discord-addon.js/src/lib/antispam.js

A addon for a discord bot made in discord.js

const authors = [];
var warned = [];
var banned = [];
var messagelog = [];

/**
   * 
   * @typedef {Object} Options
   * @property {Number} [warnBuffer=3] Maximum amount of messages allowed to send in the interval time before getting warned.
   * @property {Number} [maxBuffer=5] Maximum amount of messages allowed to send in the interval time before getting banned.
   * @property {Number} [interval=1000] Amount of time in ms users can send a maximum of the maxBuffer variable before getting banned.
   * @property {String} [warningMessage="stop spamming"] Warning message send to the user indicating they are going to fast.
   * @property {String} [banMessage="has been banned for spamming, anyone else?"] Ban message, always tags the banned user in front of it.
   * @property {Number} [maxDuplicatesWarning=7] Maximum amount of duplicate messages a user can send in a timespan before getting warned
   * @property {Number} [maxDuplicatesBan=10] Maximum amount of duplicate messages a user can send in a timespan before getting banned
   * @property {Number} [softban=false] After a ban, the user gets an unban if this option is true
   * 
   * 
   */

/**
 * 
 * @param {Discord.Client} client The client object
 * @param {Options} [options] The options that you can set
 * 
 */
module.exports = async (client, options = {}) => {
    const warnBuffer = (options && options.prefix) || 3;
    const maxBuffer = (options && options.prefix) || 5;
    const interval = (options && options.interval) || 1000;
    const warningMessage = (options && options.warningMessage) || "stop spamming...";
    const banMessage = (options && options.banMessage) || "has been banned for spamming, anyone else?";
    const maxDuplicatesWarning = (options && options.duplicates || 7);
    const maxDuplicatesBan = (options && options.duplicates || 10);
    const softbanAfterSpam = (options && options.softban || false)

    client.on('message', msg => {
        if (msg.author.bot) return;
        var now = Math.floor(Date.now());
        authors.push({
            "time": now,
            "author": msg.author.id
        });
        messagelog.push({
            "message": msg.content,
            "author": msg.author.id
        });
        var msgMatch = 0;
        for (var i = 0; i < messagelog.length; i++) {
            if (messagelog[i].message == msg.content && (messagelog[i].author == msg.author.id) && (msg.author.id !== client.user.id)) {
                msgMatch++;
            }
        }
        // Check matched count
        if (msgMatch == maxDuplicatesWarning && !warned.includes(msg.author.id)) {
            warn(msg, msg.author.id);
        }
        if (msgMatch == maxDuplicatesBan && !banned.includes(msg.author.id)) {
            ban(msg, msg.author.id);
        }

        let matched = 0;

        for (var i = 0; i < authors.length; i++) {
            if (authors[i].time > now - interval) {
                matched++;
                if (matched == warnBuffer && !warned.includes(msg.author.id)) {
                    warn(msg, msg.author.id, warningMessage);
                }
                else if (matched == maxBuffer) {
                    if (!banned.includes(msg.author.id)) {
                        ban(msg, msg.author.id, banMessage);
                        if (softbanAfterSpam == true) {
                            msg.guild.unban(msg.author.id);
                        }
                    }
                }
            }
            else if (authors[i].time < now - interval) {
                authors.splice(i);
                warned.splice(warned.indexOf(authors[i]));
                banned.splice(warned.indexOf(authors[i]));
            }
            if (messagelog.length >= 200) {
                messagelog.shift();
            }
        }
    });
}
/**
* Warn a user
* @param  {Object} msg
* @param  {string} userid userid
*/
function warn(msg, userid, warningMessage) {
    warned.push(msg.author.id);
    msg.channel.send(msg.author + " " + warningMessage);
}

/**
 * Ban a user by the user id
 * @param  {Object} msg
 * @param  {string} userid userid
 * @return {boolean} True or False
 */
function ban(msg, userid, banMessage) {
    for (var i = 0; i < messagelog.length; i++) {
        if (messagelog[i].author == msg.author.id) {
            messagelog.splice(i);

        }
    }

    banned.push(msg.author.id);

    var user = msg.channel.guild.members.get(userid);
    if (user) {
        user.ban().then((member) => {
            msg.channel.send(msg.author + " " + banMessage);
            return true;
        }).catch(() => {
            msg.channel.send("Insufficient permission to ban " + msg.author + " for spamming.");
            return false;
        });
    }
}