Recording command

package net.unidentifiedgaming.discord.bot.commands;

import org.gagravarr.opus.OpusAudioData;
import org.gagravarr.opus.OpusFile;
import sx.blah.discord.handle.audio.AudioEncodingType;
import sx.blah.discord.handle.audio.IAudioReceiver;
import sx.blah.discord.handle.impl.events.guild.channel.message.MessageEvent;
import sx.blah.discord.handle.obj.IRole;
import sx.blah.discord.handle.obj.IUser;
import sx.blah.discord.handle.obj.IVoiceChannel;
import sx.blah.discord.util.MissingPermissionsException;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class RecordingCommand extends Command implements IAudioReceiver {
    private static boolean recording = false;
    private String title = "";
    private String category = "";

    public RecordingCommand(List<IRole> permissions, String helpText) {
        super(permissions, helpText);
    }

    @Override
    public boolean action(List<String> args, MessageEvent event) {
        String arg1 = args.remove(0);
        if (arg1.equals("start")) {
            if (recording) {
                helpText = "I'm already recording in " + event.getClient().getOurUser().getVoiceStateForGuild(event.getGuild()).getChannel().getName() + ".";
                return false;
            }
            IVoiceChannel userVoiceChannel = event.getAuthor().getVoiceStateForGuild(event.getGuild()).getChannel();
            if (userVoiceChannel == null) {
                helpText = "You need to be in a voice channel to do that.";
                return false;
            }

            try {
                userVoiceChannel.join();
                event.getGuild().getAudioManager().subscribeReceiver(this);

                category = args.remove(0).toLowerCase();
                if (category.isEmpty()) {
                    category = "uncategorised";
                }
                SimpleDateFormat df = new SimpleDateFormat("MM-dd-yyyy hh-mm-ss");
                title = df.format(new Date().getTime());

                recording = true;
                event.getClient().changePlayingText("Recording!");
                event.getMessage().reply("I have started recording!");
                return true;
            } catch (MissingPermissionsException exception) {
                helpText = "I don't have permissions to go there!";
                return false;
            }
        } else if (arg1.equals("stop")) {
            if (!recording) {
                helpText = "I'm not recording!";
                return false;
            }

            event.getGuild().getAudioManager().unsubscribeReceiver(this);
            event.getClient().changePlayingText("");
            event.getClient().getOurUser().getVoiceStateForGuild(event.getGuild()).getChannel().leave();
            recording = false;
            event.getMessage().reply("I have stopped recording!");
            return true;
        }

        return false;
    }

    private void writeToFile(byte[] audio) {
        try {
            File file = new File("D:/recordings/" + category + "/" + title + ".ogg");
            if (!file.getParentFile().exists())
                file.getParentFile().mkdirs();
            OpusFile op;
            List<OpusAudioData> audioData = new ArrayList<>();
            if (file.exists()) {
                op = new OpusFile(file);
                OpusAudioData ad;
                while ((ad = op.getNextAudioPacket()) != null)
                    audioData.add(ad);
                op.close();
            }

            audioData.add(new OpusAudioData(audio));

            OpusFile out = new OpusFile(new FileOutputStream(file));
            for (OpusAudioData oad : audioData)
                out.writeAudioData(oad);
            out.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void receive(byte[] audio, IUser iUser, char sequence, int timestamp) {
        writeToFile(audio);
    }

    @Override
    public AudioEncodingType getAudioEncodingType() {
        return AudioEncodingType.OPUS;
    }
}