using System.Collections.ObjectModel;
using System.Net.Http.Headers;
using System.Runtime.InteropServices;
using System.Threading;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Input;
using System.Windows.Interop;
using System.Windows.Media;
using Microsoft.Web.WebView2.Core;
using VideoDownloader.App.Browser;
using VideoDownloader.App.Core;
using VideoDownloader.App.Detection;
using VideoDownloader.App.ViewModels;
using VideoDownloader.Core.Config;

namespace VideoDownloader.App;

public partial class MainWindow : Window
{
    private readonly DownloadManager _manager;
    private AppConfig _config;
    private int _totalRequests;
    private string _appLogPath = "";
    private string _currentTitle = "";

    private readonly ObservableCollection<Bookmark> _bookmarks = new();
    private readonly ObservableCollection<HistoryEntry> _history = new();
    private string? _pendingHistoryUrl;
    private string? _pendingSocialUrl; // 타이틀 확정 시 소셜 카드 제목 갱신용
    private bool _suggesting; // 주소창 인라인 자동완성 도중 (TextChanged 재귀 방지)

    // #15 위장 미디어(image/png 등) magic byte 검증용. 세션당 상한 두어 폭주 방지.
    private static readonly HttpClient ProbeClient = new(new HttpClientHandler { AllowAutoRedirect = true })
    { Timeout = TimeSpan.FromSeconds(15) };
    private readonly HashSet<string> _probed = new();
    private int _probeCount;

    // 범용 우측 패널: 접기/펼치기 + 폭 리사이즈 상태(설정에 저장)
    private bool _panelCollapsed;
    private double _panelExpandedWidth = 420;
    private const double CollapsedPanelWidth = 56;
    private const double MinExpandedWidth = 280;
    private const double MaxExpandedWidth = 900;

    public MainWindow()
    {
        InitializeComponent();
        _config = ConfigStore.Load();
        Directory.CreateDirectory(_config.OutputFolder);
        _appLogPath = Path.Combine(_config.OutputFolder, "app.log");
        try { File.WriteAllText(_appLogPath, $"=== 시작 {DateTime.Now:yyyy-MM-dd HH:mm:ss} ==={Environment.NewLine}"); } catch { }
        _manager = new DownloadManager(_config, GetCookiesAsync, Log);
        DataContext = _manager;

        foreach (var b in BrowserStore.LoadBookmarks()) _bookmarks.Add(b);
        foreach (var h in BrowserStore.LoadHistory()) _history.Add(h);
        BookmarksList.ItemsSource = _bookmarks;
        HistoryList.ItemsSource = _history;

        Loaded += async (_, _) => await InitializeBrowserAsync();
        PreviewKeyDown += OnPreviewKeyDown;
        StateChanged += OnWindowStateChanged;
        AddressBox.LostKeyboardFocus += (_, _) => AddressPopup.IsOpen = false;

        // 범용 우측 패널: 저장된 접힘/폭 상태 복원
        _panelExpandedWidth = ClampPanelWidth(_config.RightPanelWidth);
        ApplyPanelState(_config.RightPanelCollapsed);
        Closing += OnWindowClosing;
    }

    // 보더리스: Win11 어두운 타이틀바 + 둥근 모서리(DWMWA_WINDOW_CORNER_PREFERENCE)
    protected override void OnSourceInitialized(EventArgs e)
    {
        base.OnSourceInitialized(e);
        try
        {
            var hwnd = new WindowInteropHelper(this).Handle;
            int dark = App.IsLightTheme ? 0 : 1; // DWMWA_USE_IMMERSIVE_DARK_MODE (라이트 테마면 밝게)
            DwmSetWindowAttribute(hwnd, 20, ref dark, sizeof(int));
            int round = 2; // DWMWCP_ROUND
            DwmSetWindowAttribute(hwnd, 33, ref round, sizeof(int));
        }
        catch { }
    }

    private void OnWindowStateChanged(object? sender, EventArgs e)
    {
        // 최대화 시 모서리 각진(Fluent 표준), 복원 시 둥글게. 캡션 아이콘도 전환.
        try
        {
            var hwnd = new WindowInteropHelper(this).Handle;
            int pref = WindowState == WindowState.Maximized ? 0 : 2; // 0=기본(최대화 시 사각)
            DwmSetWindowAttribute(hwnd, 33, ref pref, sizeof(int));
            if (MaxRestoreBtn != null)
            {
                MaxRestoreBtn.Content = WindowState == WindowState.Maximized ? "" : "";
                MaxRestoreBtn.ToolTip = WindowState == WindowState.Maximized ? "복원" : "최대화";
            }
        }
        catch { }
    }

