using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;

// DisplayFusion Scripted Function, created with Anthropic Fable 5
// Cascades all visible top-level windows of the currently focused application,
// replicating the classic "Cascade windows" behavior removed in Windows 11.
// Windows are stacked diagonally on the monitor containing the focused window.

public static class DisplayFusionFunction
{
    public static void Run(IntPtr windowHandle)
    {
        // Get the focused window; fall back to the handle DisplayFusion passes in
        IntPtr focused = BFS.Window.GetFocusedWindow();
        if (focused == IntPtr.Zero)
            focused = windowHandle;
        if (focused == IntPtr.Zero)
            return;

        // Identify the owning application by process ID
        uint processId = BFS.Application.GetAppIDByWindow(focused);
        if (processId == 0)
            return;

        // Collect all candidate windows belonging to this process
        List<IntPtr> windows = new List<IntPtr>();
        foreach (IntPtr handle in BFS.Window.GetVisibleAndMinimizedWindowHandles())
        {
            if (BFS.Application.GetAppIDByWindow(handle) != processId)
                continue;

            // Skip tool windows, borderless popups, and windows without a title
            if (string.IsNullOrEmpty(BFS.Window.GetText(handle)))
                continue;

            windows.Add(handle);
        }

        if (windows.Count == 0)
            return;

        // Cascade on the monitor that contains the focused window
        Rectangle workArea = BFS.Monitor.GetMonitorWorkAreaByWindow(focused);

        // Classic cascade metrics: offset roughly one title bar height per step,
        // window sized to a large fraction of the work area
        int offset = 32; // approximate title bar height at 100% DPI
        int width = (int)(workArea.Width * 0.6);
        int height = (int)(workArea.Height * 0.6);

        // Sort by Z-order is not directly exposed, so keep enumeration order
        // but move the focused window to the end so it lands on top
        windows.Remove(focused);
        windows.Add(focused);

        int x = workArea.X;
        int y = workArea.Y;

        foreach (IntPtr handle in windows)
        {
            // Restore minimized or maximized windows so they can be positioned
            if (BFS.Window.IsMinimized(handle) || BFS.Window.IsMaximized(handle))
                BFS.Window.Restore(handle);

            // Wrap around if the cascade would run off the work area
            if (x + width > workArea.Right || y + height > workArea.Bottom)
            {
                x = workArea.X;
                y = workArea.Y;
            }

            BFS.Window.SetSizeAndLocation(handle, x, y, width, height);
            BFS.Window.Focus(handle);

            x += offset;
            y += offset;
        }

        // Leave the originally focused window active and on top
        BFS.Window.Focus(focused);
    }
}