<?php

namespace common\services;

use Exception;

class DataEncryptor
{
    /**
     * @var string 加密方法
     */
    private string $cipherMethod = 'AES-256-CBC'; // 加密方法
    /**
     * @var string 密钥
     */
    private string $secretKey; // 密钥
    /**
     * @var false|int 初始化向量长度
     */
    private $ivLength; // 初始化向量长度

    /**
     * 初始化加密类
     * @param $key
     */
    public function __construct($key) {
        $this->secretKey = hash('sha256', $key, true); // 使用SHA-256哈希生成32字节的密钥
        $this->ivLength = openssl_cipher_iv_length($this->cipherMethod);
    }

    /**
     * 加密数据
     * @param $data
     * @return string
     * @throws Exception
     */
    public function encrypt($data): string
    {
        $iv = openssl_random_pseudo_bytes($this->ivLength);
        $encryptedData = openssl_encrypt($data, $this->cipherMethod, $this->secretKey, OPENSSL_RAW_DATA, $iv);
        if ($encryptedData === false) {
            throw new Exception("加密失败" . openssl_error_string());
        }
        return 'xk_ase_256_'. base64_encode($iv . $encryptedData); // 将初始化向量和加密数据一起返回
    }

    /**
     * 解密数据
     * @param $base64EncodedEncryptedData
     * @return string
     * @throws Exception
     */
    public function decrypt($base64EncodedEncryptedData): string
    {
        if (!is_string($base64EncodedEncryptedData)) return $base64EncodedEncryptedData;
        // 替换xk_ase_256_
        $base64EncodedEncryptedData = str_replace('xk_ase_256_', '', $base64EncodedEncryptedData);
        $decodedData = base64_decode($base64EncodedEncryptedData);
        if ($decodedData === false) {
            throw new Exception("Base64 decoding failed");
        }
        $iv = substr($decodedData, 0, $this->ivLength);
        $encryptedData = substr($decodedData, $this->ivLength);
        $decryptedData = openssl_decrypt($encryptedData, $this->cipherMethod, $this->secretKey, OPENSSL_RAW_DATA, $iv);
        if ($decryptedData === false) {
            throw new Exception("解密失败" . openssl_error_string());
        }
//        $pattern = '/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F-\xFF]|[\x{E000}-\x{F8FF}]/u';
//        if (!preg_match($pattern, $str)) return $str;
//        ds($decryptedData);
        return $decryptedData;
    }
}