public static void Withdraw(string number, string pin, decimal amount)
{
TransactionOptions options = new TransactionOptions();
options.IsolationLevel = IsolationLevel.RepeatableRead;
TransactionScope scope = new TransactionScope(TransactionScopeOption.Required, options);
using (scope)
{
ATMEntities context = new ATMEntities();
using (context)
{
var account = context.CardAccounts.First(x => x.CardNumber == number && x.CardPIN == pin);
if (account != null)
{
if (amount <= account.CardCash && amount > 0)
{
account.CardCash -= amount;
AddTransaction.Add(number, DateTime.Now, amount, context);
}
}
context.SaveChanges();
scope.Complete();
}
}
}
static void Main()
{
using (ATMEntities context = new ATMEntities())
{
Add("999999", DateTime.Now, 100m, context);
}
}
public static void Add(string number, DateTime date, decimal ammount, ATMEntities context)
{
CardHistoryLog log = new CardHistoryLog();
log.CardNumber = number;
log.OperationDate = date;
log.amount = ammount;
context.CardHistoryLogs.Add(log);
context.SaveChanges();
}
public void WithdrawTo0()
{
decimal money = 1000m;
string number = "1111111111";
string cardPin = "1111";
using (ATMEntities contextOut = new ATMEntities())
{
contextOut.CardAccounts.Add(new CardAccount() { CardCash = money, CardNumber = number, CardPIN = cardPin });
contextOut.SaveChanges();
RepeatableRead.Withdraw(number, cardPin, money);
var actual = (from c in contextOut.CardAccounts
select c).First();
Assert.AreEqual(0, actual.CardCash);
contextOut.Dispose();
}
}
public void CheckRecordAmount()
{
decimal money = 2000m;
decimal toWithdraw = 1000m;
string number = "1111111111";
string cardPin = "1111";
using (ATMEntities contextOut = new ATMEntities())
{
contextOut.CardAccounts.Add(new CardAccount() { CardCash = money, CardNumber = number, CardPIN = cardPin });
contextOut.SaveChanges();
RepeatableRead.Withdraw(number, cardPin, toWithdraw);
var actual = (from c in contextOut.CardHistoryLogs
select c).First();
Assert.AreEqual(1000, actual.amount);
contextOut.Dispose();
}
}
private static void SaveTransaction(string cardNumber, DateTime timestamp, decimal amount)
{
var context = new ATMEntities();
using (context)
{
var log = new TransactionLog()
{
CardNumber = cardNumber,
TransactionDate = timestamp,
Amount = amount
};
context.TransactionLogs.Add(log);
context.SaveChanges();
}
}
public static void WithdrawFunds(string pin, string cardNumber, decimal amount)
{
var context = new ATMEntities();
using (var contextTransaction = context.Database.BeginTransaction(IsolationLevel.RepeatableRead))
{
bool isValid = false;
var account = context.CardAccounts
.Where(c => c.CardNumber == cardNumber)
.Select(c => new
{
c.CardNumber,
c.CardPIN,
c.CardCash
})
.FirstOrDefault();
do
{
string failureCode = "";
try
{
if (account == null)
{
failureCode = "account";
throw new Exception("Something went wrong with your data.");
}
if (account.CardPIN != pin)
{
failureCode = "pin";
throw new Exception("Incorrect PIN.");
}
if (account.CardCash < amount)
{
failureCode = "insufficient";
throw new Exception("Insufficient funds.");
}
if (amount <= 0)
{
failureCode = "zero";
throw new Exception("Withdraw amount must be positive.");
}
if (account.CardNumber == null)
{
failureCode = "number";
throw new Exception("Incorrect card number.");
}
isValid = true;
var accountToUpdate = context.CardAccounts
.Where(c => c.CardNumber == cardNumber)
.FirstOrDefault();
Console.WriteLine("Funds before: " + accountToUpdate.CardCash);
var updatedAmount = account.CardCash - amount;
accountToUpdate.CardCash = updatedAmount;
context.SaveChanges();
contextTransaction.Commit();
SaveTransaction(cardNumber, DateTime.Now, amount);
Console.WriteLine("---Withdrawal successful.---");
Console.WriteLine("Funds after: " + accountToUpdate.CardCash);
}
catch (Exception e)
{
isValid = false;
Console.WriteLine(e.Message);
switch (failureCode)
{
case "account":
Console.Write("PIN: ");
pin = Console.ReadLine();
Console.Write("Card number: ");
cardNumber = Console.ReadLine();
Console.Write("Amount: ");
amount = decimal.Parse(Console.ReadLine());
break;
case "pin":
Console.Write("PIN: ");
pin = Console.ReadLine();
break;
case "insufficient":
Console.Write("New amount: ");
amount = decimal.Parse(Console.ReadLine());
break;
case "zero":
Console.Write("New amount: ");
amount = decimal.Parse(Console.ReadLine());
break;
case "number":
Console.Write("Card number: ");
cardNumber = Console.ReadLine();
break;
}
}
} while (!isValid);
}
}