using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Windows;

using Microsoft.Win32;

namespace ShrlAlgoStudio
{
    /// <summary>
    /// RevitFileCipher.xaml 的交互逻辑
    /// </summary>
    public partial class RevitFileCipher
    {
        public RevitFileCipher()
        {
            InitializeComponent();
        }

        // 定义要搜索的扩展名（注意：必须带点，且通常小写，因为 Windows 文件系统不区分大小写）

        private static readonly string[] AllowedExtensions = { ".rvt", ".rfa", ".rft", ".rte" };
        private void DecryptButton_Click(object sender, RoutedEventArgs e)
        {
            var openFileDialog = new OpenFileDialog();
            if (openFileDialog.ShowDialog() == true)
            {
                var filePath = openFileDialog.FileName;
                string ext = Path.GetExtension(filePath).ToLowerInvariant();

                if (AllowedExtensions.Contains(ext))
                {
                    Decrypt(filePath);
                }
            }

        }

        private void DecryptFolderButton_Click(object sender, RoutedEventArgs e)
        {
            var dialog = new VistaFolderBrowserDialog();
            if (!dialog.ShowDialog()) return;
            var folderPath = dialog.SelectedPath;
            var directoryPath = new DirectoryInfo(folderPath);
            // 定义要搜索的扩展名（注意：必须带点，且通常小写，因为 Windows 文件系统不区分大小写）

            var files = directoryPath
                .GetFiles("*", SearchOption.AllDirectories)
                .Where(file => AllowedExtensions.Contains(file.Extension.ToLowerInvariant()))
                .ToArray();
            foreach (var filePath in files)
            {
                Decrypt(filePath.FullName);
            }

        }
        private void EncryptButton_Click(object sender, RoutedEventArgs e)
        {
            var openFileDialog = new OpenFileDialog();
            if (openFileDialog.ShowDialog() == true)
            {
                var filePath = openFileDialog.FileName;
                 string ext = Path.GetExtension(filePath).ToLowerInvariant();

                if (AllowedExtensions.Contains(ext))
                {
                    Encrypt(filePath);
                }
            }
        }

        private void EncryptFolderButton_Click(object sender, RoutedEventArgs e)
        {
            var dialog = new VistaFolderBrowserDialog();
            if (!dialog.ShowDialog()) return;
            var folderPath = dialog.SelectedPath;

            var directoryPath = new DirectoryInfo(folderPath);

            var files = directoryPath
                .GetFiles("*", SearchOption.AllDirectories)
                .Where(file => AllowedExtensions.Contains(file.Extension.ToLowerInvariant()))
                .ToArray();
            foreach (var filePath in files)
            {
                Encrypt(filePath.FullName);
            }
        }
        private bool IsEncrypted(string filePath, string tag = "VmVyc2lvbiAxLjAgU1pNZWRpRGF0YQ==")
        {
            // 关键：用写入时相同的编码（通常 UTF-8 或 ASCII）
            var tagBytes = Encoding.UTF8.GetBytes(tag); // 或 Encoding.ASCII

            var data = File.ReadAllBytes(filePath);
            // 检查开头和结尾是否匹配
            var startMatch = data.Length >= tagBytes.Length &&
                             ArrayEquals(data, 0, tagBytes, 0, tagBytes.Length);
            var endMatch = data.Length >= tagBytes.Length * 2 &&
                           ArrayEquals(data, data.Length - tagBytes.Length, tagBytes, 0, tagBytes.Length);
            return startMatch && endMatch;
        }
        private static void Decrypt(string filePath, string tag = "VmVyc2lvbiAxLjAgU1pNZWRpRGF0YQ==")
        {
            // 关键：用写入时相同的编码（通常 UTF-8 或 ASCII）
            var tagBytes = Encoding.UTF8.GetBytes(tag); // 或 Encoding.ASCII

            var data = File.ReadAllBytes(filePath);

            // 检查开头和结尾是否匹配
            var startMatch = data.Length >= tagBytes.Length &&
                             ArrayEquals(data, 0, tagBytes, 0, tagBytes.Length);
            var endMatch = data.Length >= tagBytes.Length * 2 &&
                           ArrayEquals(data, data.Length - tagBytes.Length, tagBytes, 0, tagBytes.Length);

            if (startMatch && endMatch)
            {
                // 提取中间部分：去掉开头和结尾的 tag
                var start = tagBytes.Length;
                var length = data.Length - 2 * tagBytes.Length;
                var original = new byte[length];
                Array.Copy(data, start, original, 0, length);

                File.WriteAllBytes(filePath, original);
                Console.WriteLine("✅ 文件已成功还原！");
            }
            else
            {
                Console.WriteLine("❌ 文件开头或结尾不匹配标记字符串。");
            }
        }
        private static void Encrypt(string markedRvtPath, string tag = "VmVyc2lvbiAxLjAgU1pNZWRpRGF0YQ==")
        {
            // 选择编码：通常用 UTF-8 或 ASCII（必须与后续读取时一致）
            var encoding = Encoding.UTF8; // 或 Encoding.ASCII

            var tagBytes = encoding.GetBytes(tag);
            var originalData = File.ReadAllBytes(markedRvtPath);

            // 构造新文件内容：[tag] + [原始内容] + [tag]
            var newLength = (long)tagBytes.Length * 2 + originalData.Length;
            var markedData = new byte[newLength];

            // 写入头部 tag
            //Array.Copy(tagBytes, 0, markedData, 0, tagBytes.Length);
            // 写入原始内容
            Array.Copy(originalData, 0, markedData, tagBytes.Length, originalData.Length);
            // 写入尾部 tag
            Array.Copy(tagBytes, 0, markedData, tagBytes.Length + originalData.Length, tagBytes.Length);

            // 保存新文件
            File.WriteAllBytes(markedRvtPath, markedData);
            Console.WriteLine("✅ 文件已成功加密！");
        }
        static bool ArrayEquals(byte[] a, int aStart, byte[] b, int bStart, int length)
        {
            for (var i = 0; i < length; i++)
            {
                if (a[aStart + i] != b[bStart + i])
                    return false;
            }
            return true;
        }

        private void IsDecrypt_Click(object sender, RoutedEventArgs e)
        {
            var openFileDialog = new OpenFileDialog();
            if (openFileDialog.ShowDialog() == true)
            {
                var filePath = openFileDialog.FileName;
                string ext = Path.GetExtension(filePath).ToLowerInvariant();

                if (AllowedExtensions.Contains(ext))
                {
                  MessageBox.Show($"是否加密：{IsEncrypted(filePath)}");
                }
            }
        }
    }
}