using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        InOutEvent inOutMethods = new InOutEvent();

​

        ItemsList<ICommonData> queue = new ItemsList<ICommonData>();

​

        queue.enteredItemEvent += inOutMethods.InItem;

        queue.removedItemEvent += inOutMethods.OutItem;

​

        for (int i = 1; i < 11; i++)

        {

            BookEventArgs book = new BookEventArgs("My Book Eddition No.: " + i, "Ashraf Abouelnaga", 2000 + i);

            queue.AddToQueue(book);

        }

​

        Console.WriteLine();

        BookEventArgs addedBook = new BookEventArgs("My Book Eddition No.: " + 11, "Ashraf Abouelnaga", 2000 + 11);

        queue.AddToQueue(addedBook);

​

        Console.WriteLine();

        queue.RemoveFromQueue();

        queue.RemoveFromQueue();

​

        Console.WriteLine();

        Console.WriteLine("Items List:");

        queue.ViewQueueData();

    }

}

​

public interface ICommonData

{

    string Name { get; set; }

    string GetObjectData();

}

​

public class BookEventArgs : EventArgs,ICommonData

{

    public string Name { get; set; }

    public string Author { get; set; }

    public int PublishYear { get; set; }

    public BookEventArgs() { }

    public BookEventArgs(string _name, string _author, int _published)

    {

        Name = _name;

        Author = _author;

        PublishYear = _published;

    }

    public string GetObjectData()

    {

        return $"Author: {Author}, Book Name: {Name}, Published in: {PublishYear}.";

    }

}

​

public delegate void ItemInEvent(object sender, ICommonData e);

public delegate void ItemOutEvent(object sender, ICommonData e);

​

public class InOutEvent

{

    public void InItem(object sender, ICommonData e)

    {

        Console.WriteLine($"Item Entered, {e.GetObjectData()}");

    }

​

    public void OutItem(object sender, ICommonData e)

    {

        Console.WriteLine($"Item Removed, {e.GetObjectData()}");

    }

}

​

public class ItemsList<T> where T : class, ICommonData

{

    public event ItemInEvent enteredItemEvent;

    public event ItemOutEvent removedItemEvent;

    private IList<T> queueData;

    public ItemsList()

    {

        queueData = new List<T>();

    }

    public void AddToQueue(T inputData)

    {

        queueData.Add(inputData);

        RaiseEnterItemEvent(inputData);

    }

    protected virtual void RaiseEnterItemEvent(T item)

    {

        if (enteredItemEvent != null)

        {

            enteredItemEvent(this, item);

        }

    }

    public void RemoveFromQueue()

    {

        T outData = null;

        if (queueData.Count > 0)

        {

            outData = queueData[queueData.Count - 1];

        }

        if(outData != null)

        {

            queueData.Remove(outData);

            RaiseRemoveItemEvent(outData);

        }

    }

    protected virtual void RaiseRemoveItemEvent(T item)

    {

        if (removedItemEvent != null)

        {

            removedItemEvent(this, item);

        }

    }

    public void ViewQueueData()

    {

        foreach (var item in queueData)

        {

            Console.WriteLine($"Book name: {item.GetObjectData()}");

        }

    }

}