Applied-Energistics-2-tilera-Edition/core/api/ApiPart.java

package appeng.core.api;

import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.tileentity.TileEntity;
import net.minecraft.world.World;
import net.minecraftforge.client.MinecraftForgeClient;

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.commons.Remapper;
import org.objectweb.asm.commons.RemappingClassAdapter;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.MethodInsnNode;
import org.objectweb.asm.tree.MethodNode;

import appeng.api.parts.IPartHelper;
import appeng.api.parts.IPartItem;
import appeng.api.parts.LayerBase;
import appeng.client.render.BusRenderer;
import appeng.core.AELog;
import appeng.core.AppEng;
import appeng.integration.abstraction.IFMP;
import appeng.parts.PartPlacement;
import appeng.tile.networking.TileCableBus;
import appeng.util.Platform;

import com.google.common.base.Joiner;

public class ApiPart implements IPartHelper
{

	int classNum = 1;

	HashMap<String, Class> TileImplementations = new HashMap();
	HashMap<String, ClassNode> readerCache = new HashMap();
	HashMap<Class, String> interfaces2Layer = new HashMap();
	HashMap<String, Class> roots = new HashMap();

	List<String> desc = new LinkedList();

	public void initFMPSupport()
	{
		for (Class layerInterface : interfaces2Layer.keySet())
		{
			if ( AppEng.instance.isIntegrationEnabled( "FMP" ) )
				((IFMP) AppEng.instance.getIntegration( "FMP" )).registerPassThru( layerInterface );
		}
	}

	private Class loadClass(String Name, byte[] b)
	{
		// override classDefine (as it is protected) and define the class.
		Class clazz = null;
		try
		{
			ClassLoader loader = getClass().getClassLoader();// ClassLoader.getSystemClassLoader();
			Class root = ClassLoader.class;
			Class cls = loader.getClass();
			java.lang.reflect.Method defineClassMethod = root.getDeclaredMethod( "defineClass",
					new Class[] { String.class, byte[].class, int.class, int.class } );
			java.lang.reflect.Method runTransformersMethod = cls
					.getDeclaredMethod( "runTransformers", new Class[] { String.class, String.class, byte[].class } );

			runTransformersMethod.setAccessible( true );
			defineClassMethod.setAccessible( true );
			try
			{
				Object[] argsA = new Object[] { Name, Name, b };
				b = (byte[]) runTransformersMethod.invoke( loader, argsA );

				Object[] args = new Object[] { Name, b, new Integer( 0 ), new Integer( b.length ) };
				clazz = (Class) defineClassMethod.invoke( loader, args );
			}
			finally
			{
				runTransformersMethod.setAccessible( false );
				defineClassMethod.setAccessible( false );
			}
		}
		catch (Exception e)
		{
			AELog.error( e );
			System.exit( 1 );
		}
		return clazz;
	}

	public ClassNode getReader(String name) throws IOException
	{
		ClassReader cr;
		String path = "/" + name.replace( ".", "/" ) + ".class";
		InputStream is = getClass().getResourceAsStream( path );
		cr = new ClassReader( is );
		ClassNode cn = new ClassNode();
		cr.accept( cn, ClassReader.EXPAND_FRAMES );
		return cn;
	}

	public Class getCombinedInstance(String base)
	{
		if ( desc.size() == 0 )
		{
			try
			{
				return Class.forName( base );
			}
			catch (Throwable t)
			{
				throw new RuntimeException( t );
			}
		}

		String description = base + ":" + Joiner.on( ";" ).skipNulls().join( desc.iterator() );

		if ( TileImplementations.get( description ) != null )
		{
			try
			{
				return TileImplementations.get( description );
			}
			catch (Throwable t)
			{
				throw new RuntimeException( t );
			}
		}

		String f = base;// TileCableBus.class.getName();
		String Addendum = "";
		try
		{
			Addendum = Class.forName( base ).getSimpleName();
		}
		catch (ClassNotFoundException e)
		{
			AELog.error( e );
		}
		Class myCLass;

		try
		{
			myCLass = Class.forName( f );
		}
		catch (Throwable t)
		{
			throw new RuntimeException( t );
		}

		String path = f;

		for (String name : desc)
		{
			try
			{
				String newPath = path + ";" + name;
				myCLass = getClassByDesc( Addendum, newPath, f, interfaces2Layer.get( Class.forName( name ) ) );
				path = newPath;
			}
			catch (Throwable t)
			{
				AELog.error( t );
				// throw new RuntimeException( t );
			}
			f = myCLass.getName();
		}

