using Microsoft.EntityFrameworkCore;
using SushiBarContracts.BindingModel;
using SushiBarContracts.SearchModel;
using SushiBarContracts.StoragesContracts;
using SushiBarContracts.ViewModels;
using SushiBarDatabaseImplement.Models;
using SushiBarDataModels.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SushiBarDatabaseImplement.Implements
{
    public class ShopStorage : IShopStorage
    {

        public List<ShopViewModel> GetFullList()
        {
            using var context = new SushiBarDatabase();
            return context.Shops
                .Include(x => x.Sushis)
                .ThenInclude(x => x.Sushi)
                .ToList()
                .Select(x => x.GetViewModel)
                .ToList();
        }

        /// <summary>
        /// Получение фильтрованного списка
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public List<ShopViewModel> GetFilteredList(ShopSearchModel model)
        {
            if (string.IsNullOrEmpty(model.ShopName))
            {
                return new();
            }

            using var context = new SushiBarDatabase();
            return context.Shops
                .Include(x => x.Sushis)
                .ThenInclude(x => x.Sushi)
                .Where(x => x.ShopName.Contains(model.ShopName))
                .ToList()
                .Select(x => x.GetViewModel)
                .ToList();
        }

        /// <summary>
        /// Получение элемента
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public ShopViewModel? GetElement(ShopSearchModel model)
        {
            if (string.IsNullOrEmpty(model.ShopName) && !model.Id.HasValue)
            {
                return null;
            }

            using var context = new SushiBarDatabase();
            return context.Shops
                .Include(x => x.Sushis)
                .ThenInclude(x => x.Sushi)
                .FirstOrDefault(x => (!string.IsNullOrEmpty(model.ShopName) &&
                    x.ShopName == model.ShopName) ||
                    (model.Id.HasValue && x.Id == model.Id))
                ?.GetViewModel;
        }

        /// <summary>
        /// Добавление элемента
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public ShopViewModel? Insert(ShopBindingModel model)
        {
            using var context = new SushiBarDatabase();
            var newShop = Shop.Create(context, model);
            if (newShop == null)
            {
                return null;
            }

            context.Shops.Add(newShop);
            context.SaveChanges();
            return newShop.GetViewModel;
        }

        /// <summary>
        /// Редактирование элемента
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public ShopViewModel? Update(ShopBindingModel model)
        {
            using var context = new SushiBarDatabase();
            using var transaction = context.Database.BeginTransaction();
            try
            {
                var shop = context.Shops.FirstOrDefault(rec => rec.Id == model.Id);
                if (shop == null)
                {
                    return null;
                }

                shop.Update(model);
                context.SaveChanges();
                shop.UpdateSushis(context, model);
                transaction.Commit();
                return shop.GetViewModel;
            }
            catch
            {
                transaction.Rollback();
                throw;
            }
        }

        /// <summary>
        /// Удаление элемента
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public ShopViewModel? Delete(ShopBindingModel model)
        {
            using var context = new SushiBarDatabase();
            var element = context.Shops
                .Include(x => x.Sushis)
                .FirstOrDefault(rec => rec.Id == model.Id);
            if (element != null)
            {
                context.Shops.Remove(element);
                context.SaveChanges();
                return element.GetViewModel;
            }
            return null;
        }

        /// <summary>
        /// Продажа изделий
        /// </summary>
        /// <param name="model"></param>
        /// <param name="count"></param>
        /// <returns></returns>
        public bool SellSushis(ISushiModel model, int count)
        {
            using var context = new SushiBarDatabase();
            using var transaction = context.Database.BeginTransaction();
            try
            {
                var shops = context.Shops
                    .Include(x => x.Sushis)
                    .ThenInclude(x => x.Sushi)
                    .ToList()
                    .Where(x => x.ShopSushis.ContainsKey(model.Id));

                foreach (var shop in shops)
                {
                    int countInCurrentShop = shop.ShopSushis[model.Id].Item2;
                    if (countInCurrentShop <= count)
                    {
                        var elem = context.ShopSushis
                            .Where(x => x.SushiId == model.Id)
                            .FirstOrDefault(x => x.ShopId == shop.Id);
                        context.ShopSushis.Remove(elem);
                        shop.ShopSushis.Remove(model.Id);
                        count -= countInCurrentShop;
                    }
                    else
                    {
                        shop.ShopSushis[model.Id] = (shop.ShopSushis[model.Id].Item1, countInCurrentShop - count);
                        count = 0;
                        shop.UpdateSushis(context, new ShopBindingModel
                        {
                            Id = shop.Id,
                            ShopName = shop.ShopName,
                            Address = shop.Address,
                            DateOpening = shop.DateOpening,
                            ShopSushis = shop.ShopSushis,
                            MaxCountSushis = shop.MaxCountSushis
                        });
                    }
                    if (count <= 0)
                    {
                        context.SaveChanges();
                        transaction.Commit();
                        return true;
                    }
                }
                transaction.Rollback();
                return false;
            }
            catch
            {
                transaction.Rollback();
                throw;
            }
        }

        /// <summary>
        /// Проверка наличия в нужном количестве
        /// </summary>
        /// <param name="model"></param>
        /// <param name="count"></param>
        /// <returns></returns>
        /// <exception cref="NotImplementedException"></exception>
        public bool CheckCountSushi(ISushiModel model, int count)
        {
            throw new NotImplementedException();
        }
        /*public bool CheckCountSushi(ISushiModel model, int count)
        {
            int store = _source.Shops.Select(x => x.ShopSushis.Select(y =>
            (y.Value.Item1.Id == model.Id ? y.Value.Item2 : 0)).Sum()).Sum();
            return store >= count;
        }

        public bool SellSushis(ISushiModel model, int count)
        {
            var sushi = _source.Sushis.FirstOrDefault(x => x.Id == model.Id);
            if (sushi == null || !CheckCountSushi(model, count))
            {
                throw new ArgumentNullException("Такого количества суш нет, продать столько низя ");
            }

            foreach (var shop in _source.Shops)
            {
                var sushis = shop.ShopSushis;
                foreach (var elem in sushis.Where(x => x.Value.Item1.Id == sushi.Id))
                {
                    var selling = Math.Min(elem.Value.Item2, count);
                    sushis[elem.Value.Item1.Id] = (elem.Value.Item1, elem.Value.Item2 - selling);
                    count -= selling;

                    if (count <= 0)
                    {
                        break;
                    }
                }

                shop.Update(new ShopBindingModel
                {
                    Id = model.Id,
                    ShopName = shop.ShopName,
                    Address = shop.Address,
                    DateOpening = shop.DateOpening,
                    ShopSushis = sushis,
                    MaxCountSushis = shop.MaxCountSushis
                });
            }

            _source.SaveShops();
            return true;
        }*/
    }
}