// Offline installer and ownership-scoped uninstaller. .NET Framework is part of Windows.
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Security.Cryptography;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Web.Script.Serialization;
using System.Windows.Forms;
using Microsoft.Win32;

internal static class Program
{
    const string Version = "@BUNDLE_VERSION@";
    const string BundleHash = "@BUNDLE_HASH@";
    const string Product = "YouTubeDL.Helper";
    const string Host = "com.youtubedl.native";
    const string UninstallKey = @"Software\Microsoft\Windows\CurrentVersion\Uninstall\YouTubeDL.Helper";
    static readonly string[] Browsers = { @"Google\Chrome", @"Microsoft\Edge", "Chromium" };
    static readonly JavaScriptSerializer Json = new JavaScriptSerializer { MaxJsonLength = 16 * 1024 * 1024 };

    [STAThread]
    public static int Main(string[] args)
    {
        Console.SetOut(new StreamWriter(Console.OpenStandardOutput(), new UTF8Encoding(false)) { AutoFlush = true });
        Console.SetError(new StreamWriter(Console.OpenStandardError(), new UTF8Encoding(false)) { AutoFlush = true });
        AppContext.SetSwitch("Switch.System.IO.UseLegacyPathHandling", false);
        AppContext.SetSwitch("Switch.System.IO.BlockLongPaths", false);
        if (args.Contains("--pick-folder"))
        {
            Application.EnableVisualStyles();
            using (var dialog = new FolderBrowserDialog())
            using (var owner = new Form { TopMost = true, ShowInTaskbar = false, Opacity = 0 })
            {
                string initial = Value(args, "--initial-folder");
                if (initial != null) dialog.SelectedPath = Json.Deserialize<string>(Encoding.UTF8.GetString(Convert.FromBase64String(initial)));
                dialog.Description = "YouTubeDL — папка сохранения"; dialog.ShowNewFolderButton = true;
                owner.Show();
                Console.WriteLine(Json.Serialize(dialog.ShowDialog(owner) == DialogResult.OK ? dialog.SelectedPath : null));
                return 0;
            }
        }
        bool silent = args.Contains("--silent");
        bool uninstall = args.Contains("--uninstall");
        string explicitRoot = Value(args, "--target-root");
        string appRoot = Path.GetFullPath(explicitRoot ?? (uninstall ? Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)
            : Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "YouTubeDL", "Helper"))).TrimEnd(Path.DirectorySeparatorChar);
        Action<Action<int, string>> work = report => Run(appRoot, args, uninstall, report);
        if (silent)
        {
            string previous = null;
            try { work((percent, message) => { if (message != previous) Console.WriteLine(message); previous = message; }); return 0; }
            catch (Exception error) { Console.Error.WriteLine(error.ToString()); return 1; }
        }
        Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false);
        var window = new SetupWindow(work, uninstall);
        Application.Run(window);
        return window.ExitCode;
    }

    static string Value(string[] args, string key)
    {
        int index = Array.IndexOf(args, key);
        return index >= 0 && index + 1 < args.Length ? args[index + 1] : null;
    }

