using System.Configuration;
using System.Data;
using System.IO.Compression;
using System.IO;
using System.Security.Cryptography;
using System.Text;
using System.Windows;

namespace ArchivesCenter3
{
    /// <summary>
    /// Interaction logic for App.xaml
    /// </summary>
    public partial class App : Application
    {
        protected override void OnStartup(StartupEventArgs e)
        {
            base.OnStartup(e);
            this.SessionEnding += App_SessionEnding;
        }

        private void App_SessionEnding(object sender, SessionEndingCancelEventArgs e)
        {
            try
            {
                // 获取用户文档库路径
                string documentsPath = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
                string archivesCenterPath = Path.Combine(documentsPath, "ArchivesCenter");
                string dataPath = Path.Combine(archivesCenterPath, "data");
                string configPath = Path.Combine(archivesCenterPath, "config");
                string backupPath = Path.Combine(archivesCenterPath, "backup");

                // 确保备份文件夹存在
                Directory.CreateDirectory(backupPath);

                // 获取当前时间作为文件名
                string timestamp = DateTime.Now.ToString("yyyyMMddHHmmssfff");
                string backupFileName = Path.Combine(backupPath, $"backup_{timestamp}.zip");

                // 获取加密密码
                string password = Settings1.Default.Password;

                // 创建压缩包并加密
                using (FileStream zipToOpen = new FileStream(backupFileName, FileMode.Create))
                {
                    using (ZipArchive archive = new ZipArchive(zipToOpen, ZipArchiveMode.Create, true))
                    {
                        // 添加 data 文件夹
                        if (Directory.Exists(dataPath))
                        {
                            AddDirectoryToArchive(archive, dataPath, "data");
                        }

                        // 添加 config 文件夹
                        if (Directory.Exists(configPath))
                        {
                            AddDirectoryToArchive(archive, configPath, "config");
                        }
                    }
                }

                // 加密压缩包
                EncryptFile(backupFileName, backupFileName + ".enc", password);

                // 删除未加密的压缩包
                File.Delete(backupFileName);

                MessageBox.Show("备份完成，文件已加密并保存到：\n" + backupFileName + ".enc");
            }
            catch (Exception ex)
            {
                MessageBox.Show("备份失败：" + ex.Message);
            }
        }

        private void AddDirectoryToArchive(ZipArchive archive, string directoryPath, string entryName)
        {
            foreach (string file in Directory.GetFiles(directoryPath, "*.*", SearchOption.AllDirectories))
            {
                string entryFilePath = Path.GetRelativePath(directoryPath, file);
                ZipArchiveEntry entry = archive.CreateEntry(Path.Combine(entryName, entryFilePath));
                using (FileStream fileStream = new FileStream(file, FileMode.Open, FileAccess.Read))
                {
                    using (Stream entryStream = entry.Open())
                    {
                        fileStream.CopyTo(entryStream);
                    }
                }
            }
        }

        private void EncryptFile(string inputFilePath, string outputFilePath, string password)
        {
            byte[] passwordBytes = Encoding.UTF8.GetBytes(password);
            using (Aes aesAlg = Aes.Create())
            {
                aesAlg.Key = passwordBytes;
                aesAlg.IV = new byte[16]; // IV 长度必须为 16 字节

                using (FileStream inputStream = new FileStream(inputFilePath, FileMode.Open, FileAccess.Read))
                {
                    using (FileStream outputStream = new FileStream(outputFilePath, FileMode.Create, FileAccess.Write))
                    {
                        using (ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV))
                        {
                            using (CryptoStream cryptoStream = new CryptoStream(outputStream, encryptor, CryptoStreamMode.Write))
                            {
                                inputStream.CopyTo(cryptoStream);
                            }
                        }
                    }
                }
            }
        }
    }

}