using System.Diagnostics;
using System.IO;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Threading;

namespace AeroMCSetup;

public partial class MainWindow : Window
{
    private readonly SetupMode _mode;
    private int _page;
    private bool _busy;
    private bool _done;
    private string? _installedExe;
    // andere Launcher für den optionalen Import (leer → Import-Schritt entfällt)
    private List<FoundLauncher> _found = [];
    private bool HasImport => _found.Count > 0;

    private const int PageNumImport = 3;
    private const int PageNumProgress = 4;

    public MainWindow(SetupMode mode)
    {
        InitializeComponent();
        _mode = mode;
        VersionText.Text = $"Version {Installer.Version}";
        LicenseText.Text = Installer.LicenseText;

        var installed = Installer.InstalledDir;
        DirBox.Text = installed ?? Installer.DefaultDir;
        DesktopLinkBox.IsChecked = installed is null || Installer.DesktopLinkExists;

        if (installed is not null)
        {
            UpdateHint.Visibility = Visibility.Visible;
            UpdateHintText.Text = Installer.InstalledVersion == Installer.Version
                ? $"AeroMC {Installer.Version} ist bereits installiert und wird neu installiert. Deine Instanzen, Welten und Einstellungen bleiben erhalten."
                : $"Die vorhandene Installation{(Installer.InstalledVersion is { } v ? $" (Version {v})" : "")} wird durch Version {Installer.Version} ersetzt. Deine Instanzen, Welten und Einstellungen bleiben erhalten.";
        }
        if (Installer.IsRunning(installed)) RunningHint.Visibility = Visibility.Visible;

        switch (mode)
        {
            case SetupMode.Uninstall:
                Title = WindowTitle.Text = "AeroMC deinstallieren";
                Steps.Visibility = Visibility.Collapsed;
                ShowOnly(PageUninstall);
                NextButton.Content = "Deinstallieren";
                BackButton.Visibility = Visibility.Collapsed;
                LoadDataInfo();
                break;
            case SetupMode.Update:
                // aus dem Launcher heraus: ohne Rückfragen direkt aktualisieren und danach wieder starten
                Title = WindowTitle.Text = "AeroMC wird aktualisiert";
                Steps.Visibility = Visibility.Collapsed;
                Loaded += async (_, _) => await RunInstall(DirBox.Text, DesktopLinkBox.IsChecked == true, update: true);
                ShowOnly(PageProgress);
                ProgressTitle.Text = "AeroMC wird aktualisiert …";
                BackButton.Visibility = Visibility.Hidden;
                break;
            default:
                SetupImportPage();
                ShowPage(0);
                break;
        }
    }

    // ---------- Seiten ----------

    private UIElement? _shownPage;

    /// <summary>Seite wechseln – mit kurzem Einblenden von rechts.</summary>
    private void ShowOnly(UIElement page)
    {
        foreach (var p in new UIElement[] { PageWelcome, PageLicense, PageOptions, PageImport, PageProgress, PageUninstall })
            p.Visibility = p == page ? Visibility.Visible : Visibility.Collapsed;
        if (page == _shownPage) return;
        _shownPage = page;

        var ease = new CubicEase { EasingMode = EasingMode.EaseOut };
        var slide = new TranslateTransform(18, 0);
        page.RenderTransform = slide;
        slide.BeginAnimation(TranslateTransform.XProperty, new DoubleAnimation(18, 0, TimeSpan.FromMilliseconds(260)) { EasingFunction = ease });
        page.BeginAnimation(OpacityProperty, new DoubleAnimation(0, 1, TimeSpan.FromMilliseconds(220)));
    }

    // Farben der Schritt-Anzeige in der (immer dunkelblauen) Seitenleiste
    private static readonly Brush StepDoneFill = Frozen(Color.FromRgb(0x4A, 0x86, 0xEA));
    private static readonly Brush StepCurrentFill = Brushes.White;
    private static readonly Brush StepCurrentText = Frozen(Color.FromRgb(0x1C, 0x4E, 0xB8));
    private static readonly Brush StepUpcoming = Frozen(Color.FromRgb(0x7F, 0x95, 0xC2));
    private static readonly Brush StepUpcomingStroke = Frozen(Color.FromRgb(0x46, 0x5E, 0x92));
    private static readonly Brush StepDoneText = Frozen(Color.FromRgb(0xB9, 0xC8, 0xE8));
    private static readonly Brush StepLineIdle = Frozen(Color.FromRgb(0x2E, 0x45, 0x78));

    private static Brush Frozen(Color c)
    {
        var b = new SolidColorBrush(c);
        b.Freeze();
        return b;
    }

    private void UpdateSteps(int page)
    {
        var dots = new[] { Dot0, Dot1, Dot2, Dot3, Dot4 };
        var nums = new[] { Num0, Num1, Num2, Num3, Num4 };
        var labels = new[] { Label0, Label1, Label2, Label3, Label4 };
        var lines = new[] { Line0, Line1, Line2, Line3 };
        var iconFont = (FontFamily)FindResource("IconFont");
        var uiFont = (FontFamily)FindResource("UiFont");