		TileImplementations.put( description, myCLass );

		try
		{
			return myCLass;
		}
		catch (Throwable t)
		{
			throw new RuntimeException( t );
		}
	}

	class DefaultPackageClassNameRemapper extends Remapper
	{

		public HashMap<String, String> inputOutput = new HashMap<String, String>();

		@Override
		public String map(String typeName)
		{
			String o = inputOutput.get( typeName );
			if ( o == null )
				return typeName;
			return o;
		}

	}

	public Class getClassByDesc(String Addendum, String fullPath, String root, String next) throws IOException
	{
		if ( roots.get( fullPath ) != null )
			return roots.get( fullPath );

		ClassWriter cw = new ClassWriter( ClassWriter.COMPUTE_MAXS );
		ClassNode n = getReader( next );
		String originalName = n.name;

		try
		{
			n.name = n.name + "_" + Addendum;
			n.superName = Class.forName( root ).getName().replace( ".", "/" );
		}
		catch (Throwable t)
		{
			AELog.error( t );
		}

		for (MethodNode mn : n.methods)
		{
			Iterator<AbstractInsnNode> i = mn.instructions.iterator();
			while (i.hasNext())
			{
				processNode( i.next(), n.superName );
			}
		}

		DefaultPackageClassNameRemapper remapper = new DefaultPackageClassNameRemapper();
		remapper.inputOutput.put( "appeng/api/parts/LayerBase", n.superName );
		remapper.inputOutput.put( originalName, n.name );
		n.accept( new RemappingClassAdapter( cw, remapper ) );
		// n.accept( cw );

		// n.accept( new TraceClassVisitor( new PrintWriter( System.out ) ) );
		byte[] barray = cw.toByteArray();
		int size = barray.length;
		Class nclass = loadClass( n.name.replace( "/", "." ), barray );

		try
		{
			Object fish = nclass.newInstance();
			Class rootC = Class.forName( root );

			boolean bads = false;

			if ( !rootC.isInstance( fish ) )
			{
				bads = true;
				AELog.severe( "Error, Expected layer to implement " + root + " did not." );
			}

			if ( fish instanceof LayerBase )
			{
				bads = true;
				AELog.severe( "Error, Expected layer to NOT implement LayerBase but it DID." );
			}

			if ( !fullPath.contains( ".fmp." ) )
			{
				if ( !(fish instanceof TileCableBus) )
				{
					bads = true;
					AELog.severe( "Error, Expected layer to implement TileCableBus did not." );
				}

				if ( !(fish instanceof TileEntity) )
				{
					bads = true;
					AELog.severe( "Error, Expected layer to implement TileEntity did not." );
				}
			}

			if ( !bads )
			{
				AELog.info( "Layer: " + n.name + " loaded successfully - " + size + " bytes" );
			}

		}
		catch (Throwable t)
		{
			AELog.severe( "Layer: " + n.name + " Failed." );
			AELog.error( t );
		}

		roots.put( fullPath, nclass );
		return nclass;
	}

	private void processNode(AbstractInsnNode next, String nePar)
	{
		if ( next instanceof MethodInsnNode )
		{
			MethodInsnNode min = (MethodInsnNode) next;
			if ( min.owner.equals( "appeng/api/parts/LayerBase" ) )
			{
				min.owner = nePar;
			}
		}
	}

	@Override
	public void setItemBusRenderer(IPartItem i)
	{
		if ( Platform.isClient() && i instanceof Item )
			MinecraftForgeClient.registerItemRenderer( (Item) i, BusRenderer.instance );
	}

	@Override
	public boolean placeBus(ItemStack is, int x, int y, int z, int side, EntityPlayer player, World w)
	{
		return PartPlacement.place( is, x, y, z, side, player, w, PartPlacement.PlaceType.PLACE_ITEM, 0 );
	}

	@Override
	public boolean registerNewLayer(String layer, String layerInterface)
	{
		try
		{
			if ( interfaces2Layer.get( layerInterface ) == null )
			{
				interfaces2Layer.put( Class.forName( layerInterface ), layer );
				desc.add( layerInterface );
				return true;
			}
			else
				AELog.info( "Layer " + layer + " not registered, " + layerInterface + " aready has a layer." );
		}
		catch (Throwable t)
		{
		}

		return false;
	}

}