//Copyright (C) Microsoft Corporation.  All rights reserved.

// bookstore.cs
using System;

// A set of classes for handling a bookstore:
namespace Bookstore 
{
   using System.Collections;

	
   // Describes a book in the book list:
   public class Book
   {
      public string m_Title;        // Title of the book.
      public string m_Author;       // Author of the book.
      public decimal m_Price;       // Price of the book.
      public bool m_bPaperback;      // Is it paperback?

      public Book(string title, string author, decimal price, bool paperBack)
      {
         this.m_Title = title;
         this.m_Author = author;
         this.m_Price = price;
         this.m_bPaperback = paperBack;
      }
	  public bool IsPaperback()
	  {
		  return m_bPaperback;
	  }
	  public decimal getPrice()
	  {
		  return m_Price;
	  }
	  public string getAuthor()
	  {
		  return m_Author;
	  }
	  public string getTitle()
	  {
		  return m_Title;
	  }
   }

   // Declare a delegate type for processing a book:
   public delegate void ProcessBookDelegate(Book book);

   // Maintains a book database.
   public class BookDB
   {
      // List of all books in the database:
      ArrayList list = new ArrayList();   

      // Add a book to the database:
      public void AddBook(string title, string author, decimal price, bool paperBack)
      {
         list.Add(new Book(title, author, price, paperBack));
      }

      // Call a passed-in delegate on each paperback book to process it: 
      public void ProcessPaperbackBooks(ProcessBookDelegate processBook)
      {
         foreach (Book b in list) 
         {
            if (b.IsPaperback())
			{
				// Calling the delegate:
               processBook(b);
			}
         }
      }
   }
}

// Using the Bookstore classes:
namespace BookTestClient
{
   using Bookstore;

   // Class to total and average prices of books:
   class PriceTotaller
   {
      int countBooks = 0;
      decimal priceBooks = 0.0m;

      internal void AddBookToTotal(Book book)
      {
         countBooks += 1;
         priceBooks += book.getPrice();
      }
	  
      internal decimal AveragePrice()
      {
         return priceBooks / countBooks;
      }
   }

   // Class to test the book database:
   class Test
   {
		public static void Print(string s)
		{
			#if DEBUG
				System.Diagnostics.Debug.WriteLine(s);
			#endif
			System.Console.WriteLine(s);
		}
		// Print the title of the book.
		static void PrintTitle(Book b)
		{
			string a = String.Format("  {0}", b.getTitle());
			Print(a);
		}

		// Execution starts here.
		static void Main()
		{
			RunBookStore();
		}
		  
		static void RunBookStore()
		{
			 BookDB bookDB = new BookDB();
			 // Initialize the database with some books:
			 AddBooks(bookDB);      

			 // Print all the titles of paperbacks:
			 Console.WriteLine("Paperback Book Titles:");
			 // Create a new delegate object associated with the static 
			 // method Test.PrintTitle:
			 bookDB.ProcessPaperbackBooks(new ProcessBookDelegate(PrintTitle));

			 // Get the average price of a paperback by using
			 // a PriceTotaller object:
			 PriceTotaller totaller = new PriceTotaller();
			 // Create a new delegate object associated with the nonstatic 
			 // method AddBookToTotal on the object totaller:
			 bookDB.ProcessPaperbackBooks(new ProcessBookDelegate(totaller.AddBookToTotal));
			 Console.WriteLine("Average Paperback Book Price: ${0:#.##}",
				totaller.AveragePrice());
		  }

		  // Initialize the book database with some test books:
		  static void AddBooks(BookDB bookDB)
		  {
			 bookDB.AddBook("The C Programming Language", 
				"Brian W. Kernighan and Dennis M. Ritchie", 19.95m, true);
			 bookDB.AddBook("The Unicode Standard 2.0", 
				"The Unicode Consortium", 39.95m, true);
			 bookDB.AddBook("The MS-DOS Encyclopedia", 
				"Ray Duncan", 129.95m, false);
			 bookDB.AddBook("Dogbert's Clues for the Clueless", 
				"Scott Adams", 12.00m, true);
		  }
   }
}