespace UniversityUniversityDatabaseImplement.Implements
{
    public class DirectionStorage : IDirectionStorage
    {
        public void Delete(DirectionBindingModel model)
        {
            var context = new UniversityDatabase();
            var direction = context.Directions.FirstOrDefault(rec => rec.Id == model.Id);
            if (direction != null)
            {
                context.Directions.Remove(direction);
                context.SaveChanges();
            }
            else
            {
                throw new Exception("Направление не найдено");
            }
        }

        public DirectionViewModel GetElement(DirectionBindingModel model)
        {
            if (model == null)
            {
                return null;
            }
            using var context = new UniversityDatabase();

            var direction = context.Directions
                    .ToList()
                    .FirstOrDefault(rec => rec.Id == model.Id || rec.Name == model.Name);
            return direction != null ? CreateModel(direction) : null;
        }


        public List<DirectionViewModel> GetFilteredList(DirectionBindingModel model)
        {
            if (model == null)
            {
                return null;
            }
            using var context = new UniversityDatabase();
            return context.Directions
                .Where(rec => rec.Name.Contains(model.Name))
                .Select(CreateModel)
                .ToList();
        }

        public List<DirectionViewModel> GetFullList()
        {
            using var context = new UniversityDatabase();
            return context.Directions
                .Select(CreateModel)
                .ToList();
        }

        public void Insert(DirectionBindingModel model)
        {
            var context = new UniversityDatabase();
            var transaction = context.Database.BeginTransaction();
            try
            {
                context.Directions.Add(CreateModel(model, new Direction()));
                context.SaveChanges();
                transaction.Commit();
            }
            catch
            {
                transaction.Rollback();
                throw;
            }
        }

        public void Update(DirectionBindingModel model)
        {
            var context = new UniversityDatabase();
            var transaction = context.Database.BeginTransaction();
            try
            {
                var direction = context.Directions.FirstOrDefault(rec => rec.Id == model.Id);
                if (direction == null)
                {
                    throw new Exception("Направление не найдено");
                }
                CreateModel(model, direction);
                context.SaveChanges();
                transaction.Commit();
            }
            catch
            {
                transaction.Rollback();
                throw;
            }
        }

        private static Direction CreateModel(DirectionBindingModel model, Direction direction)
        {
            direction.Name = model.Name;
            return direction;
        }

        private static DirectionViewModel CreateModel(Direction direction)
        {
            return new DirectionViewModel
            {
                Id = direction.Id,
                Name = direction.Name
            };
        }
    }
}