public static function getCompanyUnread(int $companyId)
    {
        return Channel::select(['channels.offer_id', DB::raw('COUNT(distinct messages.channel_id) as count_messages')])
            ->leftJoin('messages','messages.channel_id', '=', DB::raw('channels.id AND messages.author != "system"'))
            ->where('channels.company_id', $companyId)
            ->where(function ($query) {
                return $query->where('channels.employer_read_time', '<', DB::raw('messages.twilio_created_at'))
                    ->orWhereNull('channels.employer_read_time');
            })
            ->groupBy('channels.offer_id')
            ->get()
            ;
    }