using System;
using System.Collections.Generic;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace MOTINOVA_MC_Test
{
    internal class aes
    {
        // 加密字符串并保存到文件
        public static void EncryptToFile(string plainText, string filePath, string key, string iv)
        {
            using (Aes aesAlg = Aes.Create())
            {
                aesAlg.Key = Encoding.UTF8.GetBytes(key);  // 密钥（必须是 16、24 或 32 字节）
                aesAlg.IV = Encoding.UTF8.GetBytes(iv);    // 初始化向量（IV，必须是 16 字节）

                using (FileStream fsEncrypt = new FileStream(filePath, FileMode.Create))
                using (CryptoStream csEncrypt = new CryptoStream(fsEncrypt, aesAlg.CreateEncryptor(), CryptoStreamMode.Write))
                using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                {
                    swEncrypt.Write(plainText);
                }
            }
        }

        // 从加密文件解密刺符传
        public static string DecryptFromFile(string filePath, string key, string iv)
        {
            using (Aes aesAlg = Aes.Create())
            {
                aesAlg.Key = Encoding.UTF8.GetBytes(key);  // 密钥（必须是 16、24 或 32 字节）
                aesAlg.IV = Encoding.UTF8.GetBytes(iv);    // 初始化向量（IV，必须是 16 字节）

                using (FileStream fsDecrypt = new FileStream(filePath, FileMode.Open))
                using (CryptoStream csDecrypt = new CryptoStream(fsDecrypt, aesAlg.CreateDecryptor(), CryptoStreamMode.Read))
                using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                {
                    return srDecrypt.ReadToEnd();
                }
            }
        }

        // 加密字符串
        public static string EncryptString(string plainText, string key, string iv)
        {
            byte[] array;

            using (Aes aesAlg = Aes.Create())
            {
                aesAlg.Key = Encoding.UTF8.GetBytes(key);  // 密钥（必须是 16、24 或 32 字节）
                aesAlg.IV = Encoding.UTF8.GetBytes(iv);    // 初始化向量（IV，必须是 16 字节）

                ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);

                using (MemoryStream memoryStream = new MemoryStream())
                {
                    using (CryptoStream cryptoStream = new CryptoStream((Stream)memoryStream, encryptor, CryptoStreamMode.Write))
                    {
                        using (StreamWriter streamWriter = new StreamWriter((Stream)cryptoStream))
                        {
                            streamWriter.Write(plainText);
                        }

                        array = memoryStream.ToArray();
                    }
                }
            }

            return Convert.ToBase64String(array);
        }

        public static string DecryptString(string cipherText, string key, string iv)
        {
            byte[] buffer = Convert.FromBase64String(cipherText);

            using (Aes aesAlg = Aes.Create())
            {
                aesAlg.Key = Encoding.UTF8.GetBytes(key);  // 密钥（必须是 16、24 或 32 字节）
                aesAlg.IV = Encoding.UTF8.GetBytes(iv);    // 初始化向量（IV，必须是 16 字节）

                ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);

                using (MemoryStream memoryStream = new MemoryStream(buffer))
                {
                    using (CryptoStream cryptoStream = new CryptoStream((Stream)memoryStream, decryptor, CryptoStreamMode.Read))
                    {
                        using (StreamReader streamReader = new StreamReader((Stream)cryptoStream))
                        {
                            return streamReader.ReadToEnd();
                        }
                    }
                }
            }
        }
    }
}