    // ---- 보더리스: 툴바의 빈 공간을 드래그 (버튼/입력창 위는 제외해 클릭 전달) ----
    private void TitleBar_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        // 더블클릭 → 최대화/복원 (네이티브 타이틀바 동작)
        if (e.ClickCount >= 2) { MaximizeToggle(); return; }

        // 클릭된 대상(또는 조상)이 버튼/입력창이면 드래그하지 않고 클릭을 그대로 흘려보낸다
        for (var d = e.OriginalSource as DependencyObject; d != null; d = LogicalTreeHelper.GetParent(d) ?? VisualTreeHelper.GetParent(d))
        {
            if (d is ButtonBase || d is TextBox) return;
        }
        if (e.LeftButton == MouseButtonState.Pressed) { try { DragMove(); } catch { } }
    }

    private void Minimize_Click(object sender, RoutedEventArgs e) => WindowState = WindowState.Minimized;
    private void MaxRestore_Click(object sender, RoutedEventArgs e) => MaximizeToggle();
    private void Close_Click(object sender, RoutedEventArgs e) => Close();

    private void MaximizeToggle()
        => WindowState = WindowState == WindowState.Maximized ? WindowState.Normal : WindowState.Maximized;

    [DllImport("dwmapi.dll")]
    private static extern int DwmSetWindowAttribute(IntPtr hwnd, int attribute, ref int pvAttribute, int cbAttribute);

    /// <summary>WebView2 영속 프로필 경로. 쿠키·세션·localStorage·캐시가 여기 보존되어 앱/빌드 재시작에도 유지.</summary>
    internal static string ProfileFolder => Path.Combine(
        Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), "VideoDownloader", "webview");

    private async Task InitializeBrowserAsync()
    {
        try
        {
            // 명시적 영속 프로필: 기본(exe 디렉터리) 폴더는 빌드/재배포 시 날아가 로그인이 풀림 → %AppData% 로 고정.
            Directory.CreateDirectory(ProfileFolder);
            var env = await CoreWebView2Environment.CreateAsync(browserExecutableFolder: null, userDataFolder: ProfileFolder);
            var options = env.CreateCoreWebView2ControllerOptions();
            if (_config.PrivateMode) options.IsInPrivateModeEnabled = true; // InPrivate: 디스크에 아무것도 저장 안 함
            await Browser.EnsureCoreWebView2Async(env, options);
        }
        catch (Exception ex) { Log($"WebView2 초기화 실패: {ex.Message}"); return; }

        var cv = Browser.CoreWebView2;
        UpdatePrivateButton();
        cv.Settings.AreDevToolsEnabled = true;
        cv.WebResourceResponseReceived += OnResponseReceived;
        // #4 팝업/새창을 현재 WebView2 로 강제 라우팅
        cv.NewWindowRequested += (_, ne) =>
        {
            try { if (ne.Uri != null) { ne.Handled = true; cv.Navigate(ne.Uri); } }
            catch { }
        };
        // #13 페이지 내 다운로드(a[download])를 저장 폴더로 라우팅
        cv.DownloadStarting += (_, de) =>
        {
            try
            {
                var folder = Path.GetFullPath(_config.OutputFolder);
                Directory.CreateDirectory(folder);
                var fn = Path.GetFileName(de.ResultFilePath);
                if (string.IsNullOrWhiteSpace(fn)) fn = $"download_{DateTime.Now:yyyyMMdd_HHmmss}";
                de.ResultFilePath = MakeUniqueDownloadName(folder, fn);
                _manager.LogPanel($"📥 페이지 다운로드 → 저장 폴더: {fn}");
            }
            catch { }
        };
        cv.HistoryChanged += (_, _) => UpdateNavState();
        cv.SourceChanged += (_, _) => Dispatcher.BeginInvoke(new Action(() =>
        {
            if (_pendingHistoryUrl != null) RecordHistory(_pendingHistoryUrl, _pendingHistoryUrl);
            var url = cv.Source ?? "";
            AddressBox.Text = url;
            _pendingHistoryUrl = url.StartsWith("about:", StringComparison.OrdinalIgnoreCase) ? null : url;
            DetectSocial(url);
        }));
        cv.DocumentTitleChanged += (_, _) => Dispatcher.BeginInvoke(new Action(() =>
        {
            _currentTitle = cv.DocumentTitle ?? "";
            if (_pendingHistoryUrl != null)
            {
                RecordHistory(string.IsNullOrWhiteSpace(_currentTitle) ? _pendingHistoryUrl : _currentTitle, _pendingHistoryUrl);
                _pendingHistoryUrl = null;
            }
            // 소셜 카드 제목을 페이지 타이틀로 갱신(출력 파일명 포함, 시작 전일 때)
            if (_pendingSocialUrl != null && !string.IsNullOrWhiteSpace(_currentTitle))
            {
                _manager.RenameSocial(new Uri(_pendingSocialUrl), _currentTitle);
                _pendingSocialUrl = null;
            }
        }));

