package observer_subject;

import java.util.LinkedList;
import java.util.Iterator;

import org.omg.CORBA.ORB;
import org.omg.PortableServer.POA;
import org.omg.PortableServer.POAHelper;

class SubjectImpl extends SubjectPOA
{
    private LinkedList observers = new LinkedList();
    private boolean modif = false;

    private POA rootPOA;

    /* Classe de notification */
    public class NotifThread extends Thread
    {
	public void run()
	{
	    try {
		for(;;) 
		    {
			sleep(1000);
			if ( modif )
			    {
				notify_all();
				modif = false;
			    }
		    }
	    } catch (InterruptedException e) {
		System.out.println("erreur thread");
	    } 
	}
    
    }

    /* Classe principale */
    public SubjectImpl()
    {
	NotifThread t = new NotifThread();
	t.start();
    }

    public void attach(Observer o)
	throws DejaAttache
    {
	synchronized(observers) {
	    if ( observers.contains(o) )
		throw new DejaAttache();

	    observers.add(o);
	}
    }

    public void multiple_attach(Observer []ol)
	throws DejaAttache
    {
	synchronized(observers) {
	    /* Vérifier qu'il n'y en a pas déjà un attaché */
	    for(int i=0;i<ol.length;i++)
		{
		    if ( observers.contains(ol[i]) )
			throw new DejaAttache();
		}

	    /* Ajouter */
	    for(int i=0;i<ol.length;i++)
		{
		    observers.add(ol[i]);
		}
	}
    }


    public void detach(Observer o)
	throws PasAttache
    {
	synchronized(observers) {
	    if ( observers.contains(o) == false )
		throw new PasAttache();

	    observers.remove(o);
	}
    }

    private void notify_all()
    {
	synchronized(observers) {
	    Iterator it = observers.iterator();
	    
	    while ( it.hasNext() )
		{
		    Observer o = (Observer)it.next();
		    o.notifier(this._this());
		}
	}
    }

    public void provoc_modif()
    {
	modif = true;
    }

}