package org.parabot.randoms.locopk;

import org.parabot.core.Context;
import org.parabot.core.asm.ASMClassLoader;
import org.parabot.environment.OperatingSystem;
import org.parabot.environment.randoms.Random;
import org.parabot.environment.randoms.RandomType;

import java.lang.reflect.Field;
import java.util.UUID;

/**
 * @author EmmaStone
 */
public class MacAddressFix implements Random {

    private boolean done;

    @Override
    public boolean activate() {
        return !done;
    }

    @Override
    public void execute() {
        try {
            final ASMClassLoader classLoader = Context.getInstance().getASMClassLoader();

            Class<?> createUID = classLoader.loadClass("com.locopk.client.rs.CreateUID");

            if (OperatingSystem.getOS().equals(OperatingSystem.MAC)) {

                Field mac = createUID.getDeclaredField("mac");
                mac.set(null, randomMacAddress());
            } else {
                Field firstID = createUID.getDeclaredField("firstId");

                firstID.set(null, UUID.randomUUID().toString());
            }
        } catch (ClassNotFoundException | NoSuchFieldException | IllegalAccessException e) {
            e.printStackTrace();
        }

        done = true;
    }

    @Override
    public String getName() {
        return "Mac Address Fix";
    }

    @Override
    public String getServer() {
        return "locopk";
    }

    @Override
    public RandomType getRandomType() {
        return RandomType.ON_SERVER_START;
    }

    private String randomMacAddress() {
        java.util.Random rand    = new java.util.Random();
        byte[]           macAddr = new byte[6];
        rand.nextBytes(macAddr);

        macAddr[0] = (byte) (macAddr[0] & (byte) 254);  //zeroing last 2 bytes to make it unicast and locally adminstrated

        StringBuilder sb = new StringBuilder(18);
        for (byte b : macAddr) {

            if (sb.length() > 0) {
                sb.append("");
            }

            sb.append(String.format("%02x", b));
        }

        return sb.toString().toUpperCase();
    }
}