package de.dhbwstuttgart.bytecode;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.lang.invoke.CallSite;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.net.URL;
import java.net.URLClassLoader;

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Handle;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;

public class Test {
	private static final String rootDirectory = System.getProperty("user.dir")+"/bin/de/dhbwstuttgart/bytecode/";
	protected static ClassLoader getClassLoader() throws Exception{
		File file = new File(rootDirectory);
	    URL url = file.toURI().toURL();
	    URL[] urls = new URL[]{url};
	    System.out.println(urls[0]);
	    return new URLClassLoader(urls);
	}
	
	public static void main(String[] args) {
		// Test Lambda
		ClassWriter cw =new ClassWriter(ClassWriter.COMPUTE_MAXS);
		cw.visit(Opcodes.V1_8, Opcodes.ACC_PUBLIC+Opcodes.ACC_SUPER, "TestClass", null, "java/lang/Object", null);
	 
	// Create Constructor
	 MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PUBLIC, "<init>", "(Ljava/lang/Boolean;)V", null, null); 
	 mv.visitVarInsn(Opcodes.ALOAD, 0);
	 
	 mv.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
	  
//	 mv.visitMethodInsn(INVOKEDYNAMIC, "#0", "run", "()Ljava/lang/Runnable");
	 
	 MethodType mt = MethodType.methodType(CallSite.class, MethodHandles.Lookup.class, 
			 String.class, MethodType.class);
	 
	 Handle bootstrap = new Handle(Opcodes.H_INVOKESTATIC, "java/lang/invoke/LambdaMetafactory", 
			 "metafactory", mt.toMethodDescriptorString());
	
	 mv.visitInvokeDynamicInsn("run", "()Ljava/lang/Runnable;", bootstrap);
	 
	 mv.visitVarInsn(Opcodes.ASTORE, 1);
	 mv.visitVarInsn(Opcodes.ALOAD, 1);
	 mv.visitMethodInsn(Opcodes.INVOKEINTERFACE, "java/lang/Runnable", "run", "()V");
	 mv.visitInsn(Opcodes.RETURN);
	 mv.visitMaxs(1, 2);
	 mv.visitEnd();
	 
	 cw.visitEnd();
	 
	 byte[] b = cw.toByteArray();
		
		
//	Test if statement
/*		ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES|ClassWriter.COMPUTE_MAXS);
		
		cw.visit(Opcodes.V1_8, Opcodes.ACC_PUBLIC+Opcodes.ACC_SUPER, "TestIf", null, "java/lang/Object", null);
		MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PUBLIC, "<init>", "(Ljava/lang/Boolean;)V", null, null); 
		mv.visitCode();
		
//		Label l0 = new Label();
//		mv.visitLabel(l0);
		
		mv.visitVarInsn(Opcodes.ALOAD, 0);
		 
		mv.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
		
//		Label l1 = new Label();
//		mv.visitLabel(l1);
		mv.visitVarInsn(Opcodes.ALOAD, 1);
		mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Boolean", "booleanValue", "()Z");
		
		Label label = new Label();
		mv.visitJumpInsn(Opcodes.IFEQ, label);
		
		mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
		mv.visitLdcInsn("1");
		mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V");
		
		Label endLabel = new Label();
		mv.visitJumpInsn(Opcodes.GOTO, endLabel);
		
		mv.visitLabel(label);
		mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
		mv.visitLdcInsn("0");
		mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V");
		 
		

		mv.visitLabel(endLabel);
		mv.visitInsn(Opcodes.RETURN);
		
//		Label l2 = new Label();
//		mv.visitLabel(l2);
		
//		mv.visitLocalVariable("this", "LTestIf;", null, l0, l2, 0);
//		mv.visitLocalVariable("b", "Ljava/lang/Boolean;", null, l0, l2, 1);
		mv.visitMaxs(2, 2);
		mv.visitEnd();
		
		cw.visitEnd();
		byte[] b = cw.toByteArray();
*/		
		FileOutputStream output;
	
		try {
			output = new FileOutputStream(new File(System.getProperty("user.dir")+"/testBytecode/TestClass.class"));
			output.write(b);
			output.close();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	
 }
}