        NavHome_Click(this, null!);
        UpdateNavState();
    }

    private void UpdateNavState()
    {
        var cv = Browser.CoreWebView2;
        if (cv == null) return;
        Dispatcher.BeginInvoke(new Action(() =>
        {
            NavBack.IsEnabled = cv.CanGoBack;
            NavForward.IsEnabled = cv.CanGoForward;
        }));
    }

    private void OnResponseReceived(object? sender, CoreWebView2WebResourceResponseReceivedEventArgs e)
    {
        try
        {
            var uri = e.Request.Uri ?? "";
            var method = e.Request.Method ?? "GET";
            string ct = "", cl = "";
            int status = 0;
            try { ct = e.Response.Headers.GetHeader("Content-Type") ?? ""; } catch { }
            try { cl = e.Response.Headers.GetHeader("Content-Length") ?? ""; } catch { }
            try { status = e.Response.StatusCode; } catch { }

            int n = Interlocked.Increment(ref _totalRequests);
            var ctLow = (ct ?? "").ToLowerInvariant();
            // #8 노이즈 content-type(image/font/css/js/beacon)은 requests.log 기록 스킵
            bool loggable = !ctLow.StartsWith("image/") && !ctLow.StartsWith("font/")
                && !ctLow.Contains("/css") && !ctLow.Contains("javascript")
                && !ctLow.Contains("beacon") && !ctLow.Contains("ping");
            if (loggable) _manager.AppendAll($"{n}|{status}|{method}|{ct}|{cl}|{uri}");

            if (status >= 300) return;

            var l = uri.ToLowerInvariant();
            var c = (ct ?? "").ToLowerInvariant();
            long len = long.TryParse(cl, out var lv) ? lv : -1;
            // 206(Partial Content) Range 응답은 Content-Length 가 청크 크기라 작게 잡힘 →
            // Content-Range 의 전체 크기(/total) 로 보정 (Instagram 등 단일 MP4 Range 스트리밍 감지).
            try
            {
                var cr = e.Response.Headers.GetHeader("Content-Range");
                if (!string.IsNullOrEmpty(cr))
                {
                    var slash = cr.LastIndexOf('/');
                    if (slash >= 0 && long.TryParse(cr.AsSpan(slash + 1), out var total) && total > len)
                        len = total;
                }
            }
            catch { }

            string referer = Browser.CoreWebView2?.Source ?? "";
            try { var r = e.Request.Headers.GetHeader("Referer"); if (!string.IsNullOrEmpty(r)) referer = r; } catch { }

            var kind = MediaDetector.Classify(uri, ct, len, _config);
            if (kind == MediaKind.Hls)
            {
                _manager.LogPanel($"★ HLS 감지: {uri}");
                _manager.OnDetected(new DetectionContext(uri, referer, MediaKind.Hls, ct));
            }
            else if (kind == MediaKind.Dash)
            {
                _manager.LogPanel($"★ DASH 감지: {uri}");
                _manager.OnDetected(new DetectionContext(uri, referer, MediaKind.Dash, ct));
            }
            else if (kind == MediaKind.Direct)
            {
                // #15(b) chunked video/* (len<0) 는 크기 가드를 건너뛰어 토큰 만료 HTML 오류 페이지가 mp4 로 오탐됨 →
                //        magic-byte probe 로 본문이 실제 미디어인지 재검증(정상 chunked MP4 는 ftyp box 로 통과).
                if (c.StartsWith("video/") && len < 0 && Uri.TryCreate(uri, UriKind.Absolute, out var probeUri))
                    ProbeMediaAsync(probeUri, referer);
                else
                {
                    _manager.LogPanel($"★ 미디어 감지 [{ct}] {FmtLen(len)}: {uri}");
                    _manager.OnDetected(new DetectionContext(uri, referer, MediaKind.Direct, ct));
                }
            }
            else
            {
                // #15 위장 미디어(image/* 또는 octet-stream, 대용량) → magic byte 검증
                long minBytes = _config.MinSizeMB * 1024L * 1024L;
                bool disguised = (c.StartsWith("image/") || c.Contains("octet-stream")) && (len < 0 || len > minBytes);
                if (disguised && Uri.TryCreate(uri, UriKind.Absolute, out var probeUri))
                    ProbeMediaAsync(probeUri, referer);
                else if (MediaDetector.LooksLikeCandidate(l, c))
                    _manager.LogPanel($"[후보 {method}] {uri}");
            }
        }
        catch { }
    }

