using System;

//
// Domain Model + Active Record
//

public abstract class ActiveRecord
{
    int _id;

    public int ID
    {
        get { return _id; }
    }

    // ... métodos auxiliares de acesso a dados
    public abstract int Save();
}

public class Address
{
    string addr1;
    string addr2;
    string local;
    string postal;
}

public class Entity : ActiveRecord
{
    protected abstract object CreateObject(DataRow r);
    protected Entity(DataRow r);

    string name;
    string nif;
    Address addr;
    string email;
    string telefone;

    public static IList<Entity> GetByName(string namePattern);
    public static IList<Entity> GetByAddress(string addrPattern);
    public static IList<Entity> GetByNIF(string nifPattern);
    public static IList<Entity> GetByID(int id);
}

public class Person : Entity
{
    protected override object CreateObject(DataRow r);
    protected Person(DataRow r);

    DateTime dateOfBirth;

    public int Age
    {
        get {}
    }

    public override int Save();

    public static IList<Person> GetForecomeBirthdays(int nDaysToCome);
    public static IList<Person> GetByBirthDate(int? year, int? month, int? day);
}

public class Organization : Entity
{
    protected override object CreateObject(DataRow r);
    protected Organization(DataRow r);

    public override int Save();
}