using TravelCompanyContracts.BindingModels;
using TravelCompanyContracts.BusinessLogicsContracts;
using TravelCompanyContracts.SearchModels;
using TravelCompanyContracts.StoragesContracts;
using TravelCompanyContracts.ViewModels;
using TravelCompanyDataModels.Enums;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TravelCompanyContracts.BusinessLogicContracts;
using TravelCompanyDataModels.Models;

namespace TravelCompanyBusinessLogic.BusinessLogic
{
    public class OrderLogic : IOrderLogic
    {
        //Класс с логикой для заказов будет отвечать за получение списка заказов,
        //создания заказа и смены его статусов. Следует учитывать, что у заказа можно
        //менять статус на новый, если его текущий статус предшествует новому

        private readonly ILogger _logger;
        private readonly IOrderStorage _orderStorage;
		private readonly ITravelStorage _travelStorage;
		private readonly IShopStorage _shopStorage;
		private readonly IShopLogic _shopLogic;

        public OrderLogic(ILogger<OrderLogic> logger, IOrderStorage orderStorage, ITravelStorage travelStorage, IShopStorage shopStorage, IShopLogic shopLogic)
        {
            _logger = logger;
            _orderStorage = orderStorage;
            _travelStorage = travelStorage;
			_shopStorage = shopStorage;
			_shopLogic = shopLogic;
		}

        public List<OrderViewModel>? ReadList(OrderSearchModel? model)
        {
            _logger.LogInformation("ReadList. OrderId:{Id}", model?.Id);
            var list = model == null ? _orderStorage.GetFullList() : _orderStorage.GetFilteredList(model);
            if (list == null)
            {
                _logger.LogWarning("ReadList return null list");
                return null;
            }
            _logger.LogInformation("ReadList. Count:{Count}", list.Count);
            return list;
        }

        public bool CreateOrder(OrderBindingModel model)
        {
            CheckModel(model);

            if (model.Status != OrderStatus.Неизвестен)
                return false;
            model.Status = OrderStatus.Принят;

            if (_orderStorage.Insert(model) == null)
            {
                model.Status = OrderStatus.Неизвестен;
                _logger.LogWarning("Insert operation failed");
                return false;
            }
            return true;
        }

        public bool TakeOrderInWork(OrderBindingModel model)
        {
            return ToNextStatus(model, OrderStatus.Выполняется);
        }

        public bool FinishOrder(OrderBindingModel model)
        {
            return ToNextStatus(model, OrderStatus.Готов);
        }

        public bool DeliveryOrder(OrderBindingModel model)
        {
            return ToNextStatus(model, OrderStatus.Выдан);
        }

        public bool ToNextStatus(OrderBindingModel model, OrderStatus orderStatus)
        {
			CheckModel(model, false);
			var order = _orderStorage.GetElement(new OrderSearchModel { Id = model.Id });
			if (order == null)
			{
				_logger.LogWarning("Change status operation failed. Order not found");
				return false;
			}
			if (order.Status + 1 != orderStatus)
			{
				_logger.LogWarning("Change status operation failed. Incorrect new status: {orderStatus}. Current status: {currStatus}",
					orderStatus, order.Status);
				return false;
			}
			if (orderStatus == OrderStatus.Выдан)
			{
				var iceCream = _travelStorage.GetElement(new TravelSearchModel() { Id = order.TravelId });
				if (iceCream == null)
				{
					_logger.LogWarning("Change status operation failed. Travel not found");
					return false;
				}
				if (!DeliverTravels(iceCream, order.Count))
				{
					_logger.LogWarning("Change status operation failed. Travels delivery operation failed");
					return false;
				}
			}
			model.Status = orderStatus;
			if (model.Status == OrderStatus.Готов)
			{
				model.DateImplement = DateTime.Now;
			}
			else
			{
				model.DateImplement = order.DateImplement;
			}
			if (_orderStorage.Update(model) == null)
			{
				_logger.LogWarning("Change status operation failed");
				return false;
			}
			return true;
		}

		private bool DeliverTravels(ITravelModel travel, int count)
		{
			if (count <= 0)
			{
				_logger.LogWarning("Travels delivery operation failed. Travel count <= 0");
				return false;
			}

			var shopList = _shopStorage.GetFullList();
			int shopsCapacity = shopList.Sum(x => x.TravelsMaximum);
			int currentTravels = shopList.Select(x => x.ShopTravels.Sum(y => y.Value.Item2)).Sum();
			int freePlaces = shopsCapacity - currentTravels;

			if (freePlaces < count)
			{
				_logger.LogWarning("Travels delivery operation failed. No space for new travels");
				return false;
			}

			foreach (var shop in shopList)
			{
				freePlaces = shop.TravelsMaximum - shop.ShopTravels.Sum(x => x.Value.Item2);
				if (freePlaces == 0)
				{
					continue;
				}
				if (freePlaces >= count)
				{
					if (_shopLogic.MakeDelivery(new() { Id = shop.Id }, travel, count))
					{
						count = 0;
					}
					else
					{
						_logger.LogWarning("Travels delivery operation failed");
						return false;
					}
				}
				else
				{
					if (_shopLogic.MakeDelivery(new() { Id = shop.Id }, travel, freePlaces))
					{
						count -= freePlaces;
					}
					else
					{
						_logger.LogWarning("Travels delivery operation failed");
						return false;
					}
				}
				if (count == 0)
				{
					return true;
				}
			}
			return false;
		}

		private void CheckModel(OrderBindingModel model, bool withParams = true)
        {
            if (model == null)
            {
                throw new ArgumentNullException(nameof(model));
            }
            if (!withParams)
            {
                return;
            }
            if (model.Count <= 0)
            {
                throw new ArgumentNullException("Количество изделий должно быть больше 0", nameof(model.Count));
            }
            if (model.Sum <= 0)
            {
                throw new ArgumentNullException("Цена заказа должна быть больше 0", nameof(model.Sum));
            }
            if (model.DateImplement.HasValue && model.DateImplement < model.DateCreate)
            {
                throw new ArithmeticException($"Дата выдачи заказа {model.DateImplement} должна быть позже даты его создания {model.DateCreate}");
            }
                _logger.LogInformation("Travel. TravelId:{TravelId}.Count:{Count}.Sum:{Sum}Id:{Id}", model.TravelId, model.Count, model.Sum, model.Id);
        }
    }
}