    private async void ProbeMediaAsync(Uri uri, string referer)
    {
        try
        {
            string key = uri.GetLeftPart(UriPartial.Path);
            lock (_probed)
            {
                if (_probeCount > 40) return;          // 세션당 상한
                if (!_probed.Add(key)) return;          // 중복 URL 스킵
                _probeCount++;
            }
            using var req = new HttpRequestMessage(HttpMethod.Get, uri);
            req.Headers.Range = new RangeHeaderValue(0, 63);
            req.Headers.UserAgent.ParseAdd(_config.UserAgent);
            if (!string.IsNullOrEmpty(referer)) { try { req.Headers.Referrer = new Uri(referer); } catch { } }
            using var resp = await ProbeClient.SendAsync(req, HttpCompletionOption.ResponseHeadersRead);
            if ((int)resp.StatusCode >= 300) return;
            await using var stream = await resp.Content.ReadAsStreamAsync();
            var head = new byte[64];
            int total = 0, m;
            while (total < 64 && (m = await stream.ReadAsync(head, total, 64 - total)) > 0) total += m;
            var fmt = MediaDetector.ProbeFormat(head.AsSpan(0, total));
            if (fmt != null)
            {
                _manager.LogPanel($"★ 위장 미디어 감지 (→{fmt}): {uri}");
                _manager.OnDetected(new DetectionContext(uri.ToString(), referer, MediaKind.Direct, "video/" + fmt));
            }
        }
        catch { }
    }

    private static string FmtLen(long len) => len < 0 ? "?" : $"{len / 1048576.0:F1}MB";

    private async Task<List<CoreWebView2Cookie>> GetCookiesAsync(Uri url)
    {
        var cv = Browser.CoreWebView2;
        if (cv == null) return new();
        try { return (await cv.CookieManager.GetCookiesAsync(url.ToString())).ToList(); }
        catch { return new(); }
    }

    private void Log(string s)
    {
        var line = $"[{DateTime.Now:HH:mm:ss}] {s}";
        try { File.AppendAllText(_appLogPath, line + Environment.NewLine); } catch { }
        Dispatcher.BeginInvoke(new Action(() => { StatusText.Text = s; }));
    }

    // ---- 네비게이션 ----
    private void Go_Click(object sender, RoutedEventArgs e) => NavigateTo(AddressBox.Text);

    // ---- 주소창 자동완성/제안 ----
    private void AddressBox_TextChanged(object sender, TextChangedEventArgs e)
    {
        if (_suggesting) return;
        UpdateSuggestions(AddressBox.Text);
        TryInlineSuggest(AddressBox.Text);
    }

    private void UpdateSuggestions(string text)
    {
        text = text?.Trim() ?? "";
        if (text.Length == 0 || !AddressBox.IsKeyboardFocused)
        {
            AddressPopup.IsOpen = false;
            return;
        }
        var low = text.ToLowerInvariant();
        var matches = _history
            .Where(h => h.Url.ToLowerInvariant().Contains(low)
                        || (h.Title ?? "").ToLowerInvariant().Contains(low))
            .Take(8)
            .ToList();
        AddressSuggestions.ItemsSource = matches;
        AddressSuggestions.SelectedIndex = matches.Count > 0 ? 0 : -1;
        AddressPopup.IsOpen = matches.Count > 0;
    }

    // 인라인 자동완성: 방문한 URL 중 입력이 접두사면 나머지를 선택영역으로 채움 (Tab/→ 로 확정)
    private void TryInlineSuggest(string text)
    {
        if (text.Length == 0 || AddressBox.CaretIndex != text.Length) return;
        var low = text.ToLowerInvariant();
        var match = _history.FirstOrDefault(h => h.Url.Length > text.Length
            && h.Url.ToLowerInvariant().StartsWith(low));
        if (match == null) return;
        _suggesting = true;
        AddressBox.Text = match.Url;
        AddressBox.Select(text.Length, match.Url.Length - text.Length);
        _suggesting = false;
    }

    private void AddressBox_PreviewKeyDown(object sender, KeyEventArgs e)
    {
        var k = e.Key;

