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

namespace IceCreamShopBusinessLogic.BusinessLogic
{
    public class OrderLogic : IOrderLogic
    {
        private readonly ILogger _logger;
        private readonly IOrderStorage _orderStorage;
        private readonly IShopStorage _shopStorage;
        private readonly IShopLogic _shopLogic;
        private readonly IIceCreamStorage _iceCreamStorage;
        static readonly object locker = new object();

        public OrderLogic(IOrderStorage orderStorage, IShopStorage shopStorage, IShopLogic shopLogic, IIceCreamStorage iceCreamStorage, ILogger<OrderLogic> logger)
        {
            _orderStorage = orderStorage;
            _shopStorage = shopStorage;
            _logger = logger;
            _shopLogic = shopLogic;
            _iceCreamStorage = iceCreamStorage;
        }
		public OrderViewModel? ReadElement(OrderSearchModel model)
		{
			if (model == null)
			{
				throw new ArgumentNullException(nameof(model));
			}
			_logger.LogInformation("ReadElement. Id:{ Id}", model.Id);
			var element = _orderStorage.GetElement(model);
			if (element == null)
			{
				_logger.LogWarning("ReadElement element not found");
				return null;
			}
			_logger.LogInformation("ReadElement find. Id:{Id}", element.Id);
			return element;
		}

		public List<OrderViewModel>? ReadList(OrderSearchModel? model)
        {
            _logger.LogInformation("ReadList. Id:{ 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)
            {
                _logger.LogWarning("Insert operation failed");
                return false;
            }
            return true;
        }

        public bool CheckSupply(IIceCreamModel iceCream, int count)
        {
            if (count <= 0)
            {
                _logger.LogWarning("Check then supply operation error. IceCream count < 0.");
                return false;
            }

            int sumCapacity = 0;
            int sumCount = 0;
            sumCapacity = _shopStorage.GetFullList().Select(x => x.MaxCapacity).Sum();
            sumCount = _shopStorage.GetFullList().Select(x => x.ShopIceCreams.Select(y => y.Value.Item2).Sum()).Sum();
            int freeSpace = sumCapacity - sumCount;

            if (freeSpace - count < 0)
            {
                _logger.LogWarning("Check then supply operation error. There's no place for new IceCream in shops.");
                return false;
            }

            foreach (var shop in _shopStorage.GetFullList())
            {
                freeSpace = shop.MaxCapacity;
                foreach (var doc in shop.ShopIceCreams)
                {
                    freeSpace -= doc.Value.Item2;
                }
                if (freeSpace == 0)
                {
                    continue;
                }
                if (freeSpace - count >= 0)
                {
                    if (_shopLogic.MakeSupply(new() { Id = shop.Id }, iceCream, count)) 
                        count = 0;
                    else
                    {
                        _logger.LogWarning("Supply error");
                        return false;
                    }
                }
                if (freeSpace - count < 0)
                {
                    if (_shopLogic.MakeSupply(new() { Id = shop.Id }, iceCream, freeSpace)) 
                        count -= freeSpace;
                    else
                    {
                        _logger.LogWarning("Supply error");
                        return false;
                    }
                }
                if (count <= 0)
                {
                    return true;
                }
            }
            return false;
        }

        public bool ChangeStatus(OrderBindingModel model, OrderStatus status)
        {
            CheckModel(model, false);
            var element = _orderStorage.GetElement(new OrderSearchModel { Id = model.Id });
            if (element == null)
            {
                _logger.LogWarning("Read operation failed");
                return false;
            }
            if (element.Status != status - 1 && status != OrderStatus.Ожидается)
            {
                _logger.LogWarning("Status change operation failed");
                throw new InvalidOperationException("Текущий статус заказа не может быть переведен в выбранный");
            }
            if(element.Status == OrderStatus.Выполняется)
            {
                var icecream = _iceCreamStorage.GetElement(new IceCreamSearchModel() { Id = model.IceCreamId });
                if (icecream == null)
                {
                    _logger.LogWarning("Status update to " + status.ToString() + " operation failed. Document not found.");
                    return false;
                }
                if (CheckSupply(icecream, model.Count) == false)
                {
					model.Status = OrderStatus.Ожидается;
					_orderStorage.Update(model);
					return false;
                }
            }
            model.Status = status;
            if (model.Status == OrderStatus.Выдан) model.DateImplement = DateTime.Now;
            if (element.ImplementerId.HasValue)
                model.ImplementerId = element.ImplementerId;
            _orderStorage.Update(model);
            return true;
        }

        public bool TakeOrderInWork(OrderBindingModel model)
        {
            lock (locker)
            {
                return ChangeStatus(model, OrderStatus.Выполняется);
            }
        }

        public bool FinishOrder(OrderBindingModel model)
        {
            lock (locker)
            {
				return ChangeStatus(model, OrderStatus.Готов);

		    }
		}
		public bool TakeOrderInWaiting(OrderBindingModel model)
		{
			return ChangeStatus(model, OrderStatus.Ожидается);
		}

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

        private void CheckModel(OrderBindingModel model, bool withParams =
true)
        {
            if (model == null)
            {
                throw new ArgumentNullException(nameof(model));
            }
            if (!withParams)
            {
                return;
            }
            if (model.Sum <= 0)
            {
                throw new ArgumentNullException("Цена заказа должна быть больше 0", nameof(model.Sum));
            }
            if (model.Count <= 0)
            {
                throw new ArgumentNullException("Количество элементов в заказе должно быть больше 0", nameof(model.Count));
            }
            _logger.LogInformation("Order. Sum:{ Cost}. Id: { Id}", model.Sum, model.Id);
        }
    }
}