package info.sigterm.deob.attributes.code;

import info.sigterm.deob.attributes.Code;

import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.lang.reflect.Constructor;
import java.util.ArrayList;
import java.util.List;

public class Instructions
{
	private Code code;
	private List<Instruction> instructions = new ArrayList<>();

	public Instructions(Code code) throws IOException
	{
		this.code = code;
		DataInputStream is = code.getAttributes().getStream();

		int length = is.readInt();

		int pc;
		for (pc = 0; pc < length;)
		{
			byte opcode = is.readByte();

			InstructionType type = InstructionType.findInstructionFromCode(opcode);

			try
			{
				Constructor<? extends Instruction> con = type.getInstructionClass().getConstructor(Instructions.class, InstructionType.class, int.class);
				Instruction ins = con.newInstance(this, type, pc);

				instructions.add(ins);

				int len = ins.getLength();
				pc += len;
			}
			catch (java.lang.Exception ex)
			{
				throw new IOException(ex);
			}
		}

		assert pc == length;

		buildJumpGraph();
	}
	
	public void write(DataOutputStream out) throws IOException
	{
		ByteArrayOutputStream b = new ByteArrayOutputStream();
		DataOutputStream o = new DataOutputStream(b);
		int pc = 0;
		for (Instruction i : instructions)
		{
			i.write(o, pc);
			pc = o.size();
		}
		byte[] ba = b.toByteArray();
		out.writeInt(ba.length);
		out.write(ba);
	}

	private void buildJumpGraph()
	{
		for (Instruction i : instructions)
			i.buildJumpGraph();
	}

	public void buildInstructionGraph()
	{
		for (Instruction i : instructions)
			i.buildInstructionGraph();
	}
	
	public void buildCallGraph()
	{
		for (Instruction i : instructions)
			i.buildCallGraph();
	}

	public Code getCode()
	{
		return code;
	}
	
	public Instruction findInstruction(int pc)
	{
		for (Instruction i : instructions)
			if (i.getPc() == pc)
				return i;
		return null;
	}
}