using FluidExplorer.Services;
using FluidExplorer.Services.Operations;
using FluidExplorer.ViewModels;
using Microsoft.UI;
using Microsoft.UI.Windowing;
using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;
using Microsoft.UI.Xaml.Input;
using Microsoft.UI.Xaml.Media;
using Windows.Graphics;
using Windows.System;

namespace FluidExplorer;

public sealed partial class MainWindow : Window
{
    private readonly AppServices _services;
    private readonly AppSettings _settings;

    public MainWindow(AppServices services)
    {
        _services = services;
        _settings = services.Settings;
        ViewModel = services.Main;

        InitializeComponent();
        Shell.ViewModel = ViewModel;

        Title = "文件资源管理器";
        SystemBackdrop = new MicaBackdrop();
        ExtendsContentIntoTitleBar = true;
        SetTitleBar(Shell.DragRegion);

        RestoreWindowPlacement();
        ApplyCaptionButtonColors();
        HookServices();

        Shell.ThemedRoot.ActualThemeChanged += (_, _) => ApplyCaptionButtonColors();
        Shell.SizeChanged += (_, _) => UpdateTitleBarInsets();
        AppWindow.Changed += (_, _) => UpdateTitleBarInsets();
        AppWindow.Closing += OnClosing;

        RegisterAccelerators();

        // 启动：恢复标签页 + 建立索引（都在后台，窗口先出来）
        _ = DispatcherQueue.TryEnqueue(async () => await ViewModel.InitializeAsync());
    }

    public MainViewModel ViewModel { get; }

    public void ShowOperationQueue() => Shell.ShowOperationQueue();

    // ── 窗口外观 ────────────────────────────────────────────────────────────
    private void RestoreWindowPlacement()
    {
        if (!double.IsNaN(_settings.WindowWidth) && _settings.WindowWidth > 400)
        {
            AppWindow.ResizeClient(new SizeInt32((int)_settings.WindowWidth, (int)_settings.WindowHeight));
        }
        if (!double.IsNaN(_settings.WindowLeft) && !double.IsNaN(_settings.WindowTop) && IsOnScreen(_settings.WindowLeft, _settings.WindowTop))
        {
            AppWindow.Move(new PointInt32((int)_settings.WindowLeft, (int)_settings.WindowTop));
        }
        if (_settings.WindowMaximized && AppWindow.Presenter is OverlappedPresenter presenter)
        {
            presenter.Maximize();
        }
        UpdateTitleBarInsets();
    }

    private static bool IsOnScreen(double left, double top)
    {
        var display = DisplayArea.GetFromPoint(new PointInt32((int)left, (int)top), DisplayAreaFallback.Nearest);
        return display is not null && left >= display.WorkArea.X - 40 && top >= display.WorkArea.Y - 40;
    }

    /// <summary>把标签栏右侧的留白让给系统标题栏按钮，保证标签不被按钮压住。</summary>
    private void UpdateTitleBarInsets()
    {
        try
        {
            var scale = Shell.XamlRoot?.RasterizationScale ?? 1.0;
            var rightInset = AppWindow.TitleBar.RightInset / scale;
            if (rightInset < 0) rightInset = 0;
            if (Shell.DragRegion is FrameworkElement region) region.Margin = new Thickness(0, 0, rightInset, 0);
        }
        catch
        {
            // 最小化/全屏切换等瞬态下取不到 TitleBar 信息，忽略
        }
    }

    /// <summary>标题栏按钮颜色跟随当前主题。</summary>
    private void ApplyCaptionButtonColors()
    {
        var titleBar = AppWindow.TitleBar;
        titleBar.ButtonBackgroundColor = Colors.Transparent;
        titleBar.ButtonInactiveBackgroundColor = Colors.Transparent;