    static void Run(string root, string[] args, bool uninstall, Action<int, string> report)
    {
        if (Path.GetPathRoot(root).TrimEnd('\\') == root.TrimEnd('\\') || root == Environment.GetFolderPath(Environment.SpecialFolder.UserProfile))
            throw new Exception("Некорректная папка установки.");
        if (Directory.Exists(root) && (File.GetAttributes(root) & FileAttributes.ReparsePoint) != 0)
            throw new Exception("Папка установки не должна быть символической ссылкой.");
        string waiting = Value(args, "--wait-pid");
        if (waiting != null)
        {
            try { using (var parent = Process.GetProcessById(Int32.Parse(waiting))) { if (!parent.WaitForExit(30000)) throw new Exception("Помощник ещё работает. Закройте меню и повторите удаление."); } }
            catch (ArgumentException) { }
        }
        if (!uninstall && !args.Contains("--finish-uninstall"))
        {
            Directory.CreateDirectory(root);
            if (!args.Contains("--activate-release"))
            {
                // AppData virtualization can merge an existing real directory
                // with newly created children elsewhere. Resolve a fresh child
                // to find the directory where this install will actually write.
                string probeName = ".ytdl-location-" + Guid.NewGuid().ToString("N");
                string probe = Inside(root, probeName);
                Directory.CreateDirectory(probe);
                string physicalProbe = PhysicalDirectory(probe);
                if (!String.Equals(Path.GetFileName(physicalProbe), probeName, StringComparison.OrdinalIgnoreCase))
                    throw new Exception("Не удалось определить папку установки.");
                root = Path.GetDirectoryName(physicalProbe);
                Directory.Delete(physicalProbe, false);
            }
        }
        // Keep the manager, marker and runtime in the same physical directory.
        root = PhysicalDirectory(root).TrimEnd(Path.DirectorySeparatorChar);
        string key;
        using (var sha = SHA256.Create()) key = BitConverter.ToString(sha.ComputeHash(Encoding.UTF8.GetBytes(PhysicalDirectory(root).ToLowerInvariant()))).Replace("-", "").Substring(0, 16);
        using (var mutex = new Mutex(false, "Local\\YouTubeDL.Setup." + key))
        {
            if (!mutex.WaitOne(0)) throw new Exception("Другая установка или удаление уже выполняется.");
            try
            {
                if (args.Contains("--activate-release")) Activate(root, args, report);
                else if (args.Contains("--finish-uninstall")) FinishRemoval(root, report);
                else if (uninstall) Uninstall(root, report);
                else
                {
#if SETUP
                    Install(root, !args.Contains("--no-register"), report);
#else
                    throw new Exception("Для установки запустите YouTubeDL-Helper-Setup.exe.");
#endif
                }
            }
            finally { mutex.ReleaseMutex(); }
        }
    }

    static string Inside(string root, string relative)
    {
        if (String.IsNullOrWhiteSpace(relative) || Path.IsPathRooted(relative)) throw new Exception("Некорректный путь в комплекте.");
        string full = Path.GetFullPath(Path.Combine(root, relative));
        if (!full.StartsWith(root.TrimEnd('\\') + "\\", StringComparison.OrdinalIgnoreCase)) throw new Exception("Путь выходит за папку комплекта.");
        for (var parent = new DirectoryInfo(Path.GetDirectoryName(full)); parent != null && parent.FullName.Length >= root.Length; parent = parent.Parent)
            if (parent.Exists && (parent.Attributes & FileAttributes.ReparsePoint) != 0) throw new Exception("Символические ссылки в папке комплекта не поддерживаются.");
        if (File.Exists(full) && (File.GetAttributes(full) & FileAttributes.ReparsePoint) != 0) throw new Exception("Файл комплекта заменён символической ссылкой.");
        return full;
    }

    static string Hash(Stream stream)
    { using (var sha = SHA256.Create()) return BitConverter.ToString(sha.ComputeHash(stream)).Replace("-", "").ToLowerInvariant(); }

    static Dictionary<string, object> ObjectFile(string path)
    { return Json.Deserialize<Dictionary<string, object>>(File.ReadAllText(path, Encoding.UTF8)); }