        // ↑/↓ 제안 목록 탐색
        if (AddressPopup.IsOpen && AddressSuggestions.HasItems && (k == Key.Down || k == Key.Up))
        {
            int n = AddressSuggestions.Items.Count;
            int delta = k == Key.Down ? 1 : -1;
            int i = Math.Clamp(AddressSuggestions.SelectedIndex + delta, 0, n - 1);
            AddressSuggestions.SelectedIndex = i;
            AddressSuggestions.ScrollIntoView(AddressSuggestions.Items[i]);
            e.Handled = true;
            return;
        }

        // Tab / → 로 인라인 제안 확정 (선택영역을 끝으로 붕괴)
        if ((k == Key.Tab || k == Key.Right) && AddressBox.SelectionLength > 0
            && AddressBox.CaretIndex + AddressBox.SelectionLength == AddressBox.Text.Length)
        {
            AddressBox.CaretIndex = AddressBox.Text.Length;
            AddressBox.Select(AddressBox.Text.Length, 0);
            e.Handled = true;
            return;
        }

        if (k == Key.Escape) { AddressPopup.IsOpen = false; e.Handled = true; return; }

        if (k == Key.Enter)
        {
            AddressPopup.IsOpen = false;
            if (AddressSuggestions.SelectedItem is HistoryEntry sel)
                NavigateTo(sel.Url);
            else
                NavigateTo(AddressBox.Text);
            Keyboard.ClearFocus();
            e.Handled = true;
        }
    }

    // 제안 항목 클릭 → 이동
    private void AddressSuggestion_Click(object sender, MouseButtonEventArgs e)
    {
        if (AddressSuggestions.SelectedItem is HistoryEntry sel)
        {
            AddressPopup.IsOpen = false;
            NavigateTo(sel.Url);
        }
    }

    private void NavBack_Click(object sender, RoutedEventArgs e) => Browser.CoreWebView2?.GoBack();
    private void NavForward_Click(object sender, RoutedEventArgs e) => Browser.CoreWebView2?.GoForward();
    private void NavRefresh_Click(object sender, RoutedEventArgs e) => Browser.CoreWebView2?.Reload();
    private void NavHome_Click(object sender, RoutedEventArgs e) => NavigateTo(_config.HomeUrl);

    private void NavigateTo(string? url)
    {
        url = url?.Trim();
        if (string.IsNullOrEmpty(url)) return;
        if (!url.StartsWith("http", StringComparison.OrdinalIgnoreCase)) url = "https://" + url;
        Browser.CoreWebView2?.Navigate(url);
    }

    // 소셜 영상 페이지(YouTube/Instagram/X/...) 감지 → yt-dlp 카드 등록.
    private void DetectSocial(string? url)
    {
        if (string.IsNullOrEmpty(url)) { _pendingSocialUrl = null; return; }
        if (!Uri.TryCreate(url, UriKind.Absolute, out var uri)) { _pendingSocialUrl = null; return; }
        if (SocialSiteDetector.TryMatch(uri, out var normalized, out var label))
        {
            _manager.LogPanel($"★ 소셜 감지 [{label}]: {normalized}");
            _manager.OnDetected(new DetectionContext(normalized, normalized, MediaKind.Social, Tag: label));
            _pendingSocialUrl = normalized;
        }
        else _pendingSocialUrl = null;
    }

    // ---- 링크로 받기 (URL 붙여넣기) ----
    private void ToggleLink(object sender, RoutedEventArgs e)
    {
        BookmarksPopup.IsOpen = false;
        HistoryPopup.IsOpen = false;
        LinkPopup.IsOpen = !LinkPopup.IsOpen;
        if (LinkPopup.IsOpen) { LinkBox.Clear(); Dispatcher.BeginInvoke(new Action(() => LinkBox.Focus())); }
    }

    private void LinkBox_PreviewKeyDown(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Enter) { LinkDownload_Click(sender, e); e.Handled = true; }
    }

