<?php

namespace LinkPoint;

// Exceptions
require_once 'LinkPoint/Exception.php';

class Payment_CreditCard {
    // Root Element
    const XML_ENTITY = 'creditcard';

    // CVM Reasons
    const CVM_PROVIDED = 'provided';
    const CVM_NOT_PROVIDED = 'not_provided';
    const CVM_ILLEGIBLE = 'illegible';
    const CVM_NOT_PRESENT = 'not_present';
    const CVM_NO_IMPRINT = 'no_imprint';

    // Field Names
    const MONTH = 'month';
    const YEAR = 'year';

    /**
     * Credit card number.
     * @var string
     */
    protected $_ccNum = null;

    /**
     * Credit card MagStripe track raw data
     * @var string
     */
    protected $_track = null;

    /**
     * Credit card expiration month.
     * @var int
     */
    protected $_expMonth = 1;

    /**
     * Credit card expiration year.
     * @var int
     */
    protected $_expYear = 2000;

    /**
     * Card not present verification value.
     * @var int
     */
    protected $_cvm;

    /**
     * Cart not present verification state.
     * @var string
     */
    protected $_cvmState = 'not_provided';

    /**
     * @param string|null $ccNum
     * @param int|null $expMonth
     * @param int|null $expYear
     * @param int|null $cvm
     * @param string|null $cvmState
     */
    public function __construct($ccNum = null, $expMonth = null, $expYear = null, $cvm = null, $cvmState = null) {
        if (null !== $ccNum) {
            $this->setCcNum($ccNum);
        }
        if (null !== $expMonth && null !== $expYear) {
            $this->setExp($expMonth, $expYear);
        }
        if (null !== $cvm) {
            $this->setCvm($ccNum);
        }
        if (null !== $cvmState) {
            $this->setCvmState($cvmState);
        }
    }

    /**
     * Validates and sets the credit card number.
     *
     * @param string $ccNum
     * @return \LinkPoint\Payment_CreditCard
     * @throws \LinkPoint\Exception
     */
    public function setCcNum($ccNum) {
        if ($ccNum == 0) {
            throw new \LinkPoint\Exception('Invalid credit card number');
        }

        $revcode = strrev($ccNum);
        $sum = 0;

        for ($i = 0; $i < strlen($revcode); $i++) {
            $current_num = intval($revcode[$i]);
            if ($i & 1) {
                $current_num *= 2;
            }

            $sum += ($current_num % 10);

            if ($current_num >  9) {
                $sum += 1;
            }
        }

        if (($sum % 10) !== 0) {
            throw new \LinkPoint\Exception('Invalid credit card number');
        }

        $this->_ccNum = $ccNum;

        return $this;
    }

    /**
     * Returns the credit card number.
     * @return string
     */
    public function getCcNum() {
        return $this->_ccNum;
    }

    /**
     * Sets the raw MagStripe data from a card
     * @param string $track
     * @return \LinkPoint\Payment_CreditCard
     * @throws \LinkPoint\Exception
     */
    public function setTrack($track) {
        if (substr($track, 0, 2) != '%B') {
            throw new \LinkPoint\Exception('Invalid track data');
        }

        if (!preg_match('/^%B(\d{0,19})\^[\w\s\/]{2,26}\^(\d{7})\w*\?/', $track, $matches)) {
            throw new \LinkPoint\Exception('Could not parse track data');
        }

        $this->setCcNum($matches[1]);
        $this->setExp(substr($matches[2], 3, 2), substr($matches[2], 0, 2));

        $this->_track = $track;
        return $this;
    }

    /**
     * Returns the raw MagStripe data from a card
     *
     * @return string|bool
     */
    public function getTrack() {
        if (!empty($this->_track)) {
            return $this->_track;
        }
        return false;
    }

    /**
     * Sets the expiration date.
     *
     * @param int $expMonth
     * @param int $expYear
     * @return \LinkPoint\Payment_CreditCard
     * @throws \LinkPoint\Exception
     */
    public function setExp($expMonth, $expYear) {
        if (((int) substr($expYear, -2, 2) < (int) date('y')) && ((int) $expMonth < (int) date('j'))) {
            throw new \LinkPoint\Exception('Expiration date is in the past: '.$expMonth.'/'.$expYear);
        }