#if SETUP
    static void Install(string root, bool register, Action<int, string> report)
    {
        report(2, "Проверяю автономный комплект…");
        string releases = Path.Combine(root, "releases"); Directory.CreateDirectory(releases);
        string stage = Inside(releases, Version + "-" + Guid.NewGuid().ToString("N").Substring(0, 8)); Directory.CreateDirectory(stage);
        string archive = Inside(stage, "payload.zip");
        string release = null;
        bool installed = false;
        try
        {
            using (var input = Assembly.GetExecutingAssembly().GetManifestResourceStream("bundle.zip"))
            using (var output = File.Create(archive)) input.CopyTo(output);
            using (var input = File.OpenRead(archive)) if (Hash(input) != BundleHash) throw new Exception("Контрольная сумма комплекта не совпала.");
            using (var zip = ZipFile.OpenRead(archive))
            {
                long total = zip.Entries.Sum(entry => entry.Length), written = 0;
                if (total > 1024L * 1024 * 1024) throw new Exception("Некорректный размер комплекта.");
                foreach (var entry in zip.Entries)
                {
                    if (entry.FullName.EndsWith("/")) continue;
                    if (((entry.ExternalAttributes >> 16) & 0xF000) == 0xA000) throw new Exception("Символическая ссылка в архиве.");
                    string destination = Inside(stage, entry.FullName);
                    Directory.CreateDirectory(Path.GetDirectoryName(destination));
                    using (var input = entry.Open()) using (var output = File.Create(destination)) input.CopyTo(output);
                    written += entry.Length;
                    report(5 + (int)(written * 70 / total), "Распаковываю компоненты…");
                }
            }
            File.Delete(archive);
            report(78, "Проверяю Python, загрузчик, JavaScript и FFmpeg…");
            // Virus scanners can briefly hold a newly extracted EXE or DLL.
            for (int attempt = 0; ; attempt++)
            {
                try { Python(stage, "verify"); break; }
                catch { if (attempt == 2) throw; Thread.Sleep(700 * (attempt + 1)); }
            }
            release = stage;
            Python(release, "configure");
            string manager = Inside(root, "YouTubeDL-Manager.exe");
            using (var input = Assembly.GetExecutingAssembly().GetManifestResourceStream("manager.exe"))
            using (var output = File.Create(manager)) input.CopyTo(output);
            string marker = Inside(root, "installation.json");
            string history = Inside(root, @"data\completed-jobs.json");
            string previousHistory = Inside(root, @".runtime\completed-jobs.json");
            if (!File.Exists(history) && File.Exists(previousHistory))
            { Directory.CreateDirectory(Path.GetDirectoryName(history)); File.Copy(previousHistory, history); }
            File.WriteAllText(marker, Json.Serialize(new { product = Product, version = Version, current = release, registered = register }), Encoding.UTF8);
            string updates = Inside(root, @"data\update-settings.json");
            if (File.Exists(updates))
            { var options = ObjectFile(updates); options["lastCheck"] = 0; File.WriteAllText(updates, Json.Serialize(options), new UTF8Encoding(false)); }
            if (register)
            {
                report(92, "Подключаю помощник к Edge и Chrome…");
                foreach (string browser in Browsers)
                    using (var registry = Registry.CurrentUser.CreateSubKey(@"Software\" + browser + @"\NativeMessagingHosts\" + Host))
                        registry.SetValue("", Path.Combine(release, @".runtime\native-host.json"));
                using (var registry = Registry.CurrentUser.CreateSubKey(UninstallKey))
                {
                    registry.SetValue("DisplayName", "YouTubeDL Helper"); registry.SetValue("DisplayVersion", Version);
                    registry.SetValue("Publisher", "YouTubeDL"); registry.SetValue("InstallLocation", root);
                    registry.SetValue("UninstallString", "\"" + manager + "\" --uninstall");
                    registry.SetValue("QuietUninstallString", "\"" + manager + "\" --uninstall --silent");
                    registry.SetValue("NoModify", 1); registry.SetValue("NoRepair", 1);
                }
            }
            installed = true;
            report(100, "Готово. Вернитесь в YouTubeDL и нажмите «Запустить».");
        }
        finally
        {
            // Only this freshly generated, unpublished folder may be removed.
            // Cleanup must not hide the original validation/installation error.
            try
            {
                if (!installed && Directory.Exists(stage) && (File.GetAttributes(stage) & FileAttributes.ReparsePoint) == 0)
                {
                    var candidates = Directory.EnumerateFileSystemEntries(stage, "*", SearchOption.AllDirectories).ToArray();
                    if (candidates.All(path => (File.GetAttributes(path) & FileAttributes.ReparsePoint) == 0)) Directory.Delete(stage, true);
                }
            }
            catch (IOException) { } catch (UnauthorizedAccessException) { }
        }
    }

