using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Input;
using System.Windows.Interop;
using SpdUp.ViewModels;

namespace SpdUp.Views;

/// <summary>
/// Floating desktop widget – borderless, transparent, always-on-top.
/// </summary>
public partial class WidgetWindow : Window
{
    private bool _expanded;

    // ── Win32 click-through support ───────────────────────────────────
    private const int GWL_EXSTYLE = -20;
    private const int WS_EX_TRANSPARENT = 0x00000020;
    private const int WS_EX_TOOLWINDOW = 0x00000080;

    [DllImport("user32.dll")]
    private static extern int GetWindowLong(IntPtr hwnd, int index);

    [DllImport("user32.dll")]
    private static extern int SetWindowLong(IntPtr hwnd, int index, int newStyle);

    public WidgetWindow(MainViewModel vm)
    {
        InitializeComponent();
        DataContext = vm;

        // Restore position from settings
        Left = vm.Settings.WidgetOpacity > 0 ? 100 : 100; // default
        Top = 100;

        Loaded += (_, _) =>
        {
            // Make it a tool window (no taskbar entry)
            var hwnd = new WindowInteropHelper(this).Handle;
            var exStyle = GetWindowLong(hwnd, GWL_EXSTYLE);
            SetWindowLong(hwnd, GWL_EXSTYLE, exStyle | WS_EX_TOOLWINDOW);

            Opacity = vm.Settings.WidgetOpacity;

            if (!vm.Settings.WidgetCompactMode)
                ToggleExpand();
        };
    }

    private void Widget_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        if (e.LeftButton == MouseButtonState.Pressed)
            DragMove();
    }

    private void Widget_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
    {
        ToggleExpand();
    }

    private void Toggle_Click(object sender, RoutedEventArgs e) => ToggleExpand();
    private void Close_Click(object sender, RoutedEventArgs e) => Close();

    private void ToggleExpand()
    {
        _expanded = !_expanded;
        ExpandedPanel.Visibility = _expanded ? Visibility.Visible : Visibility.Collapsed;
    }

    /// <summary>
    /// Enable click-through: all mouse events pass through to windows below.
    /// </summary>
    public void SetClickThrough(bool enable)
    {
        var hwnd = new WindowInteropHelper(this).Handle;
        var exStyle = GetWindowLong(hwnd, GWL_EXSTYLE);

        if (enable)
            SetWindowLong(hwnd, GWL_EXSTYLE, exStyle | WS_EX_TRANSPARENT);
        else
            SetWindowLong(hwnd, GWL_EXSTYLE, exStyle & ~WS_EX_TRANSPARENT);
    }
}