Response Codes

<?php
function handleTransactionResponse($result) {
    // Check primary response
    if ($result['response'] != '1') {
        if ($result['response'] == '2') {
            // Declined
            return [
                'success' => false,
                'message' => 'Payment declined: ' . $result['responsetext'],
                'retry' => in_array($result['responsetext'], ['CALL FOR AUTHORIZATION'])
            ];
        } else {
            // Error
            return [
                'success' => false,
                'message' => 'Payment error: ' . $result['responsetext'],
                'retry' => true
            ];
        }
    }

    // Transaction approved - check AVS
    $avs_acceptable = ['X', 'Y', 'A', 'Z', 'W', 'D', 'M'];
    $avs_match = in_array($result['avsresponse'], $avs_acceptable);

    // Check CVV
    $cvv_match = ($result['cvvresponse'] == 'M');

    // Fraud score check
    $needs_review = !$avs_match || !$cvv_match;

    if ($needs_review) {
        // Flag for manual review
        flagForReview($result['transactionid'], [
            'avs' => $result['avsresponse'],
            'cvv' => $result['cvvresponse']
        ]);
    }

    return [
        'success' => true,
        'transaction_id' => $result['transactionid'],
        'needs_review' => $needs_review,
        'message' => 'Payment successful'
    ];
}
?>

function getCustomerMessage($responsetext) {
    $messages = [
        'DECLINE' => 'Your card was declined. Please use a different payment method.',
        'INSUFFICIENT FUNDS' => 'Your card has insufficient funds. Please use a different card.',
        'INVALID CARD NUMBER' => 'The card number you entered is invalid. Please check and try again.',
        'CARD EXPIRED' => 'Your card has expired. Please use a different card.',
        'DO NOT HONOR' => 'Your card was declined. Please contact your bank or use a different card.',
        'CALL FOR AUTHORIZATION' => 'Please contact your card issuer to authorize this transaction.',
    ];

    return $messages[$responsetext] ?? 'Payment processing failed. Please try again or use a different payment method.';
}