    private void LinkDownload_Click(object sender, RoutedEventArgs e)
    {
        var raw = (LinkBox.Text ?? "").Trim();
        if (string.IsNullOrEmpty(raw)) return;
        if (!raw.StartsWith("http", StringComparison.OrdinalIgnoreCase)) raw = "https://" + raw;
        if (!Uri.TryCreate(raw, UriKind.Absolute, out var uri)) { Log("올바른 링크가 아닙니다"); return; }
        if (SocialSiteDetector.TryMatch(uri, out var normalized, out var label))
        {
            _manager.LogPanel($"★ 소셜 감지 [{label}]: {normalized}");
            _manager.OnDetected(new DetectionContext(normalized, normalized, MediaKind.Social, Tag: label));
            _pendingSocialUrl = normalized;
            LinkPopup.IsOpen = false;
            Log("카드에 추가했습니다. 화질을 선택하고 받기를 누르세요");
        }
        else Log("지원하는 소셜 영상 링크가 아닙니다 (YouTube·Instagram·X·TikTok·Facebook)");
    }

    // #7 전역 키보드 단축키
    private void OnPreviewKeyDown(object sender, KeyEventArgs e)
    {
        var cv = Browser.CoreWebView2;
        var mods = Keyboard.Modifiers;
        if (mods == ModifierKeys.Control && e.Key == Key.L) { AddressBox.Focus(); AddressBox.SelectAll(); e.Handled = true; }
        else if (e.Key == Key.F5 || (mods == ModifierKeys.Control && e.Key == Key.R)) { cv?.Reload(); e.Handled = true; }
        else if (e.Key == Key.Escape) { try { cv?.Stop(); } catch { } e.Handled = true; }
        else if (mods == ModifierKeys.Alt && e.Key == Key.Left) { try { if (cv?.CanGoBack == true) cv.GoBack(); } catch { } e.Handled = true; }
        else if (mods == ModifierKeys.Alt && e.Key == Key.Right) { try { if (cv?.CanGoForward == true) cv.GoForward(); } catch { } e.Handled = true; }
        else if (mods == ModifierKeys.Control)
        {
            if (e.Key == Key.OemPlus || e.Key == Key.Add) { try { Browser.ZoomFactor = Math.Min(Browser.ZoomFactor + 0.1, 5); } catch { } e.Handled = true; }
            else if (e.Key == Key.OemMinus || e.Key == Key.Subtract) { try { Browser.ZoomFactor = Math.Max(Browser.ZoomFactor - 0.1, 0.1); } catch { } e.Handled = true; }
            else if (e.Key == Key.D0) { try { Browser.ZoomFactor = 1.0; } catch { } e.Handled = true; }
        }
    }

    private static string MakeUniqueDownloadName(string folder, string file)
    {
        var p = Path.Combine(folder, file);
        if (!File.Exists(p)) return p;
        var name = Path.GetFileNameWithoutExtension(file);
        var ext = Path.GetExtension(file);
        int i = 1;
        while (File.Exists(Path.Combine(folder, $"{name} ({i}){ext}"))) i++;
        return Path.Combine(folder, $"{name} ({i}){ext}");
    }

    // ---- 범용 우측 패널: 접기/펼치기 + 리사이즈 + 상태 저장 ----
    private static double ClampPanelWidth(double w) => Math.Clamp(w, MinExpandedWidth, MaxExpandedWidth);

    private void ApplyPanelState(bool collapsed)
    {
        _panelCollapsed = collapsed;
        RightCol.Width = new GridLength(collapsed ? CollapsedPanelWidth : _panelExpandedWidth);
        PanelBody.Visibility = collapsed ? Visibility.Collapsed : Visibility.Visible;
        PanelTitle.Visibility = collapsed ? Visibility.Collapsed : Visibility.Visible;
        PanelCountBadge.Visibility = collapsed ? Visibility.Collapsed : Visibility.Visible;
        RightSplitter.Visibility = collapsed ? Visibility.Collapsed : Visibility.Visible;
        // ←(펼치기) / →(접기) chevron. 접힘 시에도 토글 버튼은 헤더에 남아 클릭 가능.
        PanelToggle.Content = collapsed ? "" : "";
        PanelToggle.ToolTip = collapsed ? "패널 펼치기" : "패널 접기";
    }

    private void PanelToggle_Click(object sender, RoutedEventArgs e)
    {
        // 접기 직전 폭을 기억(다시 펼칠 때 복원)
        if (!_panelCollapsed) _panelExpandedWidth = ClampPanelWidth(RightCol.Width.Value);
        ApplyPanelState(!_panelCollapsed);
        PersistPanel();
    }

    private void RightSplitter_DragCompleted(object sender, DragCompletedEventArgs e)
    {
        if (_panelCollapsed) return;
        double w = RightCol.Width.Value;
        if (w <= 120) ApplyPanelState(true);   // 너무 좁히면 접기 처리
        else _panelExpandedWidth = ClampPanelWidth(w);
        PersistPanel();
    }

