ZalgoHandler.java

package com.mcmoddev.bot.handlers;

import com.mcmoddev.bot.MMDBot;
import com.mcmoddev.bot.util.Utilities;

import sx.blah.discord.api.events.EventSubscriber;
import sx.blah.discord.handle.impl.events.guild.channel.message.MessageReceivedEvent;
import sx.blah.discord.handle.obj.IMessage;
import sx.blah.discord.util.DiscordException;
import sx.blah.discord.util.MissingPermissionsException;
import sx.blah.discord.util.RateLimitException;

/**
 * Thanks to MihaiC for providing the zalgo char codes. http://stackoverflow.com/a/26927946
 */
public class ZalgoHandler {

    private static final char[] CHARS_UPPER = { '\u030d', '\u030e', '\u0304', '\u0305', '\u033f', '\u0311', '\u0306', '\u0310', '\u0352', '\u0357', '\u0351', '\u0307', '\u0308', '\u030a', '\u0342', '\u0343', '\u0344', '\u034a', '\u034b', '\u034c', '\u0303', '\u0302', '\u030c', '\u0350', '\u0300', '\u0301', '\u030b', '\u030f', '\u0312', '\u0313', '\u0314', '\u033d', '\u0309', '\u0363', '\u0364', '\u0365', '\u0366', '\u0367', '\u0368', '\u0369', '\u036a', '\u036b', '\u036c', '\u036d', '\u036e', '\u036f', '\u033e', '\u035b', '\u0346', '\u031a' };

    private static final char[] CHARS_LOWER = { '\u0316', '\u0317', '\u0318', '\u0319', '\u031c', '\u031d', '\u031e', '\u031f', '\u0320', '\u0324', '\u0325', '\u0326', '\u0329', '\u032a', '\u032b', '\u032c', '\u032d', '\u032e', '\u032f', '\u0330', '\u0331', '\u0332', '\u0333', '\u0339', '\u033a', '\u033b', '\u033c', '\u0345', '\u0347', '\u0348', '\u0349', '\u034d', '\u034e', '\u0353', '\u0354', '\u0355', '\u0356', '\u0359', '\u035a', '\u0323' };

    private static final char[] CHARS_CENTER = { '\u0315', '\u031b', '\u0340', '\u0341', '\u0358', '\u0321', '\u0322', '\u0327', '\u0328', '\u0334', '\u0335', '\u0336', '\u034f', '\u035c', '\u035d', '\u035e', '\u035f', '\u0360', '\u0362', '\u0338', '\u0337', '\u0361', '\u0489' };

    @EventSubscriber
    public void onMessageRecieved (MessageReceivedEvent event) {

        final IMessage message = event.getMessage();

        if (hasZalgo(message.getContent()))
            try {

                message.delete();
                Utilities.sendMessage(MMDBot.events, String.format("%s sent a text containing Zalgo in %s at %s.", message.getAuthor().getName(), message.getChannel().getName(), message.getCreationDate().toLocalDate().toString()));
            }

            catch (MissingPermissionsException | RateLimitException | DiscordException e) {

            }
    }

    public static boolean hasZalgo (String string) {

        for (final char character : string.toCharArray())
            if (isZalgo(character))
                return true;

        return false;
    }

    public static boolean isZalgo (char c) {

        for (final char element : CHARS_UPPER)
            if (c == element)
                return true;
        for (final char element : CHARS_LOWER)
            if (c == element)
                return true;
        for (final char element : CHARS_CENTER)
            if (c == element)
                return true;
        return false;
    }
}