        // ohne gefundene Launcher fällt der Import-Schritt weg → Nummern rücken auf
        ImportStepRow.Visibility = Line3.Visibility = HasImport ? Visibility.Visible : Visibility.Collapsed;
        int number = 0;
        for (int i = 0; i < dots.Length; i++)
        {
            if (i == PageNumImport && !HasImport) continue;
            number++;
            bool done = i < page || (_done && i == page);
            bool current = i == page && !done;
            dots[i].Background = done ? StepDoneFill : current ? StepCurrentFill : Brushes.Transparent;
            dots[i].BorderBrush = done ? StepDoneFill : current ? StepCurrentFill : StepUpcomingStroke;
            nums[i].Text = done ? "" : number.ToString();
            nums[i].FontFamily = done ? iconFont : uiFont;
            nums[i].FontSize = done ? 11 : 12;
            nums[i].Foreground = done ? Brushes.White : current ? StepCurrentText : StepUpcoming;
            labels[i].Foreground = current ? Brushes.White : done ? StepDoneText : StepUpcoming;
            labels[i].FontWeight = current ? FontWeights.SemiBold : FontWeights.Normal;
        }
        for (int i = 0; i < lines.Length; i++)
            lines[i].Background = i < page ? StepDoneFill : StepLineIdle;
    }

    private void ShowPage(int page)
    {
        _page = page;
        ShowOnly(page switch { 0 => PageWelcome, 1 => PageLicense, 2 => PageOptions, PageNumImport => PageImport, _ => PageProgress });
        UpdateSteps(page);

        BackButton.Visibility = page is 1 or 2 or PageNumImport ? Visibility.Visible : Visibility.Hidden;
        NextButton.Content = page switch
        {
            2 => HasImport ? "Weiter" : "Installieren",
            PageNumImport => "Installieren",
            PageNumProgress => "Fertigstellen",
            _ => "Weiter",
        };
        NextButton.IsEnabled = page != 1 || AcceptLicense.IsChecked == true;
    }

    private void AcceptLicense_Click(object sender, RoutedEventArgs e) => NextButton.IsEnabled = AcceptLicense.IsChecked == true;

    private void Back_Click(object sender, RoutedEventArgs e)
    {
        if (!_busy && _page > 0) ShowPage(_page - 1);
    }

    private async void Next_Click(object sender, RoutedEventArgs e)
    {
        if (_busy) return;

        if (_mode == SetupMode.Uninstall)
        {
            if (_done) { Close(); return; }
            await RunUninstall();
            return;
        }
        if (_mode == SetupMode.Update)
        {
            Close(); // nur nach einem Fehler erreichbar
            return;
        }

        switch (_page)
        {
            case 0: ShowPage(1); break;
            case 1 when AcceptLicense.IsChecked == true: ShowPage(2); break;
            case 2:
                var dir = DirBox.Text.Trim();
                if (!IsFullPath(dir) || dir.IndexOfAny(Path.GetInvalidPathChars()) >= 0)
                {
                    MessageBox.Show(this, "Bitte einen gültigen Ordner angeben, z. B. C:\\Spiele\\AeroMC.", "AeroMC Setup");
                    return;
                }
                if (dir.TrimEnd('\\', '/').Length > Installer.MaxDirLength)
                {
                    MessageBox.Show(this, $"Der Ordnerpfad ist zu lang ({dir.TrimEnd('\\', '/').Length} Zeichen). Windows erlaubt hier höchstens " +
                                          $"{Installer.MaxDirLength} Zeichen – bitte einen kürzeren Ordner wählen, z. B. C:\\Spiele\\AeroMC.", "AeroMC Setup");
                    return;
                }
                if (HasImport) ShowPage(PageNumImport);
                else await RunInstall(dir, DesktopLinkBox.IsChecked == true, update: false);
                break;
            case PageNumImport:
                await RunInstall(DirBox.Text.Trim(), DesktopLinkBox.IsChecked == true, update: false);
                break;
            case PageNumProgress:
                if (LaunchBox.IsChecked == true) StartApp();
                Close();
                break;
        }
    }

