using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Validator;
namespace hetfo_gyakorlas
{
    class Program
    {
        static void Main(string[] args)
        {



            foreach (var item in Loader2())
            {
                Console.WriteLine($"{item.Szolgaltato} {item.Netsebesseg}");
            }
            Console.ReadLine();



        }
        static List<Person> Loader()
        {
            List<Person> people = new List<Person>();
            int counter = -2;
            for (int i = 0; i < 10; i++)
            {
                Person person = new Person($"Pista{i}", counter);
                if (ValidatorClass.Validation(person))
                {
                    people.Add(person);
                }
                counter++;


            }
            return people;
        }
        static List<Internet> Loader2()
        {
            List<Internet> people = new List<Internet>();
            int counter = -2;
            for (int i = 0; i < 10; i++)
            {
                Internet person = new Internet($"Digi{i}", counter);
                if (ValidatorClass.Validation(person))
                {
                    people.Add(person);
                }
                counter++;


            }
            return people;
        }




    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Validator;
namespace hetfo_gyakorlas
{
    class Internet
    {
        public Internet(string szolgaltato, int netsebesseg)
        {
            Szolgaltato = szolgaltato;
            Netsebesseg = netsebesseg;
        }
        [NotNull]
        public string Szolgaltato { get; set; }
        [NotNull]
        [NotNegative]
        public int Netsebesseg { get; set; }
    }
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Validator;
namespace hetfo_gyakorlas
{
    class Person
    {
        public Person(string name, int age)
        {
            Name = name;
            Age = age;
        }

        [NotNull]
        public string Name { get; set; }
        [NotNull]
        [NotNegative]
        public int Age { get; set; }


    }
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Reflection;
namespace Validator
{
    public static class ValidatorClass
    {
        public static bool Validation(object o)
        {

            Type type = o.GetType();
            PropertyInfo[] properties = type.GetProperties();
            bool ok = true;


            foreach (var prop in properties)
            {
                var data = prop.GetValue(o);//o object adott property erteke
                var attr = prop.GetCustomAttributes();//attributes of property

                ok = true;
                foreach (var atrrItem in attr)
                {
                    if (atrrItem.GetType() == typeof(NotNull))
                    {

                        if (!ValidationMethods.NotNull(prop.GetValue(o)))
                        {
                            ok = false;

                        }

                    }
                    if (atrrItem.GetType() == typeof(NotNegative))
                    {

                        if (!ValidationMethods.NotNegative(prop.GetValue(o)))
                        {
                            ok = false; ;

                        }

                    }

                }
            }
            return ok;

        }


    }
    public static class ValidationMethods
    {
        public static bool NotNull(object o)
        {
            return o != null;
        }
        public static bool NotNegative(object o)
        {

            return (int)o >= 0;
        }
    }

    public class NotNull : Attribute { }
    public class NotNegative : Attribute { }
}