        $this->_expMonth = $expMonth;
        $this->_expYear = $expYear;
        return $this;
    }

    /**
     * @param null $part
     * @return array|int
     */
    public function getExp($part = null) {
        if ($part == 'month') {
            return $this->_expMonth;
        } elseif ($part == 'year') {
            return $this->_expYear;
        }
        return array($this->_expMonth, $this->_expYear);
    }

    /**
     * Sets the CVM value.
     *
     * @param int $cvm
     * @param string|null $cvmState
     * @return \LinkPoint\Payment_CreditCard
     * @throws \LinkPoint\Exception
     */
    public function setCvm($cvm, $cvmState = null) {
        $this->_cvm = $cvm;

        if (!empty($cvmState)) {
            $this->setCvmState($cvmState);
        }

        return $this;
    }

    /**
     * Returns the CVM value, or FALSE if no CVM is provided.
     *
     * @return int|boolean
     */
    public function getCvm() {
        if ($this->_cvm) {
            return $this->_cvm;
        }
        return false;
    }

    /**
     * Sets the CVM state.
     *
     * @param string $reason
     * @return \LinkPoint\Payment_CreditCard
     * @throws \LinkPoint\Exception
     */
    public function setCvmState($reason) {
        if (!in_array($reason, array('provided','not_provided','illegible','not_present','no_imprint'))) {
            throw new \LinkPoint\Exception('Invalid CVM reason');
        }

        $this->_cvmState = $reason;
        return $this;
    }

    /**
     * Returns the CVM state.
     *
     * @return string
     */
    public function getCvmState() {
        if (($this->_cvmState == Payment_CreditCard::CVM_NOT_PROVIDED) && !empty($this->_cvm)) {
            return Payment_CreditCard::CVM_PROVIDED;
        }

        return $this->_cvmState;
    }

    /**
     * Get global CVM/CVV2 states
     *
     * @return array
     */
    public function getCvmStates() {
        $cvmStates = array(
            Payment_CreditCard::CVM_NOT_PROVIDED,
            Payment_CreditCard::CVM_ILLEGIBLE,
            Payment_CreditCard::CVM_NOT_PRESENT,
            Payment_CreditCard::CVM_NO_IMPRINT
        );
        return $cvmStates;
    }

    /**
     * Generate credit card number for testing
     *
     * @param int $prefix start of the CC number as a string
     * @param int $length length of the CC number to generate
     * @return string
     */
    public function genNumber($prefix = 4227, $length = 16) {
        $ccnumber = $prefix;

        while(strlen($ccnumber) < ($length - 1)) {
            $ccnumber .= rand(0, 9);
        }

        $sum = 0;
        $pos = 0;

        $reversedCCnumber = strrev($ccnumber);

        while($pos < ($length - 1)) {
            $odd = ($reversedCCnumber[$pos] * 2);

            if ($odd > 9) {
                $odd -= 9;
            }

            $sum += $odd;

            if ($pos != ($length - 2)) {

                $sum += $reversedCCnumber[($pos + 1)];
            }

            $pos += 2;
        }

        $checkdigit = ((((floor(($sum / 10)) + 1) * 10) - $sum) % 10);
        $ccnumber .= $checkdigit;

        return $ccnumber;
    }

    /**
     * Convert the credit card object into an XML entity
     * that can be sent to the payment processor.
     */
    public function __toString() {
        $doc = new \DOMDocument();

        // Root Element
        $xml = $doc->createElement(Payment_CreditCard::XML_ENTITY);

        if (empty($this->_track)) {
            // cc num
            $xml->appendChild($doc->createElement('cardnumber', $this->getCcNum()));

            // cc exp month
            $xml->appendChild($doc->createElement('cardexpmonth', str_pad($this->getExp('month'), 2, '0', STR_PAD_LEFT)));

            // cc exp year
            $xml->appendChild($doc->createElement('cardexpyear', substr($this->getExp('year'), -2, 2)));
        } else {
            $xml->appendChild($doc->createElement('track', $this->getTrack()));
        }

        // cvm
        if ($this->_cvm != false) {
            $xml->appendChild($doc->createElement('cvmvalue', $this->getCvm()));
        }

        // cvm state
        $xml->appendChild($doc->createElement('cvmindicator', $this->getCvmState()));

        $doc->appendChild($xml);

        return $doc->saveHTML();
    }
}