/*
 * Forge Mod Loader
 * Copyright (c) 2012-2013 cpw.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser Public License v2.1
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 *
 * Contributors:
 *     cpw - implementation
 */

package cpw.mods.fml.common;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.Set;
import java.util.logging.Level;

import com.google.common.base.Strings;

import cpw.mods.fml.common.discovery.ASMDataTable;
import cpw.mods.fml.common.discovery.ASMDataTable.ASMData;
import cpw.mods.fml.relauncher.Side;

/**
 * @author cpw
 *
 */
public class ProxyInjector
{
    public static void inject(ModContainer mod, ASMDataTable data, Side side, ILanguageAdapter languageAdapter)
    {
        FMLLog.fine("Attempting to inject @SidedProxy classes into %s", mod.getModId());
        Set<ASMData> targets = data.getAnnotationsFor(mod).get(SidedProxy.class.getName());
        ClassLoader mcl = Loader.instance().getModClassLoader();

        for (ASMData targ : targets)
        {
            try
            {
                Class<?> proxyTarget = Class.forName(targ.getClassName(), true, mcl);
                Field target = proxyTarget.getDeclaredField(targ.getObjectName());

                if (target == null)
                {
                    // Impossible?
                    FMLLog.severe("Attempted to load a proxy type into %s.%s but the field was not found", targ.getClassName(), targ.getObjectName());
                    throw new LoaderException();
                }

                SidedProxy annotation = target.getAnnotation(SidedProxy.class);

                if (!Strings.isNullOrEmpty(annotation.modId()) && !annotation.modId().equals(mod.getModId()))
                {
                    FMLLog.fine("Skipping proxy injection for %s.%s since it is not for mod %s", targ.getClassName(), targ.getObjectName(), mod.getModId());
                    continue;
                }

                String targetType = side.isClient() ? annotation.clientSide() : annotation.serverSide();
                Object proxy = Class.forName(targetType, true, mcl).newInstance();

                if (languageAdapter.supportsStatics() && (target.getModifiers() & Modifier.STATIC) == 0)
                {
                    FMLLog.severe("Attempted to load a proxy type %s into %s.%s, but the field is not static", targetType, targ.getClassName(), targ.getObjectName());
                    throw new LoaderException();
                }

                if (!target.getType().isAssignableFrom(proxy.getClass()))
                {
                    FMLLog.severe("Attempted to load a proxy type %s into %s.%s, but the types don't match", targetType, targ.getClassName(), targ.getObjectName());
                    throw new LoaderException();
                }

                languageAdapter.setProxy(target, proxyTarget, proxy);
            }
            catch (Exception e)
            {
                FMLLog.log(Level.SEVERE, e, "An error occured trying to load a proxy into %s.%s", targ.getAnnotationInfo(), targ.getClassName(), targ.getObjectName());
                throw new LoaderException(e);
            }
        }

        // Allow language specific proxy injection.
        languageAdapter.setInternalProxies(mod, side, mcl);
    }
}
