public bool Buy(ItemToSale product, out string errorMessage)
{
errorMessage = null;
if (!EnoughMoneyToBuy(product))
{
errorMessage = "Недостаточно внесено денег для покупки";
return false;
}
using (var context = new VendingContext())
{
var coinsInserted = context.MoneyCache.Select(x => x.Count * x.Nominal).ToList();
var moneyInCacheCount = coinsInserted.Aggregate((arg1, arg2) => arg1 + arg2);
var needReturn = moneyInCacheCount - product.Price;
foreach (var coins in context.MoneyCache)
{
AddToBank(coins.Nominal, coins.Count, context);
}
foreach (MoneyCache cache in context.MoneyCache)
{
cache.Count = 0;
}
ReturnToCache(needReturn, context);
var productToBuy = context.ItemsToSale.First(x => x.Id == product.Id);
productToBuy.AvailableCount -= 1;
context.SaveChanges();
}
return true;
}
public void AddProduct(ItemToSale item)
{
using (var context = new VendingContext())
{
context.ItemsToSale.Add(item);
context.SaveChanges();
}
}
private bool EnoughMoneyToBuy(ItemToSale product)
{
var coins = GetCacheCoins();
return coins.Count != 0 && coins.Select(x => x.Count * x.Nominal).Aggregate((n, m) => n + m) >= product.Price;
}