// First example of classes
using System;
using System.Collections.Generic;

namespace ConsoleApp6
{
    class Program
    {
        public class Human
        {
            protected string first;
            protected string last;
            protected uint age;

            public string First
            {
                get { return first; }
                set { first = value; }
            }

            public string Last
            {
                get { return last; }
                set { last = value; }
            }

            public uint Age
            {
                get { return age; }
                set { age = value; }
            }

            public Human()
            {
                first = last = "";
                age = 0;
            }

            public Human(string _first, string _last, uint _age)
            {
                first = _first;
                last = _last;
                age = _age;
            }

            public override string ToString()
            {
                return String.Format("{0}, {1} is {2} years old.", Last, First, Age);
                //return "First = " + first
            }
        }

        public class Student : Human, IComparable
        {
            private string zid;

            public string Zid
            {
                get { return zid; }
                set
                {
                    if (value[0] != 'z' && value[0] != 'Z')
                        return;

                    if (value.Length > 8 || value.Length < 7) // zDDDDDD or zDDDDDDD
                        return;

                    // So we have a leading Z character, and the correct number of characters
                    for (int i = 1; i < value.Length; i++)
                        if (!Char.IsDigit(value[i]))
                            return;

                    zid = value;
                }
            }

            public string Nonsense => Zid + " is a student";

            public Student() : base()
            {
                zid = "";
            }

            public Student(string _first, string _last, uint _age, string _zid) : base(_first, _last, _age)
            {
                Zid = _zid;
            }

            public int CompareTo(Object alpha)
            {
                if (alpha == null) throw new ArgumentNullException();
                // otherwise
                Student rightOp = alpha as Student; // Typcasing with English!

                if (rightOp != null) // The typecast was success
                    return this.Zid.CompareTo(rightOp.Zid);
                else
                    throw new ArgumentException();
            }

            public override string ToString()
            {
                return String.Format("{0} and is an NIU student, ID == {1}.", base.ToString(), Zid);
            }
        }

        static void Main(string[] args)
        {
            Human myself = new Human("Rogness", "Daniel", 35);

            Console.WriteLine(myself.ToString());
            Student alsoMyself = new Student("Rogness", "Daniel", 35, "z174735");
            Student myAlias = new Student("Strauss", "Viktor", 36, "z1560953");
            Student myOtherAlias = new Student("Zimmerman", "Philip", 20, "z0123456");

            Console.WriteLine(alsoMyself.ToString() + "\n\n");

            SortedSet<Student> pool;

            pool = new SortedSet<Student>();

            pool.Add(alsoMyself);
            pool.Add(myAlias);
            pool.Add(myOtherAlias);

            foreach (Student i in pool)
            {
                Console.WriteLine(i);
            }
        }
    }
}