using CanteenContracts.BindingModels;
using CanteenContracts.SearchModel;
using CanteenContracts.StoragesContracts;
using CanteenContracts.View;
using CanteenDatabaseImplement.Models;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace CanteenDatabaseImplement.Implements
{
    public class DishStorage : IDishStorage
    {
        public DishViewModel? GetElement(DishSearchModel model)
        {
            if (!model.Id.HasValue)
            {
                return null;
            }

            using var context = new CanteenDatabase();

            return context.Dishes
                .Include(x => x.Products)
                .ThenInclude(x => x.Product)
                .FirstOrDefault(x => (!string.IsNullOrEmpty(model.DishName) && x.DishName == model.DishName) || (model.Id.HasValue && x.Id == model.Id)
            )?.GetViewModel;
        }

        public List<DishViewModel> GetFilteredList(DishSearchModel model)
        {
            if (string.IsNullOrEmpty(model.DishName) && !model.ManagerId.HasValue)
            {
                return new();
            }

            using var context = new CanteenDatabase();

            return context.Dishes
                .Include(x => x.Products)
                .ThenInclude(x => x.Product)
                .Where(x => x.DishName == model.DishName || (model.ManagerId.HasValue && model.ManagerId == x.ManagerId))
                .Select(x => x.GetViewModel).ToList();
        }

        public List<DishViewModel> GetFullList()
        {
            using var context = new CanteenDatabase();
            return context.Dishes
                .Include(x => x.Products)
                .ThenInclude(x => x.Product)
                .Select(x => x.GetViewModel)
                .ToList();
        }

        public DishViewModel? Insert(DishBindingModel model)
        {
            using var context = new CanteenDatabase();

            using var transaction = context.Database.BeginTransaction();
            {
                try
                {
                    var newDish = Dish.Create(context, model);
                    if (newDish == null)
                    {
                        transaction.Rollback();
                        return null;
                    }

                    context.Dishes.Add(newDish);

                    context.SaveChanges();
                    context.Database.CommitTransaction();

                    return newDish.GetViewModel;
                }
                catch (Exception)
                {
                    transaction.Rollback();
                    return null;
                }
            }
        }

        public DishViewModel? Update(DishBindingModel model)
        {
            using var context = new CanteenDatabase();

            using var transaction = context.Database.BeginTransaction();
            {
                try
                {
                    var dish = context.Dishes.FirstOrDefault(x => x.Id == model.Id);
                    if (dish == null)
                    {
                        transaction.Rollback();
                        return null;
                    }

                    dish.Update(model);

                    context.SaveChanges();
                    if (model.DishProducts.Any()) dish.UpdateDishProduct(context, model);
                    context.Database.CommitTransaction();

                    return dish.GetViewModel;
                }
                catch (Exception)
                {
                    transaction.Rollback();
                    return null;
                }
            }
        }

        public DishViewModel? Delete(DishBindingModel model)
        {
            using var context = new CanteenDatabase();

            var element = context.Dishes.FirstOrDefault(rec => rec.Id == model.Id);
            if (element != null)
            {
                context.Dishes.Remove(element);
                context.SaveChanges();

                return element.GetViewModel;
            }

            return null;
        }
    }

}