namespace ServerTest
{
    using System;
    using System.Text;

    public class Book
    {
        private double price = 0;
        private string title = null;
        private string author = null;

        public Book(string title, string author, double price)
        {
            this.Title = title;
            this.Author = author;
            this.Price = price;
        }

        public string Title
        {
            get
            {
                return this.title;
            }

            set
            {
                // We check the value of the "value" keyword, because the
                // "value" keyword holds the new value
                if (string.IsNullOrEmpty(value))
                {
                    throw new ArgumentNullException("The book musn`t have a title");
                }

                this.title = value;
            }
        }

        public string Author
        {
            get
            {
                return this.author;
            }

            set
            {
                // We check the value of the "value" keyword, because the
                // "value" keyword holds the new value
                if (string.IsNullOrEmpty(value))
                {
                    throw new ArgumentNullException("The book musn`t have a author");
                }

                this.author = value;
            }
        }

        public double Price
        {
            get
            {
                return this.price;
            }

            set
            {
                if (value < 0)
                {
                    throw new ArgumentOutOfRangeException("The price should be bigger than 0");
                }

                // We check the value of the "value" keyword, because the
                // "value" keyword holds the new value
                this.price = value;
            }
        }

        // Virtual property :)
        public virtual double ChangedPrice
        {
            get
            {
                // In this class we return the original
                return this.Price;
            }
        }

        public override string ToString()
        {
            var output = new StringBuilder();
            output.AppendFormat("-Type: {0}{1}", this.GetType().Name, Environment.NewLine);
            output.AppendFormat("-Title: {0}{1}", this.Title, Environment.NewLine);
            output.AppendFormat("-Author: {0}{1}", this.Author, Environment.NewLine);

            // We need the ChangedPrice value, not the original one
            output.AppendFormat("-Price: {0:F2}{1}", this.ChangedPrice, Environment.NewLine);
            return output.ToString();
        }
    }
}