    // ---------- Import aus anderen Launchern ----------

    private void SetupImportPage()
    {
        try { _found = LauncherImport.Detect(); } catch { _found = []; }
        ImportList.Children.Clear();
        for (int i = 0; i < _found.Count; i++)
        {
            var f = _found[i];
            var text = new StackPanel { Margin = new Thickness(4, 0, 0, 0) };
            text.Children.Add(new TextBlock { Text = f.Name, FontWeight = FontWeights.SemiBold });
            var detail = new TextBlock
            {
                Text = $"{f.Count} {f.Unit} gefunden · {f.Path}",
                FontSize = 12,
                Margin = new Thickness(0, 2, 0, 0),
                TextTrimming = TextTrimming.CharacterEllipsis,
                ToolTip = f.Path,
            };
            detail.SetResourceReference(TextBlock.ForegroundProperty, "TextSecondaryBrush");
            text.Children.Add(detail);

            var box = new CheckBox { Content = text, Tag = f, Margin = new Thickness(0, 10, 0, 10), IsChecked = false };
            if (i > 0)
            {
                var line = new Border { Height = 1 };
                line.SetResourceReference(Border.BackgroundProperty, "ControlStrokeBrush");
                ImportList.Children.Add(line);
            }
            ImportList.Children.Add(box);
        }
    }

    private List<FoundLauncher> SelectedImports() =>
        ImportList.Children.OfType<CheckBox>()
            .Where(c => c.IsChecked == true && c.Tag is FoundLauncher)
            .Select(c => (FoundLauncher)c.Tag)
            .ToList();

    private void ChangeDir_Click(object sender, RoutedEventArgs e)
    {
        using var dlg = new System.Windows.Forms.FolderBrowserDialog
        {
            Description = "Installationsordner wählen",
            SelectedPath = Directory.Exists(DirBox.Text) ? DirBox.Text : Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
            ShowNewFolderButton = true,
        };
        if (dlg.ShowDialog() != System.Windows.Forms.DialogResult.OK) return;
        var chosen = dlg.SelectedPath;
        // wie bei üblichen Installern: Unterordner "AeroMC" anhängen
        DirBox.Text = Path.GetFileName(chosen.TrimEnd('\\')).Equals("AeroMC", StringComparison.OrdinalIgnoreCase)
            ? chosen : Path.Combine(chosen, "AeroMC");
    }

    // ---------- Installation ----------

    private async Task RunInstall(string dir, bool desktop, bool update)
    {
        _busy = true;
        if (!update) ShowPage(PageNumProgress);
        SetButtons(false);
        var progress = new Progress<(double Value, string Text)>(p => SetProgress(p.Value, p.Text));
        try
        {
            await Task.Run(() => Installer.Install(dir, desktop, progress, waitForExit: update));
            _installedExe = Path.Combine(dir, Installer.ExeName);
            _done = true;

            if (update)
            {
                ShowSuccess("Update abgeschlossen", $"AeroMC {Installer.Version} wird gestartet …");
                StartApp();
                _busy = false;
                var timer = new DispatcherTimer { Interval = TimeSpan.FromSeconds(1.5) };
                timer.Tick += (_, _) => { timer.Stop(); Close(); };
                timer.Start();
                return;
            }

            // ausgewählte Launcher für den ersten Start vormerken (Fehler hier sollen die Installation nicht kippen)
            var selected = SelectedImports();
            try { LauncherImport.WritePending(selected); } catch { selected = []; }

            ShowSuccess("Alles bereit!", "AeroMC ist installiert. Du findest es im Startmenü" + (desktop ? " und auf dem Desktop." : "."));
            if (selected.Count > 0)
                ProgressText.Text += $" Beim ersten Start bietet AeroMC dir die Instanzen aus {string.Join(" und ", selected.Select(f => f.Name))} zum Übernehmen an.";
            DonePanel.Visibility = Visibility.Visible;
            ShowPage(PageNumProgress);
        }
        catch (Exception ex)
        {
            ProgressTitle.Text = update ? "Update fehlgeschlagen" : "Installation fehlgeschlagen";
            ProgressBarPanel.Visibility = Visibility.Collapsed;
            ProgressText.Text = ex.Message;
            ProgressText.Foreground = (Brush)FindResource("DangerBrush");
            NextButton.Content = "Schließen";
            _installedExe = null;
        }
        _busy = false;
        NextButton.IsEnabled = true;
        CloseButton.IsEnabled = true;
        BackButton.Visibility = Visibility.Hidden;
        CancelButton.Visibility = Visibility.Collapsed;
    }

    /// <summary>Fortschritt ausblenden und den Haken mit kurzem "Aufploppen" zeigen.</summary>
    private void ShowSuccess(string title, string text)
    {
        ProgressBarPanel.Visibility = Visibility.Collapsed;
        ProgressTitle.Text = title;
        ProgressText.Text = text;
        SuccessIcon.Visibility = Visibility.Visible;
        var pop = new DoubleAnimation(0.4, 1, TimeSpan.FromMilliseconds(420)) { EasingFunction = new BackEase { EasingMode = EasingMode.EaseOut, Amplitude = 0.5 } };
        SuccessScale.BeginAnimation(ScaleTransform.ScaleXProperty, pop);
        SuccessScale.BeginAnimation(ScaleTransform.ScaleYProperty, pop);
        SuccessIcon.BeginAnimation(OpacityProperty, new DoubleAnimation(0, 1, TimeSpan.FromMilliseconds(200)));
    }

    private void StartApp()
    {
        if (_installedExe is null || !File.Exists(_installedExe)) return;
        try
        {
            Process.Start(new ProcessStartInfo(_installedExe)
            {
                UseShellExecute = true,
                WorkingDirectory = Path.GetDirectoryName(_installedExe)!,
            });
        }
        catch { }
    }

