<?php

// phpcs:disable

namespace App;

/**
 * ccAvenue Crypto details.
 */
class ccAvenueCrypto
{
    // phpcs:enable

    /**
     * Construct funtion.
     */
    public function __construct()
    {
        //pass
    }

    /**
     * Encrypt data to be sent to ccAvenue.
     *
     * @param string $plainText Plain String
     * @param string $key       Working key provided by CCAvenue
     *
     * @return string encryptedText String
     */
    public function encrypt($plainText, $key)
    {
        $key = $this->hextobin(md5($key));
        $initVector = pack('C*', 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f);
        $openMode = openssl_encrypt($plainText, 'AES-128-CBC', $key, OPENSSL_RAW_DATA, $initVector);
        $encryptedText = bin2hex($openMode);

        return $encryptedText;
    }

    /**
     * Decrypted data from ccAvenue.
     *
     * @param string $encryptedText Encrypted String
     * @param string $key           Working key provided by CCAvenue
     *
     * @return string Plain String
     */
    public function decrypt($encryptedText, $key)
    {
        $key = $this->hextobin(md5($key));
        $initVector = pack('C*', 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f);
        $encryptedText = $this->hextobin($encryptedText);
        $decryptedText = openssl_decrypt($encryptedText, 'AES-128-CBC', $key, OPENSSL_RAW_DATA, $initVector);

        return $decryptedText;
    }

    /**
     * Convert hexa-decimal code to binary safe string.
     *
     * @param string $hexString Hexadecimal code
     *
     * @return string Binary safe string
     */
    public function hextobin($hexString)
    {
        $length = strlen($hexString);
        $binString = '';
        $count = 0;
        while ($count < $length) {
            $subString = substr($hexString, $count, 2);
            $packedString = pack('H*', $subString);
            if ($count == 0) {
                $binString = $packedString;
            } else {
                $binString .= $packedString;
            }

            $count += 2;
        }

        return $binString;
    }
}