// I used that : https://github.com/AnIdiotsGuide/discordjs-bot-guide/blob/master/coding-guides/tracking-used-invites.md
var invites = {}

try {
    require("./data.json");
} catch(err) {
    fs.writeFileSync('data.json', "{}");
}

var data = JSON.parse(fs.readFileSync("data.json", "UTF8"));
var wait = require('util').promisify(setTimeout);

client.on('ready', () => {
  wait(1000);
  client.guilds.forEach(g => {
    g.fetchInvites().then(guildInvites => {
      invites[g.id] = guildInvites;
    });
  });
});

client.on('guildMemberAdd', member => {
    member.guild.fetchInvites().then(guildInvites => {
        var ei = invites[member.guild.id];
        invites[member.guild.id] = guildInvites;
        var invite = guildInvites.find(i => ei.get(i.code).uses < i.uses);
        if (data[member.guild.id]) {
            data[member.guild.id].forEach(inv => {
                if (inv.includes(invite.code) || invite.code.includes(inv)) {
                    member.ban();
                }
            });
        }
    });
});

client.on("message", message => {
    if (!prefix) {
        var prefix = "$";
    };
    if (!message.guild) return;
    var args = message.content.slice(prefix.length).split(" ");
    switch(args[0]) {
        case "banv":
            if (!data[message.guild.id]) data[message.guild.id] = [];
            if (!args[1]) return message.reply("invite ? ");
            data[message.guild.id].push(args[1]);
        break;
    }
    client.emit("xd");
});

client.on("xd", () => {
    fs.writeFileSync("data.json", JSON.stringify(data));
});
console.log(['xD', 'lol'].find(xd => xd.includes("x")));