galactic-bot/structure/client/components/observers/AuditLog.js

const { Observer } = require("../../../interfaces");

const { Infraction } = require('../../../moderation/interfaces/');

class AuditLogObserver extends Observer {

    constructor(client) {

        super(client, {
            name: 'auditLog',
            priority: 0,
            disabled: false
        });

        this.client = client;

        this.hooks = [
            ['guildBanAdd', this.guildBanAdd.bind(this)],
            ['guildBanRemove', this.guildBanRemove.bind(this)],
            ['guildMemberRemove', this.guildMemberRemove.bind(this)],
            ['guildMemberUpdate', this.guildMemberUpdate.bind(this)]
        ];

    }

    async guildBanAdd(guild, user) {
        const settings = await guild.settings();
        if(!settings.moderationLog.channel || !settings.moderationLog.infractions.includes('BAN')) return undefined; //This is checked by the infraction handling, but it may save resources if checked earlier.
        const audit = await this._fetchFirstEntry(guild, user, 'MEMBER_BAN_ADD');
        new Infraction(this.client, {
            type: 'BAN',
            targetType: 'USER',
            guild,
            target: user,
            executor: audit.executor,
            reason: `${audit.reason || 'N/A'}\n*This action was performed without the bot.*`
        }).handle();
    }
    
    async guildBanRemove(guild, user) {
        const settings = await guild.settings();
        if(!settings.moderationLog.channel || !settings.moderationLog.infractions.includes('UNBAN')) return undefined; //This is checked by the infraction handling, but it may save resources if checked earlier.
        const audit = await this._fetchFirstEntry(guild, user, 'MEMBER_BAN_REMOVE');
        new Infraction(this.client, {
            type: 'UNBAN',
            targetType: 'USER',
            guild,
            target: user,
            executor: audit.executor,
            reason: `*This action was performed without the bot.*`
        }).handle();
    }

    async guildMemberRemove(member) {
        const settings = await member.guild.settings();
        if(!settings.moderationLog.channel || !settings.moderationLog.infractions.includes('KICK')) return undefined; //This is checked by the infraction handling, but it may save resources if checked earlier.
        const audit = await this._fetchFirstEntry(member.guild, member.user, 'MEMBER_KICK');
        new Infraction(this.client, {
            type: 'KICK',
            targetType: 'USER',
            guild: member.guild,
            target: member.user,
            executor: audit.executor,
            reason: `${audit.reason || 'N/A'}\n*This action was performed without the bot.*`
        }).handle();
    }

    async guildMemberUpdate(oldMember, newMember) {
        if(oldMember.roles.cache.size === newMember.roles.cache.size) return undefined;
        const { guild } = newMember;
        const settings = await guild.settings();
        if(!settings.moderationLog.channel) return undefined;

        const mutedRole = settings.mute.role;
        if(!mutedRole) return undefined;

        if(!oldMember.roles.cache.has(mutedRole) && newMember.roles.cache.has(mutedRole)) { //Member was assigned muted role.
            if(!settings.moderationLog.infractions.includes('MUTE')) return undefined;
            const audit = await this._fetchFirstEntry(newMember.guild, newMember.user, 'MEMBER_ROLE_UPDATE');
            new Infraction(this.client, {
                type: 'MUTE',
                targetType: 'USER',
                guild: newMember.guild,
                target: newMember.user,
                executor: audit.executor,
                reason: "*This action was performed without the bot.*"
            }).handle();

        } else if(oldMember.roles.cache.has(mutedRole) && !newMember.roles.cache.has(mutedRole)) { //Member was unassigned muted role.
            if(!settings.moderationLog.infractions.includes('UNMUTE')) return undefined;
            const audit = await this._fetchFirstEntry(newMember.guild, newMember.user, 'MEMBER_ROLE_UPDATE');
            new Infraction(this.client, {
                type: 'UNMUTE',
                targetType: 'USER',
                guild: newMember.guild,
                target: newMember.user,
                executor: audit.executor,
                reason: "*This action was performed without the bot.*"
            }).handle();
        }

    }

    async _fetchFirstEntry(guild, user, type) {
        if(!guild.me.hasPermission('VIEW_AUDIT_LOG')) return null;
        const audit = await guild.fetchAuditLogs({ limit: 1 });
        if(audit.entries.size === 0) return null;

        const entry = audit.entries.filter((e) => e?.target?.id === user.id).first();
        if(!entry || entry.executor.id === this.client.user.id) return null;
        if(entry.target.id !== user.id) return null;
        if(entry.action !== type) return null;
        
        return entry;
    }
    
}

module.exports = AuditLogObserver;