#endif

    static void Activate(string root, string[] args, Action<int, string> report)
    {
        string marker = Inside(root, "installation.json");
        var previous = ObjectFile(marker);
        if ((string)previous["product"] != Product) throw new Exception("Установленный комплект не найден.");
        string expected = PhysicalDirectory(Value(args, "--expected-current"));
        string current = PhysicalDirectory((string)previous["current"]);
        if (!String.Equals(current, expected, StringComparison.OrdinalIgnoreCase)) throw new Exception("Помощник уже изменён другой установкой. Повторите проверку обновлений.");
        string stage = PhysicalDirectory(Path.GetFullPath(Value(args, "--activate-release")));
        if (!String.Equals(Path.GetDirectoryName(stage), PhysicalDirectory(Inside(root, "releases")), StringComparison.OrdinalIgnoreCase)) throw new Exception("Папка обновления вне комплекта.");
        var metadata = ObjectFile(Inside(stage, "bundle.json"));
        if ((string)metadata["product"] != Product || (string)metadata["mode"] != "autonomous") throw new Exception("Некорректный комплект обновления.");
        report(10, "Проверяю контрольные суммы обновления…");
        foreach (var entry in ObjectFile(Inside(stage, "bundle-files.json")))
            using (var input = File.OpenRead(Inside(stage, entry.Key)))
                if (Hash(input) != (string)entry.Value) throw new Exception("Повреждён компонент обновления: " + entry.Key);
        for (int attempt = 0; ; attempt++)
        { try { Python(stage, "verify"); break; } catch { if (attempt == 2) throw; Thread.Sleep(700 * (attempt + 1)); } }
        Python(stage, "configure");
        var registrations = new Dictionary<string, string>();
        string nextMarker = Inside(root, "installation.next.json");
        try
        {
            if ((bool)previous["registered"])
                foreach (string browser in Browsers)
                {
                    string name = @"Software\" + browser + @"\NativeMessagingHosts\" + Host;
                    using (var registry = Registry.CurrentUser.OpenSubKey(name, true))
                    {
                        string value = registry == null ? null : registry.GetValue("") as string;
                        if (value == null || !String.Equals(PhysicalDirectory(Path.GetDirectoryName(value)), PhysicalDirectory(Path.Combine(current, ".runtime")), StringComparison.OrdinalIgnoreCase)) continue;
                        registrations[name] = value; registry.SetValue("", Path.Combine(stage, @".runtime\native-host.json"));
                    }
                }
            File.WriteAllText(nextMarker, Json.Serialize(new { product = Product, version = (string)metadata["version"], current = stage, registered = (bool)previous["registered"] }), Encoding.UTF8);
            File.Replace(nextMarker, marker, null);
        }
        catch
        {
            foreach (var entry in registrations) using (var registry = Registry.CurrentUser.CreateSubKey(entry.Key)) registry.SetValue("", entry.Value);
            if (File.Exists(nextMarker)) File.Delete(nextMarker);
            throw;
        }
        report(100, "Новые компоненты подключены.");
    }

    static void Python(string root, string action)
    {
        var start = new ProcessStartInfo(Inside(root, @"runtime\python\python.exe"), "-I -X utf8 -B -m host.bootstrap " + action)
        { UseShellExecute = false, CreateNoWindow = true, RedirectStandardOutput = true, RedirectStandardError = true,
          StandardOutputEncoding = Encoding.UTF8, StandardErrorEncoding = Encoding.UTF8 };
        start.EnvironmentVariables["PYTHONPATH"] = "C:\\NONEXISTENT"; start.EnvironmentVariables["PYTHONHOME"] = "C:\\NONEXISTENT";
        start.EnvironmentVariables["PYTHONDONTWRITEBYTECODE"] = "1";
        start.EnvironmentVariables["PATH"] = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Windows), "System32");
        using (var process = Process.Start(start))
        {
            var stdout = process.StandardOutput.ReadToEndAsync(); var stderr = process.StandardError.ReadToEndAsync();
            if (!process.WaitForExit(90000)) throw new Exception("Проверка комплекта заняла слишком много времени.");
            if (process.ExitCode != 0) throw new Exception("Комплект не прошёл проверку: " + stderr.Result + stdout.Result);
        }
    }

