private static void GetUserDetails(PaymentSystemDBContex db)
{
Console.Write("Enter userId: ");
var userId = int.Parse(Console.ReadLine());
var user = db.Users
.Where(u => u.UserId == userId)
.Select(u => new
{
FullName = u.FirstName + " " + u.LastName,
CreditCards = u.PaymentMethods
.Where(pm => pm.Type == PaymentMethodType.CreditCard)
.Select(pm => pm.CreditCard).ToList(),
BankAccounts = u.PaymentMethods
.Where(pm => pm.Type == PaymentMethodType.BankAccount)
.Select(pm => pm.BankAccount).ToList(),
})
.FirstOrDefault();
Console.WriteLine($"User: {user.FullName}");
var bankAccounts = user.BankAccounts;
if (bankAccounts.Any())
{
Console.WriteLine("Bank Accounts:");
foreach (var item in bankAccounts)
{
Console.WriteLine($@"-- ID: {item.BankAccountId}");
Console.WriteLine($"-- - Balance: {item.Balance:F2}");
Console.WriteLine($"-- - Bank: {item.BankName}");
Console.WriteLine($"-- - SWIFT: {item.SwiftCode}");
}
}
var creditCards = user.CreditCards;
if (creditCards.Any())
{
Console.WriteLine("Credit Cards:");
foreach (var item in creditCards)
{
Console.WriteLine($"-- ID: {item.CreditCardId}");
Console.WriteLine($"-- - Limit: {item.Limit:F2}");
Console.WriteLine($"-- - Money Owed: {item.MoneyOwed:F2}");
Console.WriteLine($"-- - Limit Left: {item.LimitLeft}");
Console.WriteLine($"-- - Expiration Date: {item.ExpirationDate.ToString("yyyy/MM", CultureInfo.InvariantCulture)}");
}
}
}
static void Main(string[] args)
{
//Creating the database and adding the check constraint with the migration
using (var context = new PaymentSystemDBContex())
{
context.Database.EnsureDeleted();
context.Database.Migrate();
}
//Seeding the database (with 1 user)
using (var contex = new PaymentSystemDBContex())
{
Seed(contex);
}
//Getting user's details
using (var context = new PaymentSystemDBContex())
{
GetUserDetails(context);
}
//Paying bills
using (var context = new PaymentSystemDBContex())
{
try
{
Console.Write("Enter userId: ");
var userId = int.Parse(Console.ReadLine());
Console.Write("Enter the amount you wish to pay: ");
var amount = decimal.Parse(Console.ReadLine());
PayBills(userId, amount, context);
Console.WriteLine("The bills have been successfully paid.");
}
catch (InvalidOperationException e)
{
Console.WriteLine(e.Message);
}
}
}
private static void Seed(PaymentSystemDBContex db)
{
var user = new User()
{
FirstName = "Guy",
LastName = "Gilbert",
Email = "*****@*****.**",
Password = "******"
};
var creditCard = new CreditCard()
{
Limit = 800.00M,
MoneyOwed = 100.00M,
ExpirationDate = DateTime.ParseExact("20.03.2020", "dd.MM.yyyy", null)
};
var bankAccounts = new BankAccount[]
{
new BankAccount()
{
Balance = 2000M,
BankName = "Unicredit Bulbank",
SwiftCode = "UNCRBGSF"
},
new BankAccount()
{
Balance = 1000M,
BankName = "First Investment Bank",
SwiftCode = "FINVBGSF"
}
};
var paymentMethods = new PaymentMethod[]
{
new PaymentMethod()
{
User = user,
CreditCard = creditCard,
Type = PaymentMethodType.CreditCard
},
new PaymentMethod()
{
User = user,
BankAccount = bankAccounts[0],
Type = PaymentMethodType.BankAccount
},
new PaymentMethod()
{
User = user,
BankAccount = bankAccounts[1],
Type = PaymentMethodType.BankAccount
}
};
db.Users.Add(user);
db.CreditCards.Add(creditCard);
db.BankAccounts.AddRange(bankAccounts);
db.PaymentMethods.AddRange(paymentMethods);
db.SaveChanges();
}
private static void PayBills(int userId, decimal amount, PaymentSystemDBContex context)
{
var user = context.Users.Find(userId);
if (user == null)
{
Console.WriteLine($"User with id {userId} not found!");
return;
}
decimal usersMoney = 0.0m;
var bankAccounts = context
.BankAccounts.Join(context.PaymentMethods,
(ba => ba.BankAccountId),
(p => p.BankAccountId),
(ba, p) => new
{
UserId = p.UserId,
BankAccountId = ba.BankAccountId,
Balance = ba.Balance
})
.Where(ba => ba.UserId == userId)
.ToList();
var creditCards = context
.CreditCards.Join(context.PaymentMethods,
(c => c.CreditCardId),
(p => p.CreditCardId),
(c, p) => new
{
UserId = p.UserId,
CreditCardId = c.CreditCardId,
LimitLeft = c.LimitLeft
})
.Where(c => c.UserId == userId)
.ToList();
usersMoney += bankAccounts.Sum(b => b.Balance);
usersMoney += creditCards.Sum(c => c.LimitLeft);
if (usersMoney < amount)
{
throw new InvalidOperationException("Insufficient funds!");
}
bool isPayBills = false;
foreach (var bankAccount in bankAccounts.OrderBy(b => b.BankAccountId))
{
var currentAccount = context.BankAccounts.Find(bankAccount.BankAccountId);
if (amount <= currentAccount.Balance)
{
currentAccount.Withdraw(amount);
isPayBills = true;
}
else
{
amount -= currentAccount.Balance;
currentAccount.Withdraw(currentAccount.Balance);
}
if (isPayBills)
{
context.SaveChanges();
return;
}
}
foreach (var creditCard in creditCards.OrderBy(c => c.CreditCardId))
{
var currentCreditCard = context.CreditCards.Find(creditCard.CreditCardId);
if (amount <= currentCreditCard.LimitLeft)
{
currentCreditCard.Withdraw(amount);
isPayBills = true;
}
else
{
amount -= currentCreditCard.LimitLeft;
currentCreditCard.Withdraw(currentCreditCard.LimitLeft);
}
if (isPayBills)
{
context.SaveChanges();
return;
}
}
}
