/*******************************************************************************
 * Copyright (c) 2014 Jeff Martin.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/gpl.html
 * 
 * Contributors:
 *     Jeff Martin - initial API and implementation
 ******************************************************************************/
package cuchaz.enigma.bytecode;

import java.util.Map;

import javassist.CtBehavior;
import javassist.CtClass;
import javassist.CtField;
import javassist.CtMethod;
import javassist.bytecode.ConstPool;
import javassist.bytecode.Descriptor;
import javassist.bytecode.SourceFileAttribute;

import com.google.common.collect.Maps;

import cuchaz.enigma.mapping.BehaviorEntry;
import cuchaz.enigma.mapping.BehaviorEntryFactory;
import cuchaz.enigma.mapping.ClassEntry;
import cuchaz.enigma.mapping.FieldEntry;
import cuchaz.enigma.mapping.MethodEntry;
import cuchaz.enigma.mapping.Translator;

public class ClassTranslator {
	
	private Translator m_translator;
	
	public ClassTranslator(Translator translator) {
		m_translator = translator;
	}
	
	public void translate(CtClass c) {
		// NOTE: the order of these translations is very important
		
		// translate all the field and method references in the code by editing the constant pool
		ConstPool constants = c.getClassFile().getConstPool();
		ConstPoolEditor editor = new ConstPoolEditor(constants);
		for (int i = 1; i < constants.getSize(); i++) {
			switch (constants.getTag(i)) {
				case ConstPool.CONST_Fieldref: {
					// translate the name
					FieldEntry entry = new FieldEntry(
						new ClassEntry(Descriptor.toJvmName(constants.getFieldrefClassName(i))),
						constants.getFieldrefName(i)
					);
					FieldEntry translatedEntry = m_translator.translateEntry(entry);
					
					// translate the type
					String type = constants.getFieldrefType(i);
					String translatedType = m_translator.translateSignature(type);
					
					if (!entry.equals(translatedEntry) || !type.equals(translatedType)) {
						editor.changeMemberrefNameAndType(i, translatedEntry.getName(), translatedType);
					}
				}
				break;
				
				case ConstPool.CONST_Methodref:
				case ConstPool.CONST_InterfaceMethodref: {
					// translate the name and type
					BehaviorEntry entry = BehaviorEntryFactory.create(
						Descriptor.toJvmName(editor.getMemberrefClassname(i)),
						editor.getMemberrefName(i),
						editor.getMemberrefType(i)
					);
					BehaviorEntry translatedEntry = m_translator.translateEntry(entry);
					
					if (!entry.getName().equals(translatedEntry.getName()) || !entry.getSignature().equals(translatedEntry.getSignature())) {
						editor.changeMemberrefNameAndType(i, translatedEntry.getName(), translatedEntry.getSignature());
					}
				}
				break;
			}
		}
		
		ClassEntry classEntry = new ClassEntry(Descriptor.toJvmName(c.getName()));
		
		// translate all the fields
		for (CtField field : c.getDeclaredFields()) {
			
			// translate the name
			FieldEntry entry = new FieldEntry(classEntry, field.getName());
			String translatedName = m_translator.translate(entry);
			if (translatedName != null) {
				field.setName(translatedName);
			}
			
			// translate the type
			String translatedType = m_translator.translateSignature(field.getFieldInfo().getDescriptor());
			field.getFieldInfo().setDescriptor(translatedType);
		}
		
		// translate all the methods and constructors
		for (CtBehavior behavior : c.getDeclaredBehaviors()) {
			if (behavior instanceof CtMethod) {
				CtMethod method = (CtMethod)behavior;
				
				// translate the name
				MethodEntry entry = new MethodEntry(classEntry, method.getName(), method.getSignature());
				String translatedName = m_translator.translate(entry);
				if (translatedName != null) {
					method.setName(translatedName);
				}
			}
			
			// translate the type
			String translatedSignature = m_translator.translateSignature(behavior.getMethodInfo().getDescriptor());
			behavior.getMethodInfo().setDescriptor(translatedSignature);
		}
		
		// translate all the class names referenced in the code
		// the above code only changed method/field/reference names and types, but not the class names themselves
		Map<ClassEntry,ClassEntry> map = Maps.newHashMap();
		for (ClassEntry obfClassEntry : ClassRenamer.getAllClassEntries(c)) {
			ClassEntry deobfClassEntry = m_translator.translateEntry(obfClassEntry);
			if (!obfClassEntry.equals(deobfClassEntry)) {
				map.put(obfClassEntry, deobfClassEntry);
			}
		}
		ClassRenamer.renameClasses(c, map);
		
		// translate the source file attribute too
		ClassEntry deobfClassEntry = map.get(classEntry);
		if (deobfClassEntry != null) {
			String sourceFile = Descriptor.toJvmName(deobfClassEntry.getOuterClassName()) + ".java";
			c.getClassFile().addAttribute(new SourceFileAttribute(constants, sourceFile));
		}
	}
}