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();
}
}
public void AddToUserWallet(decimal coin, int count)
{
using (var context = new VendingContext())
{
AddToUserWallet(coin, count, context);
context.SaveChanges();
}
}
public List<Bank> GetBankCoins()
{
using (var context = new VendingContext())
{
return context.Bank.ToList();
}
}
private void AddToUserWallet(decimal coin, int count, VendingContext context)
{
var coins = context.UserWallet.FirstOrDefault(x => x.Nominal == coin);
if (coins != null)
{
coins.Count += count;
}
else
{
context.UserWallet.Add(new UserWallet { Nominal = coin, Count = count });
}
}
private void ReturnToCache(decimal needReturn, VendingContext context)
{
var ordered = context.Bank.OrderByDescending(x => x.Nominal);
foreach (var coins in ordered)
{
while (coins.Nominal <= needReturn && coins.Count != 0)
{
coins.Count -= 1;
needReturn -= coins.Nominal;
AddToCache(coins.Nominal, 1, context);
}
if (needReturn <= 0) return;
}
}
private void AddToBank(decimal coin, int count, VendingContext context)
{
var coins = context.Bank.FirstOrDefault(x => x.Nominal == coin);
if (coins != null)
{
coins.Count += count;
}
else
{
context.Bank.Add(new Bank { Nominal = coin, Count = count });
}
}
private void AddToCache(decimal coin, int count, VendingContext context)
{
var coins = context.MoneyCache.FirstOrDefault(x => x.Nominal == coin);
if (coins != null)
{
coins.Count += count;
}
else
{
context.MoneyCache.Add(new MoneyCache { Nominal = coin, Count = count });
}
}
public void MoneyBack()
{
using (var context = new VendingContext())
{
foreach (var coins in context.MoneyCache)
{
AddToUserWallet(coins.Nominal, coins.Count, context);
}
foreach (MoneyCache cache in context.MoneyCache)
{
cache.Count = 0;
}
context.SaveChanges();
}
}
public void Reset()
{
using (var context = new VendingContext())
{
context.Database.ExecuteSqlCommand("TRUNCATE TABLE [wares]");
context.Database.ExecuteSqlCommand("TRUNCATE TABLE [bank]");
context.Database.ExecuteSqlCommand("TRUNCATE TABLE [money_cache]");
context.Database.ExecuteSqlCommand("TRUNCATE TABLE [user_wallet]");
}
}
public void InsertCoin(decimal nominal)
{
using (var context = new VendingContext())
{
var coins = context.UserWallet.FirstOrDefault(x => x.Nominal == nominal);
if (coins != null && coins.Count >= 1)
{
coins.Count -= 1;
AddToCache(nominal, 1);
context.SaveChanges();
}
}
}
public List<UserWallet> GetUserCoins()
{
using (var context = new VendingContext())
{
return context.UserWallet.Where(x => x.Count > 0).ToList();
}
}
public List<ItemToSale> GetProducts()
{
using (var context = new VendingContext())
{
return context.ItemsToSale.ToList();
}
}
public ItemToSale GetProduct(int productId)
{
using (var context = new VendingContext())
{
return context.ItemsToSale.FirstOrDefault(x => x.Id == productId);
}
}
public List<MoneyCache> GetCacheCoins()
{
using (var context = new VendingContext())
{
return context.MoneyCache.ToList();
}
}