    // ---------- Deinstallation ----------

    private async void LoadDataInfo()
    {
        var root = Installer.DataDir;
        var custom = Installer.CustomInstancesDir;
        var customNote = custom is null ? "" : $" Instanzen in deinem eigenen Ordner {custom} werden nie angefasst.";
        if (!Directory.Exists(root))
        {
            DataInfo.Text = "Es wurden keine Launcher-Daten gefunden." + customNote;
            RemoveDataBox.IsEnabled = false;
            return;
        }
        DataInfo.Text = $"Sie liegen in {root}. Größe wird berechnet …";
        var size = await Task.Run(Installer.DataSize);
        DataInfo.Text = $"Sie liegen in {root} ({Installer.FormatSize(size)}) und stehen wieder bereit, falls du AeroMC später neu installierst." + customNote;
    }

    private void RemoveDataBox_Click(object sender, RoutedEventArgs e) =>
        RemoveDataWarning.Visibility = RemoveDataBox.IsChecked == true ? Visibility.Visible : Visibility.Collapsed;

    private async Task RunUninstall()
    {
        _busy = true;
        bool removeData = RemoveDataBox.IsChecked == true;
        ShowOnly(PageProgress);
        ProgressTitle.Text = "AeroMC wird entfernt …";
        LaunchBox.Visibility = Visibility.Collapsed;
        SetButtons(false);
        var progress = new Progress<(double Value, string Text)>(p => SetProgress(p.Value, p.Text));
        try
        {
            await Task.Run(() => Installer.Uninstall(removeData, progress));
            ShowSuccess("AeroMC wurde entfernt", removeData
                ? "AeroMC, deine Instanzen, Konten und Einstellungen wurden entfernt (die Daten liegen im Papierkorb)."
                : "Deine Instanzen und Einstellungen liegen weiterhin in " + Installer.DataDir + " – falls du AeroMC später wieder installierst.");
        }
        catch (Exception ex)
        {
            ProgressTitle.Text = "Deinstallation fehlgeschlagen";
            ProgressBarPanel.Visibility = Visibility.Collapsed;
            ProgressText.Text = ex.Message;
        }
        _done = true;
        _busy = false;
        CloseButton.IsEnabled = true;
        NextButton.Content = "Schließen";
        NextButton.IsEnabled = true;
        CancelButton.Visibility = Visibility.Collapsed;
    }

    // ---------- Helfer ----------

    private void SetButtons(bool enabled)
    {
        NextButton.IsEnabled = enabled;
        BackButton.IsEnabled = enabled;
        CancelButton.IsEnabled = enabled;
        CloseButton.IsEnabled = enabled;
    }

    private void SetProgress(double value, string text)
    {
        if (_done) return;
        ProgressText.Text = text;
        PercentText.Text = $"{(int)Math.Round(value * 100)} %";
        _progress = value;
        AnimateProgress();
    }

    private double _progress;

    private void AnimateProgress()
    {
        var target = Math.Max(0, ProgressTrack.ActualWidth * _progress);
        ProgressFill.BeginAnimation(WidthProperty,
            new DoubleAnimation(target, TimeSpan.FromMilliseconds(250)) { EasingFunction = new CubicEase() });
    }

    // Kommt der erste Wert, bevor die Seite fertig angeordnet ist (Breite 0), nachträglich richtig setzen
    private void ProgressTrack_SizeChanged(object sender, SizeChangedEventArgs e) => AnimateProgress();

    private static bool IsFullPath(string p) =>
        p.Length >= 3 && char.IsLetter(p[0]) && p[1] == ':' && (p[2] == '\\' || p[2] == '/');

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

    private void Cancel_Click(object sender, RoutedEventArgs e)
    {
        if (_busy) return;
        if (!_done && _mode == SetupMode.Install && _page > 0 &&
            MessageBox.Show(this, "Installation wirklich abbrechen?", "AeroMC Setup", MessageBoxButton.YesNo, MessageBoxImage.Question) != MessageBoxResult.Yes)
            return;
        Close();
    }

    protected override void OnClosing(System.ComponentModel.CancelEventArgs e)
    {
        if (_busy) e.Cancel = true; // während der Installation nicht schließen
        base.OnClosing(e);
    }
}