    private void PersistPanel()
    {
        _config.RightPanelCollapsed = _panelCollapsed;
        _config.RightPanelWidth = _panelCollapsed ? _panelExpandedWidth : ClampPanelWidth(RightCol.Width.Value);
        ConfigStore.Save(_config);
    }

    private void OnWindowClosing(object? sender, System.ComponentModel.CancelEventArgs e)
    {
        _config.RightPanelCollapsed = _panelCollapsed;
        if (!_panelCollapsed) _config.RightPanelWidth = ClampPanelWidth(RightCol.Width.Value);
        ConfigStore.Save(_config);
    }

    // ---- 개인정보 보호 모드 + 브라우저 데이터 관리 ----
    private void UpdatePrivateButton()
    {
        if (PrivateBtn == null) return;
        try
        {
            PrivateBtn.Foreground = _config.PrivateMode
                ? (Brush)FindResource("AccentBrush")
                : (Brush)FindResource("TextSecondary");
            PrivateBtn.ToolTip = _config.PrivateMode
                ? "개인정보 보호 모드 켜짐 — 클릭 시 일반 모드로 전환(재시작)"
                : "개인정보 보호 모드(InPrivate)";
        }
        catch { }
    }

    // 토글 → 확인 → 플래그 저장 → 재시작(테마 전환과 동일 패턴)
    private void TogglePrivate_Click(object sender, RoutedEventArgs e)
    {
        bool next = !_config.PrivateMode;
        var msg = next
            ? "개인정보 보호 모드(InPrivate)로 전환합니다.\n이 모드에서는 쿠키·세션·localStorage가 저장되지 않습니다.\n앱이 재시작되며 현재 페이지는 닫힙니다."
            : "일반 모드로 전환합니다.\n앱이 재시작되며 현재 페이지는 닫힙니다.";
        if (MessageBox.Show(msg + "\n\n계속할까요?", "브라우저 모드", MessageBoxButton.OKCancel, MessageBoxImage.Question) != MessageBoxResult.OK)
            return;
        _config.PrivateMode = next;
        ConfigStore.Save(_config);
        RestartApp();
    }

    /// <summary>현재 프로필의 브라우저 데이터(쿠키·DOM 저장소·캐시) 삭제. 일반 모드: 영속 프로필 정리.</summary>
    public async Task ClearBrowsingDataAsync()
    {
        var cv = Browser.CoreWebView2;
        if (cv == null) { Log("브라우저가 아직 준비되지 않았습니다"); return; }
        try
        {
            await cv.Profile.ClearBrowsingDataAsync();
            Log("브라우저 데이터(쿠키·localStorage·캐시)를 삭제했습니다. 페이지를 새로고침하세요.");
        }
        catch (Exception ex) { Log($"데이터 삭제 실패: {ex.Message}"); }
    }

    // ---- 즐겨찾기 ----
    private void ToggleBookmarks(object sender, RoutedEventArgs e)
    {
        HistoryPopup.IsOpen = false;
        LinkPopup.IsOpen = false;
        BookmarksPopup.IsOpen = !BookmarksPopup.IsOpen;
    }

    private void AddBookmark_Click(object sender, RoutedEventArgs e)
    {
        var cv = Browser.CoreWebView2;
        var url = cv?.Source ?? "";
        if (string.IsNullOrEmpty(url) || url.StartsWith("about:", StringComparison.OrdinalIgnoreCase)) return;
        if (_bookmarks.Any(b => b.Url == url)) { Log("이미 즐겨찾기에 있습니다"); return; }
        var title = Trunc(string.IsNullOrWhiteSpace(cv!.DocumentTitle) ? url : cv.DocumentTitle, 80);
        _bookmarks.Insert(0, new Bookmark(title, url));
        BrowserStore.SaveBookmarks(_bookmarks.ToList());
        Log($"즐겨찾기 추가: {title}");
    }

    private void RemoveBookmark_Click(object sender, RoutedEventArgs e)
    {
        if (sender is FrameworkElement fe && fe.DataContext is Bookmark b)
        {
            _bookmarks.Remove(b);
            BrowserStore.SaveBookmarks(_bookmarks.ToList());
        }
    }

    private void OpenBookmark_Click(object sender, RoutedEventArgs e)
    {
        if (sender is FrameworkElement fe && fe.DataContext is Bookmark b)
        {
            BookmarksPopup.IsOpen = false;
            NavigateTo(b.Url);
        }
    }