    [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    static extern Microsoft.Win32.SafeHandles.SafeFileHandle CreateFileW(string path, uint access, uint share, IntPtr security, uint disposition, uint flags, IntPtr template);
    [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    static extern uint GetFinalPathNameByHandleW(Microsoft.Win32.SafeHandles.SafeFileHandle file, StringBuilder name, uint length, uint flags);
    static string PhysicalDirectory(string path)
    {
        using (var handle = CreateFileW(path, 0, 7, IntPtr.Zero, 3, 0x02000000, IntPtr.Zero))
        {
            if (handle.IsInvalid) return Path.GetFullPath(path);
            var name = new StringBuilder(32768);
            if (GetFinalPathNameByHandleW(handle, name, (uint)name.Capacity, 0) == 0) return Path.GetFullPath(path);
            string value = name.ToString();
            return value.StartsWith(@"\\?\UNC\") ? @"\\" + value.Substring(8) : value.StartsWith(@"\\?\") ? value.Substring(4) : value;
        }
    }

    static void Uninstall(string root, Action<int, string> report)
    {
        string marker = Inside(root, "installation.json");
        if (!File.Exists(marker) || (string)ObjectFile(marker)["product"] != Product) throw new Exception("Установленный комплект YouTubeDL не найден.");
        string physicalRoot = PhysicalDirectory(root);
        report(5, "Отключаю помощник…");
        foreach (string browser in Browsers)
        {
            string name = @"Software\" + browser + @"\NativeMessagingHosts\" + Host;
            using (var registry = Registry.CurrentUser.OpenSubKey(name))
            {
                string value = registry == null ? null : registry.GetValue("") as string;
                if (value == null || !PhysicalDirectory(Path.GetDirectoryName(value)).StartsWith(physicalRoot + "\\releases\\", StringComparison.OrdinalIgnoreCase)) continue;
            }
            Registry.CurrentUser.DeleteSubKey(name, false);
        }
        using (var registry = Registry.CurrentUser.OpenSubKey(UninstallKey))
        { if (registry != null && registry.GetValue("InstallLocation") is string && String.Equals(PhysicalDirectory((string)registry.GetValue("InstallLocation")), physicalRoot, StringComparison.OrdinalIgnoreCase)) Registry.CurrentUser.DeleteSubKeyTree(UninstallKey, false); }
        string releases = Inside(root, "releases");
        string[] packages = Directory.Exists(releases) ? Directory.GetDirectories(releases) : new string[0];
        int done = 0;
        foreach (string release in packages)
        {
            Inside(root, release.Substring(root.Length + 1) + "\\bundle.json");
            if (!File.Exists(Path.Combine(release, "bundle.json")) || !File.Exists(Path.Combine(release, "bundle-files.json")) || (string)ObjectFile(Path.Combine(release, "bundle.json"))["product"] != Product) continue;
            var records = ObjectFile(Path.Combine(release, "bundle-files.json"));
            var directories = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
            foreach (string relative in records.Keys.Concat(new[] { "bundle-files.json", ".runtime/native-host.json", ".runtime/launch-host.cmd" }))
            {
                string path = Inside(release, relative);
                if (File.Exists(path)) File.Delete(path);
                for (string parent = Path.GetDirectoryName(path); parent != null && parent.StartsWith(release, StringComparison.OrdinalIgnoreCase); parent = Path.GetDirectoryName(parent)) directories.Add(parent);
            }
            foreach (string directory in directories.OrderByDescending(path => path.Length)) TryRemoveEmpty(directory);
            report(10 + (++done * 80 / Math.Max(1, packages.Length)), "Удаляю встроенные компоненты…");
        }
        TryRemoveEmpty(releases);
        string manager = Inside(root, "YouTubeDL-Manager.exe");
        // Run the final cleanup outside the installed directory, after this EXE exits.
        // The same mutex and an installation-marker check prevent a reinstall race.
        if (File.Exists(manager))
        {
            string pending = Inside(root, "uninstall-pending.json");
            File.WriteAllText(pending, Json.Serialize(new { product = Product }), Encoding.UTF8);
            string cleanup = Path.Combine(Path.GetTempPath(), "YouTubeDL-Cleanup-" + Guid.NewGuid().ToString("N") + ".exe");
            // Do not carry EFS attributes from AppData into the browser's temp
            // directory; that directory may reside on a different volume.
            File.WriteAllBytes(cleanup, File.ReadAllBytes(manager));
            Process.Start(new ProcessStartInfo(cleanup, "--finish-uninstall --silent --target-root \"" + root + "\" --wait-pid " + Process.GetCurrentProcess().Id)
                { UseShellExecute = false, CreateNoWindow = true });
        }
        File.Delete(marker);
        report(100, "Помощник удалён. Скачанные ролики сохранены.");
    }

