package appeng.me.cache;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map.Entry;
import java.util.Set;

import appeng.api.networking.events.MENetworkStorageEvent;
import appeng.api.networking.security.BaseActionSource;
import appeng.api.storage.IMEInventoryHandler;
import appeng.api.storage.IMEMonitorHandlerReceiver;
import appeng.api.storage.MEMonitorHandler;
import appeng.api.storage.StorageChannel;
import appeng.api.storage.data.IAEStack;
import appeng.api.storage.data.IItemList;
import appeng.me.storage.ItemWatcher;

public class NetworkMonitor<T extends IAEStack<T>> extends MEMonitorHandler<T>
{

	final private GridStorageCache myGridCache;
	final private StorageChannel myChannel;

	boolean sendEvent = false;

	public void forceUpdate()
	{
		hasChanged = true;

		Iterator<Entry<IMEMonitorHandlerReceiver<T>, Object>> i = getListeners();
		while (i.hasNext())
		{
			Entry<IMEMonitorHandlerReceiver<T>, Object> o = i.next();
			IMEMonitorHandlerReceiver<T> recv = o.getKey();

			if ( recv.isValid( o.getValue() ) )
				recv.onListUpdate();
			else
				i.remove();
		}
	}

	public NetworkMonitor(GridStorageCache cache, StorageChannel chan) {
		super( null, chan );
		myGridCache = cache;
		myChannel = chan;
	}

	final static public LinkedList depth = new LinkedList();
	
	@Override
	protected void postChangesToListeners(Iterable<T> changes, BaseActionSource src)
	{
		postChange( true, changes, src );
	}
	
	protected void postChange(boolean Add, Iterable<T> changes, BaseActionSource src)
	{
		if ( depth.contains( this ) )
			return;

		depth.push( this );

		sendEvent = true;
		notifyListenersOfChange( changes, src );

		IItemList<T> myStorageList = getStorageList();

		for (T changedItem : changes)
		{
			T difference = changedItem;

			if ( !Add && changedItem != null )
				(difference = changedItem.copy()).setStackSize( -changedItem.getStackSize() );

			if ( myGridCache.interestManager.containsKey( changedItem ) )
			{
				Set<ItemWatcher> list = myGridCache.interestManager.get( changedItem );
				if ( !list.isEmpty() )
				{
					IAEStack fullStack = myStorageList.findPrecise( changedItem );
					if ( fullStack == null )
					{
						fullStack = changedItem.copy();
						fullStack.setStackSize( 0 );
					}

					myGridCache.interestManager.enableTransactions();

					for (ItemWatcher iw : list)
						iw.getHost().onStackChange( myStorageList, fullStack, difference, src, getChannel() );

					myGridCache.interestManager.disableTransactions();
				}
			}
		}

		Object last = depth.pop();
		if ( last != this )
			throw new RuntimeException( "Invalid Access to Networked Storage API detected." );
	}

	public void onTick()
	{
		if ( sendEvent )
		{
			sendEvent = false;
			myGridCache.myGrid.postEvent( new MENetworkStorageEvent( this, myChannel ) );
		}
	}

	@Override
	protected IMEInventoryHandler getHandler()
	{
		switch (myChannel)
		{
		case ITEMS:
			return myGridCache.getItemInventoryHandler();
		case FLUIDS:
			return myGridCache.getFluidInventoryHandler();
		default:
		}
		return null;
	}

}