public class BossMessage {

	private Plugin plugin;
	private static int MOB_ID = 1234;

	public BossMessage(Plugin plugin) {
		this.plugin = plugin;
	}

	@SuppressWarnings("deprecation")
	public boolean display(Player player, String message, int ticks) {
		try {
			Location loc = player.getLocation().add(player.getLocation().getDirection().multiply(3));

			Object packetOb = getEntitySpawnPacket();
			setField(packetOb, "a", MOB_ID);
			setField(packetOb, "b", (int) EntityType.WITHER.getTypeId());
			setField(packetOb, "c", (int) Math.floor(loc.getBlockX() * 32.0D));
			setField(packetOb, "d", (int) Math.floor(loc.getBlockY() * 32.0D));
			setField(packetOb, "e", (int) Math.floor(loc.getBlockZ() * 32.0D));
			setField(packetOb, "f", (int) 0);
			setField(packetOb, "g", (int) 0);
			setField(packetOb, "h", (int) 0);
			setField(packetOb, "i", (byte) 0);
			setField(packetOb, "j", (byte) 0);
			setField(packetOb, "k", (byte) 0);
			setField(packetOb, "l", buildDataWatcher(message));

			sendPacket(player, packetOb);
		} catch(Exception e) {
			e.printStackTrace();
		}
		return true;
	}

	private String getPackage() {
		return "net.minecraft.server." + Bukkit.getServer().getClass().getPackage().getName().replace(".", ",").split(",")[3];
	}

	private Object getEntitySpawnPacket() throws Exception {
		String packageName = getPackage();
		Class<?> c = null;
		if (packageName.contains("v1_7_R1")) {
			c = Class.forName(packageName + ".PacketPlayOutSpawnEntityLiving");
		} else {
			c = Class.forName(packageName + ".Packet24MobSpawn");
		}
		return c.getConstructors()[0].newInstance();
	}

	private void setField(Object object, String fieldName, Object what) throws Exception {
		Field f = object.getClass().getDeclaredField(fieldName);
		f.setAccessible(true);
		f.set(object, what);
	}

	private Object buildDataWatcher(String entityName) throws Exception {
		Class<?> c = Class.forName(getPackage() + ".DataWatcher");
		Object dataWatcher = null;
		for (Constructor<?> con : c.getConstructors()) {
			if (con.getParameterTypes().length == 1) {
				Object ob = null;
				dataWatcher = con.newInstance(ob);
				break;
			}
		}
		Method m = c.getMethod("a", int.class, Object.class);
		m.invoke(dataWatcher, 0, (Byte) (byte) 0x20);
		m.invoke(dataWatcher, 6, (Float) (float) 1);
		m.invoke(dataWatcher, 10, (String) entityName);
		m.invoke(dataWatcher, 11, (Byte) (byte) 1);
		return dataWatcher;
	}

	private void sendPacket(Player player, Object packet) throws Exception {
		Object nmsPlayer = player.getClass().getMethod("getHandle").invoke(player);
		Object playerCon = nmsPlayer.getClass().getField("playerConnection").get(nmsPlayer);
		Method send = null;
		for (Method m : playerCon.getClass().getMethods()) {
			if (m.getName().equals("sendPacket") && m.getParameterTypes().length == 1) {
				send = m;
				break;
			}
		}
		send.invoke(playerCon, packet);
	}
}