// Mediator

// Intent: "Define an object that encapsulates how a set of objects interact. 
// Mediator promotes loose coupling by keeping objects from referring to each
// other explicitly, and it lets you vary their interaction independently." 

// For further information, read "Design Patterns", p273, Gamma et al.,
// Addison-Wesley, ISBN:0-201-63361-2

/* Notes:
 * Consider a mediator as a hub, which objects that need to talk -
 * but do not wish to be interdependent - can use. 
 */
 
namespace Mediator_DesignPattern
{
    using System;

	class Mediator 
	{
		private DataProviderColleague dataProvider;
		private DataConsumerColleague dataConsumer;
		public void IntroduceColleagues(DataProviderColleague c1, DataConsumerColleague c2)
		{
			dataProvider = c1;
			dataConsumer = c2;			
		}
		
		public void DataChanged()
		{
			int i = dataProvider.MyData;
            dataConsumer.NewValue(i);
		}
	}

	class DataConsumerColleague 
	{
		public void NewValue(int i)
		{
			Console.WriteLine("New value {0}", i);
		}
	}

	class DataProviderColleague
	{
		private Mediator mediator;
		private int iMyData=0;
		public int MyData 
		{
			get 
			{
				return iMyData;
			}
			set 
			{
				iMyData = value;
			}
		}
		public DataProviderColleague(Mediator m)
		{
			mediator = m;
		}

		public void ChangeData()
		{
			iMyData = 403;

			// Inform mediator that I have changed the data
			if (mediator != null)
				mediator.DataChanged();	
		}		
	}

    /// <summary>
    ///    Summary description for Client.
    /// </summary>
    public class Client
    {
        public static int Main(string[] args)
        {            
			Mediator m = new Mediator();
			DataProviderColleague c1 = new DataProviderColleague(m);
			DataConsumerColleague c2 = new DataConsumerColleague();
			m.IntroduceColleagues(c1,c2);

			c1.ChangeData();

            return 0;
        }
    }
}