    // ---- 히스토리 ----
    private void ToggleHistory(object sender, RoutedEventArgs e)
    {
        BookmarksPopup.IsOpen = false;
        LinkPopup.IsOpen = false;
        HistoryPopup.IsOpen = !HistoryPopup.IsOpen;
    }

    private void OpenHistory_Click(object sender, RoutedEventArgs e)
    {
        if (sender is FrameworkElement fe && fe.DataContext is HistoryEntry h)
        {
            HistoryPopup.IsOpen = false;
            NavigateTo(h.Url);
        }
    }

    private void ClearHistory_Click(object sender, RoutedEventArgs e)
    {
        _history.Clear();
        BrowserStore.SaveHistory(new List<HistoryEntry>());
        Log("방문 기록을 삭제했습니다");
    }

    private void RecordHistory(string title, string url)
    {
        if (string.IsNullOrEmpty(url)) return;
        if (_history.Count > 0 && _history[0].Url == url) return;
        _history.Insert(0, new HistoryEntry(Trunc(title, 80), url, DateTime.Now));
        while (_history.Count > 500) _history.RemoveAt(_history.Count - 1);
        BrowserStore.SaveHistory(_history.ToList());
    }

    // ---- 카드 액션 ----
    private void CardDownload_Click(object sender, RoutedEventArgs e)
    {
        if (sender is FrameworkElement fe && fe.DataContext is DownloadItemViewModel it)
            _ = _manager.StartDownload(it);
    }

    // 소셜 카드: yt-dlp -J 로 사용 가능한 화질 조회 → 드롭다운 교체
    private void CardFetchFormats_Click(object sender, RoutedEventArgs e)
    {
        if (sender is FrameworkElement fe && fe.DataContext is DownloadItemViewModel it)
            _ = _manager.FetchFormatsAsync(it);
    }

    private void CardRetry_Click(object sender, RoutedEventArgs e)
    {
        if (sender is FrameworkElement fe && fe.DataContext is DownloadItemViewModel it)
            _ = _manager.RetryDownload(it);
    }

    // #1 다운로드 취소
    private void CardCancel_Click(object sender, RoutedEventArgs e)
    {
        if (sender is FrameworkElement fe && fe.DataContext is DownloadItemViewModel it)
        {
            _manager.Cancel(it);
            Log($"취소 요청: {it.Title}");
        }
    }

    private void CardFolder_Click(object sender, RoutedEventArgs e)
    {
        if (sender is FrameworkElement fe && fe.DataContext is DownloadItemViewModel it)
            OpenInExplorer(it.OutputPath);
    }

    private void OpenFolder_Click(object sender, RoutedEventArgs e) => OpenInExplorer(null);

    // #3 explorer 인자 인젝션 방지: 경로 정규화 + 존재 검증 + ArgumentList/UseShellExecute
    private void OpenInExplorer(string? selectFile)
    {
        try
        {
            var folder = Path.GetFullPath(_config.OutputFolder);
            if (!Directory.Exists(folder)) return;
            if (!string.IsNullOrEmpty(selectFile) && File.Exists(selectFile))
            {
                var psi = new System.Diagnostics.ProcessStartInfo("explorer.exe") { UseShellExecute = false };
                psi.ArgumentList.Add($"/select,{selectFile}");
                System.Diagnostics.Process.Start(psi);
            }
            else
            {
                System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo
                {
                    FileName = folder,
                    UseShellExecute = true,
                });
            }
        }
        catch { }
    }

    private void Settings_Click(object sender, RoutedEventArgs e)
    {
        var w = new SettingsWindow(_config, ClearBrowsingDataAsync) { Owner = this };
        if (w.ShowDialog() == true)
        {
            _config = w.Config;
            ConfigStore.Save(_config);
            _manager.UpdateMaxConcurrent(_config.MaxConcurrentDownloads); // #19 런타임 반영
            if (w.ThemeChanged) RestartApp();
        }
    }

    // 테마 변경 등은 리소스가 StaticResource 로 물려있어 런타임 전환이 어려움 → 재시작으로 적용.
    private static void RestartApp()
    {
        var exe = Environment.ProcessPath;
        if (!string.IsNullOrEmpty(exe))
            System.Diagnostics.Process.Start(exe);
        Application.Current.Shutdown();
    }

    private static string Trunc(string s, int n) => string.IsNullOrEmpty(s) ? "" : (s.Length <= n ? s : s[..n] + "…");
}