using OOO_WriteAndClear.DBModels;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Controls;

namespace OOO_WriteAndClear.MVP.Models.OrderFormerer
{
    public class OrderFormerer
    {
        public OrderFormerer() 
        {
            _order = new Order();
            _order.OrderProducts = new List<OrderProduct>();
        }


        /// <summary>
        /// Формируемый заказ
        /// </summary>
        public Order Order => _order;


        /// <summary>
        /// Добавляет продукт в заказ в количестве 1 штуки, если уже существует то ничего не делает        
        /// </summary>
        /// <param name="product">Продукт для добавления</param>
        public bool AddProductIntoOrder(Product product)
        {
            if (CheckAvailabilityOfProductInOrder(product))
                return false;
            _order.OrderProducts.Add(new OrderProduct()
            {
                Order = _order,
                OrderId = _order.OrderId,
                ProductArticleNumberNavigation = product,
                ProductArticleNumber = product.ProductArticleNumber,
                ProductAmount = 1
            });
            return true;
        }

        /// <summary>
        /// Удаляет продукт из заказа
        /// </summary>
        /// <param name="product">удаляемый продукт</param>
        public bool RemoveProductFromOrder(Product product) 
        {
            if (!CheckAvailabilityOfProductInOrder(product))
                return false;
            OrderProduct orderItem = GetOrderItem(product);
            _order.OrderProducts.Remove(orderItem);
            return true;
        }

        /// <summary>
        /// Добавить один продукт в заказ
        /// </summary>
        /// <param name="product"></param>
        public void AddProductUnitIntoOrder(Product product)
        {
            if(AddProductIntoOrder(product)) return;
            OrderProduct orderItem = GetOrderItem(product);
            orderItem.ProductAmount++;
        }

        /// <summary>
        /// Убрать один продукт из заказа
        /// </summary>
        /// <param name="product">продукт</param>
        public void RemoveProductUnitFromOrder(Product product)
        {
            if (!CheckAvailabilityOfProductInOrder(product))
                return;
            OrderProduct orderItem = GetOrderItem(product);
            orderItem.ProductAmount--;
            if (orderItem.ProductAmount == 0)
                _order.OrderProducts.Remove(orderItem);
        }

        /// <summary>
        /// Проверяет наличие продукта в заказе
        /// </summary>
        /// <param name="product">продукт</param>
        /// <returns>true - есть в заказе; false - нет в заказе</returns>
        public bool CheckAvailabilityOfProductInOrder(Product product) =>
            _order.OrderProducts.Where(a => a.ProductArticleNumber
            == product.ProductArticleNumber).ToList().Count > 0;

        public Order PrepareOrderForAdd()
        {
            int DeliveryDelay = GenerateDeliveryDelay();
            Order order = new Order()
            {
                OrderReceiveCode = GenerateReceiveCode(),
                OrderCustomer = Order.OrderCustomer,
                OrderStatusId = 1,
                OrderCreateDate = DateTime.Now,
                OrderDeliveryDate = DateTime.Now.AddDays(DeliveryDelay),
                OrderPickupPointId = Order.OrderPickupPoint.PickupPointId,
                OrderProducts = new List<OrderProduct>()
            };
            Order.OrderCreateDate = order.OrderCreateDate;
            Order.OrderDeliveryDate = order.OrderDeliveryDate;
            Order.OrderReceiveCode = order.OrderReceiveCode;
            foreach(var OrderProduct in Order.OrderProducts)
            {
                order.OrderProducts.Add(new OrderProduct() 
                { 
                    ProductArticleNumber = OrderProduct.ProductArticleNumber,
                    ProductAmount = OrderProduct.ProductAmount
                });
            }
            return order;
        }


        private Order _order;


        /// <summary>
        /// Получение строки заказа по продукту
        /// </summary>
        /// <param name="product">продукт</param>
        /// <returns>null - если заказа не существует; OrderProduct - если существует</returns>
        private OrderProduct? GetOrderItem(Product product) =>
            _order.OrderProducts.Where(a => a.ProductArticleNumber == product.ProductArticleNumber).FirstOrDefault();

        private int GenerateReceiveCode()
            => new Random().Next(100, 1000);

        private int GenerateDeliveryDelay()
        {
            bool IsShortageInStock = false;
            foreach (var product in Order.OrderProducts)
            {
                if(product.ProductArticleNumberNavigation.ProductQuantityInStock < 3)
                {
                    return 6;
                }
            }
            return 3;
        }
    }
}