using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;

namespace GenericDatatypeRingbuffer
{
    class Ringpuffer<T> : IEnumerable where T : class
    {
        private Element erster, letzter, current;
        private int numberofelements;

        public class Element
        {
            internal T data;
            internal Element next;

            internal Element() { }
            internal Element(T newdata)
            {
                data = newdata;
                next = null;
            }
        }

        public Ringpuffer(int anz)
        {
            numberofelements = anz;
            for (int i = 0; i < anz; i++)
            {
                Element neu = new Element();

                if (erster == null)
                { erster = neu; letzter = neu; }
                else
                {
                    letzter.next = neu;
                    letzter = neu;
                }
            }

            letzter.next = erster;
            current = erster;
        }

        public void EnQueue(T newdata, int steps)
        {
            bool placehere = false;
            int moved = 0;
            while (!placehere || current.data != default(T))
            {
                if (moved > numberofelements)
                    throw new InsufficientMemoryException();

                current = current.next;
                if (moved == steps - 1)
                    placehere = true;
                moved++;

            }

            current.data = newdata;
            Console.WriteLine("{0} @ {1}", newdata, steps);
        }

        public T DeQueue()
        {
            T returncache = current.data;
            current.data = default(T);
            current = current.next;

            return returncache;
        }

        public IEnumerator GetEnumerator()
        {
            for (int i = 0; i < numberofelements; i++)
            {
                if (erster.data != default(T))
                    yield return erster.data;
                erster = erster.next;
            }

        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Ringpuffer<string> DasDing = new Ringpuffer<string>(5);
            DasDing.EnQueue("Anna", 3);
            DasDing.EnQueue("lala", 2);
            DasDing.EnQueue("lulu", 2);
            DasDing.EnQueue("mudda", 2);
            DasDing.EnQueue("vadda", 2);
            //DasDing.EnQueue("zuvieldesguten", 2);

            Console.WriteLine();
            foreach (string E in DasDing)
            {
                Console.WriteLine(E);
            }

            Console.WriteLine();
            Console.WriteLine("Wurde entfernt: " + DasDing.DeQueue());
            Console.WriteLine();

            foreach (string E in DasDing)
            {
                Console.WriteLine(E);
            }


            Console.WriteLine();


            Console.Read();



        }
    }
}