namespace DecoratorPattern
{
// "Prototype"
abstract class GoodsProto
{
// Methods
  public abstract GoodsProto Clone();
}

// "ConcretePrototype"
class Goods : GoodsProto
{
// Fields
  private string m_title = "";
  private ArrayList m_descr = null;
  private double m_prise = 0.0;
  private int m_qty = 0;

// Constructor
public Goods( string title, double prise, int qty, ArrayList descr )
{
  m_title = title;
  m_prise = prise;
  m_qty = qty;
  m_descr = descr;
}

public Goods( Goods g )
{
  m_title = g.GetTitle();
  m_prise = g.GetPrise();
  m_qty = g.GetQty();    if (m_descr == null)
  m_descr = new ArrayList();
}

// Methods
public override GoodsProto Clone()
{
  Goods g = new Goods(m_title, m_prise, m_qty, new ArrayList());
  for (int i=0; i<m_descr.Count; i++)
    g.AddDescr(m_descr[i].ToString());      return g;
}

public double GetPrise() { return m_prise; }
public void SetPrise(double d) { m_prise=d; }
public void SetQty(int i) { m_qty = i; }
public int GetQty() {return m_qty;}
public void SetTitle(string Title) { m_title = Title; }
public string GetTitle() { return m_title; }
public void AddDescr(string descr) { m_descr.Add(descr); }

public double PrintInfo()
{
  Console.Write( " {0} \t {1} \t {2} \t {3}",
  m_title, m_prise, m_qty, m_prise*m_qty );   for (int i=0; i<m_descr.Count; i++)
  Console.Write( " Descr {0} : {1} ", i, m_descr[i]);   Console.WriteLine("");
  return m_prise*m_qty;
}
}

// "Decorator"

//=========================
abstract class Decorator : Goods
{

// Fields
protected Goods goods = null;

// Constructors
public Decorator (Goods g)
    : base( g ) { this.goods = g; } public new void PrintInfo()
{
  goods.PrintInfo();
}
}

// "ConcreteDecorator"
class Borrow : Decorator
{

// Fields
protected ArrayList borrowers = new ArrayList();

// Constructors
public Borrow( Goods g )
    : base( g ) {}
// Methods

public void BorrowGoods( string name )
{
  borrowers.Add( name );
  goods.SetQty(base.goods.GetQty()-1);
}

public new void PrintInfo()
{
  base.PrintInfo();
  foreach( string borrower in borrowers )
  Console.WriteLine( " borrower: {0}", borrower );
}
}

//==========================================
// Prototype manager
class StoreHouse
{
  private Hashtable m_goods = new Hashtable();

// Indexers
  public GoodsProto this[ string name ]
{
  get{ return (GoodsProto)m_goods[ name ]; }
  set{ m_goods.Add( name, value ); }
}

public void PrintInfo()
{
  double sum = 0;
  Goods g = null;
  Console.WriteLine("-Storehouse report begin-------------------------------------");
  Console.WriteLine( "Title: prise: qty: Amount: Description:");
  foreach (DictionaryEntry e in m_goods)
  {
    g = (Goods)e.Value;
    sum += g.PrintInfo();
  }
  Console.WriteLine("==================================== Storehouse Total : {0}", sum);
  Console.WriteLine("-Storehouse report end---------------------------------------\n");
}
}

//=============================================
class PrototypeTest
{
public static void Main( string[] args )
{

  StoreHouse storehouse = new StoreHouse();
  // Initialize with standard goods

  storehouse[ "cd" ] = new Goods( "video-cd ", 7.2, 10, new ArrayList());
  storehouse[ "dvd" ] = new Goods( "video-dvd ", 9.1, 15, new ArrayList());
  storehouse.PrintInfo();

  string goodsTitle = "dvd";
  Goods f1 = (Goods)storehouse[ goodsTitle ].Clone();
  f1.AddDescr("dvd, Ameli");
  f1.PrintInfo();

  Console.WriteLine("++Object f1, Qty = 9, title = 'Ameli, Fr.'");
  f1.SetQty(9); f1.SetTitle("Ameli, Fr.");
  f1.PrintInfo();

// Make video borrowable, then borrow and display
  Console.WriteLine( "\n++Object f1 - design pattern 'decorator' implementation begin:" );
  Borrow b = new Borrow(f1);
  b.BorrowGoods( "First borrower" );
  b.BorrowGoods( "Second borrower" );
  b.PrintInfo();

  Console.WriteLine("\n++Object f1:");
  f1.PrintInfo();

  storehouse.PrintInfo();

  Console.Read();
}
}
}

video-dvd 9.1 15 136.5 Descr 0 : dvd, Ameli
++Object f1, Qty = 9, title = 'Ameli, Fr.'
Ameli, Fr. 9.1 9 81.9 Descr 0 : dvd, Ameli

++Object f1 - design pattern 'decorator' implementation begin:
Ameli, Fr. 9.1 7 63.7 Descr 0 : dvd, Ameli
borrower: First borrower
borrower: Second borrower

++Object f1:
Ameli, Fr. 9.1 7 63.7 Descr 0 : dvd, Ameli
-Storehouse report begin--------------------------
Title: prise: qty: Amount: Description:
video-dvd 9.1 15 136.5
video-cd 7.2 10 72
============================= Storehouse Total : 208.5
-Storehouse report end-------------------------