    static void FinishRemoval(string root, Action<int, string> report)
    {
        string pending = Inside(root, "uninstall-pending.json");
        if (!File.Exists(pending) || (string)ObjectFile(pending)["product"] != Product) return;
        if (!File.Exists(Inside(root, "installation.json"))) File.Delete(Inside(root, "YouTubeDL-Manager.exe"));
        File.Delete(pending); TryRemoveEmpty(root);
    }

    static void TryRemoveEmpty(string path)
    { try { if (Directory.Exists(path) && (File.GetAttributes(path) & FileAttributes.ReparsePoint) == 0) Directory.Delete(path, false); } catch (IOException) { } }
}

internal sealed class SetupWindow : Form
{
    readonly Action<Action<int, string>> work;
    readonly Label message;
    readonly ProgressBar progress;
    readonly Button close;
    bool working = true;
    public int ExitCode = 0;
    public SetupWindow(Action<Action<int, string>> task, bool uninstall)
    {
        work = task; Text = "YouTubeDL"; Size = new Size(560, 285); StartPosition = FormStartPosition.CenterScreen;
        FormBorderStyle = FormBorderStyle.FixedDialog; MaximizeBox = false; Font = new Font("Segoe UI", 10);
        bool light = true;
        using (var theme = Registry.CurrentUser.OpenSubKey(@"Software\Microsoft\Windows\CurrentVersion\Themes\Personalize"))
            light = theme == null || Convert.ToInt32(theme.GetValue("AppsUseLightTheme", 1)) != 0;
        BackColor = light ? Color.FromArgb(248, 249, 251) : Color.FromArgb(22, 25, 31);
        ForeColor = light ? Color.FromArgb(25, 30, 40) : Color.FromArgb(235, 241, 248);
        var title = new Label { Text = uninstall ? "Удаление помощника" : "Установка помощника", Location = new Point(28, 24), AutoSize = true, Font = new Font("Segoe UI", 17, FontStyle.Bold) };
        var subtitle = new Label { Text = "YouTubeDL · автономный комплект " + "@BUNDLE_VERSION@", Location = new Point(30, 65), AutoSize = true };
        message = new Label { Text = "Подготавливаю…", Location = new Point(30, 105), Size = new Size(475, 47) };
        progress = new ProgressBar { Location = new Point(30, 154), Size = new Size(480, 8), Style = ProgressBarStyle.Continuous };
        close = new Button { Text = "Закрыть", Location = new Point(394, 189), Size = new Size(115, 33), Enabled = false, FlatStyle = FlatStyle.Flat };
        close.Click += (sender, args) => Close(); Controls.AddRange(new Control[] { title, subtitle, message, progress, close });
        FormClosing += (sender, args) => { if (working) args.Cancel = true; };
        Shown += async (sender, args) =>
        {
            try
            {
                await Task.Run(() => work((percent, text) => BeginInvoke(new Action(() => { progress.Value = Math.Max(0, Math.Min(100, percent)); message.Text = text; }))));
            }
            catch (Exception error) { ExitCode = 1; message.Text = error.Message; }
            finally { working = false; close.Enabled = true; close.Focus(); }
        };
    }
}