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

namespace OtogiStillDec
{
    class Program
    {
        static void Main(string[] args)
        {
            if (args.Length == 0) {
                Console.WriteLine(@"usage: OtogiStillDec.exeにドラッグ＆ドロップ又はコマンドラインで引数にファイルパス指定(複数可)");
                return;
            }

            var aesManager = new AesManaged() {
                KeySize = 128,
                BlockSize = 128,
                Mode = CipherMode.CBC,
                Padding = PaddingMode.PKCS7,
                IV = Encoding.UTF8.GetBytes("nekonekonyannyan"),
                Key = Encoding.UTF8.GetBytes("kms1kms2kms3kms4")
            };
            ICryptoTransform decryptor = aesManager.CreateDecryptor();
            for (int i = 0; i < args.Length; i++) {
                if (File.Exists(args[i])) {
                    byte[] bytes = File.ReadAllBytes(args[i]);
                    File.WriteAllBytes(args[i], decryptor.TransformFinalBlock(bytes, 0, bytes.Length));
                    Console.WriteLine($"Decrypted {Path.GetFileName(args[i])}");
                }
            }

        }
    }
}