        if (Shell.ThemedRoot.ActualTheme == ElementTheme.Dark)
        {
            titleBar.ButtonForegroundColor = Colors.White;
            titleBar.ButtonHoverBackgroundColor = Windows.UI.Color.FromArgb(24, 255, 255, 255);
            titleBar.ButtonHoverForegroundColor = Colors.White;
            titleBar.ButtonPressedBackgroundColor = Windows.UI.Color.FromArgb(48, 255, 255, 255);
            titleBar.ButtonPressedForegroundColor = Windows.UI.Color.FromArgb(200, 255, 255, 255);
            titleBar.ButtonInactiveForegroundColor = Windows.UI.Color.FromArgb(120, 255, 255, 255);
        }
        else
        {
            titleBar.ButtonForegroundColor = Windows.UI.Color.FromArgb(230, 0, 0, 0);
            titleBar.ButtonHoverBackgroundColor = Windows.UI.Color.FromArgb(20, 0, 0, 0);
            titleBar.ButtonHoverForegroundColor = Colors.Black;
            titleBar.ButtonPressedBackgroundColor = Windows.UI.Color.FromArgb(40, 0, 0, 0);
            titleBar.ButtonPressedForegroundColor = Windows.UI.Color.FromArgb(160, 0, 0, 0);
            titleBar.ButtonInactiveForegroundColor = Windows.UI.Color.FromArgb(100, 0, 0, 0);
        }
    }

    /// <summary>主题切换（用户手动指定时覆盖系统跟随）。</summary>
    public void ApplyThemeMode(AppThemeMode mode)
    {
        Shell.ThemedRoot.RequestedTheme = mode switch
        {
            AppThemeMode.Light => ElementTheme.Light,
            AppThemeMode.Dark => ElementTheme.Dark,
            _ => ElementTheme.Default
        };
    }

    // ── 服务接线 ────────────────────────────────────────────────────────────
    private void HookServices()
    {
        _services.Operations.ConflictResolver = ShowConflictDialogAsync;
        ViewModel.ThemeModeChanged += (_, mode) => ApplyThemeMode(mode);
        ViewModel.AnimationsToggled += (_, enabled) =>
        {
            // 关掉动画时禁用所有依赖动画（WinUI 原生总开关，克制且彻底）
            Microsoft.UI.Xaml.Media.Animation.Timeline.AllowDependentAnimations = enabled;
        };
        ViewModel.PropertyChanged += (_, e) =>
        {
            if (e.PropertyName == nameof(MainViewModel.ErrorMessage) && ViewModel.ErrorMessage is { Length: > 0 } message)
            {
                ViewModel.ActivePane?.ReportError(message);
                ViewModel.ErrorMessage = null;
            }
        };
    }

    /// <summary>文件冲突对话框：不弹系统模态框，全部由应用自己处理。</summary>
    private async Task<ConflictResolution> ShowConflictDialogAsync(ConflictInfo info)
    {
        var dialog = new ContentDialog
        {
            XamlRoot = Shell.XamlRoot,
            Title = "目标位置已有同名项目",
            DefaultButton = ContentDialogButton.Primary
        };

        var keepBoth = new RadioButton { Content = "同时保留两个文件（推荐）", IsChecked = true };
        var replace = new RadioButton { Content = "替换目标中的文件" };
        var skip = new RadioButton { Content = "跳过此文件" };
        var applyAll = new CheckBox { Content = "为后续所有冲突执行相同操作" };

        var detail = new StackPanel { Spacing = 8 };
        detail.Children.Add(new TextBlock
        {
            Text = Path.GetFileName(info.SourcePath),
            TextWrapping = TextWrapping.Wrap,
            Style = (Style)Application.Current.Resources["BodyStrongTextBlockStyle"]
        });
        detail.Children.Add(new TextBlock
        {
            Text = $"源：{info.SourcePath}\n{Models.FileEntry.FormatSize(info.SourceSize)} · {info.SourceModifiedUtc.ToLocalTime():yyyy/MM/dd HH:mm}\n\n" +
                   $"目标：{info.DestinationPath}\n{Models.FileEntry.FormatSize(info.DestinationSize)} · {info.DestinationModifiedUtc.ToLocalTime():yyyy/MM/dd HH:mm}",
            TextWrapping = TextWrapping.Wrap,
            Style = (Style)Application.Current.Resources["CaptionTextBlockStyle"]
        });
        detail.Children.Add(keepBoth);
        detail.Children.Add(replace);
        detail.Children.Add(skip);
        detail.Children.Add(applyAll);

