static void Main(string[] args)
{
// The issue that we have here is that Loan should not be coupled to the conditions or expressions that we might have as a requirement to be able to change with out any change to Loan or any clients.
// Thats where Specifications come in.
var repo = new LoanRepository();
var overdueSpec = new OverDueLoanSpecification();
//or
var funcSpec = new FunctionalSpecification<Loan>(l => l.Amount > 10000.00);
var overdueLoans = repo.FindElementsBy(overdueSpec);
var bigLoans = repo.FindElementsBy(funcSpec);
var overdueAndBigLoans = repo.FindElementsBy(overdueSpec.And(funcSpec));
var sixDaysDurationSpec = new FunctionalSpecification<Loan>(l => l.LoanPeriod == new TimeSpan(6, 0, 0, 0));
var fourteenDaysDurationSpec = new FunctionalSpecification<Loan>(l => l.LoanPeriod == new TimeSpan(14, 0, 0, 0));
var sixOrFourTeenDays = repo.FindElementsBy(sixDaysDurationSpec.Or(fourteenDaysDurationSpec));
var notSixDaysDurationLoans = repo.FindElementsBy(sixDaysDurationSpec.Not());
Console.WriteLine("overdueLoans");
ObjectDumper.Write(overdueLoans);
Console.WriteLine();
Console.WriteLine("bigLoans");
ObjectDumper.Write(bigLoans);
Console.WriteLine();
Console.WriteLine("overdueAndBigLoans");
ObjectDumper.Write(overdueAndBigLoans);
Console.WriteLine();
Console.WriteLine("sixOrFourTeenDays");
ObjectDumper.Write(sixOrFourTeenDays);
Console.WriteLine();
Console.WriteLine("notSixDaysDurationLoans");
ObjectDumper.Write(notSixDaysDurationLoans);
Console.WriteLine();
var byron = new Customer() { FirstName = "Byron", Balance = 1000.00 };
var spec = new ValuedCustomerSpecification();
Console.WriteLine("Is Customer a valued customer ? " + spec.IsSatisfiedBy(byron));
Console.ReadLine();
}