package com.rebelkeithy.dualhotbar;

import java.util.Iterator;

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.FieldInsnNode;
import org.objectweb.asm.tree.InsnList;
import org.objectweb.asm.tree.IntInsnNode;
import org.objectweb.asm.tree.MethodInsnNode;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.VarInsnNode;

import com.rebelkeithy.dualhotbar.compatability.Compatability;

import net.minecraft.launchwrapper.IClassTransformer;
import net.minecraftforge.common.ForgeVersion;

public class DualHotbarTransformer implements IClassTransformer
{

    @Override
    public byte[] transform(String className, String newClassName, byte[] data)
    {
        //System.out.println("DUALHOTBAR TEST: MC VERSION " + ForgeVersion.mcVersion);

        boolean isObfuscated = !className.equals(newClassName);

        if (newClassName.equals("net.minecraft.entity.player.InventoryPlayer"))
        {
            System.out.println("********* INSIDE InventoryPlayer TRANSFORMER ABOUT TO PATCH: " + className);

            if(!isObfuscated)
            {
                data = patchBipush(className, "isHotbar", "(I)Z", data);
                data = patchBipush(className, "getHotbarSize", "()I", data);
                data = patchBipush(className, "changeCurrentItem", "(I)V", data);
                return patchBipush(className, "getBestHotbarSlot", "()I", data);
            }
            else if(ForgeVersion.mcVersion.startsWith("1.11"))
            {
                data = patchBipush(className, "e", "(I)Z", data);
                data = patchBipush(className, "j", "()I", data);
                data = patchBipush(className, "f", "(I)V", data);
                return patchBipush(className, "l", "()I", data);
            }
            else if(ForgeVersion.mcVersion.startsWith("1.10"))
            {
                data = patchBipush(className, "e", "(I)Z", data);
                data = patchBipush(className, "i", "()I", data);
                data = patchBipush(className, "f", "(I)V", data);
                return patchBipush(className, "k", "()I", data);
            }
        }

        if(className.equals("net.minecraftforge.client.GuiIngameForge"))
        {
            System.out.println("********* INSIDE GuiIngameForge TRANSFORMER ABOUT TO PATCH: " + className);
            return patchShift(className, "renderToolHighlight", null, data);
        }

        return data;
    }

    private byte[] patchBipush(String className, String methodName, String methodDesc, byte[] data)
    {
        ClassNode classNode = new ClassNode();
        ClassReader classReader = new ClassReader(data);
        classReader.accept(classNode, 0);

        Iterator<MethodNode> iter = classNode.methods.iterator();
        while(iter.hasNext())
        {
            MethodNode methodNode = iter.next();

            if(methodNode.name.equals(methodName) && (methodDesc == null || methodNode.desc.equals(methodDesc)))
            {
                System.out.println("In " + methodName);

                Iterator<AbstractInsnNode> insnIter = methodNode.instructions.iterator();
                AbstractInsnNode insnNode = insnIter.next();

                while(insnIter.hasNext())
                {
                    if(insnNode.getOpcode() == Opcodes.BIPUSH)
                    {
                        System.out.println("found instruction to replace");

                        AbstractInsnNode newInstruction = new FieldInsnNode(Opcodes.GETSTATIC, "com/rebelkeithy/dualhotbar/DualHotbarMod", "hotbarSize", "I");

                        methodNode.instructions.insert(insnNode, newInstruction);
                        methodNode.instructions.remove(insnNode);
                    }
                    insnNode = insnIter.next();
                }
            }
        }

        ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES);
        classNode.accept(writer);
        return writer.toByteArray();
    }

    private byte[] patchShift(String className, String methodName, String methodDesc, byte[] data)
    {
        ClassNode classNode = new ClassNode();
        ClassReader classReader = new ClassReader(data);
        classReader.accept(classNode, 0);

        Iterator<MethodNode> iter = classNode.methods.iterator();
        while(iter.hasNext())
        {
            MethodNode methodNode = iter.next();

            if(methodNode.name.equals(methodName) && (methodNode.desc.equals(methodDesc) || methodDesc == null))
            {
                System.out.println("In " + methodName);

                Iterator<AbstractInsnNode> insnIter = methodNode.instructions.iterator();


                AbstractInsnNode insnNode = insnIter.next();

                AbstractInsnNode newInstruction = new MethodInsnNode(Opcodes.INVOKESTATIC, "com/rebelkeithy/dualhotbar/RenderHandler", "shiftUp", "()V");
                methodNode.instructions.insertBefore(insnNode, newInstruction);

                while(insnNode.getOpcode() != Opcodes.RETURN)
                {
                    insnNode = insnIter.next();
                }

                newInstruction = new MethodInsnNode(Opcodes.INVOKESTATIC, "com/rebelkeithy/dualhotbar/RenderHandler", "shiftDown", "()V");
                methodNode.instructions.insertBefore(insnNode, newInstruction);
            }
        }


        ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS);
        classNode.accept(writer);
        return writer.toByteArray();
    }

    private boolean containsMethod(String methodName, String methodDesc, byte[] data)
    {
        ClassNode classNode = new ClassNode();
        ClassReader classReader = new ClassReader(data);
        classReader.accept(classNode, 0);

        Iterator<MethodNode> iter = classNode.methods.iterator();
        while(iter.hasNext())
        {
            MethodNode methodNode = iter.next();

            if(methodNode.name.equals(methodName) && methodNode.desc.equals(methodDesc))
            {
                return true;
            }
        }

        return false;
    }
}