using System.Runtime.InteropServices;
using Microsoft.UI.Windowing;
using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Media;
using OneClickRun.App.Controls;
using OneClickRun.App.Services;
using OneClickRun.Core.Logic;
using OneClickRun.Core.Models;
using Windows.Graphics;
using Windows.UI;

namespace OneClickRun.App;

/// <summary>
/// 轮盘悬浮窗：无边框、透明背景、置顶、不进 Alt+Tab。
/// 尺寸/位置一律使用物理像素；内容按 PerMonitorV2 DPI 自动缩放。
/// </summary>
public sealed partial class WheelWindow : Window
{
    private const double WheelDiameterDips = 560;

    private int _x;
    private int _y;
    private int _size;
    private double _scale = 1.0;

    public event Action<int>? SectorClicked;
    public event Action? DismissRequested;

    public WheelWindow()
    {
        InitializeComponent();
        Title = "OneClickRun Wheel";
        AppWindow.IsShownInSwitchers = false;
        AppWindow.SetPresenter(AppWindowPresenterKind.Overlapped);
        if (AppWindow.Presenter is OverlappedPresenter presenter)
        {
            presenter.SetBorderAndTitleBar(false, false);
            presenter.IsAlwaysOnTop = true;
            presenter.IsResizable = false;
            presenter.IsMaximizable = false;
            presenter.IsMinimizable = false;
        }
        SystemBackdrop = new TransparentBackdrop();
        // alpha=1 的“透明”背景：肉眼不可见，但可命中鼠标事件（用于点击轮盘外关闭）
        Root.Background = new SolidColorBrush(Color.FromArgb(1, 0, 0, 0));
        Wheel.SectorClicked += i => SectorClicked?.Invoke(i);
        Wheel.DismissRequested += () => DismissRequested?.Invoke();
    }

    public bool IsVisible => AppWindow.IsVisible;

    public void SetItems(IReadOnlyList<CommandItem> items) => Wheel.SetItems(items);

    public void SetHoverIndex(int index) => Wheel.SetHoverIndex(index);

    public void SetPendingIndex(int index) => Wheel.SetPendingIndex(index);

    public void ClearPending() => Wheel.ClearPending();

    public void ClearHover() => Wheel.SetHoverIndex(-1);

    /// <summary>按住模式轮询：光标所在扇区（窗口外也能计算方向）。</summary>
    public int GetSectorIndexAtCursor()
    {
        if (Wheel.Count == 0) return -1;
        NativeMethods.GetCursorPos(out var pt);
        double cx = _x + _size / 2.0;
        double cy = _y + _size / 2.0;
        double dx = pt.X - cx;
        double dy = pt.Y - cy;
        double dist = Math.Sqrt(dx * dx + dy * dy);
        if (dist < 76 * _scale || dist > 282 * _scale) return -1;
        return WheelMath.GetSectorIndex(Wheel.Count, WheelMath.AngleFromVector(dx, dy));
    }

    /// <summary>滑动选择：松开时按光标相对轮盘中心方位决定扇区（死区 24 DIP）。</summary>
    public bool TryGetSwipeIndex(int count, out int index)
    {
        index = -1;
        if (!NativeMethods.GetCursorPos(out var pt)) return false;
        double cx = _x + _size / 2.0;
        double cy = _y + _size / 2.0;
        return WheelMath.TryGetSwipeIndex(count, pt.X - cx, pt.Y - cy, 24 * _scale, out index);
    }

    /// <summary>在屏幕指定中心点显示轮盘（自动钳制到工作区并换算 DPI）。</summary>
    internal void ShowAt(POINT center)
    {
        var monitor = NativeMethods.MonitorFromPoint(center, NativeMethods.MONITOR_DEFAULTTONEAREST);
        _scale = GetMonitorScale(monitor);
        _size = (int)Math.Round(WheelDiameterDips * _scale);
        int half = _size / 2;

        var info = new MONITORINFO { cbSize = Marshal.SizeOf<MONITORINFO>() };
        if (NativeMethods.GetMonitorInfo(monitor, ref info))
        {
            int left = Math.Max(info.rcWork.Left + half, Math.Min(info.rcWork.Right - half, center.X));
            int top = Math.Max(info.rcWork.Top + half, Math.Min(info.rcWork.Bottom - half, center.Y));
            center.X = left;
            center.Y = top;
        }

        _x = center.X - half;
        _y = center.Y - half;
        AppWindow.MoveAndResize(new RectInt32(_x, _y, _size, _size));
        if (!AppWindow.IsVisible) AppWindow.Show();
        Activate();
    }

    public void Hide() => AppWindow.Hide();

    private static double GetMonitorScale(IntPtr monitor)
    {
        if (NativeMethods.GetDpiForMonitor(monitor, NativeMethods.MDT_EFFECTIVE_DPI, out uint dpiX, out _) == 0 && dpiX > 0)
        {
            return dpiX / 96.0;
        }
        return 1.0;
    }
}