phpnuxbill/system/autoload/Balance.php

<?php

/**
 * PHP Mikrotik Billing (https://github.com/hotspotbilling/phpnuxbill/)
 * This script is for managing user balance
 **/

class Balance
{

    public static function plus($id_customer, $amount)
    {
        $c = ORM::for_table('tbl_customers')->where('id', $id_customer)->find_one();
        $c->balance = $amount + $c['balance'];
        $c->save();
    }

    public static function transfer($id_customer, $phoneTarget, $amount)
    {
        global $config;
        if ($config['allow_balance_transfer'] == 'yes') {
            if(Balance::min($id_customer, $amount)){
                if(Balance::plusByPhone($phoneTarget, $amount)){
                    return true;
                }else{
                    Balance::plus($id_customer, $amount);
                    return false;
                }
            }else{
                return false;
            }
        }else{
            return false;
        }
    }

    public static function min($id_customer, $amount)
    {
        $c = ORM::for_table('tbl_customers')->where('id', $id_customer)->find_one();
        if ($c && $c['balance'] >= $amount) {
            $c->balance = $amount - $c['balance'];
            $c->save();
            return true;
        } else {
            return false;
        }
    }

    public static function plusByPhone($phone_customer, $amount)
    {
        $c = ORM::for_table('tbl_customers')->where('username', $phone_customer)->find_one();
        if($c){
            $c->balance = $amount + $c['balance'];
            $c->save();
            return true;
        }
        return false;
    }

    public static function minByPhone($phone_customer, $amount)
    {
        $c = ORM::for_table('tbl_customers')->where('username', $phone_customer)->find_one();
        if ($c && $c['balance'] >= $amount) {
            $c->balance = $amount - $c['balance'];
            $c->save();
            return true;
        } else {
            return false;
        }
    }
}