<?php
/**
 * 重庆赤晓店信息科技有限公司
 * https://www.chixiaodian.com
 * Copyright (c) 2023 赤店商城 All rights reserved.
 */
/*
 * This file is part of the overtrue/wechat.
 *
 * (c) overtrue <i@overtrue.me>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

namespace ByteDance\Kernel;

use ByteDance\Kernel\Exceptions\RuntimeException;
use ByteDance\Kernel\Support\AES;
use Throwable;
use function ByteDance\Kernel\Support\str_random;

/**
 * Class Encryptor.
 *
 * @author overtrue <i@overtrue.me>
 */
class Encryptor
{
    const ERROR_INVALID_SIGNATURE = -40001; // Signature verification failed
    const ERROR_CALC_SIGNATURE = -40003; // Calculating the signature failed
    const ERROR_INVALID_AES_KEY = -40004; // Invalid AESKey
    const ERROR_INVALID_APP_ID = -40005; // Check AppID failed
    const ERROR_ENCRYPT_AES = -40006; // AES EncryptionInterface failed
    const ERROR_DECRYPT_AES = -40007; // AES decryption failed
    const ERROR_BASE64_ENCODE = -40009; // Base64 encoding failed
    const ERROR_BASE64_DECODE = -40010; // Base64 decoding failed
    const ILLEGAL_BUFFER = -41003; // Illegal buffer

    /**
     * @var string
     */
    protected $aesKey;

    /**
     * Block size.
     *
     * @var int
     */
    protected $blockSize = 32;

    /**
     * Constructor.
     *
     * @param string      $appId
     * @param string|null $token
     * @param string|null $aesKey
     */
    public function __construct(string $aesKey = null)
    {
        $this->aesKey = base64_decode($aesKey.'=', true);
    }


    /**
     * Get SHA1.
     *
     * @return string
     *
     * @throws self
     */
    public function signature(): string
    {
        $array = func_get_args();
        sort($array, SORT_STRING);

        return sha1(implode($array));
    }

    /**
     * PKCS#7 pad.
     *
     * @param string $text
     * @param int    $blockSize
     *
     * @return string
     *
     * @throws \ByteDance\Kernel\Exceptions\RuntimeException
     */
    public function pkcs7Pad(string $text, int $blockSize): string
    {
        if ($blockSize > 256) {
            throw new RuntimeException('$blockSize may not be more than 256');
        }
        $padding = $blockSize - (strlen($text) % $blockSize);
        $pattern = chr($padding);

        return $text.str_repeat($pattern, $padding);
    }

    /**
     * PKCS#7 unpad.
     *
     * @param string $text
     *
     * @return string
     */
    public function pkcs7Unpad(string $text): string
    {
        $pad = ord(substr($text, -1));
        if ($pad < 1 || $pad > $this->blockSize) {
            $pad = 0;
        }

        return substr($text, 0, (strlen($text) - $pad));
    }
}