        dialog.Content = detail;
        dialog.PrimaryButtonText = "继续";
        dialog.CloseButtonText = "取消本次操作";

        var result = await dialog.ShowAsync();
        info.ApplyToAll = applyAll.IsChecked == true;
        if (result != ContentDialogResult.Primary) return ConflictResolution.Cancel;
        if (replace.IsChecked == true) return ConflictResolution.Replace;
        if (skip.IsChecked == true) return ConflictResolution.Skip;
        return ConflictResolution.KeepBoth;
    }

    // ── 快捷键 ──────────────────────────────────────────────────────────────
    private void RegisterAccelerators()
    {
        AddAccelerator(VirtualKey.T, VirtualKeyModifiers.Control, () => ViewModel.NewTabCommand.Execute(null));
        AddAccelerator(VirtualKey.W, VirtualKeyModifiers.Control, () => ViewModel.CloseTabCommand.Execute(ViewModel.SelectedTab));
        AddAccelerator(VirtualKey.Z, VirtualKeyModifiers.Control, () => ViewModel.UndoCommand.Execute(null));
        AddAccelerator(VirtualKey.D, VirtualKeyModifiers.Control | VirtualKeyModifiers.Shift, () => ViewModel.ToggleDualPaneCommand.Execute(null));
        AddAccelerator(VirtualKey.F, VirtualKeyModifiers.Control, () => ViewModel.ActivePane?.RequestSearchFocus());
        AddAccelerator(VirtualKey.Tab, VirtualKeyModifiers.Control, CycleTab);
    }

    private void AddAccelerator(VirtualKey key, VirtualKeyModifiers modifiers, Action action)
    {
        var accelerator = new KeyboardAccelerator { Key = key, Modifiers = modifiers };
        accelerator.Invoked += (_, args) =>
        {
            // 文本输入状态下不抢 Ctrl+Z / Ctrl+F
            if (key is VirtualKey.Z or VirtualKey.F
                && modifiers == VirtualKeyModifiers.Control
                && FocusManager.GetFocusedElement(Shell.XamlRoot) is TextBox)
            {
                return;
            }
            args.Handled = true;
            action();
        };
        Shell.ThemedRoot.KeyboardAccelerators.Add(accelerator);
    }

    private void CycleTab()
    {
        if (ViewModel.Tabs.Count < 2 || ViewModel.SelectedTab is null) return;
        var index = ViewModel.Tabs.IndexOf(ViewModel.SelectedTab);
        ViewModel.SelectedTab = ViewModel.Tabs[(index + 1) % ViewModel.Tabs.Count];
    }

    // ── 关闭 ────────────────────────────────────────────────────────────────
    private void OnClosing(AppWindow sender, AppWindowClosingEventArgs args)
    {
        try
        {
            // 有正在进行的复制/移动时不静默退出，避免用户以为文件已搬完
            var hasActiveJob = _services.Operations.Jobs.Any(j => !j.IsFinished);
            if (hasActiveJob && !_settings.KeepWindowOpenDuringOperations)
            {
                args.Cancel = true;
                return;
            }

            ViewModel.SaveOpenTabs();

            // 索引持有卷句柄，退出时显式释放
            foreach (var index in _services.Search.AllIndexes)
            {
                if (index is IDisposable disposable) disposable.Dispose();
            }

            _settings.WindowMaximized = AppWindow.Presenter is OverlappedPresenter { State: OverlappedPresenterState.Maximized };
            if (!_settings.WindowMaximized)
            {
                _settings.WindowLeft = AppWindow.Position.X;
                _settings.WindowTop = AppWindow.Position.Y;
                _settings.WindowWidth = AppWindow.Size.Width;
                _settings.WindowHeight = AppWindow.Size.Height;
            }
            _settings.Save();
        }
        catch
        {
            // 关闭时保存失败不应阻塞退出
        }
    }
}