<?php

class Authnet
{
    private $login    = "";
    private $transkey = "";
    private $params   = array();
    private $results  = array();

    private $approved = false;
    private $declined = false;
    private $error    = true;

    private $test;
    private $fields;
    private $response;

    static $instances = 0;

    public function __construct($test = false)
    {
        if (self::$instances == 0)
        {
            $this->test    = trim($test);
            if ($this->test)
            {
                $this->url = "https://test.authorize.net/gateway/transact.dll";
            }
            else
            {
                $this->url = "https://secure.authorize.net/gateway/transact.dll";
            }
            $this->params['x_delim_data']     = "TRUE";
            $this->params['x_delim_char']     = "|";
            $this->params['x_relay_response'] = "FALSE";
            $this->params['x_url']            = "FALSE";
            $this->params['x_version']        = "3.1";
            $this->params['x_method']         = "CC";
            $this->params['x_type']           = "AUTH_CAPTURE";
            $this->params['x_login']          = $this->login;
            $this->params['x_tran_key']       = $this->transkey;

            self::$instances++;
        }
        else
        {
            return false;
        }
    }

    public function transaction($cardnum, $expiration, $amount, $cvv = "", $invoice = "", $tax = "")
    {
        $this->params['x_card_num']  = trim($cardnum);
        $this->params['x_exp_date']  = trim($expiration);
        $this->params['x_amount']    = trim($amount);
    	$this->params['x_po_num']    = trim($invoice);
    	$this->params['x_tax']       = trim($tax);
    	$this->params['x_card_code'] = trim($cvv);
    }

    public function process($retries = 3)
    {
        $this->_prepareParameters();
        $ch = curl_init($this->url);

        $count = 0;
        while ($count < $retries)
        {
            curl_setopt($ch, CURLOPT_HEADER, 0);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($ch, CURLOPT_POSTFIELDS, rtrim($this->fields, "& "));
            $this->response = curl_exec($ch);
            $this->_parseResults();
            if ($this->getResultResponseFull() == "Approved")
            {
                $this->approved = true;
                $this->declined = false;
                $this->error    = false;
                break;
            }
            else if ($this->getResultResponseFull() == "Declined")
            {
                $this->approved = false;
                $this->declined = true;
                $this->error    = false;
                break;
            }
            $count++;
        }
        curl_close($ch);
    }

    private function _parseResults()
    {
        $this->results = explode("|", $this->response);
    }

    public function setParameter($param, $value)
    {
        $param                = trim($param);
        $value                = trim($value);
        $this->params[$param] = $value;
    }

    public function setTransactionType($type)
    {
        $this->params['x_type'] = strtoupper(trim($type));
    }

    private function _prepareParameters()
    {
        foreach($this->params as $key => $value)
        {
            $this->fields .= "$key=" . urlencode($value) . "&";
        }
    }

    public function getResultResponse()
    {
        return $this->results[0];
    }

    public function getResultResponseFull()
    {
        $response = array("", "Approved", "Declined", "Error");
        return $response[$this->results[0]];
    }

    public function isApproved()
    {
        return $this->approved;
    }

    public function isDeclined()
    {
        return $this->declined;
    }

    public function isError()
    {
        return $this->error;
    }

    public function getResponseText()
    {
        return $this->results[3];
    }

    public function getAuthCode()
    {
        return $this->results[4];
    }

    public function getAVSResponse()
    {
        return $this->results[5];
    }

    public function getTransactionID()
    {
        return $this->results[6];
    }
}

?>